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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    min-height: 100vh;
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
}

.background-slideshow {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.background-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    transition: opacity 2s ease-in-out;
}

.background-slide.active {
    opacity: 0.3;
}

.background-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.7) 0%, rgba(118, 75, 162, 0.7) 100%);
    z-index: -1;
}

.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: inherit;
}

.logo img {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    object-fit: cover;
}

.logo span {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 30px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #667eea;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

.hero {
    text-align: center;
    color: white;
    padding: 60px 0;
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero p {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.95;
}

.platform-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.platform-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
    color: inherit;
    display: block;
}

.platform-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}

.platform-icon {
    font-size: 64px;
    margin-bottom: 20px;
}

.platform-card h2 {
    font-size: 24px;
    margin-bottom: 15px;
    color: #333;
}

.platform-card p {
    color: #666;
    font-size: 14px;
}

.section {
    background: white;
    border-radius: 15px;
    padding: 40px;
    margin-bottom: 30px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.section h2 {
    font-size: 28px;
    margin-bottom: 25px;
    color: #333;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

.section h3 {
    font-size: 20px;
    margin: 25px 0 15px;
    color: #667eea;
}

.section p, .section li {
    color: #666;
    margin-bottom: 15px;
    font-size: 16px;
}

.section ul, .section ol {
    margin-left: 30px;
    margin-bottom: 20px;
}

.step-list {
    list-style: none;
    margin-left: 0;
}

.step-list li {
    padding: 20px;
    margin-bottom: 20px;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #667eea;
    position: relative;
    padding-left: 60px;
}

.step-list li::before {
    content: counter(step-counter);
    counter-increment: step-counter;
    position: absolute;
    left: 20px;
    top: 20px;
    background: #667eea;
    color: white;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

.step-list {
    counter-reset: step-counter;
}

.faq-item {
    margin-bottom: 25px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
}

.faq-question {
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
    font-size: 18px;
}

.faq-answer {
    color: #666;
    line-height: 1.8;
}

.footer {
    background: rgba(255, 255, 255, 0.95);
    padding: 40px 0;
    text-align: center;
    color: #666;
    margin-top: 60px;
}

.btn-primary {
    display: inline-block;
    padding: 15px 40px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.parse-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    margin-bottom: 40px;
}

.form-group {
    margin-bottom: 25px;
}

.form-label {
    display: block;
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

.input-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.url-input {
    flex: 1;
    padding: 15px 20px;
    font-size: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    transition: all 0.3s ease;
    outline: none;
}

.url-input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.paste-button {
    padding: 15px 20px;
    background: #f5f5f5;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    color: #555;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.paste-button:hover {
    background: #e0e7ff;
    border-color: #667eea;
    color: #667eea;
}

.parse-button {
    width: 100%;
    padding: 18px;
    font-size: 18px;
    font-weight: bold;
    color: white;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    margin-top: 10px;
}

.parse-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.parse-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.loading {
    display: none;
    text-align: center;
    padding: 40px;
    color: #667eea;
}

.loading.show {
    display: block;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.result-container {
    display: none;
    margin-top: 30px;
}

.result-container.show {
    display: block;
}

.result-title {
    font-size: 20px;
    font-weight: bold;
    color: #333;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f0f0f0;
}

.result-content {
    display: grid;
    gap: 20px;
}

.result-item {
    background: #f9f9f9;
    border-radius: 12px;
    padding: 20px;
    border: 1px solid #e0e0e0;
}

.result-item-title {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

.video-info {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 15px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #666;
}

.info-item strong {
    color: #333;
}

.video-cover {
    width: 100%;
    max-width: 300px;
    border-radius: 8px;
    margin-bottom: 15px;
}

.video-description {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 15px;
    color: #666;
    font-size: 14px;
    line-height: 1.6;
}

.action-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 15px;
}

.action-button {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    background: white;
    border: 2px solid #667eea;
    color: #667eea;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.action-button:hover {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
}

.action-button.secondary {
    border-color: #28a745;
    color: #28a745;
}

.action-button.secondary:hover {
    background: #28a745;
    color: white;
}

.quality-selector {
    margin-bottom: 15px;
    padding: 10px;
    background: #f8f9fa;
    border-radius: 8px;
}

.quality-selector label {
    font-size: 14px;
    color: #333;
    margin-right: 10px;
    font-weight: 600;
}

.quality-selector select {
    padding: 8px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 14px;
    background: white;
    color: #333;
    cursor: pointer;
}

.quality-selector select:focus {
    outline: none;
    border-color: #667eea;
}

.video-preview {
    width: 100%;
    max-width: 100%;
    border-radius: 10px;
    margin-bottom: 15px;
    background: #000;
}

.image-preview {
    width: 100%;
    max-width: 100%;
    border-radius: 10px;
    margin-bottom: 15px;
    display: block;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 15px;
}

.image-grid img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    object-fit: cover;
}

.cover-wrapper {
    position: relative;
    display: inline-block;
}

.cover-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background: rgba(0, 0, 0, 0.7);
    color: #fff;
    font-size: 12px;
    padding: 4px 10px;
    border-radius: 999px;
}

.download-button {
    display: inline-block;
    padding: 12px 24px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
    margin-right: 10px;
    margin-bottom: 10px;
}

.download-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.error-message {
    display: none;
    background: #fee;
    color: #c33;
    padding: 15px 20px;
    border-radius: 10px;
    border-left: 4px solid #c33;
    margin-top: 20px;
}

.error-message.show {
    display: block;
}

.info-text {
    color: #666;
    font-size: 14px;
    margin-top: 10px;
    line-height: 1.6;
}

#extractedUrl {
    display: none;
    margin-top: 10px;
    padding: 10px;
    background: #f0f7ff;
    border-radius: 8px;
    border-left: 3px solid #667eea;
}

#extractedUrlText {
    font-size: 14px;
    color: #333;
    word-break: break-all;
}

.download-tip {
    margin-top: 15px;
    padding: 12px 16px;
    background: #e8f4fd;
    border: 1px solid #b3d9f2;
    border-radius: 8px;
    color: #0066cc;
    font-size: 14px;
    line-height: 1.6;
    display: flex;
    align-items: center;
    gap: 8px;
}

.download-tip::before {
    content: "💡";
    font-size: 18px;
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
        font-size: 14px;
    }

    .container {
        padding: 30px 15px;
    }

    .hero {
        padding: 40px 0;
    }

    .hero h1 {
        font-size: 32px;
    }

    .platform-cards {
        grid-template-columns: 1fr;
    }

    .parse-card {
        padding: 25px 20px;
    }

    .input-group {
        flex-direction: column;
        align-items: stretch;
    }

    .paste-button {
        width: 100%;
    }

    .image-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }
}