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

        body {
            font-family: 'Poppins', -apple-system, BlinkMacSystemFont, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 25%, #6B73FF 50%, #000DFF 75%, #9A4AE2 100%);
            color: white;
            min-height: 100vh;
            padding: 20px;
        }

        .container {
            max-width: 800px;
            margin: 0 auto;
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(20px);
            border-radius: 25px;
            padding: 40px;
            border: 1px solid rgba(255, 255, 255, 0.2);
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.25);
        }

        .back-button {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: rgba(255, 255, 255, 0.2);
            color: white;
            text-decoration: none;
            padding: 12px 20px;
            border-radius: 12px;
            margin-bottom: 30px;
            transition: all 0.3s ease;
            font-weight: 500;
        }

        .back-button:hover {
            background: rgba(255, 255, 255, 0.3);
            transform: translateY(-2px);
        }

        .header {
            text-align: center;
            margin-bottom: 40px;
        }

        .header h1 {
            font-size: 2.5em;
            margin-bottom: 10px;
            background: linear-gradient(45deg, #ffffff, #00d4ff);
            background-size: 200% 200%;
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .url-section {
            margin-bottom: 30px;
        }

        .url-input {
            width: 100%;
            padding: 18px 24px;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 15px;
            font-size: 1.1em;
            background: rgba(255, 255, 255, 0.1);
            color: white;
            outline: none;
            transition: all 0.3s ease;
        }

        .url-input::placeholder {
            color: rgba(255, 255, 255, 0.7);
        }

        .url-input:focus {
            border-color: #00d4ff;
            box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
            background: rgba(255, 255, 255, 0.15);
        }

        .format-section {
            margin-bottom: 30px;
        }

        .format-title {
            font-size: 1.3em;
            margin-bottom: 20px;
            text-align: center;
        }

        .format-grid {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            gap: 15px;
        }

        .format-option {
            background: rgba(255, 255, 255, 0.1);
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 15px;
            padding: 20px;
            text-align: center;
            cursor: pointer;
            transition: all 0.3s ease;
            position: relative;
        }

        .format-option:hover {
            background: rgba(255, 255, 255, 0.2);
            transform: translateY(-3px);
        }

        .format-option.selected {
            background: rgba(0, 212, 255, 0.2);
            border-color: #00d4ff;
            box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
        }

        .format-option input {
            display: none;
        }

        .format-icon {
            font-size: 2em;
            margin-bottom: 10px;
        }

        .format-name {
            font-weight: 600;
            margin-bottom: 5px;
        }

        .format-desc {
            font-size: 0.9em;
            opacity: 0.8;
        }

        .convert-button {
            width: 100%;
            background: linear-gradient(135deg, #00d4ff, #0099cc);
            color: white;
            border: none;
            border-radius: 15px;
            padding: 18px;
            font-size: 1.2em;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-bottom: 30px;
        }

        .convert-button:hover:not(:disabled) {
            background: linear-gradient(135deg, #0099cc, #0066aa);
            transform: translateY(-3px);
            box-shadow: 0 10px 25px rgba(0, 212, 255, 0.4);
        }

        .convert-button:disabled {
            background: rgba(255, 255, 255, 0.2);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }

        .progress-section {
            display: none;
            margin-bottom: 30px;
        }

        .progress-bar {
            width: 100%;
            height: 8px;
            background: rgba(255, 255, 255, 0.2);
            border-radius: 4px;
            overflow: hidden;
            margin-bottom: 15px;
        }

        .progress-fill {
            height: 100%;
            background: linear-gradient(90deg, #00d4ff, #0099cc);
            width: 0%;
            transition: width 0.3s ease;
        }

        .progress-text {
            text-align: center;
            font-weight: 500;
        }

        .result-section {
            display: none;
            text-align: center;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 15px;
            padding: 30px;
        }

        .download-button {
            background: linear-gradient(135deg, #4CAF50, #45a049);
            color: white;
            text-decoration: none;
            padding: 15px 30px;
            border-radius: 12px;
            font-size: 1.1em;
            font-weight: 600;
            display: inline-block;
            margin: 20px 10px;
            transition: all 0.3s ease;
        }

        .download-button:hover {
            background: linear-gradient(135deg, #45a049, #3e8e41);
            transform: translateY(-2px);
            box-shadow: 0 8px 20px rgba(76, 175, 80, 0.3);
        }

        .error-message {
            display: none;
            background: rgba(255, 107, 107, 0.2);
            border: 2px solid rgba(255, 107, 107, 0.5);
            border-radius: 12px;
            padding: 20px;
            margin-top: 20px;
            text-align: center;
            color: #ffcccb;
        }

        .info-box {
            background: rgba(255, 193, 7, 0.1);
            border: 1px solid rgba(255, 193, 7, 0.3);
            border-radius: 12px;
            padding: 20px;
            margin-top: 30px;
        }

        .info-box h3 {
            color: #ffd700;
            margin-bottom: 15px;
        }

        .info-box ul {
            padding-left: 20px;
            line-height: 1.6;
        }

        .video-info {
            display: none;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 12px;
            padding: 20px;
            margin: 20px 0;
            text-align: center;
        }

        .video-thumbnail {
            max-width: 200px;
            border-radius: 8px;
            margin-bottom: 15px;
        }

        .video-title {
            font-size: 1.2em;
            font-weight: 600;
            margin-bottom: 10px;
        }

        .video-duration {
            opacity: 0.8;
        }

        @keyframes pulse {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.05); }
        }

        .loading {
            animation: pulse 2s infinite;
        }

        @media (max-width: 768px) {
            .format-grid {
                grid-template-columns: 1fr;
            }
            
            .container {
                padding: 20px;
                margin: 10px;
            }
            
            .header h1 {
                font-size: 2em;
            }
        }
    @keyframes particleFloat {
        0% { transform: translateY(100vh) translateX(-10px) rotate(0deg); opacity: 0; }
        10% { opacity: 1; }
        90% { opacity: 1; }
        100% { transform: translateY(-100px) translateX(10px) rotate(360deg); opacity: 0; }
    }

    .particle {
        position: fixed;
        pointer-events: none;
        border-radius: 50%;
        z-index: 1;
    }

    .particle-1 {
        width: 4px;
        height: 4px;
        background: rgba(255, 255, 255, 0.6);
        animation: particleFloat 15s infinite linear;
        animation-delay: 0s;
        left: 10%;
    }

    .particle-2 {
        width: 6px;
        height: 6px;
        background: rgba(0, 212, 255, 0.4);
        animation: particleFloat 18s infinite linear;
        animation-delay: -5s;
        left: 20%;
    }

    .particle-3 {
        width: 3px;
        height: 3px;
        background: rgba(255, 255, 255, 0.8);
        animation: particleFloat 12s infinite linear;
        animation-delay: -8s;
        left: 35%;
    }

    .particle-4 {
        width: 5px;
        height: 5px;
        background: rgba(154, 74, 226, 0.5);
        animation: particleFloat 20s infinite linear;
        animation-delay: -12s;
        left: 50%;
    }

    .particle-5 {
        width: 4px;
        height: 4px;
        background: rgba(255, 255, 255, 0.5);
        animation: particleFloat 16s infinite linear;
        animation-delay: -3s;
        left: 65%;
    }

    .particle-6 {
        width: 7px;
        height: 7px;
        background: rgba(0, 212, 255, 0.3);
        animation: particleFloat 14s infinite linear;
        animation-delay: -10s;
        left: 80%;
    }

    .particle-7 {
        width: 3px;
        height: 3px;
        background: rgba(255, 255, 255, 0.7);
        animation: particleFloat 22s infinite linear;
        animation-delay: -6s;
        left: 90%;
    }

    .particle-8 {
        width: 5px;
        height: 5px;
        background: rgba(102, 126, 234, 0.4);
        animation: particleFloat 17s infinite linear;
        animation-delay: -2s;
        left: 15%;
    }

    .particle-9 {
        width: 4px;
        height: 4px;
        background: rgba(255, 255, 255, 0.6);
        animation: particleFloat 19s infinite linear;
        animation-delay: -9s;
        left: 25%;
    }

    .particle-10 {
        width: 6px;
        height: 6px;
        background: rgba(118, 75, 162, 0.5);
        animation: particleFloat 13s infinite linear;
        animation-delay: -4s;
        left: 40%;
    }

    .particle-11 {
        width: 3px;
        height: 3px;
        background: rgba(0, 212, 255, 0.7);
        animation: particleFloat 21s infinite linear;
        animation-delay: -11s;
        left: 55%;
    }

    .particle-12 {
        width: 7px;
        height: 7px;
        background: rgba(255, 255, 255, 0.3);
        animation: particleFloat 15s infinite linear;
        animation-delay: -1s;
        left: 70%;
    }

    .particle-13 {
        width: 4px;
        height: 4px;
        background: rgba(107, 115, 255, 0.6);
        animation: particleFloat 18s infinite linear;
        animation-delay: -7s;
        left: 85%;
    }

    .particle-14 {
        width: 5px;
        height: 5px;
        background: rgba(255, 255, 255, 0.8);
        animation: particleFloat 16s infinite linear;
        animation-delay: -13s;
        left: 5%;
    }

    .particle-15 {
        width: 6px;
        height: 6px;
        background: rgba(154, 74, 226, 0.4);
        animation: particleFloat 20s infinite linear;
        animation-delay: -14s;
        left: 95%;
    }

    @keyframes spin {
        from { transform: rotate(0deg); }
        to { transform: rotate(360deg); }
    }

    .particle-dynamic {
        position: fixed;
        border-radius: 50%;
        pointer-events: none;
        z-index: 1;
    }

    .particle-star {
        position: fixed;
        pointer-events: none;
        z-index: 1;
        font-size: 12px;
        color: rgba(255, 255, 255, 0.7);
        animation: particleFloat 25s infinite linear, spin 4s infinite linear;
    }

    .particle-star::before {
        content: "✦";
    }

    .particle-triangle {
        width: 0;
        height: 0;
        border-left: 3px solid transparent;
        border-right: 3px solid transparent;
        border-bottom: 5px solid rgba(0, 212, 255, 0.5);
        position: fixed;
        pointer-events: none;
        z-index: 1;
        animation: particleFloat 22s infinite linear, spin 6s infinite linear;
    }

    .particle-diamond {
        width: 6px;
        height: 6px;
        background: rgba(154, 74, 226, 0.6);
        transform: rotate(45deg);
        position: fixed;
        pointer-events: none;
        z-index: 1;
        animation: particleFloat 20s infinite linear, spin 8s infinite linear;
    }