:root {
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #e0e0e0;
    
    /* Text Colors */
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    
    /* Accessible Text Colors for Status Indicators (4.5:1+ on white) */
    --text-success: #166534;
    --text-warning: #92400e;
    --text-danger: #b91c1c;
    --text-info: #1e40af;
    
    /* Border Colors */
    --border-color: #dddddd;
    --border-color-hover: #bbbbbb;
    
    /* Semantic Colors */
    --primary-color: #4CAF50;
    --primary-color-hover: #45a049;
    --secondary-color: #2196F3;
    --secondary-color-hover: #1976D2;
    --danger-color: #f44336;
    --danger-color-hover: #d32f2f;
    --success-color: #4CAF50;
    --success-color-hover: #45a049;
    --warning-color: #ff9800;
    --warning-color-hover: #f57c00;
    --info-color: #2196F3;
    --info-color-hover: #1976D2;
    
    /* Card & Surface Colors */
    --card-bg: #ffffff;
    --hover-bg: #f8f9fa;
    
    /* Shadow System */
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);
    
    /* Transition Timing */
    --transition-fast: 0.15s ease;
    --transition-base: 0.2s ease;
    --transition-slow: 0.3s ease;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    --radius-full: 9999px;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    --gradient-success: linear-gradient(135deg, #4CAF50, #66BB6A);
    --gradient-info: linear-gradient(135deg, #2196F3, #42A5F5);
    --gradient-danger: linear-gradient(135deg, #f44336, #EF5350);
    
    /* Focus Ring - WCAG 2.1 AA Compliant */
    --focus-ring: 0 0 0 3px rgba(76, 175, 80, 0.4);
    --focus-ring-info: 0 0 0 3px rgba(33, 150, 243, 0.4);
    --focus-ring-danger: 0 0 0 3px rgba(244, 67, 54, 0.4);
    
    /* Accessibility Focus Outline Colors */
    --focus-outline-color: #2563eb;
    --focus-outline-color-success: #16a34a;
    --focus-outline-color-danger: #dc2626;
    --focus-outline-color-info: #0284c7;
}

[data-theme="dark"] {
    /* Background Colors */
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #404040;
    
    /* Text Colors */
    --text-primary: #f3f4f6;
    --text-secondary: #d1d5db;
    
    /* Accessible Text Colors for Status Indicators (4.5:1+ on dark bg) */
    --text-success: #86efac;
    --text-warning: #fcd34d;
    --text-danger: #fca5a5;
    --text-info: #93c5fd;
    
    /* Border Colors */
    --border-color: #404040;
    --border-color-hover: #555555;
    
    /* Card & Surface Colors */
    --card-bg: #2d2d2d;
    --hover-bg: #353535;
    
    /* Shadow System (darker for dark mode) */
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.25), 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.3), 0 4px 6px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.35), 0 10px 10px rgba(0, 0, 0, 0.2);
    
    /* Focus Ring (brighter for dark mode) - WCAG 2.1 AA Compliant */
    --focus-ring: 0 0 0 3px rgba(76, 175, 80, 0.5);
    --focus-ring-info: 0 0 0 3px rgba(33, 150, 243, 0.5);
    --focus-ring-danger: 0 0 0 3px rgba(244, 67, 54, 0.5);
    
    /* Accessibility Focus Outline Colors (brighter for dark mode) */
    --focus-outline-color: #60a5fa;
    --focus-outline-color-success: #4ade80;
    --focus-outline-color-danger: #f87171;
    --focus-outline-color-info: #38bdf8;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

.hidden {
    display: none !important;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 30px;
}

header h1 {
    font-size: 28px;
    color: #2c2c2c;
    margin: 0;
    line-height: 1.2;
}

[data-theme="dark"] header h1 {
    color: #d0d0d0;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.header-brand-content {
    display: flex;
    align-items: center;
}

.header-logo {
    height: 35px;
    width: auto;
    margin-right: 0.5rem;
}

.header-text p {
    margin: 0;
    margin-top: -4px;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.header-controls {
    display: flex;
    gap: 10px;
    align-items: center;
}

/* Mobile Footer - hidden on desktop, shown on mobile */
.mobile-footer {
    display: none;
}

.user-info {
    color: var(--text-secondary);
    font-size: 14px;
}

.badge {
    background: var(--bg-secondary);
    padding: 8px 16px;
    border-radius: 20px;
    text-align: center;
    font-size: 14px;
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.share-counter {
    background: var(--bg-secondary);
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    margin-bottom: 20px;
}

.share-counter p {
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 5px;
}

.tooltip {
    color: var(--text-secondary);
    font-size: 12px;
}

.drop-zone {
    border: 3px dashed var(--border-color);
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    transition: all 0.3s;
    background: var(--bg-secondary);
}

.drop-zone.drag-over {
    border-color: var(--primary-color);
    background: var(--bg-tertiary);
}

.upload-icon {
    font-size: 64px;
    margin-bottom: 20px;
}

.or-text {
    margin: 20px 0;
    color: var(--text-secondary);
}

.drop-zone .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
}

.file-info {
    margin-top: 20px;
    font-size: 14px;
    color: var(--text-secondary);
}

.file-queue {
    margin-top: 20px;
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.file-queue h3 {
    margin-bottom: 15px;
    font-size: 18px;
    color: var(--text-primary);
}

.file-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.file-item {
    background: var(--bg-primary);
    padding: 12px 15px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    transition: background 0.2s;
}

.file-item:hover {
    background: var(--bg-tertiary);
}

.file-item-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.file-item-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex: 1;
}

.file-progress {
    margin-top: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.file-progress-bar {
    flex: 1;
    height: 6px;
    background: var(--bg-tertiary);
    border-radius: 3px;
    overflow: hidden;
}

.file-progress-fill {
    height: 100%;
    background: var(--primary-color);
    transition: width 0.3s;
    width: 0%;
}

.file-progress-text {
    font-size: 12px;
    color: var(--text-secondary);
    min-width: 35px;
    text-align: right;
}

.file-name {
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-word;
}

.file-size {
    font-size: 12px;
    color: var(--text-secondary);
}

.btn-remove {
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    width: 28px;
    height: 28px;
    cursor: pointer;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-base), transform var(--transition-fast);
    flex-shrink: 0;
}

.btn-remove:hover {
    background: var(--danger-color-hover);
    transform: scale(1.05);
}

.btn-cancel {
    background: var(--warning-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    padding: 4px 12px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 500;
    transition: background var(--transition-base);
}

.btn-cancel:hover {
    background: var(--warning-color-hover);
}

.upload-options {
    margin-top: 30px;
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"],
.form-group select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 16px;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.form-group input[type="text"]:focus-visible,
.form-group input[type="email"]:focus-visible,
.form-group input[type="password"]:focus-visible,
.form-group select:focus-visible {
    border-color: var(--focus-outline-color);
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

.form-group input[type="checkbox"] {
    margin-right: 8px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 16px;
    cursor: pointer;
    transition: all var(--transition-slow);
    text-decoration: none;
    display: inline-block;
    font-weight: 500;
}

.btn-primary {
    background: var(--secondary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--secondary-color-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: var(--success-color-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
    transform: translateY(-1px);
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: var(--danger-color-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-info {
    background: var(--info-color);
    color: white;
}

.btn-info:hover {
    background: var(--info-color-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-warning {
    background: var(--warning-color);
    color: white;
}

.btn-warning:hover {
    background: var(--warning-color-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-large {
    width: 100%;
    padding: 16px;
    font-size: 18px;
}

.btn-sm {
    padding: 10px 16px;
    font-size: 14px;
    min-height: 44px;
    min-width: 44px;
}

.btn-icon {
    background: transparent;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 10px;
    color: var(--primary-color);
    min-width: 44px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-icon:hover {
    color: var(--primary-color-hover);
}

.btn-icon[title="Logout"] {
    color: #999;
}

.btn-icon[title="Logout"]:hover {
    color: #444;
}

.manage-files-banner {
    width: 100%;
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    padding: 12px 0;
    margin: -10px 0 20px 0;
    text-align: center;
}

.manage-files-banner a {
    color: white;
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    display: block;
    transition: opacity 0.3s;
}

.manage-files-banner a:hover {
    opacity: 0.9;
}

.ad-container {
    width: 100%;
    height: 90px;
    margin: 20px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: border-color var(--transition-base);
}

.ad-placeholder {
    color: var(--text-secondary);
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.progress-bar {
    width: 100%;
    height: 30px;
    background: var(--bg-secondary);
    border-radius: 15px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    transition: width 0.3s;
}

.share-result {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.share-link-container {
    display: flex;
    gap: 10px;
    margin: 20px 0;
}

.share-link-container input {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color var(--transition-base);
}

.share-link-container input:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: var(--focus-ring);
}

.expiry-text {
    color: var(--text-secondary);
    font-size: 14px;
    margin: 10px 0;
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--bg-primary);
    padding: 30px;
    border-radius: var(--radius-xl);
    max-width: 500px;
    width: 90%;
    position: relative;
    box-shadow: var(--shadow-xl);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    font-size: 28px;
    cursor: pointer;
    color: var(--text-secondary);
}

.modal-buttons {
    display: flex;
    gap: 12px;
    margin-top: 24px;
    justify-content: flex-end;
}

.modal h3 {
    margin-bottom: 20px;
    color: var(--text-primary);
}

.download-section,
.upload-section,
.auth-section,
.admin-section,
.error-section {
    margin-top: 20px;
}

.upload-section {
    padding-bottom: 500px;
}

.file-details {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
}

.file-details p {
    margin: 10px 0;
}

.batch-info {
    background: var(--bg-secondary);
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
}

.batch-info p {
    margin: 5px 0;
}

.files-list {
    background: var(--bg-secondary);
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
}

.file-item-download {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-primary);
    padding: 15px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    margin-bottom: 10px;
    transition: background 0.2s;
}

.file-item-download:last-child {
    margin-bottom: 0;
}

.file-item-download:hover {
    background: var(--bg-tertiary);
}

.file-item-download .file-item-info {
    display: flex;
    flex-direction: column;
    gap: 5px;
    flex: 1;
}

.file-item-download .file-name {
    font-weight: 500;
    font-size: 16px;
}

.file-item-download .file-size {
    font-size: 14px;
    color: var(--text-secondary);
}

.file-item-download .file-meta {
    font-size: 12px;
    color: var(--text-secondary);
}

.btn-download-single {
    min-width: 120px;
}

.preview-container {
    margin: 20px 0;
    text-align: center;
}

.preview-container img,
.preview-container video {
    max-width: 100%;
    border-radius: 8px;
}

.auth-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.tab-btn {
    flex: 1;
    padding: 12px;
    border: none;
    background: var(--bg-secondary);
    color: var(--text-primary);
    cursor: pointer;
    border-radius: 6px;
    font-size: 16px;
}

.tab-btn.active {
    background: var(--primary-color);
    color: white;
}

.auth-form {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: 8px;
}

.auth-footer {
    text-align: center;
    margin-top: 20px;
}

.auth-footer a {
    color: var(--secondary-color);
    text-decoration: none;
}

.error-message {
    background: #ffebee;
    color: #c62828;
    padding: 12px;
    border-radius: 6px;
    margin: 10px 0;
}

.success-message {
    background: #e8f5e9;
    color: #2e7d32;
    padding: 12px;
    border-radius: 6px;
    margin: 10px 0;
}

.info-message {
    background: #fff3cd;
    color: #856404;
    padding: 12px;
    border-radius: 6px;
    margin: 10px 0;
    border: 1px solid #ffc107;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: 8px;
    text-align: center;
}

.stat-card h3 {
    font-size: 36px;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.admin-links {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.admin-tool-card {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.admin-tool-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-secondary);
    border-radius: 8px;
    overflow: hidden;
}

.admin-table th,
.admin-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.admin-table th {
    background: var(--bg-tertiary);
    font-weight: 600;
}

.error-section {
    text-align: center;
    padding: 60px 20px;
}

.error-section h2 {
    font-size: 48px;
    margin-bottom: 20px;
}

.account-info {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.account-info h3 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

.account-info p {
    margin: 10px 0;
    font-size: 16px;
}

.account-actions {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.account-actions h3 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

.account-actions .form-group {
    margin-bottom: 15px;
}

.files-table {
    overflow-x: auto;
    margin: 20px 0;
}

.files-table table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-secondary);
    border-radius: 8px;
    overflow: hidden;
}

.files-table th,
.files-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.files-table th {
    background: var(--bg-tertiary);
    font-weight: 600;
}

.files-table tr:hover {
    background: var(--bg-tertiary);
}

.file-info-details {
    margin-top: 20px;
}

.file-info-details p {
    margin: 15px 0;
    font-size: 16px;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    background: var(--bg-secondary);
    border-radius: 8px;
}

.empty-state p {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

/* Floating Dark Mode Toggle */
.floating-dark-mode {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    background: transparent;
    border: none;
    border-radius: 50%;
    font-size: 28px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px var(--shadow);
    transition: all 0.3s;
    z-index: 1000;
}

.floating-dark-mode:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px var(--shadow);
}

/* Navigation Menu */
.nav-menu {
    position: fixed;
    top: 0;
    left: -300px;
    width: 280px;
    height: 100%;
    background: var(--bg-primary);
    border-right: 2px solid var(--border-color);
    box-shadow: 2px 0 10px var(--shadow);
    transition: left 0.3s ease;
    z-index: 2000;
    overflow-y: auto;
}

.nav-menu.open {
    left: 0;
}

.nav-menu-header {
    padding: 20px;
    border-bottom: 2px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-menu-header h3 {
    margin: 0;
    color: var(--primary-color);
}

.nav-menu-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-primary);
    padding: 5px;
}

.nav-menu-items {
    padding: 0;
    margin: 0;
    list-style: none;
}

.nav-menu-items li {
    border-bottom: 1px solid var(--border-color);
}

.nav-menu-items a {
    display: block;
    padding: 15px 20px;
    color: var(--text-primary);
    text-decoration: none;
    transition: background 0.2s;
}

.nav-menu-items a:hover {
    background: var(--bg-secondary);
}

.nav-menu-items a.active {
    background: var(--bg-secondary);
    color: var(--primary-color);
    font-weight: bold;
}

.nav-menu-items a i {
    margin-right: 10px;
}

.nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    z-index: 1999;
}

.nav-overlay.open {
    display: block;
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        text-align: center;
    }
    
    .header-controls {
        margin-top: 15px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .files-table {
        font-size: 14px;
    }
    
    .files-table th,
    .files-table td {
        padding: 10px;
    }
    
    .floating-dark-mode {
        width: 50px;
        height: 50px;
        bottom: 20px;
        right: 20px;
        font-size: 24px;
    }
    
    .account-grid {
        grid-template-columns: 1fr;
    }
}

/* Account Settings Improvements */
.account-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-bottom: 20px;
}

.account-card {
    background: var(--bg-secondary);
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: transform 0.2s, box-shadow 0.2s;
}

.account-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.account-card h3 {
    margin-bottom: 20px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
}

.account-card.full-width {
    grid-column: 1 / -1;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.stat-row:last-child {
    border-bottom: none;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 14px;
}

.stat-value {
    font-weight: 600;
    font-size: 16px;
}

.profile-section {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.profile-image-container {
    flex-shrink: 0;
}

.profile-preview {
    width: 120px;
    height: 120px;
    border-radius: 8px;
    object-fit: cover;
    border: 2px solid var(--border-color);
}

.profile-placeholder {
    width: 120px;
    height: 120px;
    border-radius: 8px;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
    border: 2px solid var(--border-color);
}

.trial-badge {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    margin-left: 10px;
}

.warning-badge {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.tier-limits {
    background: var(--bg-tertiary);
    padding: 16px;
    border-radius: 8px;
    margin-top: 12px;
}

.tier-limits ul {
    list-style: none;
    padding: 0;
    margin: 8px 0 0 0;
}

.tier-limits li {
    padding: 6px 0;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.tier-limits li::before {
    content: "✓";
    color: var(--primary-color);
    font-weight: bold;
}

.danger-zone {
    background: linear-gradient(135deg, rgba(244, 67, 54, 0.1) 0%, rgba(244, 67, 54, 0.05) 100%);
    padding: 24px;
    border-radius: 12px;
    border: 2px solid var(--danger-color);
    margin-top: 30px;
}

.danger-zone h3 {
    color: var(--danger-color);
    margin-bottom: 16px;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: 16px 24px;
    border-radius: 8px;
    box-shadow: 0 4px 12px var(--shadow);
    min-width: 300px;
    display: flex;
    align-items: center;
    gap: 12px;
    animation: slideIn 0.3s ease-out;
    border-left: 4px solid var(--primary-color);
}

.toast.success {
    border-left-color: var(--success-color);
}

.toast.error {
    border-left-color: var(--danger-color);
}

.toast.warning {
    border-left-color: #ff9800;
}

.toast-icon {
    font-size: 24px;
}

.toast-close {
    margin-left: auto;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 20px;
    padding: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.image-preview-container {
    margin-top: 16px;
    display: none;
}

.image-preview-container.show {
    display: block;
}

.image-preview {
    max-width: 200px;
    max-height: 200px;
    border-radius: 8px;
    border: 2px solid var(--border-color);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.icon-text {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.account-icon {
    width: 20px;
    height: 20px;
    vertical-align: middle;
}

/* Spinner animation for verification modal */
.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid var(--border-color);
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

/* ==================== Skeleton UI Loading States ==================== */

/* Skeleton shimmer animation */
@keyframes skeleton-shimmer {
    0% {
        background-position: -200% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

/* Base skeleton element */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--bg-tertiary) 25%,
        var(--bg-secondary) 50%,
        var(--bg-tertiary) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-shimmer 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

/* Skeleton text line */
.skeleton-text {
    height: 1rem;
    border-radius: var(--radius-sm);
    margin-bottom: 0.5rem;
}

.skeleton-text.short {
    width: 40%;
}

.skeleton-text.medium {
    width: 65%;
}

.skeleton-text.long {
    width: 85%;
}

.skeleton-text.full {
    width: 100%;
}

/* Skeleton avatar/icon */
.skeleton-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    flex-shrink: 0;
}

.skeleton-avatar.small {
    width: 24px;
    height: 24px;
}

.skeleton-avatar.large {
    width: 60px;
    height: 60px;
}

/* Skeleton card */
.skeleton-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 16px;
    margin-bottom: 12px;
}

.skeleton-card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.skeleton-card-body {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Skeleton table row */
.skeleton-row {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 16px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 8px;
}

.skeleton-row .skeleton-cell {
    height: 1rem;
    border-radius: var(--radius-sm);
}

.skeleton-row .skeleton-cell:nth-child(1) {
    width: 24px;
    height: 24px;
    border-radius: 4px;
    flex-shrink: 0;
}

.skeleton-row .skeleton-cell:nth-child(2) {
    flex: 2;
}

.skeleton-row .skeleton-cell:nth-child(3) {
    width: 80px;
}

.skeleton-row .skeleton-cell:nth-child(4) {
    width: 100px;
}

/* Skeleton button */
.skeleton-btn {
    height: 44px;
    width: 120px;
    border-radius: var(--radius-md);
}

/* Skeleton file item */
.skeleton-file-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 8px;
}

.skeleton-file-icon {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
}

.skeleton-file-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.skeleton-file-name {
    height: 1rem;
    width: 60%;
    border-radius: var(--radius-sm);
}

.skeleton-file-meta {
    height: 0.75rem;
    width: 40%;
    border-radius: var(--radius-sm);
}

.skeleton-file-actions {
    display: flex;
    gap: 8px;
}

.skeleton-file-btn {
    height: 36px;
    width: 80px;
    border-radius: var(--radius-sm);
}

/* Transfer card skeleton */
.skeleton-transfer {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 14px 16px;
    margin-bottom: 12px;
}

.skeleton-transfer-header {
    display: flex;
    align-items: center;
    gap: 12px;
}

.skeleton-transfer-checkbox {
    width: 22px;
    height: 22px;
    border-radius: 4px;
    flex-shrink: 0;
}

.skeleton-transfer-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.skeleton-transfer-link {
    height: 1.1rem;
    width: 120px;
    border-radius: var(--radius-sm);
}

.skeleton-transfer-meta {
    display: flex;
    gap: 16px;
}

.skeleton-transfer-meta-item {
    height: 0.85rem;
    border-radius: var(--radius-sm);
}

.skeleton-transfer-actions {
    display: flex;
    gap: 8px;
}

.skeleton-transfer-btn {
    height: 40px;
    width: 100px;
    border-radius: var(--radius-md);
}

/* Skeleton container for page loading */
.skeleton-container {
    opacity: 1;
    transition: opacity 0.3s ease;
}

.skeleton-container.hidden {
    opacity: 0;
    pointer-events: none;
    position: absolute;
}

/* ==================== Button Loading States ==================== */

/* Button loading state */
.btn-loading {
    position: relative;
    pointer-events: none;
    opacity: 0.85;
    cursor: not-allowed !important;
}

.btn-loading .btn-text {
    visibility: hidden;
}

.btn-loading::after {
    content: "";
    position: absolute;
    left: 50%;
    top: 50%;
    width: 18px;
    height: 18px;
    margin-left: -9px;
    margin-top: -9px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* Button with spinner and text */
.btn-loading-inline {
    pointer-events: none;
    opacity: 0.85;
    cursor: not-allowed !important;
}

.btn-loading-inline .btn-spinner {
    display: inline-block;
    width: 14px;
    height: 14px;
    margin-right: 8px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    vertical-align: middle;
}

.btn-spinner {
    display: none;
}

.btn-loading-inline .btn-spinner {
    display: inline-block;
}

/* Disabled button state during loading */
.btn[disabled],
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed !important;
    pointer-events: none;
}

/* ==================== Page Transition Effects ==================== */

/* Fade-in animation for content */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Content fade-in class */
.content-fade-in {
    animation: fadeIn 0.3s ease-out forwards;
}

.content-fade-in-up {
    animation: fadeInUp 0.4s ease-out forwards;
}

/* Staggered animation for list items */
.stagger-fade-in > * {
    opacity: 0;
    animation: fadeIn 0.3s ease-out forwards;
}

.stagger-fade-in > *:nth-child(1) { animation-delay: 0.05s; }
.stagger-fade-in > *:nth-child(2) { animation-delay: 0.1s; }
.stagger-fade-in > *:nth-child(3) { animation-delay: 0.15s; }
.stagger-fade-in > *:nth-child(4) { animation-delay: 0.2s; }
.stagger-fade-in > *:nth-child(5) { animation-delay: 0.25s; }
.stagger-fade-in > *:nth-child(6) { animation-delay: 0.3s; }
.stagger-fade-in > *:nth-child(7) { animation-delay: 0.35s; }
.stagger-fade-in > *:nth-child(8) { animation-delay: 0.4s; }
.stagger-fade-in > *:nth-child(9) { animation-delay: 0.45s; }
.stagger-fade-in > *:nth-child(10) { animation-delay: 0.5s; }

/* Page content transition wrapper */
.page-content {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.page-content.loaded {
    opacity: 1;
}

/* Upload progress bar enhancement */
.upload-progress-enhanced {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 16px 20px;
    margin-bottom: 16px;
}

.upload-progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.upload-progress-title {
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.upload-progress-title .spinner-inline {
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.upload-progress-percentage {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.upload-progress-bar-container {
    width: 100%;
    height: 12px;
    background: var(--bg-tertiary);
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 12px;
}

.upload-progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--success-color) 100%);
    border-radius: 6px;
    transition: width 0.3s ease;
    position: relative;
    overflow: hidden;
}

.upload-progress-bar-fill::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: progress-shine 1.5s ease-in-out infinite;
}

@keyframes progress-shine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.upload-progress-details {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.upload-progress-file {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    color: var(--text-primary);
    max-width: 50%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.upload-progress-stats {
    display: flex;
    gap: 16px;
}

/* Reduce motion preference */
@media (prefers-reduced-motion: reduce) {
    .skeleton {
        animation: none;
        background: var(--bg-tertiary);
    }
    
    .btn-loading::after,
    .btn-loading-inline .btn-spinner,
    .spinner,
    .spinner-inline {
        animation: none;
    }
    
    .content-fade-in,
    .content-fade-in-up,
    .stagger-fade-in > * {
        animation: none;
        opacity: 1;
        transform: none;
    }
    
    .upload-progress-bar-fill::after {
        animation: none;
    }
}

/* ==================== Feedback FAB and Modal ==================== */

.feedback-fab {
    position: fixed;
    bottom: 30px;
    left: 30px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: #FF9800;
    color: white;
    border: none;
    font-size: 24px;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    z-index: 999;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feedback-fab:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
}

.feedback-fab:active {
    transform: scale(0.95);
}

.feedback-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.feedback-modal.show {
    display: flex;
    background-color: rgba(0, 0, 0, 0.7) !important;
    backdrop-filter: blur(2px);
}

.feedback-modal-content {
    background: var(--bg-primary);
    padding: 2rem;
    border-radius: 12px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.feedback-modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.feedback-modal-header h2 {
    margin: 0;
    color: var(--text-primary);
}

.feedback-close-btn {
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-primary);
    line-height: 1;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feedback-close-btn:hover {
    color: var(--danger-color);
}

.feedback-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.feedback-tab {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
}

.feedback-tab:hover {
    border-color: var(--primary-color);
}

.feedback-tab.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.feedback-form-group {
    margin-bottom: 1.25rem;
}

.feedback-form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.feedback-form-group input,
.feedback-form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 14px;
    transition: border-color 0.2s;
}

.feedback-form-group input:focus,
.feedback-form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: var(--focus-ring);
}

.feedback-form-group textarea {
    min-height: 100px;
    resize: vertical;
}

.feedback-form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 2px solid var(--border-color);
}

.feedback-submit-btn {
    flex: 1;
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition-base), transform var(--transition-fast);
}

.feedback-submit-btn:hover {
    background: var(--primary-color-hover);
    transform: translateY(-1px);
}

.feedback-submit-btn:disabled {
    background: var(--border-color);
    cursor: not-allowed;
}

.feedback-cancel-btn {
    padding: 0.75rem 1.5rem;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
}

.feedback-cancel-btn:hover {
    border-color: var(--border-color-hover);
    background: var(--hover-bg);
}

.feedback-success-message {
    display: none;
    text-align: center;
    padding: 2rem;
}

.feedback-success-message.show {
    display: block;
}

.feedback-success-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    .feedback-fab {
        bottom: 20px;
        left: 20px;
        width: 50px;
        height: 50px;
        font-size: 20px;
    }
    
    .feedback-modal-content {
        width: 95%;
        padding: 1.5rem;
    }
}

/* ==================== Notification Badge ==================== */

.notification-badge {
    display: inline-block;
    background-color: var(--danger-color);
    color: white;
    border-radius: var(--radius-full);
    min-width: 20px;
    height: 20px;
    padding: 2px 6px;
    font-size: 11px;
    font-weight: bold;
    text-align: center;
    line-height: 16px;
    vertical-align: middle;
    margin-left: 6px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.notification-badge.hidden {
    display: none;
}

/* ==================== Development Banner ==================== */

.dev-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: var(--danger-color-hover);
    color: #fffacd;
    text-align: center;
    padding: 4px 0;
    font-size: 12px;
    font-weight: 500;
    z-index: 10000;
    height: 20px;
    line-height: 12px;
    box-shadow: 0 -2px 5px rgba(0, 0, 0, 0.2);
}

body {
    padding-bottom: 20px;
}

/* ==================== Visual Polish Refinements ==================== */

/* Typography Refinements */
h1, h2, h3, h4, h5, h6 {
    letter-spacing: -0.02em;
    line-height: 1.3;
}

h1 {
    font-size: 2rem;
    font-weight: 700;
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

h4 {
    font-size: 1.1rem;
    font-weight: 500;
}

/* Card Shadows & Hover Effects - Base Card Styles */
.account-card,
.stat-card,
.admin-tool-card,
.file-queue,
.file-details,
.batch-info,
.files-list,
.share-result,
.auth-form,
.empty-state,
.controls-bar,
.transfer-card {
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.account-card:hover,
.stat-card:hover,
.admin-tool-card:hover,
.file-queue:hover,
.transfer-card:hover {
    box-shadow: var(--shadow-md);
}

/* File Item Cards Enhancement */
.file-item,
.file-item-download {
    box-shadow: var(--shadow-sm);
    transition: background var(--transition-base), box-shadow var(--transition-base), transform var(--transition-fast);
}

.file-item:hover,
.file-item-download:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

/* Modal Enhancement */
.modal-content,
.feedback-modal-content {
    box-shadow: var(--shadow-xl);
}

/* Button Focus States - WCAG 2.1 AA Compliant with :focus-visible */
.btn:focus-visible,
.btn-primary:focus-visible,
.btn-secondary:focus-visible,
.btn-success:focus-visible,
.btn-danger:focus-visible,
.btn-info:focus-visible,
.btn-warning:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring), var(--shadow-md);
}

.btn-danger:focus-visible {
    outline-color: var(--focus-outline-color-danger);
    box-shadow: var(--focus-ring-danger), var(--shadow-md);
}

.btn-info:focus-visible,
.btn-primary:focus-visible {
    outline-color: var(--focus-outline-color-info);
    box-shadow: var(--focus-ring-info), var(--shadow-md);
}

.btn-success:focus-visible {
    outline-color: var(--focus-outline-color-success);
}

/* Button Hover Enhancement - Ensure all buttons have consistent hover */
.btn {
    transition: all var(--transition-fast);
}

.btn:active {
    transform: translateY(0);
}

/* Icon Button Focus States - WCAG 2.1 AA Compliant */
.btn-icon:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
    border-radius: var(--radius-md);
}

/* Tab Button Focus States - WCAG 2.1 AA Compliant */
.tab-btn:focus-visible,
.feedback-tab:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* Link Focus States - WCAG 2.1 AA Compliant */
a:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
    border-radius: var(--radius-sm);
}

/* Navigation Link Focus - WCAG 2.1 AA Compliant */
.nav-menu-items a:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: -2px;
    box-shadow: inset var(--focus-ring);
}

/* Input Field Enhancements */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="search"],
input[type="tel"],
input[type="url"],
input[type="file"],
select,
textarea {
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}

input[type="text"]:hover,
input[type="email"]:hover,
input[type="password"]:hover,
input[type="number"]:hover,
input[type="search"]:hover,
input[type="tel"]:hover,
input[type="url"]:hover,
select:hover,
textarea:hover {
    border-color: var(--border-color-hover);
}

/* Checkbox and Radio Focus States - WCAG 2.1 AA Compliant */
input[type="checkbox"]:focus-visible,
input[type="radio"]:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* Search Box Enhancement - WCAG 2.1 AA Compliant */
.search-box input:focus-visible {
    border-color: var(--focus-outline-color);
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* Select Dropdown Focus - WCAG 2.1 AA Compliant */
.sort-dropdown select:focus-visible {
    border-color: var(--focus-outline-color);
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* Drop Zone Enhancement */
.drop-zone {
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.drop-zone:hover {
    border-color: var(--border-color-hover);
    box-shadow: var(--shadow-md);
}

.drop-zone.drag-over {
    box-shadow: var(--shadow-lg);
}

/* Badge Enhancement */
.badge,
.status-badge {
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

/* Toast Enhancement */
.toast {
    box-shadow: var(--shadow-lg);
}

/* Navigation Menu Enhancement */
.nav-menu {
    box-shadow: var(--shadow-xl);
}

/* Floating Dark Mode Button Enhancement */
.floating-dark-mode {
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.floating-dark-mode:hover {
    box-shadow: var(--shadow-lg);
}

.floating-dark-mode:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring), var(--shadow-lg);
}

/* Feedback FAB Enhancement */
.feedback-fab {
    box-shadow: var(--shadow-md);
}

.feedback-fab:hover {
    box-shadow: var(--shadow-lg);
}

.feedback-fab:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring), var(--shadow-lg);
}

/* CTA Button Enhancement (for landing page) - WCAG 2.1 AA Compliant */
.cta-button:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring), var(--shadow-lg);
}

/* Remove Button Focus State - WCAG 2.1 AA Compliant */
.btn-remove:focus-visible {
    outline: 2px solid var(--focus-outline-color-danger);
    outline-offset: 2px;
    box-shadow: var(--focus-ring-danger);
}

/* Cancel Button Focus State - WCAG 2.1 AA Compliant */
.btn-cancel:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* Progress Bar Enhancement */
.progress-bar,
.file-progress-bar {
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
}

/* Share Counter Enhancement */
.share-counter {
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-base);
}

.share-counter:hover {
    box-shadow: var(--shadow-md);
}

/* Upload Options Panel Enhancement */
.upload-options {
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-base);
}

/* Ad Container Enhancement */
.ad-container {
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-base), border-color var(--transition-base);
}

.ad-container:hover {
    box-shadow: var(--shadow-md);
}

/* Manage Files Banner Enhancement */
.manage-files-banner {
    box-shadow: var(--shadow-sm);
}

/* Danger Zone Enhancement */
.danger-zone {
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-base);
}

.danger-zone:hover {
    box-shadow: var(--shadow-md);
}

/* Tier Limits Box Enhancement */
.tier-limits {
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.05);
}

/* Gradient Enhancement for Cards (subtle top border gradient) */
.account-card::before,
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.account-card,
.stat-card {
    position: relative;
    overflow: hidden;
}

.account-card:hover::before,
.stat-card:hover::before {
    opacity: 1;
}

/* Password Strength Container Enhancement */
.password-strength-container {
    transition: all var(--transition-base);
}

/* Trial Banner Enhancement */
.trial-banner {
    box-shadow: var(--shadow-md);
}

/* Bulk Actions Bar Enhancement */
.bulk-actions {
    box-shadow: var(--shadow-sm);
}

.bulk-actions.active {
    box-shadow: var(--shadow-md);
}

/* ========================================
   ACCESSIBILITY ENHANCEMENTS (WCAG 2.1 AA)
   ======================================== */

/* Skip Link for Keyboard Users */
.skip-link {
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    z-index: 10000;
    text-decoration: none;
    font-weight: 600;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 10px;
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
}

/* Drop Zone Focus State */
.drop-zone:focus-visible,
.drop-zone:focus-within {
    border-color: var(--focus-outline-color);
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring), var(--shadow-md);
}

/* Interactive Card Focus States */
.pricing-card:focus-visible,
.account-card:focus-visible,
.transfer-card:focus-visible,
.file-item:focus-visible,
.file-item-download:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring), var(--shadow-lg);
}

/* Modal Close Button Focus */
.modal-close:focus-visible,
.nav-menu-close:focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
    border-radius: var(--radius-sm);
}

/* Textarea Focus State */
textarea:focus-visible {
    border-color: var(--focus-outline-color);
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* General Input Focus States for inputs not in .form-group */
input:not([type="checkbox"]):not([type="radio"]):focus-visible {
    border-color: var(--focus-outline-color);
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* Ensure focus indicators are visible on all clickable elements */
[role="button"]:focus-visible,
[tabindex]:not([tabindex="-1"]):focus-visible {
    outline: 2px solid var(--focus-outline-color);
    outline-offset: 2px;
    box-shadow: var(--focus-ring);
}

/* High Contrast Focus Mode - For users who enable it */
@media (prefers-contrast: high) {
    :focus-visible {
        outline: 3px solid currentColor !important;
        outline-offset: 3px !important;
    }
}

/* Reduce Motion for Users Who Prefer It */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ========================================
   TOUCH TARGET SIZING (WCAG 2.1 AA - 44px)
   ======================================== */

/* Ensure all buttons meet 44x44px minimum touch target */
button,
.btn,
[role="button"] {
    min-height: 44px;
}

/* Tab buttons - increase touch target */
.tab-btn {
    min-height: 44px;
    padding: 12px 20px;
}

/* Close buttons (× character) - ensure adequate size */
.nav-menu-close,
.modal-close,
[class*="close"] {
    min-width: 44px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

/* Checkbox and Radio - increase touch area with label wrapping */
input[type="checkbox"],
input[type="radio"] {
    min-width: 20px;
    min-height: 20px;
    cursor: pointer;
}

/* Ensure form labels have adequate touch areas when clickable */
label[for] {
    cursor: pointer;
    padding: 4px 0;
    display: inline-block;
}

/* Floating action buttons - increase size */
.floating-dark-mode {
    min-width: 48px;
    min-height: 48px;
    font-size: 1.25rem;
}

.feedback-fab {
    min-width: 56px;
    min-height: 56px;
}

/* Link buttons in navigation - increase padding */
.nav-menu-items a {
    min-height: 44px;
    display: flex;
    align-items: center;
    padding: 12px 20px;
}

/* Mobile-specific touch target improvements */
@media (max-width: 768px) {
    /* Increase button sizes on mobile */
    .btn {
        min-height: 48px;
        padding: 14px 24px;
    }
    
    .btn-sm {
        min-height: 44px;
        padding: 12px 18px;
    }
    
    /* Larger touch targets for icon buttons on mobile */
    .btn-icon {
        min-width: 48px;
        min-height: 48px;
        padding: 12px;
    }
    
    /* Increase spacing between inline buttons */
    .transfer-actions,
    .header-controls,
    .modal-actions {
        gap: 12px;
    }
    
    /* Ensure file item action buttons are tappable */
    .file-actions button,
    .file-item button {
        min-height: 44px;
        min-width: 44px;
        padding: 10px 14px;
    }
    
    /* Tab buttons - full width on mobile */
    .auth-tabs {
        gap: 8px;
    }
    
    .tab-btn {
        min-height: 48px;
        flex: 1;
        padding: 14px 16px;
    }
    
    /* Checkboxes and radios with larger hit areas */
    input[type="checkbox"],
    input[type="radio"] {
        min-width: 24px;
        min-height: 24px;
    }
    
    /* Navigation items - taller for easier tapping */
    .nav-menu-items a {
        min-height: 52px;
        padding: 16px 20px;
    }
    
    /* Form inputs - taller on mobile */
    .form-group input[type="text"],
    .form-group input[type="email"],
    .form-group input[type="password"],
    .form-group select,
    textarea {
        min-height: 48px;
        padding: 14px;
    }
}

/* ========================================
   ENHANCED MOBILE RESPONSIVENESS (UX-3)
   Section 3: Mobile-first responsive design
   Breakpoints: Mobile (<768px), Tablet (768-1024px)
   ======================================== */

/* --- Navigation Enhancement --- */
.nav-menu {
    width: 85vw;
    max-width: 320px;
    left: -100%;
    transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-menu.open {
    left: 0;
}

.nav-overlay {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.nav-overlay.open {
    display: block;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

/* --- Mobile Breakpoint (<768px) --- */
@media (max-width: 767px) {
    /* Container padding */
    .container {
        padding: 12px;
    }
    
    /* Header improvements - Mobile logo above text */
    header {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        padding: 12px 0;
        text-align: left;
        gap: 8px;
    }
    
    .header-brand {
        gap: 0.5rem;
    }
    
    .header-brand-content {
        display: flex !important;
        flex-direction: column !important;
        align-items: flex-start !important;
        gap: 2px;
    }
    
    .header-logo {
        height: 12px !important;
        width: auto;
        margin-right: 0 !important;
    }
    
    .header-text {
        text-align: left;
    }
    
    .header-text h1 {
        font-size: 12px !important;
        line-height: 1.1;
        margin: 0;
    }
    
    /* Hide tagline in header on mobile - it's in the footer now */
    .header-text p {
        display: none !important;
    }
    
    /* Mobile Footer Branding */
    .mobile-footer {
        display: flex;
        justify-content: center;
        align-items: center;
        gap: 12px;
        padding: 24px 16px;
        margin-top: 40px;
        margin-bottom: 36px;
        border-top: 1px solid var(--border-color);
    }
    
    .mobile-footer-logo {
        height: 24px;
        width: auto;
        flex-shrink: 0;
    }
    
    .mobile-footer-text {
        font-size: 0.85rem;
        color: var(--text-secondary);
        line-height: 1.3;
    }
    
    .mobile-footer-text strong {
        color: var(--text-primary);
        font-weight: 600;
    }
    
    /* Normalize all header elements to 32px height */
    .header-brand .btn-icon,
    header .btn-icon {
        width: 32px !important;
        height: 32px !important;
        min-width: 32px !important;
        min-height: 32px !important;
        font-size: 1rem !important;
        display: flex !important;
        align-items: center !important;
        justify-content: center !important;
        padding: 0 !important;
    }
    
    /* Hamburger menu icon - 20% larger */
    #navMenuToggle {
        width: 38px !important;
        height: 38px !important;
        min-width: 38px !important;
        min-height: 38px !important;
        font-size: 1.2rem !important;
    }
    
    .header-controls {
        margin-top: 0;
        gap: 4px;
        align-items: center;
    }
    
    .header-controls .btn {
        height: 32px !important;
        min-height: 32px !important;
        padding: 0 10px !important;
        font-size: 0.7rem !important;
        display: flex !important;
        align-items: center !important;
        justify-content: center !important;
    }
    
    .header-controls .btn-icon {
        width: 32px !important;
        height: 32px !important;
        min-width: 32px !important;
        min-height: 32px !important;
        padding: 0 !important;
        font-size: 1rem !important;
    }
    
    /* Profile image in header */
    .header-controls .btn-icon img {
        width: 32px !important;
        height: 32px !important;
    }
    
    /* Hide text on small buttons, show icon only */
    .header-controls .btn.btn-primary:not(.btn-icon) {
        height: 32px !important;
        padding: 0 10px !important;
        font-size: 0.7rem !important;
    }
    
    /* Transfer Card Mobile Layout - Condensed */
    .transfer-card {
        margin-bottom: 10px;
        border-left: 4px solid var(--border-color);
        border-radius: 4px 8px 8px 4px;
    }
    
    .transfer-card.status-active-card {
        border-left-color: #15803d;
    }
    
    .transfer-card.status-expiring-card {
        border-left-color: #b45309;
    }
    
    .transfer-card.status-empty-card,
    .transfer-card.status-archived-card {
        border-left-color: #525252;
    }
    
    .transfer-header {
        flex-direction: row;
        align-items: flex-start;
        gap: 8px;
        padding: 10px 12px;
        flex-wrap: wrap;
    }
    
    .transfer-checkbox {
        flex-shrink: 0;
        padding-top: 2px;
    }
    
    .transfer-info {
        display: flex;
        flex-direction: column;
        gap: 6px;
        width: 100%;
    }
    
    /* Row 1: Link + Status badge inline */
    .transfer-title {
        width: 100%;
        display: flex;
        flex-wrap: wrap;
        align-items: center;
        gap: 8px;
    }
    
    .transfer-link {
        font-size: 0.9rem;
        word-break: break-all;
        flex: 1;
        min-width: 120px;
    }
    
    /* Row 2: Compact meta info */
    .transfer-meta {
        font-size: 0.8rem;
        display: flex;
        flex-wrap: wrap;
        gap: 6px 12px;
    }
    
    .transfer-meta span {
        white-space: nowrap;
    }
    
    /* Status badge inline with title */
    .status-badge {
        margin-top: 0;
        padding: 3px 8px;
        font-size: 0.7rem;
    }
    
    /* Action buttons - horizontal auto-fit grid */
    .transfer-actions {
        width: 100%;
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
        gap: 6px;
        margin-top: 6px;
        padding-top: 8px;
        border-top: 1px solid var(--border-color);
    }
    
    .transfer-actions button {
        justify-content: center;
        width: 100%;
        display: flex;
        align-items: center;
        padding: 8px 10px;
        font-size: 0.8rem;
        min-height: 44px;
    }
    
    /* File items in expanded card - Condensed */
    .files-list {
        padding: 10px 12px;
    }
    
    .file-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
        padding: 8px 10px;
        margin-bottom: 6px;
    }
    
    .file-name {
        width: 100%;
        min-width: unset;
        font-size: 0.85rem;
    }
    
    .file-stat {
        font-size: 0.75rem;
    }
    
    .file-actions {
        width: 100%;
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(70px, 1fr));
        gap: 6px;
    }
    
    .file-action-btn {
        justify-content: center;
        padding: 6px 8px;
        font-size: 0.75rem;
        min-height: 44px;
    }
    
    /* Controls bar mobile layout */
    .controls-bar {
        padding: 12px;
        gap: 12px;
    }
    
    .search-box {
        min-width: 100%;
        order: 1;
    }
    
    .sort-dropdown {
        order: 2;
        width: 100%;
    }
    
    .sort-dropdown select {
        width: 100%;
        min-height: 48px;
    }
    
    .toggle-switch {
        order: 3;
        width: 100%;
        justify-content: space-between;
        padding: 12px 0;
    }
    
    /* Bulk actions mobile */
    .bulk-actions {
        flex-direction: column;
        padding: 16px;
        gap: 12px;
    }
    
    .bulk-actions-label {
        margin-right: 0;
        margin-bottom: 8px;
    }
    
    .bulk-actions button {
        width: 100%;
    }
    
    /* Pagination mobile */
    .pagination-controls {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
    
    .page-size-selector {
        width: 100%;
    }
    
    .page-size-selector select {
        width: 100%;
    }
    
    /* Account grid single column */
    .account-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .account-card {
        padding: 16px;
    }
    
    .account-card.full-width {
        grid-column: 1;
    }
    
    /* Profile section mobile */
    .profile-section {
        flex-direction: column;
        gap: 16px;
    }
    
    .profile-image-container {
        text-align: center;
        width: 100%;
    }
    
    .profile-preview,
    .profile-placeholder {
        width: 100px;
        height: 100px;
        margin: 0 auto;
    }
    
    /* Form rows stack vertically */
    .form-row {
        flex-direction: column;
        gap: 16px;
    }
    
    .form-row .form-group {
        width: 100%;
    }
    
    /* Stat rows mobile */
    .stat-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
        padding: 12px 0;
    }
    
    .stat-value {
        font-size: 1.1rem;
    }
    
    /* Modal mobile */
    .modal-content {
        width: 95%;
        max-width: none;
        padding: 20px;
        margin: 20px;
        max-height: 90vh;
        overflow-y: auto;
    }
    
    .modal-buttons,
    .modal-actions {
        flex-direction: column;
        gap: 10px;
    }
    
    .modal-buttons button,
    .modal-actions button {
        width: 100%;
    }
    
    /* Download page mobile */
    .download-section {
        padding: 16px;
    }
    
    .file-item-download {
        flex-direction: column;
        gap: 12px;
        padding: 16px;
    }
    
    .file-item-download .btn {
        width: 100%;
    }
    
    .file-item-info {
        width: 100%;
    }
    
    /* Upload page mobile */
    .drop-zone {
        padding: 40px 20px;
    }
    
    .upload-icon {
        font-size: 48px;
    }
    
    /* Storage displays */
    .storage-display,
    .upload-limit-display {
        padding: 12px;
    }
    
    /* Trial banner mobile */
    .trial-banner {
        flex-direction: column;
        align-items: stretch;
        padding: 16px;
        gap: 16px;
    }
    
    .trial-banner-actions {
        width: 100%;
    }
    
    .trial-upgrade-btn {
        width: 100%;
        text-align: center;
    }
    
    /* Manage files banner */
    .manage-files-banner {
        padding: 12px;
        margin-bottom: 16px;
    }
    
    /* Ad container */
    .ad-container {
        margin-bottom: 16px;
    }
    
    /* Danger zone mobile */
    .danger-zone {
        padding: 16px;
    }
    
    /* Toast notifications mobile */
    .toast-container {
        left: 12px;
        right: 12px;
        top: auto;
        bottom: 20px;
    }
    
    .toast {
        min-width: auto;
        width: 100%;
    }
    
    /* Floating button repositioning */
    .floating-dark-mode {
        bottom: 16px;
        right: 16px;
        width: 52px;
        height: 52px;
    }
    
    .feedback-fab {
        bottom: 16px;
        left: 16px;
        right: auto;
    }
    
    /* Prevent horizontal scroll */
    body {
        overflow-x: hidden;
    }
    
    .container {
        max-width: 100vw;
        overflow-x: hidden;
    }
    
    /* Pricing cards mobile */
    .pricing-container {
        flex-direction: column;
        gap: 16px;
    }
    
    .pricing-card {
        width: 100%;
    }
    
    /* Summary bar mobile */
    .summary-bar {
        padding: 12px 16px;
        font-size: 0.85rem;
    }
    
    /* Input type optimizations for mobile keyboards */
    input[type="email"] {
        -webkit-text-size-adjust: none;
    }
    
    input[type="tel"] {
        -webkit-text-size-adjust: none;
    }
    
    /* Ensure proper input font size to prevent iOS zoom */
    input, select, textarea {
        font-size: 16px;
    }
}

/* --- Tablet Breakpoint (768px - 1024px) --- */
@media (min-width: 768px) and (max-width: 1024px) {
    .container {
        padding: 16px;
    }
    
    /* Two-column grid for account cards */
    .account-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    /* Transfer cards remain full width but with better spacing */
    .transfer-card {
        margin-bottom: 16px;
    }
    
    .transfer-info {
        grid-template-columns: 2fr 1fr auto;
    }
    
    /* Pricing cards in row */
    .pricing-container {
        flex-wrap: wrap;
    }
    
    .pricing-card {
        flex: 1 1 calc(50% - 12px);
        min-width: 280px;
    }
    
    /* Modal sizing */
    .modal-content {
        max-width: 600px;
    }
}

/* --- Extra Small Mobile (<375px) --- */
@media (max-width: 374px) {
    .container {
        padding: 8px;
    }
    
    header h1 {
        font-size: 18px;
    }
    
    .btn {
        padding: 12px 16px;
        font-size: 0.85rem;
    }
    
    .transfer-actions {
        flex-direction: column;
    }
    
    .file-action-btn {
        flex: 1 1 100%;
    }
    
    .header-controls {
        gap: 4px;
    }
    
    .header-controls .btn {
        padding: 8px 10px;
        font-size: 0.75rem;
    }
}

/* --- Landscape Mobile Orientation --- */
@media (max-width: 896px) and (orientation: landscape) {
    .nav-menu {
        width: 50vw;
        max-width: 280px;
    }
    
    .modal-content {
        max-height: 85vh;
    }
    
    .drop-zone {
        padding: 30px 20px;
    }
    
    .upload-icon {
        font-size: 40px;
        margin-bottom: 12px;
    }
}

/* --- Touch Interaction Enhancements --- */
@media (hover: none) and (pointer: coarse) {
    /* Remove hover effects that don't work on touch */
    .transfer-card:hover {
        transform: none;
    }
    
    .account-card:hover {
        transform: none;
    }
    
    /* Add active state feedback instead */
    .transfer-card:active {
        transform: scale(0.99);
        opacity: 0.9;
    }
    
    .btn:active {
        transform: scale(0.97);
    }
    
    /* Ensure adequate tap spacing */
    .transfer-actions button + button,
    .file-actions button + button {
        margin-left: 0;
    }
}

/* ==================== UX-4: Forms & Inputs Enhancement ==================== */

/* Form Field Container with Label and Validation */
.form-field {
    margin-bottom: 1.25rem;
    position: relative;
}

.form-field:last-child {
    margin-bottom: 0;
}

/* Enhanced Labels */
.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.form-label.required::after {
    content: " *";
    color: var(--danger-color);
    font-weight: 600;
}

/* Enhanced Input Styling */
.form-input,
.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"],
.form-group input[type="number"],
.form-group input[type="tel"],
.form-group input[type="url"],
.form-group input[type="search"],
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    line-height: 1.5;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color var(--transition-fast), 
                box-shadow var(--transition-fast), 
                background-color var(--transition-fast);
}

.form-input::placeholder,
.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-secondary);
    opacity: 0.7;
}

/* Hover State */
.form-input:hover:not(:focus):not(:disabled):not(.is-invalid),
.form-group input:hover:not(:focus):not(:disabled):not(.is-invalid),
.form-group select:hover:not(:focus):not(:disabled):not(.is-invalid),
.form-group textarea:hover:not(:focus):not(:disabled):not(.is-invalid) {
    border-color: var(--border-color-hover);
    background-color: var(--hover-bg);
}

/* Focus State - Blue primary focus ring */
.form-input:focus,
.form-group input[type="text"]:focus,
.form-group input[type="email"]:focus,
.form-group input[type="password"]:focus,
.form-group input[type="number"]:focus,
.form-group input[type="tel"]:focus,
.form-group input[type="url"]:focus,
.form-group input[type="search"]:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--secondary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.25);
    background-color: var(--bg-primary);
}

/* Disabled State */
.form-input:disabled,
.form-group input:disabled,
.form-group select:disabled,
.form-group textarea:disabled {
    background-color: var(--bg-tertiary);
    border-color: var(--border-color);
    color: var(--text-secondary);
    cursor: not-allowed;
    opacity: 0.7;
}

/* Validation States */
.form-input.is-valid,
.form-group input.is-valid,
.form-group select.is-valid,
.form-group textarea.is-valid {
    border-color: var(--success-color);
}

.form-input.is-valid:focus,
.form-group input.is-valid:focus,
.form-group select.is-valid:focus,
.form-group textarea.is-valid:focus {
    border-color: var(--success-color);
    box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.25);
}

.form-input.is-invalid,
.form-group input.is-invalid,
.form-group select.is-invalid,
.form-group textarea.is-invalid {
    border-color: var(--danger-color);
}

.form-input.is-invalid:focus,
.form-group input.is-invalid:focus,
.form-group select.is-invalid:focus,
.form-group textarea.is-invalid:focus {
    border-color: var(--danger-color);
    box-shadow: 0 0 0 3px rgba(244, 67, 54, 0.25);
}

/* Helper Text */
.form-helper {
    display: block;
    margin-top: 0.375rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.form-helper i {
    margin-right: 0.25rem;
    opacity: 0.8;
}

/* Validation Feedback Messages */
.form-feedback {
    display: flex;
    align-items: flex-start;
    gap: 0.375rem;
    margin-top: 0.375rem;
    font-size: 0.85rem;
    line-height: 1.4;
    opacity: 0;
    max-height: 0;
    overflow: hidden;
    transition: opacity var(--transition-fast), max-height var(--transition-fast);
}

.form-feedback.show {
    opacity: 1;
    max-height: 100px;
}

.form-feedback.error {
    color: var(--text-danger);
}

.form-feedback.success {
    color: var(--text-success);
}

.form-feedback.warning {
    color: var(--text-warning);
}

.form-feedback i {
    flex-shrink: 0;
    margin-top: 0.125rem;
}

/* Inline Validation Icon */
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper .form-input,
.input-wrapper input {
    padding-right: 2.5rem;
}

.validation-icon {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1rem;
    opacity: 0;
    transition: opacity var(--transition-fast);
    pointer-events: none;
}

.validation-icon.show {
    opacity: 1;
}

.validation-icon.valid {
    color: var(--success-color);
}

.validation-icon.invalid {
    color: var(--danger-color);
}

/* Enhanced File Upload Zone */
.drop-zone {
    border: 3px dashed var(--border-color);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    text-align: center;
    transition: all var(--transition-base);
    background: var(--bg-secondary);
    cursor: pointer;
    position: relative;
    min-height: 280px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.drop-zone:hover {
    border-color: var(--secondary-color);
    background: var(--hover-bg);
    box-shadow: var(--shadow-md);
}

.drop-zone.drag-over {
    border-color: var(--primary-color);
    background: rgba(76, 175, 80, 0.08);
    box-shadow: var(--shadow-lg), inset 0 0 0 2px rgba(76, 175, 80, 0.2);
    transform: scale(1.01);
}

.drop-zone.drag-over .upload-icon {
    transform: scale(1.1);
    color: var(--primary-color);
}

.upload-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
    transition: transform var(--transition-base), color var(--transition-base);
}

.drop-zone-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.drop-zone-subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.drop-zone .or-text {
    margin: 1rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    position: relative;
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
    max-width: 200px;
}

.drop-zone .or-text::before,
.drop-zone .or-text::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--border-color);
}

.drop-zone .file-info {
    margin-top: 1.5rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    font-size: 0.85rem;
}

.drop-zone .file-info p {
    margin: 0.25rem 0;
    color: var(--text-secondary);
}

.drop-zone .file-info p:first-child {
    font-weight: 500;
    color: var(--text-primary);
}

/* Select Dropdown Enhancement */
.form-group select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%234b5563' d='M6 8L1 3h10L6 8z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    padding-right: 2.5rem;
    cursor: pointer;
}

[data-theme="dark"] .form-group select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23d1d5db' d='M6 8L1 3h10L6 8z'/%3E%3C/svg%3E");
}

/* Checkbox & Radio Enhancement */
.form-check {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    cursor: pointer;
}

.form-check input[type="checkbox"],
.form-check input[type="radio"] {
    width: 1.25rem;
    height: 1.25rem;
    margin: 0;
    cursor: pointer;
    accent-color: var(--primary-color);
    flex-shrink: 0;
}

.form-check-label {
    font-size: 0.95rem;
    color: var(--text-primary);
    cursor: pointer;
    user-select: none;
}

.form-check-description {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

/* Password Toggle Button */
.password-toggle {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition-fast);
}

.password-toggle:hover {
    color: var(--text-primary);
}

/* Form Section Divider */
.form-divider {
    display: flex;
    align-items: center;
    margin: 1.5rem 0;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.form-divider::before,
.form-divider::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--border-color);
}

.form-divider span {
    padding: 0 1rem;
}

/* Form Actions */
.form-actions {
    display: flex;
    gap: 0.75rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.form-actions.centered {
    justify-content: center;
}

.form-actions.end {
    justify-content: flex-end;
}

/* Character Counter */
.char-counter {
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-align: right;
    margin-top: 0.25rem;
}

.char-counter.warning {
    color: var(--text-warning);
}

.char-counter.error {
    color: var(--text-danger);
}

/* Input Group (for prefix/suffix) */
.input-group {
    display: flex;
    align-items: stretch;
}

.input-group .form-input,
.input-group input {
    flex: 1;
    min-width: 0;
    border-radius: 0;
}

.input-group .form-input:first-child,
.input-group input:first-child {
    border-top-left-radius: var(--radius-lg);
    border-bottom-left-radius: var(--radius-lg);
}

.input-group .form-input:last-child,
.input-group input:last-child {
    border-top-right-radius: var(--radius-lg);
    border-bottom-right-radius: var(--radius-lg);
}

.input-group-text {
    display: flex;
    align-items: center;
    padding: 0 1rem;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.95rem;
    white-space: nowrap;
}

.input-group-text:first-child {
    border-right: none;
    border-top-left-radius: var(--radius-lg);
    border-bottom-left-radius: var(--radius-lg);
}

.input-group-text:last-child {
    border-left: none;
    border-top-right-radius: var(--radius-lg);
    border-bottom-right-radius: var(--radius-lg);
}

/* File Input Styling */
.file-input-wrapper {
    position: relative;
    display: inline-block;
    width: 100%;
}

.file-input-wrapper input[type="file"] {
    position: absolute;
    left: 0;
    top: 0;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.file-input-display {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    transition: all var(--transition-fast);
    cursor: pointer;
}

.file-input-wrapper:hover .file-input-display {
    border-color: var(--secondary-color);
    background: var(--hover-bg);
}

.file-input-display i {
    font-size: 1.25rem;
    color: var(--secondary-color);
}

.file-input-text {
    flex: 1;
    color: var(--text-secondary);
}

.file-input-text.has-file {
    color: var(--text-primary);
    font-weight: 500;
}

/* Responsive Form Adjustments */
@media (max-width: 768px) {
    .drop-zone {
        padding: 2rem 1.5rem;
        min-height: 240px;
    }
    
    .upload-icon {
        font-size: 3rem;
        margin-bottom: 1rem;
    }
    
    .drop-zone-title {
        font-size: 1.1rem;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .form-actions .btn {
        width: 100%;
    }
}