/* ========================================
   全局样式
   ======================================== */

/* CSS Reset 和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    background-color: #ffffff;
    color: #111827;
    line-height: 1.6;
    font-size: 16px;
}

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

/* ========================================
   顶部导航栏
   ======================================== */

.header {
    background-color: #f9fafb;
    border-bottom: 2px solid #e5e7eb;
    padding: 0;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: #2563eb;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-menu a {
    color: #111827;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
    border-bottom: 2px solid transparent;
    padding-bottom: 4px;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #2563eb;
    border-bottom-color: #2563eb;
}

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    background: none;
    border: 2px solid #111827;
    font-size: 24px;
    cursor: pointer;
    padding: 8px 12px;
    color: #111827;
    border-radius: 4px;
}

/* ========================================
   主内容区域
   ======================================== */

.main-content {
    margin-top: 70px;
    min-height: calc(100vh - 240px);
}

/* 页面标题区域 */
.page-header {
    background-color: #f9fafb;
    border-bottom: 1px solid #e5e7eb;
    padding: 60px 0 40px;
    text-align: center;
}

.page-title {
    font-size: 48px;
    font-weight: 700;
    color: #111827;
    margin-bottom: 16px;
}

.page-subtitle {
    font-size: 20px;
    color: #6b7280;
    margin-bottom: 0;
}

/* ========================================
   按钮样式
   ======================================== */

.btn {
    display: inline-block;
    padding: 12px 32px;
    font-size: 16px;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.btn-primary {
    background-color: #2563eb;
    color: #ffffff;
}

.btn-primary:hover {
    background-color: #1d4ed8;
}

/* 醒目下载按钮 - 更大更显眼 */
.btn-download {
    background-color: #16a34a;
    color: #ffffff;
    padding: 18px 56px;
    font-size: 20px;
    font-weight: 700;
    border-radius: 8px;
    display: inline-block;
    text-decoration: none;
    border: 3px solid #16a34a;
}

.btn-download:hover {
    background-color: #15803d;
    border-color: #15803d;
}

/* 超大下载按钮 */
.btn-download-xl {
    padding: 20px 64px;
    font-size: 22px;
}

/* 下载按钮闪烁提示 */
.btn-download-pulse {
    animation: pulse-border 2s infinite;
}

@keyframes pulse-border {
    0%, 100% {
        border-color: #16a34a;
    }
    50% {
        border-color: #22c55e;
    }
}

.btn-secondary {
    background-color: #ffffff;
    color: #2563eb;
    border: 2px solid #2563eb;
}

.btn-secondary:hover {
    background-color: #f9fafb;
}

.btn-large {
    padding: 16px 48px;
    font-size: 18px;
}

/* ========================================
   卡片样式
   ======================================== */

.card {
    background-color: #ffffff;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    padding: 32px;
    margin-bottom: 24px;
}

.card-title {
    font-size: 24px;
    font-weight: 700;
    color: #111827;
    margin-bottom: 16px;
}

.card-text {
    color: #4b5563;
    line-height: 1.8;
}

/* ========================================
   网格布局
   ======================================== */

.grid {
    display: grid;
    gap: 24px;
}

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

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* ========================================
   特性列表
   ======================================== */

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-item {
    padding: 20px;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    margin-bottom: 16px;
}

.feature-icon {
    font-size: 32px;
    margin-bottom: 12px;
    color: #2563eb;
}

.feature-title {
    font-size: 20px;
    font-weight: 600;
    color: #111827;
    margin-bottom: 8px;
}

.feature-description {
    color: #6b7280;
    font-size: 15px;
}

/* ========================================
   下载区域
   ======================================== */

.download-section {
    text-align: center;
    padding: 80px 0;
}

.download-box {
    background-color: #f9fafb;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    padding: 48px 32px;
    max-width: 600px;
    margin: 0 auto;
}

.download-info {
    margin: 24px 0;
    color: #6b7280;
}

/* ========================================
   页脚
   ======================================== */

.footer {
    background-color: #f9fafb;
    border-top: 2px solid #e5e7eb;
    padding: 40px 0 20px;
    margin-top: 80px;
}

.footer-content {
    text-align: center;
    color: #6b7280;
}

.footer-links {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 20px;
}

.footer-links a {
    color: #6b7280;
    text-decoration: none;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: #2563eb;
}

.copyright {
    font-size: 14px;
    color: #9ca3af;
}

/* ========================================
   返回顶部按钮
   ======================================== */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: #2563eb;
    color: #ffffff;
    width: 50px;
    height: 50px;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 24px;
    display: none;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

.back-to-top:hover {
    background-color: #1d4ed8;
}

.back-to-top.show {
    display: flex;
}

/* ========================================
   系统要求表格
   ======================================== */

.requirements-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.requirements-table th,
.requirements-table td {
    padding: 16px;
    text-align: left;
    border: 1px solid #e5e7eb;
}

.requirements-table th {
    background-color: #f9fafb;
    font-weight: 600;
    color: #111827;
}

.requirements-table td {
    color: #4b5563;
}

/* ========================================
   安装步骤
   ======================================== */

.steps-list {
    counter-reset: step-counter;
    list-style: none;
}

.step-item {
    counter-increment: step-counter;
    padding: 24px;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    margin-bottom: 16px;
    position: relative;
    padding-left: 80px;
}

.step-item:before {
    content: counter(step-counter);
    position: absolute;
    left: 24px;
    top: 24px;
    width: 40px;
    height: 40px;
    background-color: #2563eb;
    color: #ffffff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
}

.step-title {
    font-weight: 600;
    color: #111827;
    margin-bottom: 8px;
}

.step-description {
    color: #6b7280;
}

/* ========================================
   FAQ 区域
   ======================================== */

.faq-item {
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    margin-bottom: 16px;
    padding: 24px;
}

.faq-question {
    font-size: 18px;
    font-weight: 600;
    color: #111827;
    margin-bottom: 12px;
}

.faq-answer {
    color: #4b5563;
    line-height: 1.8;
}

/* ========================================
   站点地图
   ======================================== */

.sitemap-section {
    margin-bottom: 48px;
}

.sitemap-title {
    font-size: 24px;
    font-weight: 700;
    color: #111827;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid #e5e7eb;
}

.sitemap-list {
    list-style: none;
}

.sitemap-list li {
    padding: 12px 0;
    border-bottom: 1px solid #f3f4f6;
}

.sitemap-list a {
    color: #2563eb;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.sitemap-list a:hover {
    color: #1d4ed8;
    text-decoration: underline;
}

/* ========================================
   内容区域
   ======================================== */

.section {
    padding: 60px 0;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    color: #111827;
    margin-bottom: 24px;
    text-align: center;
}

.section-text {
    color: #4b5563;
    line-height: 1.8;
    margin-bottom: 16px;
}

/* ========================================
   响应式设计 - 平板
   ======================================== */

@media (max-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }

    .section-title {
        font-size: 28px;
    }

    .page-title {
        font-size: 40px;
    }
}

/* ========================================
   响应式设计 - 移动端
   ======================================== */

@media (max-width: 768px) {
    /* 导航栏 */
    .menu-toggle {
        display: block;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: #ffffff;
        flex-direction: column;
        gap: 0;
        border-bottom: 2px solid #e5e7eb;
    }

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

    .nav-menu li {
        border-bottom: 1px solid #f3f4f6;
    }

    .nav-menu a {
        display: block;
        padding: 16px 20px;
        border-bottom: none;
    }

    /* 网格布局 */
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    /* 标题 */
    .page-title {
        font-size: 32px;
    }

    .page-subtitle {
        font-size: 16px;
    }

    .section-title {
        font-size: 24px;
    }

    /* 按钮 */
    .btn-large {
        padding: 14px 32px;
        font-size: 16px;
    }

    /* 卡片 */
    .card {
        padding: 24px 16px;
    }

    /* 下载区域 */
    .download-section {
        padding: 40px 0;
    }

    .download-box {
        padding: 32px 20px;
    }

    /* 步骤列表 */
    .step-item {
        padding-left: 20px;
        padding-top: 70px;
    }

    .step-item:before {
        left: 50%;
        transform: translateX(-50%);
        top: 16px;
    }

    /* 返回顶部 */
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }

    /* 页面头部 */
    .page-header {
        padding: 40px 0 30px;
    }

    /* 区域 */
    .section {
        padding: 40px 0;
    }

    /* 表格 */
    .requirements-table {
        font-size: 14px;
    }

    .requirements-table th,
    .requirements-table td {
        padding: 12px 8px;
    }
}

/* ========================================
   工具类
   ======================================== */

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

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

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

.mb-1 {
    margin-bottom: 8px;
}

.mb-2 {
    margin-bottom: 16px;
}

.mb-3 {
    margin-bottom: 24px;
}

.mb-4 {
    margin-bottom: 32px;
}

.mt-1 {
    margin-top: 8px;
}

.mt-2 {
    margin-top: 16px;
}

.mt-3 {
    margin-top: 24px;
}

.mt-4 {
    margin-top: 32px;
}

.fw-bold {
    font-weight: 700;
}

.fw-semibold {
    font-weight: 600;
}

/* ========================================
   打印样式
   ======================================== */

@media print {
    .header,
    .footer,
    .back-to-top,
    .menu-toggle {
        display: none;
    }

    .main-content {
        margin-top: 0;
    }
}