/* Base Styles */
:root {
    --primary-color: #4e54c8;
    --primary-dark: #363a87;
    --secondary-color: #8f94fb;
    --text-color: #333333;
    --text-light: #666666;
    --background-light: #f5f7fa;
    --background-white: #ffffff;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    --header-height: 8rem; /* 定义header高度变量，方便计算 */
}

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

html {
    font-size: 62.5%; /* 1rem = 10px */
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 1.6rem;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-white);
    overflow-x: hidden; /* 防止水平滚动条 */
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 2rem 0;
    box-shadow: var(--box-shadow);
    position: relative;
    z-index: 100;
    height: var(--header-height);
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.logo-img {
    height: 4.5rem;
    width: auto;
}

.logo-text {
    color: white;
    font-size: 3.2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

/* Software Demo Styles */
.software-demo {
    height: calc(100vh - var(--header-height)); /* 占满除header外的所有垂直空间 */
    width: 100vw; /* 占满整个视口宽度 */
    position: relative;
    overflow: hidden;
}

.software-iframe {
    width: 100%;
    height: 100%;
    border: none;
    display: block; /* 消除iframe下方可能的空白 */
}

/* 其它section的样式需要添加上边距，确保不被iframe遮挡 */
.hero, .video-tutorial, .features, .seo-content, .testimonials, .pricing, .faq, .cta {
    margin-top: 2rem; /* 添加间距，使滚动后的内容有适当的间隔 */
}

/* Video Tutorial Section Styles */
.video-tutorial {
    padding: 8rem 0;
    background-color: var(--background-light);
    text-align: center;
}

.video-tutorial h2 {
    font-size: 3.6rem;
    margin-bottom: 1.5rem;
}

.video-tutorial p {
    font-size: 1.8rem;
    max-width: 700px;
    margin: 0 auto 4rem;
    color: var(--text-light);
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 电脑端显示两列 */
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

.video-container {
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
    background-color: var(--background-white);
    transition: var(--transition);
}

.video-container:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.youtube-iframe {
    width: 100%;
    aspect-ratio: 16/9; /* 保持16:9的视频比例 */
    border: none;
    display: block;
}

.video-container h3 {
    padding: 1.5rem;
    font-size: 1.8rem;
    color: var(--text-color);
    text-align: left;
    margin: 0;
}

/* 响应式设计：手机端一排一个视频 */
@media (max-width: 768px) {
    :root {
        --header-height: 7rem; /* 移动端header高度稍小 */
    }
    
    .logo-img {
        height: 3.5rem;
    }
    
    .logo-text {
        font-size: 2.6rem;
    }
    
    .video-grid {
        grid-template-columns: 1fr; /* 手机端显示单列 */
    }
    
    .video-tutorial {
        padding: 6rem 0;
    }
    
    .video-tutorial h2 {
        font-size: 2.8rem;
    }
    
    .video-tutorial p {
        font-size: 1.6rem;
        margin-bottom: 3rem;
    }
}

@media (max-width: 480px) {
    :root {
        --header-height: 6rem; /* 小屏幕header更小 */
    }
    
    .logo-img {
        height: 3rem;
    }
    
    .logo-text {
        font-size: 2.2rem;
    }
}

/* Features Section Styles */
.features {
    padding: 10rem 0;
    background-color: var(--background-white);
}

.features h2 {
    font-size: 3.6rem;
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--primary-dark);
}

.section-intro {
    font-size: 1.8rem;
    max-width: 800px;
    margin: 0 auto 6rem;
    text-align: center;
    color: var(--text-light);
}

.feature-row {
    display: flex;
    align-items: center;
    gap: 6rem;
    margin-bottom: 8rem;
    padding-bottom: 8rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.feature-row:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.feature-image {
    flex: 1;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
}

.feature-image img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

.feature-image:hover img {
    transform: scale(1.02);
}

.feature-content {
    flex: 1;
}

.feature-content h3 {
    font-size: 2.8rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.feature-content p {
    font-size: 1.6rem;
    line-height: 1.8;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.feature-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    padding-bottom: 0.3rem;
    border-bottom: 2px solid transparent;
    transition: border-color 0.3s ease;
}

.feature-link:hover {
    border-color: var(--primary-color);
}

/* Responsive design for features section */
@media (max-width: 992px) {
    .feature-row {
        gap: 4rem;
    }
}

@media (max-width: 768px) {
    .feature-row {
        flex-direction: column;
        gap: 3rem;
    }
    
    /* Reverse order for even rows on mobile */
    .feature-row:nth-child(even) {
        flex-direction: column-reverse;
    }
    
    .features {
        padding: 6rem 0;
    }
    
    .feature-content h3 {
        font-size: 2.4rem;
    }
}

/* SEO Content Section Styles */
.seo-content {
    padding: 10rem 0;
    background-color: var(--background-light);
}

.seo-content .container {
    max-width: 1000px;
}

.section-title {
    font-size: 4rem;
    text-align: center;
    margin-bottom: 6rem;
    color: var(--primary-dark);
}

.seo-block {
    margin-bottom: 8rem;
    padding-bottom: 8rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.seo-block:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.seo-block h2 {
    font-size: 3.2rem;
    color: var(--primary-color);
    margin-bottom: 3rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--secondary-color);
}

.seo-block h3 {
    font-size: 2.4rem;
    color: var(--primary-dark);
    margin: 4rem 0 2rem;
}

.seo-block h4 {
    font-size: 2rem;
    color: var(--text-color);
    margin: 3rem 0 1.5rem;
}

.seo-block p {
    font-size: 1.6rem;
    line-height: 1.8;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.feature-list, .numbered-list {
    margin: 2rem 0 3rem;
    padding-left: 2rem;
}

.feature-list li, .numbered-list li {
    margin-bottom: 1.5rem;
    font-size: 1.6rem;
    line-height: 1.6;
}

.highlight, .step {
    font-weight: 700;
    color: var(--primary-color);
    margin-right: 0.5rem;
}

.comparison-table {
    overflow-x: auto;
    margin: 3rem 0;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    font-size: 1.5rem;
}

.comparison-table th, .comparison-table td {
    padding: 1.5rem;
    text-align: left;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.comparison-table th {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

.comparison-table tr:nth-child(even) {
    background-color: rgba(0, 0, 0, 0.03);
}

/* FAQ Styles - 修改版，默认展开 */
.faq-container {
    margin-top: 4rem;
}

.faq-item {
    margin-bottom: 3rem;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    background-color: white;
}

.faq-question {
    padding: 2rem 2rem 0;
    margin: 0;
    font-size: 2rem;
    font-weight: 600;
    color: var(--primary-color);
    /* 移除cursor: pointer，因为不再需要点击 */
}

.faq-answer {
    padding: 1.5rem 2rem 2rem;
}

.faq-answer p {
    margin-bottom: 0; /* 最后一个段落不需要底部边距 */
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .seo-content {
        padding: 6rem 0;
    }
    
    .section-title {
        font-size: 3.2rem;
        margin-bottom: 4rem;
    }
    
    .seo-block h2 {
        font-size: 2.8rem;
    }
    
    .seo-block h3 {
        font-size: 2.2rem;
    }
    
    .seo-block h4 {
        font-size: 1.8rem;
    }
    
    .comparison-table {
        font-size: 1.4rem;
    }
    
    .faq-question {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .seo-content {
        padding: 5rem 0;
    }
    
    .section-title {
        font-size: 2.8rem;
    }
    
    .seo-block h2 {
        font-size: 2.4rem;
    }
    
    .seo-block h3 {
        font-size: 2rem;
    }
    
    .seo-block h4 {
        font-size: 1.7rem;
    }
}