/* ==========================================================================
   糖心在线观看论坛 · 全站样式
   站点根：/assets/css/site.css
   分组：base / layout / components / pages / responsive
   ========================================================================== */

/* ==========================================================================
   Base —— 变量、重置、字体、通用元素
   ========================================================================== */

:root {
  --bg-page: #f6f4ef;
  --bg-card: #ffffff;
  --bg-soft: #f1ede6;
  --text-main: #1f1e1d;
  --text-secondary: #8a817c;
  --text-light: #a89f99;
  --color-primary: #e8590c;
  --color-primary-dark: #d9480f;
  --color-primary-soft: #fce8dc;
  --color-accent: #2f6f4f;
  --color-accent-soft: #e3efe8;
  --border-color: #e8e2d9;
  --shadow-card: 0 1px 4px rgba(31, 30, 29, 0.06);
  --shadow-hover: 0 6px 18px rgba(31, 30, 29, 0.1);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --container-width: 1200px;
  --content-width: 760px;
  --sidebar-width: 260px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --header-height: 64px;
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-xxl: 48px;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-stack);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-main);
  background-color: var(--bg-page);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img,
figure {
  max-width: 100%;
}

img {
  display: block;
  height: auto;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-primary-dark);
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-main);
}

h1 {
  font-size: 28px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 17px;
}

p {
  margin-bottom: 12px;
}

p:last-child {
  margin-bottom: 0;
}

table {
  border-collapse: collapse;
  width: 100%;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ==========================================================================
   Layout —— 页头、页脚、主容器、侧栏、面包屑
   ========================================================================== */

/* ---- 页头 ---- */

.site-header {
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.brand-logo {
  flex-shrink: 0;
}

.brand-logo a {
  display: inline-flex;
  align-items: center;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-main);
}

.brand-logo a:hover {
  color: var(--color-primary);
}

.brand-name {
  letter-spacing: 0.02em;
}

.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-list a {
  display: block;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--text-main);
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-list a:hover {
  background-color: var(--bg-soft);
  color: var(--color-primary);
}

.nav-list a.is-current {
  background-color: var(--color-primary-soft);
  color: var(--color-primary-dark);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
}

.nav-toggle-icon {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--text-main);
  position: relative;
  transition: background-color 0.2s ease;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 22px;
  height: 2px;
  background-color: var(--text-main);
  transition: transform 0.2s ease;
}

.nav-toggle-icon::before {
  top: -7px;
}

.nav-toggle-icon::after {
  top: 7px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
  transform: translateY(-7px) rotate(-45deg);
}

.btn-post {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: var(--radius-md);
  white-space: nowrap;
  transition: background-color 0.2s ease, transform 0.1s ease;
}

.btn-post:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
}

.btn-post:active {
  transform: translateY(1px);
}

/* ---- 页脚 ---- */

.site-footer {
  background-color: #2a2825;
  color: #cfc9c2;
  margin-top: var(--space-xxl);
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px var(--space-lg) 24px;
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
}

.footer-brand-name {
  font-size: 18px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.footer-tagline {
  font-size: 14px;
  line-height: 1.6;
  color: #a8a29b;
  margin-bottom: 0;
}

.footer-heading {
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 12px;
}

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

.footer-col ul a {
  color: #b8b2ab;
  font-size: 14px;
}

.footer-col ul a:hover {
  color: #ffffff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 16px var(--space-lg);
  max-width: var(--container-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.footer-bottom p {
  font-size: 13px;
  color: #8f8982;
  margin-bottom: 0;
}

/* ---- 主容器 ---- */

.site-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg) var(--space-xxl);
  min-height: 60vh;
}

.home-main {
  max-width: var(--container-width);
}

.inner-main {
  max-width: var(--container-width);
}

/* ---- 面包屑 ---- */

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

.breadcrumb a {
  color: var(--text-secondary);
}

.breadcrumb a:hover {
  color: var(--color-primary);
}

.breadcrumb-sep {
  color: var(--text-light);
}

.breadcrumb-current {
  color: var(--text-main);
  font-weight: 500;
}

/* ---- 页面标题区 ---- */

.page-header {
  margin-bottom: var(--space-xl);
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
}

.page-description {
  font-size: 15px;
  color: var(--text-secondary);
  max-width: 720px;
}

/* ---- 侧栏布局 ---- */

.layout-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  gap: var(--space-xl);
  align-items: start;
}

.layout-shell.sidebar-left {
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
}

.layout-shell .sidebar {
  order: 1;
}

.layout-shell .content-area {
  order: 2;
  min-width: 0;
}

.page-layout {
  display: grid;
  gap: var(--space-xl);
  align-items: start;
}

.page-layout.sidebar-left {
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
}

.page-layout.sidebar-left .sidebar {
  order: 1;
}

.page-layout.sidebar-left .content-area {
  order: 2;
  min-width: 0;
}

.page-layout.sidebar-right {
  grid-template-columns: minmax(0, 1fr) var(--sidebar-width);
}

.page-layout.sidebar-right .main-content {
  order: 1;
  min-width: 0;
}

.page-layout.sidebar-right .sidebar-area {
  order: 2;
}

.page-layout.hot-layout {
  grid-template-columns: minmax(0, 1fr) var(--sidebar-width);
}

.page-layout.hot-layout .main-content {
  order: 1;
  min-width: 0;
}

.page-layout.hot-layout .sidebar {
  order: 2;
}

/* ---- 侧栏卡片通用 ---- */

.sidebar {
  min-width: 0;
}

.sidebar-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.sidebar-card:last-child {
  margin-bottom: 0;
}

.sidebar-title,
.sidebar-card h2,
.sidebar-card .sidebar-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--space-md);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-links li,
.sidebar-list li {
  margin-bottom: 10px;
}

.sidebar-links a,
.sidebar-list a {
  display: block;
  font-size: 14px;
  color: var(--text-main);
  padding: 4px 0;
}

.sidebar-links a:hover,
.sidebar-list a:hover {
  color: var(--color-primary);
}

/* ==========================================================================
   Components —— 按钮、卡片、列表、标签、表格、FAQ、步骤、时间线
   ========================================================================== */

/* ---- 按钮 ---- */

.btn-primary,
.btn-secondary,
.btn-back {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 600;
  padding: 10px 24px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: background-color 0.2s ease, box-shadow 0.2s ease,
    transform 0.1s ease;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
  box-shadow: var(--shadow-hover);
}

.btn-secondary {
  background-color: var(--bg-card);
  color: var(--color-primary-dark);
  border: 1px solid var(--color-primary);
}

.btn-secondary:hover {
  background-color: var(--color-primary-soft);
  color: var(--color-primary-dark);
}

.btn-back {
  background-color: var(--color-primary);
  color: #ffffff;
  padding: 10px 28px;
}

.btn-back:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
}

/* ---- 更多链接 ---- */

.more-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  margin-top: var(--space-md);
}

.more-link:hover {
  color: var(--color-primary-dark);
}

/* ---- 区块标题 ---- */

.section-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: var(--space-md);
  position: relative;
  padding-bottom: 10px;
}

.section-title::after {
  content: "";
  display: block;
  width: 36px;
  height: 3px;
  background-color: var(--color-primary);
  border-radius: 2px;
  position: absolute;
  bottom: 0;
  left: 0;
}

.section-desc {
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

/* ---- 版块卡片 ---- */

.boards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.board-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.board-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.board-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  margin-bottom: var(--space-md);
}

.board-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.board-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.board-card a {
  font-size: 14px;
  font-weight: 600;
}

/* ---- 话题列表（首页时间线） ---- */

.topic-timeline {
  position: relative;
  padding-left: 20px;
}

.topic-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background-color: var(--border-color);
}

.topic-timeline .topic-item {
  position: relative;
  padding: 12px 0 12px 16px;
}

.topic-timeline .topic-item::before {
  content: "";
  position: absolute;
  left: -18px;
  top: 20px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 2px solid var(--bg-page);
}

.topic-meta {
  display: flex;
  gap: var(--space-md);
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.topic-board {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.topic-board::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
  display: inline-block;
}

.topic-replies {
  color: var(--text-light);
}

.topic-timeline .topic-item h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.topic-timeline .topic-item h3 a {
  color: var(--text-main);
}

.topic-timeline .topic-item h3 a:hover {
  color: var(--color-primary);
}

.topic-timeline .topic-item p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ---- 首页首屏 ---- */

.hero-section {
  margin-bottom: var(--space-xxl);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: var(--space-lg);
  align-items: stretch;
  margin-bottom: var(--space-lg);
}

.hero-feature {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.hero-media {
  width: 100%;
  aspect-ratio: 16 / 8.5;
  overflow: hidden;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-content {
  padding: var(--space-lg) var(--space-xl) var(--space-xl);
}

.hero-content h1 {
  font-size: 28px;
  margin-bottom: 8px;
}

.hero-lead {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 8px;
}

.hero-text {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

.hero-side {
  display: grid;
  grid-template-rows: auto auto;
  gap: var(--space-lg);
}

.notice-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.notice-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.notice-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 8px;
}

.notice-card a {
  font-size: 14px;
  font-weight: 600;
}

.mini-hot {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.mini-hot-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.mini-hot ul li {
  padding: 8px 0;
  border-bottom: 1px solid var(--bg-soft);
}

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

.mini-hot ul a {
  font-size: 14px;
  color: var(--text-main);
  display: block;
  line-height: 1.5;
}

.mini-hot ul a:hover {
  color: var(--color-primary);
}

.mini-hot .more-link {
  margin-top: 8px;
}

.content-media-primary {
  margin-top: var(--space-md);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.content-media-primary img {
  width: 100%;
  aspect-ratio: 21 / 9;
  object-fit: cover;
}

.content-media-primary figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

/* ---- 首页指南反馈入口 ---- */

.entry-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.entry-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-xl);
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.2s ease;
}

.entry-card:hover {
  box-shadow: var(--shadow-hover);
}

.entry-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.entry-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

/* ---- 内容区块 ---- */

.content-section {
  margin-bottom: var(--space-xxl);
}

.content-section:last-child {
  margin-bottom: 0;
}

.content-section h2 {
  font-size: 22px;
  margin-bottom: 8px;
}

.content-section .section-desc {
  margin-bottom: var(--space-lg);
}

/* ---- 表格 ---- */

.table-wrap {
  overflow-x: auto;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.board-table {
  width: 100%;
  min-width: 560px;
  font-size: 14px;
}

.board-table th,
.board-table td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
  vertical-align: top;
}

.board-table th {
  background-color: var(--bg-soft);
  font-weight: 600;
  white-space: nowrap;
}

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

.board-table td {
  color: var(--text-main);
  line-height: 1.6;
}

.compare-table {
  width: 100%;
  min-width: 560px;
  font-size: 14px;
}

.compare-table th,
.compare-table td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
  vertical-align: top;
}

.compare-table th {
  background-color: var(--bg-soft);
  font-weight: 600;
}

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

.compare-table td {
  color: var(--text-main);
  line-height: 1.6;
}

/* ---- 标签 ---- */

.tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag-btn {
  display: inline-flex;
  align-items: center;
  padding: 6px 14px;
  font-size: 13px;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  background-color: var(--bg-card);
  color: var(--text-main);
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease,
    border-color 0.2s ease;
}

.tag-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
}

.tag-btn.is-active {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: #ffffff;
  font-weight: 500;
}

.tag-item {
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  font-size: 13px;
  background-color: var(--bg-soft);
  border-radius: 20px;
  color: var(--text-main);
}

.tag-groups {
  display: grid;
  gap: var(--space-lg);
}

.tag-group h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 8px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---- 步骤条（指南页） ---- */

.steps-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.step-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 15px;
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.step-item p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ---- 角色卡片 ---- */

.role-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.role-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.role-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.role-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ---- 规范列表 ---- */

.guideline-list li,
.etiquette-list li {
  position: relative;
  padding: 8px 0 8px 24px;
  font-size: 15px;
  line-height: 1.6;
  border-bottom: 1px solid var(--bg-soft);
}

.guideline-list li:last-child,
.etiquette-list li:last-child {
  border-bottom: none;
}

.guideline-list li::before,
.etiquette-list li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 18px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-primary);
}

/* ---- FAQ ---- */

.faq-list {
  display: grid;
  gap: var(--space-sm);
}

.faq-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-item summary {
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 40px;
  transition: background-color 0.2s ease;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  color: var(--color-primary);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  transform: translateY(-50%) rotate(45deg);
}

.faq-item summary:hover {
  background-color: var(--bg-soft);
}

.faq-item p {
  padding: 0 18px 16px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0;
}

/* ---- 时间线（更新日志页） ---- */

.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background-color: var(--border-color);
}

.timeline-item {
  position: relative;
  margin-bottom: var(--space-xl);
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-marker {
  position: absolute;
  left: -28px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 3px solid var(--bg-card);
  box-shadow: 0 0 0 2px var(--border-color);
}

.timeline-content {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.timeline-content h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.timeline-content p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* ---- 版本卡片 ---- */

.version-list {
  display: grid;
  gap: var(--space-lg);
}

.version-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.version-number {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: 4px;
}

.version-date {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.change-list li {
  position: relative;
  padding: 4px 0 4px 20px;
  font-size: 14px;
  line-height: 1.6;
}

.change-list li::before {
  content: "·";
  position: absolute;
  left: 6px;
  font-size: 18px;
  color: var(--color-primary);
}

/* ---- 历史导航链接 ---- */

.history-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.history-link {
  display: block;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-main);
  text-align: center;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.history-link:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-hover);
  color: var(--color-primary-dark);
}

/* ---- 相关链接列表 ---- */

.related-list li {
  margin-bottom: 10px;
}

.related-list a {
  display: block;
  font-size: 14px;
  color: var(--text-main);
  padding: 6px 0;
  border-bottom: 1px solid var(--bg-soft);
}

.related-list a:hover {
  color: var(--color-primary);
}

.related-topics {
  margin-top: var(--space-xxl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border-color);
}

.related-topics h2 {
  font-size: 18px;
  margin-bottom: var(--space-md);
}

/* ---- 图片容器 ---- */

.content-media {
  margin: var(--space-lg) 0;
}

.content-media img {
  width: 100%;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.content-media figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

.media-figure {
  margin: var(--space-lg) 0;
}

.media-figure img {
  width: 100%;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.media-figure figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

.post-figure {
  margin: var(--space-lg) 0;
}

.post-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.post-figure figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

.guide-figure {
  margin: var(--space-lg) 0;
}

.guide-figure img {
  width: 100%;
  aspect-ratio: 21 / 8;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.guide-figure figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

.updates-media {
  margin: var(--space-lg) 0;
}

.updates-media img {
  width: 100%;
  aspect-ratio: 21 / 8;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.updates-media figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

.feedback-figure {
  margin: var(--space-lg) 0;
}

.feedback-figure img {
  width: 100%;
  aspect-ratio: 21 / 8;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.feedback-figure figcaption {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 0;
  text-align: center;
}

/* ---- 反馈模块 ---- */

.module-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
  margin-bottom: var(--space-lg);
}

.module-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--space-md);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

.feedback-type-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--bg-soft);
}

.feedback-type-list li:last-child {
  border-bottom: none;
}

.type-icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  color: var(--color-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
}

.type-text {
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-main);
}

.module-block {
  margin-bottom: var(--space-xxl);
}

.module-block:last-child {
  margin-bottom: 0;
}

.module-block .module-title {
  font-size: 20px;
  border-bottom: none;
  padding-bottom: 0;
}

.module-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.process-steps .step-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  text-align: center;
  box-shadow: var(--shadow-card);
}

.process-steps .step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 10px;
}

.process-steps .step-body {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.reminder-list li {
  position: relative;
  padding: 8px 0 8px 24px;
  font-size: 14px;
  line-height: 1.6;
  border-bottom: 1px solid var(--bg-soft);
}

.reminder-list li:last-child {
  border-bottom: none;
}

.reminder-list li::before {
  content: "!";
  position: absolute;
  left: 4px;
  top: 10px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 11px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.related-links {
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border-color);
}

.related-links p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.related-links ul li {
  margin-bottom: 8px;
}

.related-links ul a {
  font-size: 14px;
  color: var(--color-primary);
}

/* ---- 话题页 ---- */

.topic-post {
  margin-bottom: var(--space-xxl);
}

.post-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-xl);
  box-shadow: var(--shadow-card);
}

.post-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.post-author {
  font-weight: 600;
  color: var(--text-main);
}

.post-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.post-content p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-main);
  margin-bottom: var(--space-md);
}

.replies-section {
  margin-bottom: var(--space-xxl);
}

.replies-section h2 {
  font-size: 20px;
  margin-bottom: var(--space-lg);
}

.reply-list {
  display: grid;
  gap: var(--space-md);
}

.reply-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.reply-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.reply-author {
  font-weight: 600;
  color: var(--text-main);
}

.reply-time {
  color: var(--text-light);
}

.reply-content {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-main);
  margin-bottom: 0;
}

/* ---- 热门话题页 ---- */

.tag-filter {
  margin-bottom: var(--space-xl);
}

.tag-filter .tag-group {
  gap: 6px;
}

.hot-topics {
  margin-bottom: var(--space-xxl);
}

.hot-topics h2 {
  font-size: 20px;
  margin-bottom: var(--space-lg);
}

.topic-rank-list {
  counter-reset: topic-rank;
  display: grid;
  gap: var(--space-md);
}

.topic-rank-list .topic-item {
  counter-increment: topic-rank;
}

.topic-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg) var(--space-lg) var(--space-lg) 64px;
  box-shadow: var(--shadow-card);
  position: relative;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: var(--shadow-hover);
}

.topic-card::before {
  content: counter(topic-rank);
  position: absolute;
  left: 16px;
  top: 20px;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  color: var(--color-primary-dark);
  font-size: 16px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.topic-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.topic-card h3 a {
  color: var(--text-main);
}

.topic-card h3 a:hover {
  color: var(--color-primary);
}

.topic-meta {
  display: flex;
  gap: var(--space-md);
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.topic-excerpt {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 8px;
  max-width: 640px;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.topic-tags .tag-item {
  font-size: 12px;
  padding: 2px 10px;
}

.related-boards li {
  margin-bottom: 8px;
}

.related-boards a {
  display: block;
  font-size: 14px;
  color: var(--text-main);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease;
}

.related-boards a:hover {
  background-color: var(--bg-soft);
  color: var(--color-primary);
}

.sidebar-note {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border-color);
}

.sidebar-note a {
  font-size: 13px;
}

/* ---- 对比页 ---- */

.source-list li {
  margin-bottom: 10px;
}

.source-list a {
  display: block;
  font-size: 14px;
  color: var(--text-main);
  padding: 6px 0;
  border-bottom: 1px solid var(--bg-soft);
}

.source-list a:hover {
  color: var(--color-primary);
}

.sidebar-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* ---- 404 ---- */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
}

.error-section {
  text-align: center;
  max-width: 480px;
  padding: var(--space-xl) 0;
}

.error-code {
  font-size: 72px;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--space-md);
}

.error-section h1 {
  font-size: 24px;
  margin-bottom: var(--space-md);
}

.error-desc {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
}

.error-help {
  margin-top: var(--space-lg);
  font-size: 14px;
  color: var(--text-secondary);
}

.error-help a {
  margin: 0 6px;
}

/* ---- 滚动出现动画（轻量增强） ---- */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.boards-section,
.hot-topics-section,
.guide-feedback-section,
.content-section {
  animation: fadeInUp 0.5s ease both;
}

.boards-section {
  animation-delay: 0.05s;
}

.hot-topics-section {
  animation-delay: 0.1s;
}

.guide-feedback-section {
  animation-delay: 0.15s;
}

/* ==========================================================================
   Pages —— 页面级专用样式（仅内部业务模块）
   ========================================================================== */

/* ---- 首页 ---- */

.site-home .boards-section {
  margin-bottom: var(--space-xxl);
}

.site-home .hot-topics-section {
  margin-bottom: var(--space-xxl);
}

.site-home .guide-feedback-section {
  margin-bottom: var(--space-xxl);
}

/* ---- 目录页 ---- */

.page-catalog .board-card-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

/* ---- 指南页 ---- */

.page-guide .content-area .related-links {
  margin-top: var(--space-xl);
}

/* ---- 反馈页 ---- */

.page-feedback .content-area {
  min-width: 0;
}

/* ==========================================================================
   Responsive —— 响应式断点（768px 主断点，390px 手机验证）
   ========================================================================== */

@media (max-width: 992px) {
  .boards-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .hero-side {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: none;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }

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

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

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

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

@media (max-width: 768px) {
  /* ---- 页头 ---- */

  .header-inner {
    padding: 0 var(--space-md);
    gap: var(--space-sm);
  }

  .site-nav {
    margin-left: auto;
  }

  .nav-toggle {
    display: block;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-sm) var(--space-md) var(--space-md);
    gap: 2px;
    box-shadow: var(--shadow-hover);
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-list a {
    padding: 12px 14px;
    font-size: 15px;
  }

  .btn-post {
    padding: 8px 14px;
    font-size: 13px;
  }

  /* ---- 布局 ---- */

  .layout-shell,
  .layout-shell.sidebar-left,
  .page-layout.sidebar-left,
  .page-layout.sidebar-right,
  .page-layout.hot-layout {
    grid-template-columns: 1fr;
  }

  .layout-shell .sidebar,
  .layout-shell.sidebar-left .sidebar,
  .page-layout.sidebar-left .sidebar,
  .page-layout.sidebar-right .sidebar-area,
  .page-layout.hot-layout .sidebar {
    order: 2;
  }

  .layout-shell .content-area,
  .layout-shell.sidebar-left .content-area,
  .page-layout.sidebar-left .content-area,
  .page-layout.sidebar-right .main-content,
  .page-layout.hot-layout .main-content {
    order: 1;
  }

  .site-main {
    padding: var(--space-lg) var(--space-md) var(--space-xl);
  }

  .breadcrumb {
    margin-bottom: var(--space-md);
  }

  .page-header {
    margin-bottom: var(--space-lg);
  }

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

  /* ---- 首页 ---- */

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

  .hero-content {
    padding: var(--space-lg);
  }

  .hero-content h1 {
    font-size: 24px;
  }

  .entry-grid {
    grid-template-columns: 1fr;
  }

  /* ---- 组件 ---- */

  .boards-grid,
  .page-catalog .board-card-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }

  .steps-list,
  .role-cards,
  .process-steps {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
  }

  .history-links {
    grid-template-columns: 1fr 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    padding: var(--space-xl) var(--space-md) var(--space-lg);
  }

  .footer-bottom {
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: var(--space-md);
  }

  .topic-card {
    padding-left: var(--space-lg);
  }

  .topic-card::before {
    position: static;
    margin-bottom: 8px;
  }
}

@media (max-width: 480px) {
  .header-inner {
    padding: 0 var(--space-sm);
  }

  .brand-name {
    font-size: 17px;
  }

  .btn-post {
    padding: 8px 10px;
    font-size: 12px;
  }

  .boards-grid,
  .page-catalog .board-card-grid {
    grid-template-columns: 1fr;
  }

  .steps-list,
  .role-cards,
  .process-steps,
  .history-links {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

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

  .section-title {
    font-size: 20px;
  }

  .page-title {
    font-size: 22px;
  }

  .post-card {
    padding: var(--space-lg);
  }

  .topic-card {
    padding: var(--space-md);
  }

  .table-wrap {
    padding: var(--space-sm);
  }

  .board-table,
  .compare-table {
    min-width: 480px;
  }

  .error-code {
    font-size: 56px;
  }

  .error-section h1 {
    font-size: 20px;
  }
}

/* ==========================================================================
   可访问性与细节
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

::selection {
  background-color: var(--color-primary-soft);
  color: var(--color-primary-dark);
}