/* 重置样式和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* 导航栏样式 */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

/* Logo和品牌区域 */
.nav-brand {
    flex-shrink: 0;
}

.brand-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #2d3748;
    transition: all 0.3s ease;
}

.brand-link:hover {
    transform: translateY(-1px);
}

.nav-logo {
    width: 32px;
    height: 32px;
    margin-right: 12px;
    border-radius: 6px;
}

.brand-text {
    font-size: 1.2rem;
    font-weight: 600;
    color: #2d3748;
}

/* PC端导航链接 */
.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: #4a5568;
    font-weight: 500;
    font-size: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #667eea;
    background: rgba(102, 126, 234, 0.1);
    transform: translateY(-1px);
}

/* 移动端汉堡菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 30px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1001;
}

.hamburger-line {
    width: 100%;
    height: 3px;
    background: #4a5568;
    border-radius: 2px;
    transition: all 0.3s ease;
    transform-origin: center;
}

/* 汉堡菜单动画 */
.mobile-menu-btn.active .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-btn.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
    margin-top: 1rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.mobile-menu.active {
    display: flex;
}

.mobile-nav-link {
    text-decoration: none;
    color: #4a5568;
    font-weight: 500;
    font-size: 1.1rem;
    padding: 1rem 1.5rem;
    transition: all 0.3s ease;
    border-radius: 8px;
    margin: 0 1rem;
}

.mobile-nav-link:hover {
    color: #667eea;
    background: rgba(102, 126, 234, 0.1);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .brand-text {
        font-size: 1rem;
    }
    
    .nav-logo {
        width: 28px;
        height: 28px;
        margin-right: 8px;
    }
}

@media (max-width: 480px) {
    .brand-text {
        display: none;
    }
    
    .nav-content {
        padding: 0.8rem 0;
    }
}

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

/* 头部英雄区域 */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.hero-subtitle {
    font-size: 2.2rem;
    font-weight: 500;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero-description {
    font-size: 1.1rem;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0.9;
    line-height: 1.7;
}

/* 使用步骤说明区域 */
.steps-section {
    padding: 80px 0;
    background: white;
}

.steps-title {
    font-size: 2.2rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 2rem;
    color: #2d3748;
}

/* 视频教程样式 */
.video-tutorial {
    text-align: center;
    margin-bottom: 60px;
}

.video-intro {
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 30px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.video-container {
    position: relative;
    width: 100%;
    max-width: 560px;
    margin: 0 auto;
    aspect-ratio: 16/9;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.1);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.step-card {
    background: #f7fafc;
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.step-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    border-color: #667eea;
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 1.5rem;
}

.step-card h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.step-card p {
    color: #718096;
    line-height: 1.6;
}

/* 工具区域 */
.tool-section {
    padding: 80px 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    margin: 2rem;
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.tool-container {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}



/* 上传区域 */
.upload-area {
    margin-bottom: 3rem;
}

.upload-zone {
    border: 3px dashed #cbd5e0;
    border-radius: 16px;
    padding: 60px 40px;
    background: #f7fafc;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-zone:hover {
    border-color: #667eea;
    background: #edf2f7;
    transform: translateY(-2px);
}

.upload-zone.dragover {
    border-color: #667eea;
    background: #e6fffa;
    transform: scale(1.02);
}

.upload-icon {
    color: #667eea;
    margin-bottom: 1.5rem;
}

.upload-instruction {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    color: #4a5568;
}

.upload-zone p {
    font-size: 1rem;
    color: #718096;
    margin-bottom: 2rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.upload-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 16px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    display: block;
    margin: 0 auto;
}

.upload-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6);
}

.supported-formats {
    margin-top: 1.5rem;
    font-size: 0.9rem;
    color: #718096;
}

/* 文件选择后的样式 */
.file-selected {
    text-align: center;
}

.file-selected .file-icon {
    color: #48bb78;
    margin-bottom: 1rem;
}

.file-selected h4 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.file-selected .file-name {
    font-size: 1.1rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 0.5rem;
}

.file-selected .file-size {
    font-size: 0.9rem;
    color: #718096;
    margin-bottom: 2rem;
}

.file-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.convert-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 16px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6);
}

.change-file-btn {
    background: transparent;
    color: #718096;
    border: 2px solid #e2e8f0;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.change-file-btn:hover {
    border-color: #667eea;
    color: #667eea;
    transform: translateY(-2px);
}

/* 处理区域 */
.processing-area {
    margin-bottom: 3rem;
}

.processing-content {
    padding: 60px 40px;
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid #e2e8f0;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 2rem;
}

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

.processing-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.processing-content p {
    font-size: 1rem;
    color: #718096;
    margin-bottom: 2rem;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

.progress-text {
    font-size: 1rem;
    font-weight: 600;
    color: #667eea;
}

/* 下载区域 */
.download-area {
    margin-bottom: 3rem;
}

.download-content {
    padding: 60px 40px;
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.success-icon {
    color: #48bb78;
    margin-bottom: 1.5rem;
}

.download-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.download-content p {
    font-size: 1rem;
    color: #718096;
    margin-bottom: 2rem;
}

.download-btn {
    background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
    color: white;
    border: none;
    padding: 16px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(72, 187, 120, 0.4);
    margin-right: 1rem;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(72, 187, 120, 0.6);
}

.new-conversion-btn {
    background: transparent;
    color: #667eea;
    border: 2px solid #667eea;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.new-conversion-btn:hover {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
}

/* 功能特色区域 */
.features-section {
    padding: 80px 0;
    background: #f7fafc;
}

.features-section h2 {
    font-size: 2.2rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 1.5rem;
    color: #2d3748;
}

.features-section h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.features-intro {
    font-size: 1.1rem;
    text-align: center;
    color: #718096;
    max-width: 800px;
    margin: 0 auto 4rem;
    line-height: 1.7;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    text-align: center;
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}



.feature-card p {
    color: #718096;
    line-height: 1.6;
}

/* 用户评价区域 */
.testimonials-section {
    padding: 80px 0;
    background: white;
}

.testimonials-section h2 {
    font-size: 2.2rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 1.5rem;
    color: #2d3748;
}

.testimonials-section > p {
    font-size: 1.1rem;
    text-align: center;
    color: #718096;
    max-width: 800px;
    margin: 0 auto 4rem;
    line-height: 1.7;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.testimonial-card {
    background: #f7fafc;
    padding: 2.5rem;
    border-radius: 16px;
    border-left: 4px solid #667eea;
    transition: all 0.3s ease;
    text-align: left;
}

.testimonial-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.testimonial-header {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
    gap: 1rem;
}

.testimonial-avatar {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    transition: transform 0.3s ease;
}

.testimonial-card:hover .testimonial-avatar {
    transform: scale(1.05);
}

.avatar-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

.testimonial-info {
    flex-grow: 1;
}

.testimonial-name {
    font-weight: 600;
    font-size: 1.1rem;
    color: #2d3748;
    margin-bottom: 0.25rem;
}

.testimonial-location {
    font-size: 0.9rem;
    color: #718096;
    font-weight: 400;
}

.testimonial-card p {
    font-size: 1.1rem;
    color: #2d3748;
    margin-bottom: 0;
    font-style: italic;
    line-height: 1.6;
}

/* 常见问题区域 */
.faq-section {
    padding: 80px 0;
    background: #f7fafc;
}

.faq-section h2 {
    font-size: 2.2rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 3rem;
    color: #2d3748;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    margin-bottom: 1rem;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.faq-question {
    padding: 1.5rem 2rem;
    font-weight: 600;
    color: #2d3748;
    cursor: pointer;
    transition: all 0.3s ease;
    border-bottom: 1px solid #e2e8f0;
}

.faq-question:hover {
    background: #f7fafc;
    color: #667eea;
}

.faq-answer {
    padding: 1.5rem 2rem;
    color: #718096;
    line-height: 1.6;
    display: none;
}

.faq-item.active .faq-answer {
    display: block;
}

.faq-item.active .faq-question {
    background: #f7fafc;
    color: #667eea;
}

/* 行动号召区域 */
.cta-section {
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta-section h2 {
    font-size: 2.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.cta-section p {
    font-size: 1.1rem;
    max-width: 800px;
    margin: 0 auto 2.5rem;
    opacity: 0.9;
    line-height: 1.7;
}

.cta-btn {
    background: white;
    color: #667eea;
    border: none;
    padding: 18px 36px;
    font-size: 1.2rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
}

/* 页脚 */
.footer {
    background-color: #1F2937;
    color: rgba(255, 255, 255, 0.7);
    padding: 3rem 0 1.5rem 0;
    border-top: 1px solid;
    border-image: linear-gradient(to right, #4c42f5, #a342f5) 1;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

/* 左侧网站信息 */
.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-brand-name {
    font-size: 1.5rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    margin: 0;
}

.footer-brand-description {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
    margin: 0;
}

/* 右侧链接分组 */
.footer-links-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.footer-links-column {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links-title {
    font-size: 1rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    margin: 0 0 0.5rem 0;
}

.footer-link {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.6);
    transition: color 0.3s ease;
    padding: 0.25rem 0;
    font-size: 0.9rem;
}

.footer-link:hover {
    color: rgba(255, 255, 255, 0.9);
}

/* 页脚底部版权 */
.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1.5rem;
    text-align: center;
}

.footer-copyright {
    margin: 0;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
}

.footer-copyright a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

.footer-copyright a:hover {
    color: rgba(255, 255, 255, 0.9);
}

/* 响应式设计 - 页脚 */
@media (max-width: 768px) {
    .footer {
        padding: 2rem 0 1rem 0;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        margin-bottom: 1.5rem;
    }
    
    .footer-links-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .footer-brand-name {
        font-size: 1.3rem;
    }
    
    .footer-brand-description {
        font-size: 0.9rem;
    }
    
    .footer-copyright {
        font-size: 0.8rem;
        line-height: 1.4;
    }
}

@media (max-width: 480px) {
    .footer-content {
        gap: 1.5rem;
    }
    
    .footer-links-grid {
        gap: 1rem;
    }
}

/* 工具类 */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.mb-2 {
    margin-bottom: 1rem;
}

.mb-4 {
    margin-bottom: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.4rem;
    }
    
    .steps-title {
        font-size: 1.8rem;
    }
    
    .video-intro {
        font-size: 1rem;
        margin-bottom: 20px;
    }
    
    .video-container {
        max-width: 100%;
        margin: 0 20px;
    }
    
    .steps-grid {
        grid-template-columns: 1fr;
    }
    
    .step-card {
        padding: 2rem;
    }
    
    .features-section h2,
    .testimonials-section h2,
    .faq-section h2,
    .cta-section h2 {
        font-size: 1.8rem;
    }
    
    .features-section h3,
    .step-card h3 {
        font-size: 1.2rem;
    }
    
    .upload-zone {
        padding: 40px 20px;
    }
    
    .processing-content,
    .download-content {
        padding: 40px 20px;
    }
    
    .feature-card,
    .testimonial-card {
        padding: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .download-btn,
    .new-conversion-btn {
        display: block;
        width: 100%;
        margin: 0.5rem 0;
    }
    
    .container {
        padding: 0 15px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .steps-title {
        font-size: 1.5rem;
    }
    
    .step-card {
        padding: 1.5rem;
    }
    
    .step-number {
        width: 50px;
        height: 50px;
        font-size: 1.2rem;
    }
    
    .upload-zone {
        padding: 30px 15px;
    }
    
    .upload-btn {
        padding: 14px 24px;
        font-size: 1rem;
    }
    
    .feature-card,
    .testimonial-card {
        padding: 1.5rem;
    }
    
    .faq-question,
    .faq-answer {
        padding: 1rem 1.5rem;
    }
}