:root {
    --primary-color: #2DD4BF;
    --primary-hover: #99F6E4;
    --card-bg: rgba(11, 58, 74, 0.5);
    --text-main: #e0f2fe;
}
/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f9f9f9;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 0;
}

h1, h2, h3 {
    margin-bottom: 20px;
    text-align: center;
    color: #222;
}

h2 {
    font-size: 2rem;
    margin-bottom: 40px;
}

p {
    margin-bottom: 15px;
    color: #555;
}

/* Typography and Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    background-color: #007bff;
    color: #fff;
    text-decoration: none;
    border-radius: 25px;
    font-size: 1.1rem;
    font-weight: bold;
    text-align: center;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #0056b3;
}

/* Navigation */
.top-nav {
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0 !important;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #007bff;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 20px;
}

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

.nav-links a:hover, .nav-links a.active {
    color: #007bff;
}

.nav-actions .nav-btn {
    padding: 8px 20px;
    font-size: 0.95rem;
    border-radius: 20px;
}

/* Layout Utilities */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

/* Sections */
.hero {
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
    color: white;
    text-align: center;
    padding: 80px 0;
}

.hero h1 {
    color: white;
    font-size: 3rem;
    margin-bottom: 10px;
}

.hero p {
    color: #ddd;
    font-size: 1.2rem;
    margin-bottom: 30px;
}

.hero .cta-btn {
    background-color: #ff9800;
}

.hero .cta-btn:hover {
    background-color: #e68a00;
}

.hero .blog-btn:hover {
    background-color: #218838 !important;
}

/* Cards */
.card, .price-card, .review-card {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    text-align: center;
}

.card h3 {
    color: #007bff;
}

.support-card {
    background: #eef5ff;
    border: 1px solid #d0e3ff;
}

/* Pricing */
.price-card {
    border: 1px solid #eee;
    display: flex;
    flex-direction: column;
}

.price-card.highlight {
    border: 2px solid #007bff;
    transform: scale(1.05);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.price {
    font-size: 2.5rem;
    font-weight: bold;
    color: #333;
    margin: 20px 0;
}

.price span {
    font-size: 1rem;
    color: #777;
}

.price-card ul {
    list-style: none;
    margin-bottom: 30px;
    flex-grow: 1;
}

.price-card ul li {
    padding: 10px 0;
    border-bottom: 1px solid #eee;
    color: #555;
}

/* Reviews */
.review-card {
    text-align: left;
    font-style: italic;
}
.review-card .author {
    margin-top: 15px;
    font-weight: bold;
    text-align: right;
    color: #222;
    font-style: normal;
}

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

.faq-item {
    background: white;
    padding: 20px;
    margin-bottom: 15px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.faq-item h3 {
    text-align: left;
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: #333;
}

/* Footer */
footer {
    background: #222;
    color: #aaa;
    text-align: center;
    padding: 40px 0 20px;
}

.footer-links {
    padding: 0;
    margin-bottom: 20px;
}

.footer-links a {
    color: #ddd;
    text-decoration: none;
    margin: 0 15px;
    font-size: 1rem;
}

.footer-links a:hover {
    color: white;
}

.copyright {
    font-size: 0.9rem;
    margin-bottom: 0;
}

/* Sub-pages layout */
.sub-page-header {
    background: #1e3c72;
    color: white;
    padding: 40px 0;
    text-align: center;
}
.sub-page-header h1 {
    color: white;
    margin: 0;
}
.sub-page-content {
    background: white;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-top: -20px;
    margin-bottom: 40px;
}
.sub-page-content h2, .sub-page-content h3 {
    text-align: left;
    margin-top: 20px;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 15px;
    }
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .grid-3, .grid-2 {
        grid-template-columns: 1fr;
    }
    
    .price-card.highlight {
        transform: scale(1);
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .footer-links a {
        display: block;
        margin: 10px 0;
    }
    
    .btn {
        width: 100%;
        box-sizing: border-box;
    }
}

/* =========================================
   深海悠游 · DEEP OCEAN 视觉风格覆盖
   注：仅修改颜色、背景、阴影等视觉属性，绝不修改布局
========================================= */

/* 全局与排版色彩 */
body {
    background-color: transparent !important; 
    color: var(--primary-hover) !important; 
}

h1, h2, h3, .logo {
    color: var(--primary-hover) !important; 
}

p, li, .faq-item h3 {
    color: var(--text-main) !important;
}

/* 导航栏 */
.top-nav {
    background-color: rgba(5, 30, 48, 0.8) !important; 
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(45, 212, 191, 0.2);
}

.nav-links a {
    color: var(--text-main) !important;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--primary-color) !important; 
}

/* 按钮统一风格 */
.btn {
    background-color: var(--primary-color) !important;
    color: #051E30 !important;
}

.btn:hover {
    background-color: var(--primary-hover) !important;
}

/* 博客按钮特殊区分（但不破坏色系） */
.hero .blog-btn {
    background-color: rgba(45, 212, 191, 0.2) !important;
    color: var(--primary-hover) !important;
    border: 1px solid var(--primary-color) !important;
}

.hero .blog-btn:hover {
    background-color: var(--primary-color) !important;
    color: #051E30 !important;
}

/* 移除原有的背景渐变 */
.hero, .sub-page-header {
    background: transparent !important;
}
.hero p {
    color: var(--primary-hover) !important;
}

/* 卡片风格 */
.card, .price-card, .review-card, .faq-item, .sub-page-content {
    background: var(--card-bg) !important;
    border: 1px solid rgba(45, 212, 191, 0.2) !important;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3) !important;
    backdrop-filter: blur(8px);
}

.support-card {
    background: rgba(45, 212, 191, 0.1) !important;
    border: 1px solid rgba(45, 212, 191, 0.3) !important;
}

/* 套餐高亮卡片 */
.price-card.highlight {
    border: 2px solid var(--primary-color) !important;
    background: rgba(11, 58, 74, 0.8) !important;
    box-shadow: 0 0 20px rgba(45, 212, 191, 0.2) !important;
}

.price {
    color: var(--primary-hover) !important;
}
.price span {
    color: var(--primary-color) !important;
}
.price-card ul li {
    border-bottom: 1px solid rgba(45, 212, 191, 0.1) !important;
}

/* Footer */
footer {
    background: rgba(4, 24, 40, 0.9) !important;
    border-top: 1px solid rgba(45, 212, 191, 0.1);
}
.footer-links a {
    color: var(--primary-hover) !important;
}
.footer-links a:hover {
    color: var(--primary-color) !important;
}

/* =========================================
   卡片小图卡 (SVG Icons)
   通过 CSS 伪元素添加，避免修改 HTML 结构
========================================= */
.card h3 {
    position: relative;
    padding-top: 55px; /* 为顶部图标预留空间 */
    margin-bottom: 25px; /* 增加底部间距让视觉更平衡 */
}

.card h3::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 42px;
    height: 42px;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    opacity: 0.9;
    filter: drop-shadow(0 0 8px rgba(45, 212, 191, 0.4)); /* 添加微光效果契合深海主题 */
}

/* 1. 极速专线 (闪电) */
.features .card:nth-child(1) h3::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2399F6E4' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolygon points='13 2 3 14 12 14 11 22 21 10 12 10 13 2'%3E%3C/polygon%3E%3C/svg%3E");
}

/* 2. 安全隐私 (护盾) */
.features .card:nth-child(2) h3::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2399F6E4' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 22s8-4 8-10V5l-8-3-8 3v7c0 6 8 10 8 10z'%3E%3C/path%3E%3C/svg%3E");
}

/* 3. 多端支持 (设备) */
.features .card:nth-child(3) h3::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2399F6E4' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='2' y='3' width='20' height='14' rx='2' ry='2'%3E%3C/rect%3E%3Crect x='16' y='15' width='4' height='6' rx='1'%3E%3C/rect%3E%3Cline x1='2' y1='21' x2='12' y2='21'%3E%3C/line%3E%3C/svg%3E");
}

/* 4. 原生流媒体解锁 (播放器) */
.media-ai .card:nth-child(1) h3::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2399F6E4' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='2' y='3' width='20' height='14' rx='2' ry='2'%3E%3C/rect%3E%3Cpolygon points='10 8 16 12 10 16 10 8'%3E%3C/polygon%3E%3C/svg%3E");
}

/* 5. AI 生产力工具加速 (神经网络/六边形节点) */
.media-ai .card:nth-child(2) h3::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2399F6E4' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21 16V8a2 2 0 0 0-1-1.73l-7-4a2 2 0 0 0-2 0l-7 4A2 2 0 0 0 3 8v8a2 2 0 0 0 1 1.73l7 4a2 2 0 0 0 2 0l7-4A2 2 0 0 0 21 16z'%3E%3C/path%3E%3Cpolyline points='3.27 6.96 12 12.01 20.73 6.96'%3E%3C/polyline%3Cline x1='12' y1='22.08' x2='12' y2='12'%3E%3C/line%3E%3C/svg%3E");
}

/* =========================================
   知识科普 - 文章板块图卡
========================================= */
.article-card {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    padding: 25px;
    border-radius: 10px;
    background: var(--card-bg) !important;
    border: 1px solid rgba(45, 212, 191, 0.2) !important;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3) !important;
    backdrop-filter: blur(8px);
    transition: transform 0.3s ease, border-color 0.3s ease, background 0.3s ease;
}

.article-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color) !important;
    background: rgba(11, 58, 74, 0.8) !important;
}

.article-card h3 {
    font-size: 1.15rem;
    margin-bottom: 12px !important;
    color: var(--primary-hover) !important;
    padding-top: 0 !important; /* 覆盖旧有 h3 占位 */
    text-align: left;
}

.article-card p {
    font-size: 0.9rem;
    color: var(--text-main) !important;
    margin-bottom: 20px;
    line-height: 1.6;
    flex-grow: 1;
}

.article-card .read-more {
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: bold;
    text-align: right;
    align-self: flex-end;
}

/* =========================================
   子页面内容链接通用样式 (如网站地图) - 小图卡风格
========================================= */
.sitemap-list {
    list-style-type: none;
    margin-left: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.sitemap-list li {
    display: block;
}

.sitemap-list a {
    display: flex;
    align-items: center;
    padding: 15px 20px;
    background: rgba(45, 212, 191, 0.05) !important;
    border: 1px solid rgba(45, 212, 191, 0.2) !important;
    border-radius: 8px;
    color: var(--primary-hover) !important;
    text-decoration: none !important;
    font-size: 0.95rem;
    line-height: 1.4;
    transition: all 0.3s ease;
    height: 100%;
}

.sitemap-list a:hover {
    background: rgba(45, 212, 191, 0.15) !important;
    border-color: var(--primary-color) !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: #000;
    padding: 8px;
    z-index: 10000;
    transition: top 0.2s;
}
.skip-link:focus { top: 0; }

section[id] { scroll-margin-top: 80px; }

details.faq-item { cursor: pointer; }
details.faq-item summary { list-style: none; outline: none; }
details.faq-item summary::-webkit-details-marker { display: none; }
details.faq-item[open] summary h3 { color: var(--primary-hover); }