:root {
            /* Palette Neon (Mirip TikTok style tapi versi YouTube Red/Blue) */
            --primary: #ff0050; /* YouTube Red Neon */
            --primary-glow: rgba(255, 0, 80, 0.4);
            --secondary: #00f2ff; /* Cyan Neon */
            --secondary-glow: rgba(0, 242, 255, 0.4);
            --bg-dark: #050511;
            --glass-bg: rgba(20, 20, 35, 0.7);
            --glass-border: rgba(255, 255, 255, 0.08);
            --text-main: #ffffff;
            --text-muted: #a0a0b0;
            --success: #00ff9d;
            --error: #ff4d4d;
        }

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

        body {
            background-color: var(--bg-dark);
            background-image: 
                radial-gradient(circle at 10% 20%, rgba(29, 0, 65, 0.8) 0%, transparent 40%),
                radial-gradient(circle at 90% 80%, rgba(0, 45, 60, 0.8) 0%, transparent 40%);
            color: var(--text-main);
            font-family: 'Outfit', sans-serif;
            min-height: 100vh;
            overflow-x: hidden;
            position: relative;
        }

        /* Background Mesh */
        body::before {
            content: '';
            position: fixed;
            top: 0; left: 0; width: 100%; height: 100%;
            background: url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMjAwIiBoZWlnaHQ9IjIwMCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48cGF0aCBkPSJNMTAwIDB2MjAwTTAgMTAwaDIwMCIgc3Ryb2tlPSJyZ2JhKDI1NSwyNTUsMjU1LDAuMDMpIiBzdHJva2Utd2lkdGg9IjIiLz48L3N2Zz4=');
            background-size: 40px 40px;
            z-index: -1;
            opacity: 0.5;
        }

        .container {
            max-width: 900px;
            margin: 0 auto;
            padding: 2rem 1.5rem;
            position: relative;
            z-index: 1;
        }

        /* HEADER */
        header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding-bottom: 2rem;
            margin-bottom: 2rem;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 0.8rem;
            font-size: 1.5rem;
            font-weight: 800;
            cursor: pointer;
        }

        .logo i {
            font-size: 2rem;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            filter: drop-shadow(0 0 10px var(--primary-glow));
        }

        /* HERO TEXT */
        .hero { text-align: center; margin-bottom: 3rem; }
        .hero h1 {
            font-size: 3rem;
            font-weight: 900;
            line-height: 1.2;
            margin-bottom: 1rem;
            background: linear-gradient(to right, #fff, var(--text-muted));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .hero p { color: var(--text-muted); font-size: 1.1rem; }

        /* GLASS CARD (Input Section) */
        .glass-card {
            background: var(--glass-bg);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border: 1px solid var(--glass-border);
            border-radius: 24px;
            padding: 3rem 2.5rem;
            box-shadow: 0 20px 50px -10px rgba(0,0,0,0.5);
            margin-bottom: 3rem;
            position: relative;
        }

        .input-group {
            display: flex;
            gap: 15px;
            flex-wrap: wrap;
        }

        /* Dropdown Styling */
        .custom-select-wrapper {
            position: relative;
            flex: 0 0 100px;
        }
        
        .custom-select {
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.3);
            border: 2px solid var(--glass-border);
            border-radius: 12px;
            color: #fff;
            padding: 0 15px;
            font-size: 1rem;
            font-weight: 700;
            cursor: pointer;
            appearance: none;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s;
        }
        
        .custom-select:focus {
            border-color: var(--secondary);
            box-shadow: 0 0 15px var(--secondary-glow);
            outline: none;
        }

        /* URL Input Styling */
        .url-input-container {
            flex: 1;
            position: relative;
        }

        .url-input-container i {
            position: absolute;
            left: 20px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--text-muted);
        }

        .url-input {
            width: 100%;
            padding: 18px 20px 18px 55px;
            background: rgba(0, 0, 0, 0.3);
            border: 2px solid var(--glass-border);
            border-radius: 12px;
            color: #fff;
            font-family: 'JetBrains Mono', monospace;
            font-size: 1rem;
            transition: all 0.3s;
        }

        .url-input:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 20px var(--primary-glow);
            background: rgba(0, 0, 0, 0.5);
        }

        /* Convert Button */
        .convert-btn {
            width: 100%;
            margin-top: 20px;
            padding: 18px;
            background: linear-gradient(90deg, var(--primary), #ff4d4d);
            border: none;
            border-radius: 12px;
            color: #fff;
            font-weight: 800;
            font-size: 1.1rem;
            text-transform: uppercase;
            letter-spacing: 1px;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 0 15px var(--primary-glow);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }

        .convert-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 0 30px var(--primary-glow);
        }
        
        .convert-btn:disabled { opacity: 0.7; cursor: wait; }

        /* LOADING SPINNER */
        .spinner {
            width: 20px; height: 20px;
            border: 3px solid rgba(255,255,255,0.3);
            border-radius: 50%;
            border-top-color: #fff;
            animation: spin 1s linear infinite;
            display: none;
        }
        @keyframes spin { to { transform: rotate(360deg); } }

        /* RESULT SECTION */
        .result-area { display: none; margin-top: 2rem; animation: slideUp 0.5s ease; }
        
        .video-card {
            background: rgba(0,0,0,0.4);
            border-radius: 16px;
            border: 1px solid var(--glass-border);
            padding: 1.5rem;
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
        }

        .thumbnail-box {
            position: relative;
            width: 100%;
            max-width: 480px;
            border-radius: 12px;
            overflow: hidden;
            margin-bottom: 1.5rem;
            box-shadow: 0 10px 30px rgba(0,0,0,0.5);
        }
        
        .thumbnail-box img { width: 100%; display: block; }
        
        .video-title {
            font-size: 1.1rem;
            font-weight: 700;
            margin-bottom: 1.5rem;
            line-height: 1.4;
            color: #fff;
        }

        .format-list {
            width: 100%;
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .format-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            background: rgba(255,255,255,0.05);
            padding: 12px 20px;
            border-radius: 8px;
            border: 1px solid transparent;
            transition: 0.3s;
        }

        .format-item:hover {
            background: rgba(255,255,255,0.1);
            border-color: var(--secondary);
        }

        .download-link {
            padding: 8px 20px;
            background: rgba(0, 242, 255, 0.15);
            color: var(--secondary);
            text-decoration: none;
            border-radius: 50px;
            font-size: 0.9rem;
            font-weight: 700;
            border: 1px solid var(--secondary);
            transition: 0.3s;
        }

        .download-link:hover {
            background: var(--secondary);
            color: #000;
            box-shadow: 0 0 15px var(--secondary-glow);
        }

        /* TOAST NOTIFICATION */
        .toast {
            position: fixed;
            bottom: 30px; left: 50%;
            transform: translateX(-50%) translateY(100px);
            background: rgba(10, 10, 20, 0.95);
            border: 1px solid var(--glass-border);
            color: #fff;
            padding: 12px 24px;
            border-radius: 50px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.5);
            display: flex; align-items: center; gap: 10px;
            opacity: 0; transition: all 0.4s;
            z-index: 1000;
        }
        .toast.active { transform: translateX(-50%) translateY(0); opacity: 1; }
        .toast.error i { color: var(--error); }
        .toast.success i { color: var(--success); }

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

        /* Responsive */
        @media (max-width: 768px) {
            .hero h1 { font-size: 2rem; }
            .glass-card { padding: 1.5rem; }
            .input-group { flex-direction: column; }
            .custom-select-wrapper { flex: 1; }
        }