:root {
            --primary: #6366f1;
            --primary-dark: #4f46e5;
            --bg: #f8fafc;
            --card-bg: #ffffff;
            --text: #1e293b;
            --text-secondary: #64748b;
            --border: #e2e8f0;
            --success: #22c55e;
            --error: #ef4444;
            --warning: #f59e0b;
            --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
            --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
        }

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            background: var(--bg);
            color: var(--text);
            line-height: 1.6;
            min-height: 100vh;
        }

        /* Header */
        header {
            padding: 2rem 1rem;
            text-align: center;
        }

        header h1 {
            font-size: 1.8rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }

        header p {
            opacity: 0.9;
            font-size: 1rem;
        }

        /* Main Container */
        .container {
            max-width: 900px;
            margin: 0 auto;
            padding: 1.5rem;
        }

        /* Player Card */
        .player-card {
            background: var(--card-bg);
            border-radius: 16px;
            box-shadow: var(--shadow-lg);
            overflow: hidden;
            margin-bottom: 2rem;
        }

        /* Input Area */
        .input-section {
            padding: 1.5rem;
            border-bottom: 1px solid var(--border);
        }

        .input-group {
            display: flex;
            gap: 0.75rem;
            flex-wrap: wrap;
        }

        .input-group input {
            flex: 1;
            min-width: 250px;
            padding: 0.875rem 1rem;
            border: 2px solid var(--border);
            border-radius: 10px;
            font-size: 1rem;
            transition: all 0.2s;
            outline: none;
        }

        .input-group input:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
        }

        .input-group input::placeholder {
            color: var(--text-secondary);
        }

        .btn {
            padding: 0.875rem 1.5rem;
            border: none;
            border-radius: 10px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.2s;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
        }

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

        .btn-primary:hover {
            background: var(--primary-dark);
            transform: translateY(-1px);
            box-shadow: var(--shadow-lg);
        }

        .btn-secondary {
            background: var(--bg);
            color: var(--text);
            border: 2px solid var(--border);
        }

        .btn-secondary:hover {
            background: var(--border);
        }

        /* Video Container */
        .video-container {
            position: relative;
            background: #000;
            aspect-ratio: 16/9;
            display: none;
        }

        .video-container.active {
            display: block;
        }

        video {
            width: 100%;
            height: 100%;
            display: block;
        }

        /* Empty State */
        .empty-state {
            aspect-ratio: 16/9;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
            color: var(--text-secondary);
            padding: 2rem;
            text-align: center;
        }

        .empty-state svg {
            width: 64px;
            height: 64px;
            margin-bottom: 1rem;
            opacity: 0.5;
        }

        .empty-state p {
            font-size: 1.1rem;
            margin-bottom: 0.5rem;
        }

        .empty-state span {
            font-size: 0.875rem;
            opacity: 0.7;
        }

        /* Status */
        .status-bar {
            padding: 0.75rem 1.5rem;
            background: #f8fafc;
            border-top: 1px solid var(--border);
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 0.875rem;
            min-height: 44px;
        }

        .status-bar .status-icon {
            width: 8px;
            height: 8px;
            border-radius: 50%;
            background: var(--text-secondary);
        }

        .status-bar .status-icon.loading {
            background: var(--warning);
            animation: pulse 1.5s infinite;
        }

        .status-bar .status-icon.playing {
            background: var(--success);
        }

        .status-bar .status-icon.error {
            background: var(--error);
        }

        @keyframes pulse {
            0%, 100% { opacity: 1; }
            50% { opacity: 0.4; }
        }

        /* History */
        .history-section {
            margin-top: 1rem;
        }

        .history-section h3 {
            font-size: 0.875rem;
            color: var(--text-secondary);
            margin-bottom: 0.75rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .history-list {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }

        .history-item {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0.75rem 1rem;
            background: var(--bg);
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.2s;
            border: 1px solid transparent;
        }

        .history-item:hover {
            background: #e2e8f0;
            border-color: var(--border);
        }

        .history-item .url-text {
            font-size: 0.875rem;
            color: var(--text);
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
            flex: 1;
            margin-right: 1rem;
        }

        .history-item .time {
            font-size: 0.75rem;
            color: var(--text-secondary);
            white-space: nowrap;
        }

        .history-item .delete-btn {
            background: none;
            border: none;
            color: var(--text-secondary);
            cursor: pointer;
            padding: 0.25rem;
            margin-left: 0.5rem;
            opacity: 0;
            transition: opacity 0.2s;
        }

        .history-item:hover .delete-btn {
            opacity: 1;
        }

        .history-item .delete-btn:hover {
            color: var(--error);
        }

        /* Info Cards */
        .info-section {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1.5rem;
            margin-top: 2rem;
        }

        .info-card {
            background: var(--card-bg);
            border-radius: 12px;
            padding: 1.5rem;
            box-shadow: var(--shadow);
        }

        .info-card h2 {
            font-size: 1.1rem;
            margin-bottom: 1rem;
            color: var(--text);
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .info-card p, .info-card li {
            font-size: 0.95rem;
            color: var(--text-secondary);
            line-height: 1.7;
        }

        .info-card ul {
            padding-left: 1.2rem;
        }

        .info-card li {
            margin-bottom: 0.5rem;
        }

        .info-card code {
            background: #f1f5f9;
            padding: 0.15rem 0.4rem;
            border-radius: 4px;
            font-size: 0.85rem;
            color: var(--primary-dark);
        }

        /* FAQ */
        .faq-item {
            border-bottom: 1px solid var(--border);
            padding: 1rem 0;
        }

        .faq-item:last-child {
            border-bottom: none;
        }

        .faq-question {
            font-size: 1rem;
            font-weight: 600;
            color: var(--text);
            margin-bottom: 0.5rem;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .faq-answer {
            color: var(--text-secondary);
            font-size: 0.95rem;
            line-height: 1.7;
        }

        /* Footer */
        footer {
            text-align: center;
            padding: 2rem 1rem;
            color: var(--text-secondary);
            font-size: 0.875rem;
            border-top: 1px solid var(--border);
            margin-top: 2rem;
        }

        footer a {
            color: var(--primary);
            text-decoration: none;
        }

        /* Responsive */
        @media (max-width: 640px) {
            header h1 {
                font-size: 1.4rem;
            }

            .input-group {
                flex-direction: column;
            }

            .input-group input {
                min-width: 100%;
            }

            .btn {
                width: 100%;
                justify-content: center;
            }

            .container {
                padding: 1rem;
            }
        }

        /* Loading Spinner */
        .spinner {
            display: inline-block;
            width: 16px;
            height: 16px;
            border: 2px solid rgba(255,255,255,0.3);
            border-radius: 50%;
            border-top-color: white;
            animation: spin 0.8s linear infinite;
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }

        /* Toast Notification */
        .toast {
            position: fixed;
            bottom: 2rem;
            left: 50%;
            transform: translateX(-50%) translateY(100px);
            background: #1e293b;
            color: white;
            padding: 0.875rem 1.5rem;
            border-radius: 10px;
            font-size: 0.875rem;
            z-index: 1000;
            opacity: 0;
            transition: all 0.3s ease;
            box-shadow: var(--shadow-lg);
        }

        .toast.show {
            transform: translateX(-50%) translateY(0);
            opacity: 1;
        }

        .toast.error {
            background: var(--error);
        }

        .toast.success {
            background: var(--success);
        }