/* =========================================================
   海角网 · 整站样式表
   生活论坛风 · 浅色背景 · 内容密度适中
   ========================================================= */

/* =========================================================
   Base · 基础变量与全局设定
   ========================================================= */
:root {
  --color-bg: #f5f6f8;
  --color-text: #2c3e50;
  --color-accent: #3b82f6;
  --color-card: #ffffff;
  --color-border: #e5e7eb;
  --color-text-light: #6b7a8d;
  --color-text-lighter: #8a97a6;
  --color-header-bg: #ffffff;
  --color-footer-bg: #2c3e50;
  --color-footer-text: #cbd5e1;
  --color-footer-heading: #f1f5f9;
  --color-hot-badge: #ef4444;
  --color-step-bg: #eff6ff;
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.08);
  --radius: 6px;
  --radius-card: 8px;
  --shell-width: 1160px;
  --header-height: 64px;
  --font-body: 16px;
  --font-h1: 28px;
  --font-h2: 22px;
  --font-h3: 18px;
  --line-height-body: 1.8;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  font-size: var(--font-body);
  line-height: var(--line-height-body);
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

a:hover {
  color: #2563eb;
  text-decoration: underline;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  line-height: 1.4;
  font-weight: 600;
  color: var(--color-text);
}

h1 {
  font-size: var(--font-h1);
}

h2 {
  font-size: var(--font-h2);
}

h3 {
  font-size: var(--font-h3);
}

p {
  margin-bottom: 0.75em;
}

/* 布局容器 */
.layout-shell {
  max-width: var(--shell-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 视觉隐藏（仅用于屏幕阅读器） */
.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 · 全站骨架：页头、页脚、面包屑、页面标题
   ========================================================= */

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

.header-inner {
  max-width: var(--shell-width);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

.brand-slogan {
  font-size: 12px;
  color: var(--color-text-lighter);
  white-space: nowrap;
}

/* 主导航 */
.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  gap: 4px;
}

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

.nav-list li a:hover {
  background-color: #eff6ff;
  color: var(--color-accent);
  text-decoration: none;
}

.nav-list li a.is-current {
  background-color: var(--color-accent);
  color: #ffffff;
}

/* 汉堡按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  cursor: pointer;
  margin-left: auto;
}

.nav-toggle-line {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 1px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

/* 主内容区 */
.site-main {
  flex: 1 0 auto;
}

/* 内页主容器 */
.inner-main {
  padding: 0 0 48px;
}

/* 面包屑 */
.breadcrumb {
  max-width: var(--shell-width);
  margin: 0 auto;
  padding: 16px 24px 0;
  font-size: 14px;
  color: var(--color-text-light);
  display: flex;
  align-items: center;
  gap: 8px;
}

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

.breadcrumb a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

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

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

/* 页面标题区 */
.page-header {
  max-width: var(--shell-width);
  margin: 0 auto;
  padding: 24px 24px 20px;
}

.page-title {
  font-size: var(--font-h1);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

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

/* 页脚 */
.site-footer {
  background-color: var(--color-footer-bg);
  color: var(--color-footer-text);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--shell-width);
  margin: 0 auto;
  padding: 40px 24px 24px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
}

.footer-col h3 {
  color: var(--color-footer-heading);
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
}

.footer-col p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-footer-text);
}

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul li a {
  color: var(--color-footer-text);
  font-size: 14px;
}

.footer-col ul li a:hover {
  color: #ffffff;
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 16px 24px;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
}

/* =========================================================
   Components · 通用组件
   ========================================================= */

/* 区块标题 */
.section-title {
  font-size: var(--font-h2);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 20px;
  position: relative;
}

/* 更多链接 */
.more-link {
  display: inline-block;
  font-size: 14px;
  color: var(--color-accent);
  padding: 4px 0;
}

.more-link:hover {
  text-decoration: underline;
}

/* 主按钮 */
.btn-primary {
  display: inline-block;
  padding: 10px 24px;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 15px;
  border-radius: var(--radius);
  transition: background-color 0.2s ease, transform 0.15s ease;
}

.btn-primary:hover {
  background-color: #2563eb;
  color: #ffffff;
  text-decoration: none;
  transform: translateY(-1px);
}

/* 图片与图注 */
figure {
  margin: 0;
}

figcaption {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.6;
  padding-top: 8px;
}

.content-media img,
.topic-media img,
.hot-media img,
.sidebar-figure img,
.aside-media img,
.aside-figure img,
.topic-figure img,
.gallery-track img {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-card);
}

.content-media-primary {
  margin-bottom: 20px;
}

.content-media-inline {
  margin-bottom: 20px;
}

/* 话题条目内的元信息 */
.topic-meta {
  font-size: 13px;
  color: var(--color-text-lighter);
}

/* 内页双栏布局 */
.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 32px;
  align-items: start;
}

.page-layout > section,
.page-layout > article {
  min-width: 0;
}

.page-layout > aside {
  min-width: 0;
}

/* 侧栏在左侧的布局 */
.sidebar-left {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.sidebar-left .category-tree {
  grid-column: 1;
}

.sidebar-left .board-list {
  grid-column: 2;
  min-width: 0;
}

/* 通用侧栏卡片 */
.aside-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-card);
}

.aside-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

/* 侧栏链接列表 */
.aside-link-list li {
  margin-bottom: 10px;
}

.aside-link-list li a {
  font-size: 14px;
  color: var(--color-text);
}

.aside-link-list li a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

/* =========================================================
   Pages · 首页
   ========================================================= */

.home-main {
  padding-bottom: 0;
}

/* 首屏社区概览 */
.overview {
  padding-top: 28px;
  padding-bottom: 28px;
}

.overview-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.overview-col {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
}

.overview-col .section-title {
  font-size: 18px;
  margin-bottom: 14px;
}

.overview-col ul {
  flex: 1;
}

.overview-col ul li {
  margin-bottom: 10px;
  line-height: 1.6;
}

.overview-col ul li a {
  color: var(--color-text);
  font-size: 14px;
}

.overview-col ul li a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.announce-list li {
  position: relative;
  padding-left: 12px;
}

.announce-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

.hot-topic-list li {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 10px;
}

.hot-topic-list li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.hot-topic-list .topic-meta {
  display: block;
  margin-top: 2px;
}

.board-entry-list li a {
  display: flex;
  align-items: center;
  gap: 8px;
}

.board-entry-list li a::before {
  content: "→";
  color: var(--color-accent);
  font-size: 13px;
}

.overview-col .more-link {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
}

/* 版块分类展示 */
.board-category {
  padding-top: 36px;
  padding-bottom: 36px;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.board-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  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-card h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.board-card p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.board-card a {
  font-size: 14px;
  font-weight: 500;
}

/* 最新话题流 */
.latest {
  padding-top: 36px;
  padding-bottom: 36px;
}

.topic-flow {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.topic-group h3 {
  font-size: 16px;
  color: var(--color-text-light);
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.topic-list li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--color-border);
}

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

.topic-list li a {
  color: var(--color-text);
  font-size: 15px;
  flex: 0 0 auto;
}

.topic-list li a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.topic-board {
  font-size: 12px;
  color: var(--color-accent);
  background-color: #eff6ff;
  border-radius: 4px;
  padding: 2px 8px;
  flex-shrink: 0;
}

.topic-excerpt {
  font-size: 13px;
  color: var(--color-text-light);
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-bottom: 0;
}

/* 精华内容推荐 */
.recommend {
  padding-top: 36px;
  padding-bottom: 36px;
}

.recommend-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.recommend-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.2s ease;
}

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

.recommend-card h3 {
  font-size: 16px;
  margin-bottom: 10px;
}

.recommend-card p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 14px;
}

.recommend-card a {
  font-size: 14px;
}

/* 新手指南 */
.guide {
  padding-top: 36px;
  padding-bottom: 36px;
}

.guide-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.step {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 24px;
  box-shadow: var(--shadow-card);
  position: relative;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background-color: var(--color-step-bg);
  color: var(--color-accent);
  font-size: 16px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 12px;
}

.step h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.step p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.step a {
  font-size: 14px;
}

/* 反馈说明 */
.feedback {
  padding-top: 36px;
  padding-bottom: 48px;
}

.feedback p {
  font-size: 15px;
  color: var(--color-text-light);
  max-width: 640px;
  margin-bottom: 20px;
}

/* =========================================================
   Pages · 版块导航 boards.html
   ========================================================= */

.category-tree {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-card);
}

.category-tree h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.tree-root > li {
  margin-bottom: 18px;
}

.tree-category {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}

.tree-children li {
  margin-bottom: 6px;
  padding-left: 14px;
  position: relative;
}

.tree-children li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--color-accent);
  font-weight: 700;
}

.tree-children li a {
  font-size: 14px;
  color: var(--color-text-light);
}

.tree-children li a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.tree-tip {
  font-size: 13px;
  color: var(--color-text-lighter);
  border-top: 1px solid var(--color-border);
  padding-top: 12px;
  margin-top: 8px;
}

.tree-tip a {
  font-size: 13px;
}

.board-list h2 {
  margin-bottom: 18px;
}

.section-intro {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.board-category-block {
  margin-bottom: 28px;
}

.board-category-block h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.board-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.board-card-head {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}

.board-desc {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 10px;
}

.board-rule {
  font-size: 13px;
  color: var(--color-text-lighter);
  margin-bottom: 12px;
  line-height: 1.6;
}

.board-link {
  font-size: 14px;
  font-weight: 500;
}

.board-rule-summary {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  margin-top: 12px;
  box-shadow: var(--shadow-card);
}

.board-rule-summary h3 {
  font-size: 16px;
  margin-bottom: 10px;
}

.board-rule-summary p {
  font-size: 14px;
  color: var(--color-text-light);
}

.board-rule-summary ul {
  margin: 12px 0;
}

.board-rule-summary ul li {
  font-size: 14px;
  color: var(--color-text);
  padding: 4px 0;
  padding-left: 16px;
  position: relative;
}

.board-rule-summary ul li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--color-accent);
  font-weight: 700;
}

.board-rule-summary p a {
  font-size: 14px;
  margin-right: 16px;
}

/* =========================================================
   Pages · 最新话题 topics.html
   ========================================================= */

.topic-list {
  min-width: 0;
}

.topic-group {
  margin-bottom: 28px;
}

.topic-group-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.topic-items {
  display: flex;
  flex-direction: column;
}

.topic-item {
  padding: 14px 0;
  border-bottom: 1px dashed var(--color-border);
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 12px;
}

.topic-item:last-child {
  border-bottom: none;
}

.topic-item .topic-board {
  order: 1;
}

.topic-item .topic-link {
  order: 2;
  font-size: 15px;
  color: var(--color-text);
  font-weight: 500;
}

.topic-item .topic-link:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.topic-item .topic-summary {
  order: 3;
  width: 100%;
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 0;
}

.topic-media {
  margin: 32px 0;
}

.related-entry {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-card);
  margin-top: 8px;
}

.related-entry p {
  font-size: 14px;
  color: var(--color-text-light);
}

.related-entry p a {
  margin-right: 16px;
  font-size: 14px;
}

/* =========================================================
   Pages · 热门精华 hot.html
   ========================================================= */

.hot-list {
  min-width: 0;
}

.hot-list h2 {
  margin-bottom: 18px;
}

.hot-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--color-border);
}

.hot-item:last-child {
  border-bottom: none;
}

.hot-rank {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-text-lighter);
  line-height: 1.2;
  text-align: center;
}

.hot-item:nth-child(2) .hot-rank {
  color: #f59e0b;
}

.hot-item:nth-child(3) .hot-rank {
  color: #94a3b8;
}

.hot-item:nth-child(4) .hot-rank {
  color: #b45309;
}

.hot-content {
  min-width: 0;
}

.hot-content h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.hot-content h3 a {
  color: var(--color-text);
}

.hot-content h3 a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.hot-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}

.badge-hot {
  display: inline-block;
  background-color: #fef2f2;
  color: var(--color-hot-badge);
  font-size: 12px;
  font-weight: 600;
  border-radius: 4px;
  padding: 1px 8px;
}

.hot-summary {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 8px;
}

.hot-content > a {
  font-size: 13px;
}

.hot-media {
  margin-top: 28px;
}

.hot-boards {
  min-width: 0;
}

.hot-boards h2 {
  font-size: 17px;
  margin-bottom: 14px;
}

.board-mini-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 16px;
  margin-bottom: 12px;
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.2s ease;
}

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

.board-mini-card h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.board-mini-card h3 a {
  color: var(--color-text);
}

.board-mini-card h3 a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.board-mini-card p {
  font-size: 13px;
  color: var(--color-text-light);
  margin-bottom: 0;
}

.sidebar-figure {
  margin-top: 20px;
}

.sidebar-more {
  margin-top: 16px;
}

.sidebar-more a {
  font-size: 14px;
}

/* =========================================================
   Pages · 社区公告 notices.html
   ========================================================= */

.notice-timeline {
  min-width: 0;
}

.notice-item {
  position: relative;
  padding-left: 28px;
  padding-bottom: 28px;
  border-left: 2px solid var(--color-border);
  margin-left: 8px;
}

.notice-item:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.notice-marker {
  position: absolute;
  left: -7px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 2px solid var(--color-card);
  box-shadow: 0 0 0 2px var(--color-accent);
}

.notice-content {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 18px 20px;
  box-shadow: var(--shadow-card);
}

.notice-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.notice-summary {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 8px;
}

.notice-body {
  font-size: 14px;
  color: var(--color-text);
  margin-bottom: 10px;
  line-height: 1.7;
}

.notice-link {
  font-size: 13px;
}

.related-help {
  min-width: 0;
}

.related-help .aside-card:last-child {
  margin-bottom: 0;
}

.aside-media {
  margin-top: 20px;
}

.related-links {
  max-width: var(--shell-width);
  margin: 28px auto 0;
  padding: 0 24px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 16px;
}

.related-links-label {
  font-size: 14px;
  color: var(--color-text-light);
}

.related-links-item {
  font-size: 14px;
}

/* =========================================================
   Pages · 帮助反馈 help.html
   ========================================================= */

.faq {
  min-width: 0;
}

.faq h2 {
  margin-bottom: 18px;
}

.faq-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  margin-bottom: 12px;
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.faq-item summary {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 44px;
  transition: background-color 0.2s ease;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  font-weight: 400;
  color: var(--color-accent);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item summary:hover {
  background-color: #f8fafc;
}

.faq-answer {
  padding: 0 20px 18px;
}

.faq-answer p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 10px;
}

.faq-answer p:last-child {
  margin-bottom: 0;
}

.feedback-info {
  min-width: 0;
}

.feedback-info .aside-card p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.aside-figure {
  margin: 16px 0;
}

.feedback-info .aside-card > p:last-of-type {
  margin-bottom: 8px;
}

.feedback-info .aside-card > p a {
  font-size: 14px;
  margin-right: 12px;
}

/* =========================================================
   Pages · 话题详情 topic-detail.html
   ========================================================= */

.topic-content {
  min-width: 0;
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 32px;
  box-shadow: var(--shadow-card);
}

.topic-lead {
  font-size: 17px;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
}

.topic-content > p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
}

.topic-figure {
  margin: 24px 0;
}

.topic-gallery {
  margin: 32px 0 24px;
}

.gallery-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.gallery-prev,
.gallery-next {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-border);
  background-color: var(--color-card);
  border-radius: var(--radius);
  font-size: 18px;
  color: var(--color-text);
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.gallery-prev:hover,
.gallery-next:hover {
  background-color: #eff6ff;
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.gallery-track {
  flex: 1;
  min-width: 0;
}

.gallery-track img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  border-radius: var(--radius-card);
}

.related-topics {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.related-topics h2 {
  font-size: 17px;
  margin-bottom: 14px;
}

.related-list li {
  padding: 10px 0;
  border-bottom: 1px dashed var(--color-border);
  display: flex;
  align-items: baseline;
  gap: 10px;
}

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

.related-list li a {
  font-size: 15px;
  color: var(--color-text);
}

.related-list li a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.related-list .topic-meta {
  font-size: 12px;
  flex-shrink: 0;
}

.board-info {
  min-width: 0;
}

.board-info .board-card {
  box-shadow: var(--shadow-card);
  margin-bottom: 20px;
}

.board-info .board-card h2 {
  font-size: 18px;
  margin-bottom: 10px;
}

.board-info .board-card h3 {
  font-size: 15px;
  margin-top: 14px;
  margin-bottom: 8px;
}

.board-rules li {
  font-size: 13px;
  color: var(--color-text-light);
  padding: 4px 0;
  padding-left: 16px;
  position: relative;
  line-height: 1.6;
}

.board-rules li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--color-accent);
  font-weight: 700;
}

.board-enter {
  display: inline-block;
  margin-top: 14px;
  font-size: 14px;
  font-weight: 500;
}

.board-links {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-card);
}

.board-links h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.board-links ul li {
  margin-bottom: 10px;
}

.board-links ul li a {
  font-size: 14px;
  color: var(--color-text);
}

.board-links ul li a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

/* =========================================================
   Pages · 404 页面
   ========================================================= */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  flex: 1;
}

.error-panel {
  text-align: center;
  max-width: 560px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 48px 40px;
  box-shadow: var(--shadow-card);
}

.error-panel h1 {
  font-size: 32px;
  margin-bottom: 8px;
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.1;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 16px;
  color: var(--color-text);
  margin-bottom: 8px;
}

.error-guide {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.btn-back-home {
  display: inline-block;
  padding: 10px 28px;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 15px;
  border-radius: var(--radius);
  transition: background-color 0.2s ease;
}

.btn-back-home:hover {
  background-color: #2563eb;
  color: #ffffff;
  text-decoration: none;
}

/* =========================================================
   Responsive · 响应式断点
   ========================================================= */

/* 平板：1024px */
@media (max-width: 1024px) {
  .overview-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .overview-col:last-child {
    grid-column: 1 / -1;
  }

  .category-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .recommend-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .guide-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .guide-steps .step:last-child {
    grid-column: 1 / -1;
    max-width: 420px;
  }

  .page-layout {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 24px;
  }

  .sidebar-left {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 24px;
  }

  .board-cards {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .footer-col.about {
    grid-column: 1 / -1;
  }
}

/* 手机：768px */
@media (max-width: 768px) {
  :root {
    --font-body: 15px;
    --font-h1: 24px;
    --font-h2: 20px;
    --font-h3: 17px;
  }

  .layout-shell {
    padding-left: 16px;
    padding-right: 16px;
  }

  .header-inner {
    padding: 0 16px;
  }

  /* 汉堡菜单 */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--color-card);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.08);
    margin-left: 0;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    padding: 8px 16px 16px;
    gap: 2px;
  }

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

  .nav-list li a {
    padding: 12px 16px;
    font-size: 16px;
    border-radius: var(--radius);
  }

  /* 面包屑 */
  .breadcrumb {
    padding: 12px 16px 0;
    font-size: 13px;
  }

  /* 页面标题 */
  .page-header {
    padding: 16px 16px 14px;
  }

  .page-title {
    font-size: var(--font-h1);
  }

  .page-description {
    font-size: 14px;
  }

  /* 首页首屏：热门话题在前 */
  .overview-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .overview-col {
    grid-column: 1 / -1;
  }

  /* 移动端顺序：hot → announcement → boards */
  .overview-col.hot {
    order: 1;
  }

  .overview-col.announcement {
    order: 2;
  }

  .overview-col.boards {
    order: 3;
  }

  /* 首页版块卡片 */
  .category-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .board-card {
    padding: 16px;
  }

  /* 首页最新话题流 */
  .topic-list li {
    flex-wrap: wrap;
    gap: 6px 10px;
  }

  .topic-excerpt {
    width: 100%;
    white-space: normal;
    overflow: visible;
    text-overflow: clip;
  }

  /* 首页精华推荐 */
  .recommend-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  /* 首页新手指南 */
  .guide-steps {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .guide-steps .step:last-child {
    grid-column: auto;
    max-width: none;
  }

  /* 内页双栏：侧栏在正文之后 */
  .page-layout {
    display: flex;
    flex-direction: column;
    gap: 24px;
  }

  .page-layout > aside {
    order: 2;
    width: 100%;
  }

  .page-layout > section,
  .page-layout > article {
    order: 1;
    width: 100%;
  }

  /* 侧栏在左的布局：正文在前 */
  .sidebar-left {
    display: flex;
    flex-direction: column;
    gap: 24px;
  }

  .sidebar-left .board-list {
    order: 1;
    width: 100%;
  }

  .sidebar-left .category-tree {
    order: 2;
    width: 100%;
  }

  /* 版块卡片 */
  .board-cards {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  /* 话题详情 */
  .topic-content {
    padding: 20px 16px;
  }

  .topic-content > p {
    font-size: 15px;
    line-height: 1.75;
  }

  .gallery-controls {
    gap: 8px;
  }

  .gallery-prev,
  .gallery-next {
    width: 40px;
    height: 40px;
  }

  /* 热门列表 */
  .hot-item {
    grid-template-columns: 32px minmax(0, 1fr);
    gap: 12px;
    padding: 14px 0;
  }

  .hot-rank {
    font-size: 20px;
  }

  /* 公告时间线 */
  .notice-item {
    padding-left: 20px;
    margin-left: 4px;
  }

  /* FAQ */
  .faq-item summary {
    padding: 14px 16px;
    padding-right: 40px;
    font-size: 15px;
  }

  .faq-answer {
    padding: 0 16px 14px;
  }

  /* 页脚 */
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 16px 20px;
  }

  .footer-col.about {
    grid-column: auto;
  }

  .footer-bottom {
    padding: 14px 16px;
    font-size: 12px;
  }

  /* 404 */
  .error-main {
    padding: 48px 16px;
  }

  .error-panel {
    padding: 32px 20px;
  }

  .error-code {
    font-size: 48px;
  }
}

/* 小屏手机：390px 及以下 */
@media (max-width: 390px) {
  .brand-slogan {
    display: none;
  }

  .brand-name {
    font-size: 20px;
  }

  .header-inner {
    gap: 12px;
  }

  .overview-col {
    padding: 16px;
  }

  .topic-list li a {
    font-size: 14px;
  }

  .topic-board {
    font-size: 11px;
    padding: 1px 6px;
  }

  .hot-content h3 {
    font-size: 15px;
  }

  .hot-summary {
    font-size: 13px;
  }

  .notice-content {
    padding: 14px 16px;
  }

  .notice-title {
    font-size: 15px;
  }

  .gallery-prev,
  .gallery-next {
    width: 36px;
    height: 36px;
    font-size: 16px;
  }
}