/* ===== CSS 变量和基础样式 ===== */
:root {
    --primary-color: #0d3b66;
    --primary-light: #1a5490;
    --primary-dark: #0a2d4d;
    --accent-color: #f18f01;
    --text-color: #2d3748;
    --text-light: #718096;
    --bg-light: #f7fafc;
    --bg-lighter: #edf2f7;
    --border-color: #e2e8f0;
    --sidebar-width: 200px;
}

* {
    box-sizing: border-box;
}

/* ===== 顶栏样式 ===== */
.topbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 0 30px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-sizing: border-box;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(13, 59, 102, 0.15);
}

.topbar h2 {
    margin: 0;
    font-size: 24px;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: white;
}

.menu-btn {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 28px;
    cursor: pointer;
    padding: 8px 15px;
    margin-right: 10px;
    transition: all 0.3s ease;
    border-radius: 6px;
}

.menu-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: scale(1.1);
}

.menu-btn:active {
    transform: scale(0.95);
}

.nav-links {
    display: flex;
    gap: 35px;
}

.topbar a {
    color: white;
    text-decoration: none;
    white-space: nowrap;
    font-size: 15px;
    font-weight: 600;
    position: relative;
    transition: all 0.3s ease;
    padding: 8px 0;
}

.topbar a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

.topbar a:hover {
    color: #fff;
}

.topbar a:hover::after {
    width: 100%;
}

/* ===== 页面整体布局 ===== */
body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #f8fafb 0%, #eef3f8 100%);
    color: var(--text-color);
    min-height: 100vh;
    line-height: 1.6;
}

/* ===== 侧边栏样式 ===== */
.sidebar {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    width: var(--sidebar-width, 200px);
    background: white;
    padding: 20px 15px;
    box-sizing: border-box;
    position: fixed;
    top: 70px;
    bottom: 0;
    left: 0;
    overflow-y: auto;
    box-shadow: 2px 0 12px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, width 0.3s ease;
    z-index: 98;
}

.sidebar.hidden {
    transform: translateX(-100%);
}

.sidebar h2 {
    margin: 0 0 20px 0;
    color: var(--primary-color);
    font-size: 16px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: color 0.3s ease;
}

/* ===== 侧边栏菜单列表 ===== */
.sidebar ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
    width: 100%;
}

.sidebar > ul > li {
    margin: 0 0 8px 0;
    border-radius: 6px;
    background: var(--bg-light);
    overflow: hidden;
    transition: all 0.3s ease;
}

.sidebar > ul > li:hover {
    background: var(--bg-lighter);
    box-shadow: 0 2px 8px rgba(13, 59, 102, 0.1);
}

.sidebar > ul > li > a {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 14px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
}

.sidebar > ul > li > a:hover {
    color: var(--primary-light);
    background: rgba(13, 59, 102, 0.08);
    text-decoration: none;
}

.sidebar > ul > li > a.active {
    color: var(--primary-light);
    background: rgba(26, 84, 144, 0.15);
    font-weight: 700;
}

/* ===== 折叠按钮 ===== */
.toggle-btn {
    display: inline-block;
    width: 18px;
    height: 18px;
    text-align: center;
    line-height: 18px;
    transition: transform 0.3s ease;
    flex-shrink: 0;
    font-size: 12px;
}

.toggle-btn.collapsed {
    transform: rotate(-90deg);
}

/* ===== 二级菜单 ===== */
.sidebar ul ul {
    padding: 0;
    background: var(--bg-lighter);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.sidebar ul ul.expanded {
    max-height: 1500px;
    padding: 8px 0;
}

.sidebar ul ul li {
    margin: 0;
    border-bottom: 1px solid var(--border-color);
}

.sidebar ul ul li:last-child {
    border-bottom: none;
}

.sidebar ul ul li a {
    display: block;
    padding: 10px 14px 10px 28px;
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 13px;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}

.sidebar ul ul li a:hover {
    color: var(--primary-light);
    background: rgba(26, 84, 144, 0.08);
    border-left-color: var(--accent-color);
    text-decoration: none;
}

.sidebar ul ul li a.active {
    color: var(--primary-light);
    background: rgba(26, 84, 144, 0.15);
    border-left-color: var(--accent-color);
    font-weight: 600;
}

/* ===== 简单链接菜单 ===== */
.sidebar a {
    display: block;
    margin: 0;
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
    font-size: 14px;
    padding: 8px 12px;
    border-radius: 4px;
}

.sidebar a:hover {
    color: var(--primary-light);
    background: rgba(13, 59, 102, 0.08);
    text-decoration: none;
}

.sidebar a.active {
    font-weight: 700;
    color: var(--primary-light);
    background: rgba(26, 84, 144, 0.15);
    border-radius: 6px;
    padding: 8px 12px;
}

/* ===== 可拖拽分隔线 ===== */
.resizer {
    position: fixed;
    top: 70px;
    left: calc(var(--sidebar-width, 200px));
    width: 6px;
    height: calc(100vh - 70px);
    background: linear-gradient(to right, transparent, var(--border-color), transparent);
    cursor: col-resize;
    transition: background 0.2s ease;
    z-index: 99;
    user-select: none;
}

.resizer:hover {
    background: linear-gradient(to right, transparent, var(--primary-color), transparent);
}

/* ===== 主体内容区 ===== */
.main {
    margin-top: 70px;
    margin-left: calc(var(--sidebar-width, 200px) + 40px);
    padding: 50px 60px;
    max-width: calc(100% - var(--sidebar-width, 200px) - 40px);
    transition: margin-left 0.3s ease, max-width 0.3s ease;
    background: white;
    border-radius: 12px;
    margin-right: 40px;
    margin-bottom: 40px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

/* ===== 标题样式 ===== */
.main h1 {
    color: var(--primary-color);
    font-size: 36px;
    margin: 50px 0 25px 0;
    font-weight: 700;
    letter-spacing: -0.8px;
    border-bottom: 3px solid var(--accent-color);
    padding-bottom: 12px;
    display: inline-block;
}

.main h1:first-of-type {
    margin-top: 0;
}

.main h2 {
    color: var(--primary-color);
    font-size: 28px;
    margin: 40px 0 20px 0;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.main h3 {
    color: var(--primary-light);
    font-size: 22px;
    margin: 30px 0 15px 0;
    font-weight: 600;
}

.main h4,
.main h5,
.main h6 {
    color: var(--text-color);
    margin: 20px 0 10px 0;
    font-weight: 600;
}

/* ===== 段落和文本 ===== */
.main p {
    line-height: 1.8;
    font-size: 16px;
    color: var(--text-color);
    margin: 20px 0;
}

.main strong {
    color: var(--primary-color);
    font-weight: 700;
}

.main em {
    color: var(--primary-light);
    font-style: italic;
}

/* ===== 链接样式 ===== */
.main a {
    color: var(--primary-light);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border-bottom: 2px solid transparent;
}

.main a:hover {
    color: var(--primary-color);
    border-bottom-color: var(--accent-color);
}

/* ===== 列表样式 ===== */
.main ul,
.main ol {
    margin: 20px 0;
    padding-left: 30px;
    line-height: 1.8;
}

.main li {
    margin: 10px 0;
    color: var(--text-color);
}

.main ul li::marker {
    color: var(--accent-color);
    font-weight: bold;
}

.main ol li::marker {
    color: var(--primary-light);
    font-weight: bold;
}

/* ===== 代码块样式 ===== */
.main code {
    background: var(--bg-light);
    color: #d73a49;
    padding: 3px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 14px;
    font-weight: 500;
}

.main pre {
    background: var(--text-color);
    color: #e1e4e8;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
    line-height: 1.5;
    margin: 20px 0;
    border-left: 4px solid var(--accent-color);
    font-size: 14px;
}

.main pre code {
    background: none;
    color: #e1e4e8;
    padding: 0;
    border-radius: 0;
}

/* ===== 表格样式 ===== */
.main table {
    width: 100%;
    border-collapse: collapse;
    margin: 25px 0;
    font-size: 15px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    border-radius: 8px;
    overflow: hidden;
}

.main table thead {
    background: var(--primary-color);
    color: white;
}

.main table th {
    padding: 14px 16px;
    font-weight: 700;
    text-align: left;
    border: none;
}

.main table td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
}

.main table tbody tr {
    transition: background 0.3s ease;
}

.main table tbody tr:hover {
    background: var(--bg-lighter);
}

.main table tbody tr:last-child td {
    border-bottom: none;
}

/* ===== 引用块样式 ===== */
.main blockquote {
    border-left: 4px solid var(--accent-color);
    padding: 12px 18px;
    margin: 20px 0;
    background: var(--bg-light);
    border-radius: 6px;
    color: var(--text-light);
    font-style: italic;
}

.main blockquote p {
    margin: 0;
}

/* ===== 图片样式 ===== */
.main img {
    max-width: 100%;
    height: auto;
    margin: 25px 0;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.main img:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

/* ===== iframe 和视频 ===== */
.main iframe {
    border: 1px solid var(--border-color);
    margin: 20px 0;
    border-radius: 8px;
    max-width: 100%;
    height: auto;
}

/* ===== 按钮样式 ===== */
button {
    margin-right: 10px;
    padding: 12px 24px;
    cursor: pointer;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    border: none;
    border-radius: 6px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(13, 59, 102, 0.25);
    font-size: 15px;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(13, 59, 102, 0.35);
}

button:active {
    transform: translateY(0);
}

/* ===== 隐藏的标题块 ===== */
header#title-block-header {
    display: none;
}

/* ===== 水平线 ===== */
.main hr {
    border: none;
    height: 2px;
    background: linear-gradient(to right, transparent, var(--border-color), transparent);
    margin: 40px 0;
}

/* ===== 响应式设计 - 平板 ===== */
@media (max-width: 1024px) {
    :root {
        --sidebar-width: 180px;
    }

    .main {
        margin-left: calc(var(--sidebar-width, 180px) + 30px);
        max-width: calc(100% - var(--sidebar-width, 180px) - 30px);
        padding: 40px 40px;
        margin-right: 30px;
    }

    .resizer {
        left: calc(var(--sidebar-width, 180px));
    }

    .topbar h2 {
        font-size: 20px;
    }

    .nav-links {
        gap: 25px;
    }

    .main h1 {
        font-size: 28px;
    }

    .main h2 {
        font-size: 24px;
    }
}

/* ===== 响应式设计 - 手机 ===== */
@media (max-width: 768px) {
    :root {
        --sidebar-width: 200px;
    }

    .topbar {
        height: 60px;
        padding: 0 15px;
    }

    .topbar h2 {
        font-size: 18px;
        order: 2;
    }

    .menu-btn {
        display: block;
        order: 1;
    }

    .nav-links {
        display: none;
        gap: 15px;
    }

    .sidebar {
        width: 280px;
        top: 60px;
        box-shadow: -2px 0 12px rgba(0, 0, 0, 0.2);
    }

    .sidebar.hidden {
        transform: translateX(-100%);
    }

    .sidebar h2 {
        font-size: 15px;
        margin-bottom: 15px;
    }

    .sidebar a {
        padding: 10px 12px;
        font-size: 13px;
    }

    .main {
        margin-top: 60px;
        margin-left: 20px;
        max-width: calc(100% - 20px);
        margin-right: 20px;
        padding: 25px 20px;
    }

    .main h1 {
        font-size: 26px;
        margin: 30px 0 15px 0;
    }

    .main h2 {
        font-size: 22px;
    }

    .main h3 {
        font-size: 18px;
    }

    .main p {
        font-size: 15px;
        line-height: 1.7;
    }

    .main code {
        font-size: 13px;
    }

    .main pre {
        padding: 12px;
        font-size: 12px;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .main table {
        font-size: 13px;
    }

    .main table th,
    .main table td {
        padding: 10px 12px;
    }

    .resizer {
        display: none;
    }

    button {
        padding: 10px 20px;
        font-size: 14px;
    }
}

/* ===== 超小屏幕 ===== */
@media (max-width: 480px) {
    .topbar {
        height: 55px;
        padding: 0 10px;
    }

    .topbar h2 {
        font-size: 16px;
    }

    .main {
        padding: 20px 15px;
        margin-left: 15px;
        margin-right: 15px;
    }

    .main h1 {
        font-size: 22px;
    }

    .main h2 {
        font-size: 19px;
    }

    .main p {
        font-size: 14px;
    }

    .main ul,
    .main ol {
        padding-left: 20px;
    }

    .main table {
        font-size: 12px;
    }

    .main table th,
    .main table td {
        padding: 8px 10px;
    }
}

/* ===== Homepage ===== */
.home-page .menu-btn {
    display: none;
}

.home-page .main {
    max-width: 980px;
    margin: 110px auto 48px;
    padding: 56px 64px;
}

.home-page .main h1:first-of-type {
    display: block;
    margin: 0 0 12px 0;
    border-bottom: none;
    padding-bottom: 0;
    font-size: 42px;
}

.home-page .main h2 {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
    font-size: 24px;
}

.home-page .main > p:first-of-type {
    color: var(--text-light);
    font-size: 18px;
    max-width: 680px;
}

.home-page .main figure {
    float: right;
    margin: 0 0 28px 40px;
}

.home-page .main figure figcaption {
    display: none;
}

.home-page .main img.profile-photo {
    display: block;
    width: 168px;
    aspect-ratio: 1;
    object-fit: cover;
    margin: 0;
    border-radius: 50%;
    border: 4px solid white;
}

@media (max-width: 768px) {
    .home-page .main {
        margin: 82px 20px 28px;
        max-width: none;
        padding: 30px 24px;
    }

    .home-page .main h1:first-of-type {
        font-size: 30px;
    }

    .home-page .main figure {
        float: none;
        display: block;
        margin: 0 0 22px 0;
    }

    .home-page .main img.profile-photo {
        width: 128px;
    }
}