:root {
    --primary: #2B3A67;
    --secondary: #14B8A6;
    --accent: #F59E0B;
    --dark: #1F2937;
    --light: #F9FAFB;
    --white: #FFFFFF;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    line-height: 1.5;
    color: var(--dark);
    background: var(--light);
}

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

h1, h2, h3, h4 {
    margin-bottom: 1rem;
}

h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.section-desc {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 2rem;
    color: #4B5563;
}

/* 头部样式 */
.site-header {
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
    background: var(--white);
    box-shadow: var(--shadow);
}

.top-bar {
    background: var(--primary);
    color: var(--white);
    padding: 8px 0;
}

.top-notice {
    color: var(--white);
    font-size: 14px;
    text-align: center;
    display: block;
}

.main-nav {
    padding: 15px 0;
}

.main-nav .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo a {
    color: var(--primary);
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
}

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

.nav-list a {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-list a:hover {
    color: var(--accent);
}

/* 英雄区域 */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
    color: #fff;
    position: relative;
    overflow: hidden;
}

.hero .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.hero-desc {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.quick-download {
    margin: 30px 0;
    display: flex;
    gap: 20px;
    justify-content: center;
}

.quick-btn {
    padding: 12px 30px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
}

.quick-btn.android {
    background: var(--accent);
    color: var(--white);
}

.quick-btn.ios {
    background: transparent;
    border: 2px solid var(--white);
    color: var(--white);
}

.quick-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 3rem;
}

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

.stat-item strong {
    display: block;
    font-size: 2rem;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

/* 版本选择区域 */
.versions {
    padding: 6rem 0;
    background: var(--white);
}

.version-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.version-card {
    background: var(--light);
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    transition: transform 0.3s;
}

.version-card:hover {
    transform: translateY(-5px);
}

/* 响应式设计 */
@media (max-width: 768px) {
    h2 {
        font-size: 1.75rem;
    }

    .menu-toggle {
        display: block;
        width: 24px;
        height: 18px;
        position: relative;
        background: none;
        border: none;
        cursor: pointer;
    }

    .menu-toggle span {
        display: block;
        width: 100%;
        height: 2px;
        background: var(--dark);
        position: absolute;
        left: 0;
        top: 8px;
        transition: all 0.3s;
    }

    .menu-toggle::before,
    .menu-toggle::after {
        content: '';
        position: absolute;
        width: 100%;
        height: 2px;
        background: var(--dark);
        left: 0;
        transition: all 0.3s;
    }

    .menu-toggle::before {
        top: 0;
    }

    .menu-toggle::after {
        bottom: 0;
    }

    .menu-toggle.active span {
        opacity: 0;
    }

    .menu-toggle.active::before {
        transform: rotate(45deg);
        top: 8px;
    }

    .menu-toggle.active::after {
        transform: rotate(-45deg);
        bottom: 8px;
    }

    .nav-list {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--white);
        padding: 0;
        flex-direction: column;
        gap: 0;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }

    .nav-list.active {
        display: flex;
    }

    .nav-list li {
        width: 100%;
    }

    .nav-list a {
        display: block;
        padding: 15px 20px;
        border-bottom: 1px solid var(--light);
    }

    .hero .container {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-image {
        margin-top: 30px;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero-desc {
        font-size: 1rem;
    }

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

    .hero-stats {
        grid-template-columns: 1fr;
    }

    .download-cards,
    .features-grid,
    .guide-steps,
    .security-grid,
    .footer-grid {
        grid-template-columns: 1fr;
    }

    .footer-col h4::after {
        left: 50%;
        transform: translateX(-50%);
    }

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

/* 下载区域样式 */
.download-section {
    padding: 80px 0;
    background: var(--light);
}

.download-section h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--primary-color);
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.download-card {
    background: var(--white);
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.download-card:hover {
    transform: translateY(-5px);
}

.download-card h3 {
    color: var(--primary-color);
    font-size: 24px;
    margin-bottom: 20px;
}

.feature-list {
    list-style: none;
    margin: 25px 0;
}

.feature-list li {
    margin: 12px 0;
    padding-left: 25px;
    position: relative;
}

.feature-list li::before {
    content: "✓";
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.download-btn {
    display: inline-block;
    padding: 14px 32px;
    background: var(--secondary-color);
    color: var(--light-text);
    text-decoration: none;
    border-radius: 8px;
    transition: var(--transition);
    text-align: center;
    width: 100%;
}

.download-btn:hover {
    background: #008c69;
    transform: translateY(-2px);
}

/* 特色功能区域 */
.features-section {
    padding: 80px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.feature-item {
    background: var(--light);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
}

.feature-item:hover {
    transform: translateY(-5px);
}

/* 安装教程区域 */
.guide-section {
    padding: 80px 0;
    background: var(--light);
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.step-item {
    text-align: center;
    padding: 30px;
    position: relative;
}

.step-num {
    font-size: 64px;
    color: var(--secondary-color);
    opacity: 0.15;
    font-weight: bold;
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
}

/* 安全保障区域 */
.security-section {
    padding: 80px 0;
}

.security-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.security-item {
    background: var(--light);
    padding: 30px;
    border-radius: 12px;
    transition: all 0.3s;
}

.security-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

/* 页脚样式 */
.site-footer {
    background: var(--primary);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h4 {
    color: var(--white);
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--accent);
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 0.75rem;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: all 0.3s;
}

.footer-col ul li a:hover {
    color: var(--white);
    padding-left: 5px;
}

.related-links {
    padding: 20px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 20px;
}

.copyright {
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* 广告区域样式 */
.ad-section {
    padding: 40px 0;
    background: var(--background);
}

.ad-section .container {
    text-align: center;
}

/* 友情链接和相关站点样式 */
.related-links {
    padding: 40px 0;
    background: var(--section-bg);
}

.friend-links {
    margin-bottom: 30px;
}

.related-sites ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
}

.related-sites li a {
    color: var(--text-color);
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 4px;
    background: var(--background);
    transition: var(--transition);
}

.related-sites li a:hover {
    color: var(--secondary-color);
    box-shadow: var(--card-shadow);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .related-sites ul {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }
}

/* 底部导航样式 */
.footer-nav {
    padding: 80px 0;
    background: var(--primary-color);
    color: var(--light-text);
}

.footer-nav-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
}

.footer-nav-column h4 {
    color: var(--light-text);
    font-size: 18px;
    margin-bottom: 20px;
    font-weight: 600;
}

.footer-nav-column ul {
    list-style: none;
}

.footer-nav-column ul li {
    margin-bottom: 12px;
}

.footer-nav-column ul li a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-nav-column ul li a:hover {
    color: var(--secondary-color);
    padding-left: 5px;
}

/* 调整页脚样式 */
.site-footer {
    background: #162b33; /* 稍深一点的背景色 */
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .footer-nav {
        padding: 40px 0;
    }

    .footer-nav-grid {
        grid-template-columns: 1fr 1fr;
        gap: 30px;
    }

    .footer-nav-column {
        text-align: center;
    }

    .footer-nav-column h4 {
        font-size: 16px;
    }

    .footer-nav-column ul li a {
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .footer-nav-grid {
        grid-template-columns: 1fr;
    }
}

/* PC端导航样式（1200px以上） */
@media screen and (min-width: 1201px) {
    .container {
        max-width: 1200px;
        padding: 0 20px;
    }

    .nav-toggle {
        display: none;
    }

    .nav-menu {
        display: flex !important;
        gap: 30px;
    }
}

/* 平板端适配（768px - 1200px） */
@media screen and (max-width: 1200px) {
    .container {
        max-width: 100%;
        padding: 0 30px;
    }

    .banner-content h1 {
        font-size: 40px;
    }

    .features-grid,
    .download-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 移动端适配（768px以下） */
@media screen and (max-width: 768px) {
    .main-nav {
        height: 50px; /* 降低导航栏高度 */
    }

    .main-nav .container {
        height: 50px;
        padding: 0 15px;
    }

    .logo a {
        font-size: 18px; /* 调整logo大小 */
    }

    /* 汉堡菜单按钮优化 */
    .nav-toggle {
        width: 22px;
        height: 16px;
        margin-right: 5px;
    }

    .nav-toggle span {
        height: 1px; /* 更细的线条 */
    }

    /* 移动导航菜单优化 */
    .nav-menu {
        top: 50px; /* 对应新的导航栏高度 */
        background: rgba(30, 65, 81, 0.98); /* 半透明背景 */
        padding: 10px 0;
    }

    .nav-menu li a {
        padding: 12px 20px;
        font-size: 15px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    /* Banner区域适配 */
    .intro-banner {
        padding: 80px 0 40px;
    }

    .banner-content h1 {
        font-size: 24px;
        margin-bottom: 15px;
    }

    .intro-text {
        font-size: 14px;
        margin-bottom: 25px;
    }

    .action-btns {
        gap: 15px;
    }

    .btn-primary, .btn-outline {
        padding: 10px 25px;
        font-size: 14px;
    }

    /* 内容区域适配 */
    .download-section,
    .features-section,
    .guide-section,
    .security-section {
        padding: 40px 0;
    }

    .download-section h2,
    .features-section h2,
    .guide-section h2,
    .security-section h2 {
        font-size: 20px;
        margin-bottom: 25px;
    }

    .download-card {
        padding: 20px;
    }

    .download-card h3 {
        font-size: 18px;
    }

    .feature-list li {
        font-size: 14px;
        margin: 8px 0;
    }

    .download-btn {
        padding: 10px 20px;
        font-size: 14px;
    }

    /* 底部导航样式 */
    .footer-nav {
        padding: 30px 0;
    }

    .footer-nav-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .footer-nav-column {
        text-align: center;
        padding: 0 15px 15px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }

    .footer-nav-column:last-child {
        border-bottom: none;
        padding-bottom: 0;
    }

    .footer-nav-column h4 {
        font-size: 16px;
        margin-bottom: 10px;
        padding-bottom: 8px;
    }

    .footer-nav-column h4::after {
        left: 50%;
        transform: translateX(-50%);
    }

    .footer-nav-column ul li {
        margin-bottom: 8px;
    }

    .footer-nav-column ul li a {
        font-size: 13px;
        padding: 4px 0;
    }
}

/* 超小屏幕优化 */
@media screen and (max-width: 360px) {
    .container {
        padding: 0 12px;
    }

    .banner-content h1 {
        font-size: 22px;
    }

    .intro-text {
        font-size: 13px;
    }

    .btn-primary, .btn-outline {
        padding: 8px 20px;
        font-size: 13px;
    }
}

/* 按钮样式 */
.btn-download,
.btn-guide {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
}

.btn-download {
    background: var(--accent);
    color: var(--white);
}

.btn-guide {
    background: transparent;
    border: 2px solid var(--white);
    color: var(--white);
}