/* ============================================
   Modern Video Player 2025 - Stylesheet
   Features: Glassmorphism, Dark Mode, Smooth Animations
   ============================================ */

/* CSS Variables for Theming */
:root {
    /* Light Mode Colors */
    --bg-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --bg-secondary: #f7fafc;
    --bg-card: rgba(255, 255, 255, 0.7);
    --bg-card-hover: rgba(255, 255, 255, 0.85);

    /* Text Colors */
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;

    /* Accent Colors */
    --accent-primary: #667eea;
    --accent-secondary: #764ba2;
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    /* UI Elements */
    --border-color: rgba(255, 255, 255, 0.3);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.15);

    /* Glass Effect */
    --glass-bg: rgba(255, 255, 255, 0.25);
    --glass-border: rgba(255, 255, 255, 0.18);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --bg-secondary: #0f0f1e;
    --bg-card: rgba(30, 30, 46, 0.7);
    --bg-card-hover: rgba(30, 30, 46, 0.85);

    --text-primary: #e2e8f0;
    --text-secondary: #cbd5e0;
    --text-tertiary: #a0aec0;

    --accent-primary: #818cf8;
    --accent-secondary: #a78bfa;
    --accent-gradient: linear-gradient(135deg, #818cf8 0%, #a78bfa 100%);

    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);

    --glass-bg: rgba(30, 30, 46, 0.4);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.5);
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Theme Toggle Button */
.theme-toggle {
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1000;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
}

.theme-toggle:hover {
    transform: scale(1.1) rotate(15deg);
    box-shadow: var(--shadow-lg);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.theme-toggle svg {
    color: var(--text-primary);
    transition: all var(--transition-normal);
}

.theme-toggle .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: block;
}

/* App Container */
.app-container {
    max-width: 1920px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: 100vh;
}

/* Header */
.app-header {
    margin-bottom: var(--spacing-lg);
    animation: slideDown 0.6s ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo svg {
    color: var(--accent-primary);
    filter: drop-shadow(0 2px 4px rgba(102, 126, 234, 0.3));
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav-link {
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all var(--transition-normal);
    position: relative;
}

.nav-link:hover {
    color: var(--accent-primary);
    background: var(--glass-bg);
}

.nav-link.active {
    color: var(--accent-primary);
    background: var(--glass-bg);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 2px;
    background: var(--accent-gradient);
    border-radius: 2px;
}

/* Main Content Layout */
.main-content {
    display: grid;
    grid-template-columns: 300px 1fr 320px;
    gap: var(--spacing-lg);
    animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* Glass Card Component */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
}

.glass-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.45);
}

.card-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* Sidebar Styles */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Upload Area */
.upload-area {
    margin-bottom: var(--spacing-md);
}

.upload-label {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-align: center;
    gap: var(--spacing-md);
}

.upload-label:hover {
    border-color: var(--accent-primary);
    background: var(--glass-bg);
    transform: scale(1.02);
}

.upload-label svg {
    color: var(--accent-primary);
}

.upload-label span {
    color: var(--text-secondary);
    font-weight: 500;
}

.upload-hint {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.file-info {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--glass-bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.file-details {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.file-details svg {
    color: var(--accent-primary);
    flex-shrink: 0;
}

.file-text {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-size {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

/* Playlist Empty State */
.playlist-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    text-align: center;
    color: var(--text-tertiary);
    gap: var(--spacing-md);
}

.playlist-empty svg {
    opacity: 0.5;
}

/* Video Section */
.video-section {
    display: flex;
    flex-direction: column;
}

.video-card {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.video-container {
    position: relative;
    background: #000;
    border-radius: var(--radius-md);
    overflow: hidden;
    aspect-ratio: 16/9;
    margin-bottom: var(--spacing-lg);
}

.video-player {
    width: 100%;
    height: 100%;
    display: block;
    cursor: grab;
    position: relative;
    transition: transform var(--transition-normal);
}

.video-player:active {
    cursor: grabbing;
}

/* Video Overlay */
.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity var(--transition-normal);
    pointer-events: none;
}

.video-container:hover .video-overlay {
    opacity: 1;
}

.play-overlay {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    border: none;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    color: white;
    cursor: pointer;
    transition: all var(--transition-normal);
    pointer-events: all;
    display: flex;
    align-items: center;
    justify-content: center;
}

.play-overlay:hover {
    transform: scale(1.1);
    background: var(--accent-primary);
}

.play-overlay:active {
    transform: scale(0.95);
}

/* Video Coordinates */
.video-coordinates {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    color: white;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.video-container:hover .video-coordinates {
    opacity: 1;
}

.video-coordinates span {
    display: inline-block;
    min-width: 60px;
}

/* Video Controls */
.video-controls {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Progress Bar */
.progress-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.progress-bar {
    position: relative;
    height: 8px;
    background: var(--glass-bg);
    border-radius: 4px;
    cursor: pointer;
    overflow: visible;
}

.progress-filled {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 4px;
    width: 0%;
    transition: width 0.1s linear;
    position: relative;
}

.progress-handle {
    position: absolute;
    top: 50%;
    transform: translate(-50%, -50%);
    left: 0%;
    width: 16px;
    height: 16px;
    background: white;
    border-radius: 50%;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    cursor: pointer;
    transition: all var(--transition-fast);
    opacity: 0;
}

.progress-bar:hover .progress-handle {
    opacity: 1;
}

.progress-handle:hover {
    transform: translate(-50%, -50%) scale(1.2);
}

.time-display {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.time-separator {
    color: var(--text-tertiary);
}

.frame-label {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    font-weight: 400;
}

/* Control Buttons */
.controls-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
}

.controls-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.control-btn {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    border: none;
    background: var(--glass-bg);
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
    flex-shrink: 0;
}

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

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

.control-btn-primary {
    width: 52px;
    height: 52px;
    background: var(--accent-gradient);
    color: white;
}

.control-btn-primary:hover {
    transform: translateY(-2px) scale(1.05);
}

/* Frame Selector */
.frame-selector {
    display: flex;
    gap: var(--spacing-sm);
}

.frame-selector input {
    width: 100px;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background: var(--glass-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all var(--transition-normal);
}

.frame-selector input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.frame-selector input::placeholder {
    color: var(--text-tertiary);
}

/* Transform Controls */
.control-section {
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.section-title svg {
    color: var(--accent-primary);
}

.button-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

.tool-btn {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background: var(--glass-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
}

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

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

.tool-btn svg {
    flex-shrink: 0;
}

.tool-btn-secondary {
    grid-column: span 1;
}

/* Position Grid */
.position-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
}

.position-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: var(--spacing-sm);
}

/* Reset Button */
.reset-btn {
    width: 100%;
    padding: var(--spacing-md);
    margin-top: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 2px solid var(--accent-primary);
    background: transparent;
    color: var(--accent-primary);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
}

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

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

/* Transform Info */
.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.info-item {
    padding: var(--spacing-md);
    background: var(--glass-bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.info-label {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.info-value {
    font-size: 1.125rem;
    color: var(--accent-primary);
    font-weight: 700;
}

/* Responsive Design */
@media (max-width: 1400px) {
    .main-content {
        grid-template-columns: 280px 1fr 280px;
    }
}

@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr auto;
    }

    .sidebar-left {
        order: 1;
    }

    .video-section {
        order: 2;
    }

    .sidebar-right {
        order: 3;
    }

    .sidebar {
        flex-direction: row;
        overflow-x: auto;
    }

    .glass-card {
        min-width: 300px;
    }
}

@media (max-width: 768px) {
    .app-container {
        padding: var(--spacing-sm);
    }

    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .logo h1 {
        font-size: 1.25rem;
    }

    .main-content {
        gap: var(--spacing-md);
    }

    .controls-row {
        flex-direction: column;
    }

    .theme-toggle {
        width: 44px;
        height: 44px;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

/* Loading State */
.loading {
    animation: pulse 2s infinite;
}

/* Smooth Transitions for All Interactive Elements */
button, a, input {
    -webkit-tap-highlight-color: transparent;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--glass-bg);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

/* Selection Styling */
::selection {
    background: var(--accent-primary);
    color: white;
}

::-moz-selection {
    background: var(--accent-primary);
    color: white;
}

/* Focus Visible for Accessibility */
*:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .theme-toggle,
    .header-nav,
    .sidebar {
        display: none;
    }
}

/* Help Button */
.help-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background: var(--glass-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
    font-family: inherit;
    white-space: nowrap;
}

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

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

.help-btn svg {
    flex-shrink: 0;
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    max-width: 700px;
    width: 90%;
    max-height: 80vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transform: scale(0.9) translateY(20px);
    transition: all var(--transition-normal);
}

.modal-overlay.active .modal-content {
    transform: scale(1) translateY(0);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.modal-close {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
}

.modal-close:hover {
    background: var(--glass-bg);
    color: var(--accent-primary);
    transform: rotate(90deg);
}

.modal-body {
    padding: var(--spacing-lg);
    overflow-y: auto;
}

/* Shortcuts Grid */
.shortcuts-grid {
    display: grid;
    gap: var(--spacing-xl);
}

.shortcut-category h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--accent-primary);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.shortcut-category h3::before {
    content: '';
    width: 4px;
    height: 1.125rem;
    background: var(--accent-gradient);
    border-radius: 2px;
}

.shortcut-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    color: var(--text-secondary);
}

.shortcut-item kbd {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 32px;
    padding: 0 var(--spacing-sm);
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-family: 'Inter', monospace;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.shortcut-desc {
    flex: 1;
    color: var(--text-secondary);
}

.tips-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.tips-list li {
    padding: var(--spacing-sm) 0;
    padding-right: var(--spacing-lg);
    position: relative;
    color: var(--text-secondary);
    line-height: 1.6;
}

.tips-list li::before {
    content: '•';
    position: absolute;
    right: 0;
    color: var(--accent-primary);
    font-weight: bold;
    font-size: 1.2em;
}

/* Responsive Modal */
@media (max-width: 768px) {
    .modal-content {
        width: 95%;
        max-height: 90vh;
    }

    .modal-header h2 {
        font-size: 1.25rem;
    }

    .shortcuts-grid {
        gap: var(--spacing-lg);
    }

    .shortcut-item {
        flex-wrap: wrap;
    }

    .help-btn span {
        display: none;
    }

    .help-btn {
        width: 40px;
        height: 40px;
        padding: var(--spacing-sm);
        justify-content: center;
    }
}