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

:root {
    --primary-color: #667eea;
    --primary-hover: #5a6fd6;
    --success-color: #48bb78;
    --danger-color: #f56565;
    --text-color: #2d3748;
    --text-light: #718096;
    --bg-color: #f7fafc;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --radius: 12px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 0 20px;
}

.header {
    padding: 40px 0 30px;
    text-align: center;
    color: white;
}

.logo {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 8px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    letter-spacing: 2px;
}

.main {
    padding: 0 0 40px;
}

.download-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 30px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.input-section {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
}

.input-wrapper {
    flex: 1;
    position: relative;
}

.url-input {
    width: 100%;
    padding: 16px 45px 16px 18px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    outline: none;
    transition: all 0.3s ease;
    background: var(--bg-color);
}

.url-input:focus {
    border-color: var(--primary-color);
    background: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.url-input::placeholder {
    color: #a0aec0;
}

.platform-icon {
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.3rem;
    opacity: 0.7;
}

.parse-btn {
    padding: 16px 28px;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, var(--primary-color), #764ba2);
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 120px;
    position: relative;
    overflow: hidden;
}

.parse-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

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

.parse-btn.loading .btn-text {
    opacity: 0;
}

.parse-btn.loading .btn-loader {
    display: block;
}

.btn-loader {
    display: none;
    position: absolute;
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.platform-btns {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.platform-btn {
    padding: 8px 16px;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-color);
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text-light);
}

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

.platform-btn.active {
    background: linear-gradient(135deg, var(--primary-color), #764ba2);
    color: white;
    border-color: transparent;
}

.result-section {
    animation: fadeIn 0.4s ease;
}

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

.result-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.video-preview {
    background: #000;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 250px;
}

.video-preview video {
    width: 100%;
    max-height: 450px;
    display: block;
}

.video-info {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.video-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-color);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-author {
    font-size: 0.9rem;
    color: var(--text-light);
}

.download-actions {
    padding: 20px;
    display: flex;
    gap: 12px;
}

.download-btn {
    flex: 1;
    padding: 14px 20px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
}

.download-btn.primary {
    background: linear-gradient(135deg, var(--success-color), #38a169);
    color: white;
}

.download-btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(72, 187, 120, 0.4);
}

.download-btn.secondary {
    background: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

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

.btn-icon {
    font-size: 1.2rem;
}

.tips-section {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 25px;
    box-shadow: var(--shadow);
}

.tips-section h3 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

.tips-section ul {
    list-style: none;
}

.tips-section li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: var(--text-light);
    font-size: 0.95rem;
}

.tips-section li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

.footer {
    text-align: center;
    padding: 30px 0;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
}

.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 14px 28px;
    border-radius: 30px;
    font-size: 0.95rem;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

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

.toast.error {
    background: linear-gradient(135deg, var(--danger-color), #c53030);
}

.toast.success {
    background: linear-gradient(135deg, var(--success-color), #38a169);
}

@media (max-width: 480px) {
    .header {
        padding: 30px 0 20px;
    }

    .logo {
        font-size: 1.6rem;
    }

    .subtitle {
        font-size: 0.9rem;
    }

    .download-card {
        padding: 20px;
    }

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

    .parse-btn {
        width: 100%;
    }

    .platform-btns {
        gap: 6px;
    }

    .platform-btn {
        padding: 6px 12px;
        font-size: 0.85rem;
    }

    .download-actions {
        flex-direction: column;
    }

    .video-preview {
        min-height: 200px;
    }

    .video-preview video {
        max-height: 300px;
    }
}