/* ==========================================================================
   base — 基础样式
   ========================================================================== */

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

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

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #2b2b2b;
  background-color: #f7f6f2;
}

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

a {
  color: #2e6fd8;
  text-decoration: none;
}

a:hover {
  color: #f28c2b;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0 0 0.5em;
  font-weight: 600;
  line-height: 1.4;
  color: #2b2b2b;
}

p {
  margin: 0 0 1em;
}

figure {
  margin: 0;
}

/* ==========================================================================
   layout — 全站布局骨架
   ========================================================================== */

.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: #f7f6f2;
}

.site-header {
  background-color: #fff;
  border-bottom: 1px solid #e3e0d8;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  color: #2b2b2b;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand:hover {
  color: #f28c2b;
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
}

.nav-toggle-line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: #2b2b2b;
  border-radius: 2px;
}

.nav-list {
  display: flex;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-list li {
  margin: 0;
}

.nav-list a {
  display: block;
  padding: 10px 14px;
  font-size: 15px;
  color: #2b2b2b;
  border-radius: 4px;
  transition: color 0.2s ease, background-color 0.2s ease;
}

.nav-list a:hover {
  color: #f28c2b;
  background-color: #f7f6f2;
}

.nav-list a.is-current {
  color: #f28c2b;
  font-weight: 600;
  background-color: rgba(242, 140, 43, 0.08);
}

.site-main {
  flex: 1;
}

.inner-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px 48px;
}

.breadcrumb {
  font-size: 14px;
  color: #888;
  margin-bottom: 16px;
  line-height: 1.5;
}

.breadcrumb a {
  color: #2e6fd8;
}

.breadcrumb a:hover {
  color: #f28c2b;
}

.breadcrumb-sep {
  margin: 0 6px;
  color: #aaa;
}

.breadcrumb-current {
  color: #666;
}

.page-header {
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 1px solid #e3e0d8;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 10px;
  color: #2b2b2b;
}

.page-description {
  font-size: 16px;
  color: #666;
  max-width: 760px;
  margin: 0;
}

.site-footer {
  background-color: #fff;
  border-top: 1px solid #e3e0d8;
}

.footer-columns {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.footer-col h3 {
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 12px;
  color: #2b2b2b;
}

.footer-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

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

.footer-col a {
  font-size: 14px;
  color: #666;
}

.footer-col a:hover {
  color: #f28c2b;
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 20px 24px;
  border-top: 1px solid #e3e0d8;
}

.footer-bottom p {
  font-size: 13px;
  color: #999;
  margin: 0;
  line-height: 1.6;
}

/* ==========================================================================
   components — 通用组件
   ========================================================================== */

/* 按钮 */
.btn-primary {
  display: inline-block;
  padding: 10px 24px;
  background-color: #f28c2b;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: background-color 0.2s ease;
  min-height: 44px;
  line-height: 1.5;
}

.btn-primary:hover {
  background-color: #e07a1a;
  color: #fff;
}

.btn-secondary {
  display: inline-block;
  padding: 10px 24px;
  background-color: #fff;
  color: #f28c2b;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid #f28c2b;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease;
  min-height: 44px;
  line-height: 1.5;
}

.btn-secondary:hover {
  background-color: #f28c2b;
  color: #fff;
}

/* 版块标签 */
.board-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 4px;
  font-size: 13px;
  font-weight: 500;
  line-height: 1.5;
  vertical-align: middle;
}

.board-baoliao,
.board-gossip {
  background-color: #fdecea;
  color: #e85d4f;
}

.board-campus {
  background-color: #e8f5ec;
  color: #3ba55c;
}

.board-data {
  background-color: #f1ebfe;
  color: #8b5cf6;
}

.board-guide {
  background-color: #e6f6f5;
  color: #0ea5a0;
}

/* 话题状态 */
.topic-status {
  font-size: 13px;
  color: #999;
  white-space: nowrap;
}

/* 标签 */
.tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 4px;
  font-size: 13px;
  background-color: #f0eee8;
  color: #666;
  margin-right: 6px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

/* FAQ 折叠面板 */
.faq-item {
  border: 1px solid #e3e0d8;
  border-radius: 6px;
  margin-bottom: 10px;
  background-color: #fff;
}

.faq-item summary {
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  color: #2b2b2b;
  list-style: none;
  position: relative;
  padding-right: 40px;
}

.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: #f28c2b;
  font-weight: 400;
}

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

.faq-item summary:hover {
  color: #f28c2b;
}

.faq-item p {
  padding: 0 18px 14px;
  margin: 0;
  font-size: 15px;
  color: #555;
  line-height: 1.7;
}

.faq-answer {
  padding: 0 18px 14px;
}

.faq-answer p {
  padding: 0;
}

/* 步骤列表 */
.step-list {
  counter-reset: step;
  margin: 0;
  padding: 0;
  list-style: none;
}

.step-list li {
  position: relative;
  padding-left: 40px;
  margin-bottom: 16px;
}

.step-list li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0;
  top: 2px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: #f28c2b;
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  text-align: center;
  line-height: 28px;
}

.step-list h3 {
  font-size: 16px;
  margin: 0 0 4px;
  color: #2b2b2b;
}

.step-list p {
  font-size: 15px;
  color: #666;
  margin: 0;
  line-height: 1.6;
}

/* 内容区块 */
.content-section {
  margin-bottom: 40px;
}

.content-section h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid #f28c2b;
  display: inline-block;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  color: #2b2b2b;
}

.section-lead {
  font-size: 15px;
  color: #555;
  margin-bottom: 16px;
}

/* 侧栏布局 */
.layout-shell {
  display: grid;
  gap: 32px;
}

.layout-shell.sidebar-left {
  grid-template-columns: 280px 1fr;
  align-items: start;
}

.layout-shell.sidebar-left .campus-aside,
.layout-shell.sidebar-left .help-sidebar,
.layout-shell.sidebar-left .sidebar.sidebar-left-col {
  grid-column: 1;
}

.layout-shell.sidebar-left .campus-main,
.layout-shell.sidebar-left .help-content,
.layout-shell.sidebar-left .main-col {
  grid-column: 2;
}

/* 页面布局带侧栏 */
.page-layout.sidebar-left {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 32px;
  align-items: start;
}

.page-layout.sidebar-left .page-sidebar,
.page-layout.sidebar-left .topic-tree {
  grid-column: 1;
}

.page-layout.sidebar-left .learning-path,
.page-layout.sidebar-left .inner-main {
  grid-column: 2;
}

/* 锚点目录 */
.anchor-nav {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 6px;
  padding: 20px;
  position: sticky;
  top: 20px;
}

.anchor-nav h2 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid #e3e0d8;
}

.anchor-nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.anchor-nav li {
  margin-bottom: 4px;
}

.anchor-nav a {
  display: block;
  padding: 6px 10px;
  font-size: 14px;
  color: #555;
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.anchor-nav a:hover {
  background-color: #f7f6f2;
  color: #f28c2b;
}

/* 图片容器 */
.data-figure,
.board-figure,
.step-figure,
.about-figure,
.help-sidebar-img,
.content-media,
.rule-entry-img,
.hero-figure {
  border-radius: 6px;
  overflow: hidden;
  background-color: #f0eee8;
}

.data-figure img,
.board-figure img,
.step-figure img,
.about-figure img,
.help-sidebar-img img,
.content-media img,
.rule-entry-img img,
.hero-figure img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

figcaption {
  padding: 8px 12px;
  font-size: 13px;
  color: #888;
  background-color: #fff;
  border-top: 1px solid #e3e0d8;
  line-height: 1.5;
}

/* ==========================================================================
   pages — 首页
   ========================================================================== */

.home-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px 48px;
}

/* 双通道 hero */
.hero-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  padding: 40px 0 36px;
  align-items: center;
}

.hero-intro h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
  color: #2b2b2b;
}

.hero-slogan {
  font-size: 17px;
  font-weight: 600;
  color: #f28c2b;
  margin-bottom: 12px;
}

.hero-text {
  font-size: 15px;
  color: #555;
  margin-bottom: 20px;
  line-height: 1.7;
}

.hero-quick-links {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
}

.quick-title {
  font-size: 15px;
  font-weight: 600;
  color: #2b2b2b;
  margin-bottom: 12px;
}

.hero-quick-links a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: #2e6fd8;
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.hero-quick-links a:hover {
  background-color: #f7f6f2;
  color: #f28c2b;
}

.hero-figure {
  grid-column: 1 / -1;
  margin-top: 8px;
}

.hero-figure img {
  width: 100%;
  height: auto;
  max-height: 320px;
  object-fit: cover;
}

/* 数据工具横条 */
.data-tool-strip {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 20px;
  align-items: center;
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 24px 28px;
  margin-bottom: 40px;
}

.data-tool-icon {
  width: 52px;
  height: 52px;
  border-radius: 8px;
  background-color: #f1ebfe;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: #8b5cf6;
}

.data-tool-desc h2 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 4px;
}

.data-tool-desc p {
  font-size: 14px;
  color: #666;
  margin: 0;
  line-height: 1.6;
}

/* 版块市集 */
.boards-market {
  margin-bottom: 40px;
}

.boards-market h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 20px;
  color: #2b2b2b;
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.board-card {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
}

.board-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.board-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.board-card h3 {
  font-size: 17px;
  font-weight: 600;
  padding: 14px 16px 4px;
  margin: 0;
  color: #2b2b2b;
}

.board-card h3 a {
  color: inherit;
}

.board-card > p {
  font-size: 14px;
  color: #666;
  padding: 0 16px;
  margin: 0 0 8px;
  line-height: 1.6;
}

.board-card .tag-list {
  padding: 0 16px;
  margin-top: 0;
}

.board-link {
  display: block;
  padding: 12px 16px;
  font-size: 14px;
  color: #2e6fd8;
  border-top: 1px solid #f0eee8;
  margin-top: auto;
}

.board-link:hover {
  color: #f28c2b;
}

/* 首页主内容 + 侧栏 */
.home-columns {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
  margin-bottom: 40px;
}

.recent-topics h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  color: #2b2b2b;
}

.topic-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-item {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 6px;
  padding: 16px 20px;
  margin-bottom: 12px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.topic-item:hover {
  border-color: #f28c2b;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.topic-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 6px;
  line-height: 1.5;
}

.topic-item h3 a {
  color: #2b2b2b;
}

.topic-item h3 a:hover {
  color: #f28c2b;
}

.topic-item .board-tag {
  margin-right: 8px;
}

.topic-excerpt {
  font-size: 14px;
  color: #888;
  margin: 6px 0 0;
  line-height: 1.6;
}

.topic-item .topic-status {
  font-size: 13px;
  color: #bbb;
}

/* 首页侧栏 */
.sidebar-home {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.notice-box,
.rules-summary {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
}

.notice-box h2,
.rules-summary h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 14px;
  color: #2b2b2b;
}

.notice-box ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.notice-box li {
  margin-bottom: 10px;
  padding-left: 14px;
  position: relative;
}

.notice-box li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: #f28c2b;
}

.notice-box a {
  font-size: 14px;
  color: #555;
  line-height: 1.5;
}

.notice-box a:hover {
  color: #f28c2b;
}

.rules-summary p {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 10px;
}

.rules-summary > a {
  font-size: 14px;
  font-weight: 500;
  display: inline-block;
  margin-top: 4px;
}

/* 新手引导条 */
.guide-entry-strip {
  background-color: #e6f6f5;
  border: 1px solid #b8e2df;
  border-radius: 8px;
  padding: 24px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.guide-entry-text h2 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 4px;
  color: #0ea5a0;
}

.guide-entry-text p {
  font-size: 14px;
  color: #555;
  margin: 0;
  line-height: 1.6;
}

/* ==========================================================================
   pages — 吃瓜头条 (baoliao)
   ========================================================================== */

.page-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
  align-items: start;
}

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

.topic-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.topic-tag {
  display: inline-block;
  padding: 6px 16px;
  font-size: 14px;
  color: #555;
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 20px;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  min-height: 36px;
  line-height: 1.5;
}

.topic-tag:hover {
  border-color: #f28c2b;
  color: #f28c2b;
}

.topic-tag.is-active {
  background-color: #f28c2b;
  border-color: #f28c2b;
  color: #fff;
}

.topic-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-list .topic-item {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 6px;
  padding: 18px 20px;
  margin-bottom: 12px;
  transition: border-color 0.2s ease;
}

.topic-list .topic-item:hover {
  border-color: #f28c2b;
}

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

.topic-title {
  font-size: 17px;
  font-weight: 600;
  margin: 0 0 6px;
  line-height: 1.5;
}

.topic-title a {
  color: #2b2b2b;
}

.topic-title a:hover {
  color: #f28c2b;
}

/* 吃瓜侧栏 */
.aside-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.aside-card {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
}

.aside-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid #f0eee8;
  color: #2b2b2b;
}

.aside-card p {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 0;
}

.aside-card ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.aside-card li {
  font-size: 14px;
  color: #666;
  padding-left: 14px;
  position: relative;
  margin-bottom: 8px;
  line-height: 1.6;
}

.aside-card li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: #f28c2b;
}

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

/* ==========================================================================
   pages — 校园赛区 (campus)
   ========================================================================== */

.campus-aside {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.aside-block {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
}

.aside-block h2 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid #f0eee8;
  color: #2b2b2b;
}

.team-list,
.exp-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.team-item,
.exp-list li {
  padding: 10px 0;
  border-bottom: 1px solid #f7f6f2;
}

.team-item:last-child,
.exp-list li:last-child {
  border-bottom: none;
}

.team-item a,
.exp-list a {
  display: block;
  font-size: 14px;
  color: #2b2b2b;
  margin-bottom: 4px;
  line-height: 1.5;
}

.team-item a:hover,
.exp-list a:hover {
  color: #f28c2b;
}

.item-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
  background-color: #f0eee8;
  color: #666;
  line-height: 1.5;
}

.campus-main {
  min-width: 0;
}

.exp-card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.exp-card {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 18px 20px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.exp-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.exp-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 8px;
  line-height: 1.5;
}

.exp-card h3 a {
  color: #2b2b2b;
}

.exp-card h3 a:hover {
  color: #f28c2b;
}

.exp-card .item-tag {
  margin-bottom: 8px;
}

.exp-card p {
  font-size: 14px;
  color: #666;
  margin: 8px 0 0;
  line-height: 1.6;
}

/* 规则入口 */
.rule-entry {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 24px;
  margin-bottom: 32px;
}

.rule-entry-content {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 24px;
  align-items: center;
}

.rule-entry-img {
  width: 100%;
  height: 140px;
  object-fit: cover;
}

.rule-entry-text p {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 10px;
}

.rule-entry-text a {
  font-size: 14px;
  font-weight: 500;
}

/* 相关链接 */
.related-links {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
}

.related-links p {
  font-size: 14px;
  color: #666;
  margin: 0;
}

.related-links a {
  font-size: 14px;
  font-weight: 500;
  margin-right: 16px;
}

/* ==========================================================================
   pages — 大赛数据 (data)
   ========================================================================== */

.page-sidebar {
  position: sticky;
  top: 20px;
}

.content-section ol.step-list {
  margin-bottom: 16px;
}

.content-section ol.step-list li {
  padding-left: 44px;
}

.content-section ol.step-list li::before {
  background-color: #8b5cf6;
}

.data-figure {
  margin: 20px 0;
}

.data-figure img {
  width: 100%;
  height: auto;
  max-height: 300px;
  object-fit: cover;
}

.limit-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.limit-list li {
  font-size: 15px;
  color: #555;
  padding-left: 20px;
  position: relative;
  margin-bottom: 10px;
  line-height: 1.6;
}

.limit-list li::before {
  content: "!";
  position: absolute;
  left: 0;
  top: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: #f28c2b;
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  text-align: center;
  line-height: 16px;
}

/* ==========================================================================
   pages — 新手路线 (guide)
   ========================================================================== */

.topic-tree {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
  position: sticky;
  top: 20px;
}

.topic-tree h2 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid #f0eee8;
  color: #2b2b2b;
}

.topic-tree-list {
  counter-reset: tree;
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-tree-list li {
  counter-increment: tree;
  margin-bottom: 4px;
}

.topic-tree-list a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: #555;
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.topic-tree-list a::before {
  content: counter(tree);
  display: inline-block;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background-color: #e6f6f5;
  color: #0ea5a0;
  font-size: 12px;
  font-weight: 600;
  text-align: center;
  line-height: 22px;
  margin-right: 8px;
}

.topic-tree-list a:hover {
  background-color: #f7f6f2;
  color: #f28c2b;
}

.topic-tree-note {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid #f0eee8;
}

.topic-tree-note p {
  font-size: 13px;
  color: #888;
  margin: 0;
  line-height: 1.6;
}

.topic-tree-note a {
  font-size: 13px;
  display: inline-block;
  margin-top: 6px;
}

.learning-path {
  min-width: 0;
}

.learn-goal,
.prepare-condition,
.operate-steps,
.finish-check {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 24px 28px;
  margin-bottom: 24px;
}

.learn-goal h2,
.prepare-condition h2,
.operate-steps h2,
.finish-check h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
  color: #2b2b2b;
}

.learn-goal > p,
.prepare-condition > p,
.operate-steps > p,
.finish-check > p {
  font-size: 15px;
  color: #666;
  margin-bottom: 14px;
}

.learn-goal ul,
.prepare-condition ul,
.finish-check ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.learn-goal li,
.prepare-condition li,
.finish-check li {
  font-size: 15px;
  color: #555;
  padding-left: 20px;
  position: relative;
  margin-bottom: 8px;
  line-height: 1.6;
}

.learn-goal li::before,
.prepare-condition li::before,
.finish-check li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: #3ba55c;
  font-weight: 600;
}

.prepare-condition li a {
  font-size: 14px;
}

.operate-steps .step-list li {
  margin-bottom: 18px;
}

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

.step-figure img {
  width: 100%;
  height: auto;
  max-height: 280px;
  object-fit: cover;
}

.finish-check > p:last-child {
  margin-top: 14px;
}

.finish-check > p:last-child a {
  display: inline-block;
  padding: 8px 20px;
  background-color: #0ea5a0;
  color: #fff;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
}

.finish-check > p:last-child a:hover {
  background-color: #0b8f8b;
  color: #fff;
}

.featured-entry {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 24px 28px;
}

.featured-entry h2 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #2b2b2b;
}

.featured-entry > p {
  font-size: 14px;
  color: #666;
  margin-bottom: 14px;
}

.featured-entry ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.featured-entry li a {
  display: inline-block;
  padding: 8px 18px;
  border: 1px solid #e3e0d8;
  border-radius: 20px;
  font-size: 14px;
  color: #555;
  background-color: #f7f6f2;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.featured-entry li a:hover {
  border-color: #f28c2b;
  color: #f28c2b;
}

/* ==========================================================================
   pages — 发言公约 (rules)
   ========================================================================== */

.sidebar.sidebar-left-col {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 0;
  position: sticky;
  top: 20px;
}

.sidebar-inner {
  padding: 20px 24px;
}

.sidebar-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid #f0eee8;
  color: #2b2b2b;
}

.sidebar-nav {
  margin: 0;
  padding: 0;
  list-style: none;
}

.sidebar-nav li {
  margin-bottom: 4px;
}

.sidebar-nav a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: #555;
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.sidebar-nav a:hover {
  background-color: #f7f6f2;
  color: #f28c2b;
}

.sidebar-note {
  margin-top: 16px;
  padding: 14px;
  background-color: #f7f6f2;
  border-radius: 6px;
}

.sidebar-note p {
  font-size: 13px;
  color: #888;
  margin: 0;
  line-height: 1.6;
}

.sidebar-note a {
  font-size: 13px;
  display: inline-block;
  margin-top: 6px;
}

.main-col {
  min-width: 0;
}

.content-media {
  margin: 0 0 20px;
}

.content-media img {
  width: 100%;
  height: auto;
  max-height: 260px;
  object-fit: cover;
}

.rule-list {
  margin: 0 0 16px;
  padding: 0;
  list-style: none;
}

.rule-list li {
  font-size: 15px;
  color: #555;
  padding-left: 20px;
  position: relative;
  margin-bottom: 10px;
  line-height: 1.6;
}

.rule-list li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: #f28c2b;
  font-weight: 700;
}

.rule-list-forbidden li::before {
  content: "✕";
  color: #e85d4f;
}

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

.content-section > p:last-child a {
  font-weight: 500;
}

.content-section strong {
  font-weight: 600;
  color: #2b2b2b;
}

.faq-panel {
  margin-top: 16px;
}

/* ==========================================================================
   pages — 帮助中心 (help)
   ========================================================================== */

.help-sidebar {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 20px 24px;
  position: sticky;
  top: 20px;
}

.help-sidebar .sidebar-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid #f0eee8;
  color: #2b2b2b;
}

.help-category-list {
  margin: 0 0 16px;
  padding: 0;
  list-style: none;
}

.help-category-list li {
  margin-bottom: 4px;
}

.help-category-list a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: #555;
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.help-category-list a:hover {
  background-color: #f7f6f2;
  color: #f28c2b;
}

.help-sidebar-img {
  margin-top: 12px;
}

.help-sidebar-img img {
  width: 100%;
  height: auto;
  max-height: 160px;
  object-fit: cover;
}

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

.help-section {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 24px 28px;
  margin-bottom: 24px;
}

.help-section h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
  color: #2b2b2b;
}

.help-section > p {
  font-size: 15px;
  color: #666;
  margin-bottom: 16px;
}

.help-category-block {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid #f0eee8;
}

.help-category-block:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.help-category-block h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #2b2b2b;
}

.help-category-block > p {
  font-size: 14px;
  color: #666;
  margin-bottom: 10px;
}

.help-item-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.help-item-list li {
  font-size: 14px;
  color: #555;
  padding-left: 16px;
  position: relative;
  margin-bottom: 6px;
  line-height: 1.6;
}

.help-item-list li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: #f28c2b;
  font-weight: 700;
}

.faq-list {
  margin-top: 8px;
}

.answer-guide-block {
  margin-top: 16px;
}

.answer-guide-block h3,
.feedback-block h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 10px;
  color: #2b2b2b;
}

.guide-steps {
  counter-reset: gs;
  margin: 0;
  padding: 0;
  list-style: none;
}

.guide-steps li {
  counter-increment: gs;
  font-size: 14px;
  color: #555;
  padding-left: 28px;
  position: relative;
  margin-bottom: 8px;
  line-height: 1.6;
}

.guide-steps li::before {
  content: counter(gs);
  position: absolute;
  left: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: #f28c2b;
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  text-align: center;
  line-height: 20px;
}

.feedback-block {
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid #f0eee8;
}

.feedback-block p {
  font-size: 14px;
  color: #666;
}

.feedback-list {
  margin: 0 0 10px;
  padding: 0;
  list-style: none;
}

.feedback-list li {
  font-size: 14px;
  color: #555;
  padding-left: 16px;
  position: relative;
  margin-bottom: 6px;
  line-height: 1.6;
}

.feedback-list li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: #f28c2b;
}

/* ==========================================================================
   pages — 关于与反馈 (about)
   ========================================================================== */

.about-section {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 28px;
  margin-bottom: 24px;
}

.about-section h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 16px;
  color: #2b2b2b;
  padding-bottom: 8px;
  border-bottom: 2px solid #f28c2b;
  display: inline-block;
}

.about-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

.about-intro p {
  font-size: 15px;
  color: #555;
  line-height: 1.7;
  margin-bottom: 12px;
}

.about-figure {
  margin-top: 4px;
}

.about-figure img {
  width: 100%;
  height: auto;
  max-height: 240px;
  object-fit: cover;
}

.about-section ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-section ul li {
  font-size: 15px;
  color: #555;
  padding-left: 20px;
  position: relative;
  margin-bottom: 10px;
  line-height: 1.6;
}

.about-section ul li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: #f28c2b;
  font-weight: 700;
}

.feedback-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: fb;
}

.feedback-steps li {
  counter-increment: fb;
  padding-left: 32px;
  position: relative;
  font-size: 15px;
  color: #555;
  margin-bottom: 10px;
  line-height: 1.6;
}

.feedback-steps li::before {
  content: counter(fb);
  position: absolute;
  left: 0;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background-color: #f28c2b;
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  text-align: center;
  line-height: 22px;
}

/* ==========================================================================
   pages — 404 页面
   ========================================================================== */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  flex: 1;
}

.error-panel {
  background-color: #fff;
  border: 1px solid #e3e0d8;
  border-radius: 8px;
  padding: 48px 40px;
  text-align: center;
  max-width: 520px;
  width: 100%;
}

.error-panel h1 {
  font-size: 48px;
  font-weight: 700;
  color: #f28c2b;
  margin-bottom: 12px;
}

.error-lead {
  font-size: 18px;
  font-weight: 600;
  color: #2b2b2b;
  margin-bottom: 10px;
}

.error-desc {
  font-size: 14px;
  color: #888;
  margin-bottom: 24px;
}

.error-back {
  display: inline-block;
  padding: 10px 28px;
  background-color: #f28c2b;
  color: #fff;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 500;
  transition: background-color 0.2s ease;
}

.error-back:hover {
  background-color: #e07a1a;
  color: #fff;
}

/* ==========================================================================
   responsive — 响应式
   ========================================================================== */

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

  .home-columns {
    grid-template-columns: 1fr 280px;
    gap: 24px;
  }

  .hero-split {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .hero-figure {
    grid-column: 1;
  }

  .data-tool-strip {
    grid-template-columns: auto 1fr;
  }

  .data-tool-strip .btn-secondary {
    grid-column: 2;
    justify-self: start;
  }

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

@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
    min-height: 56px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background-color: #fff;
    border-bottom: 1px solid #e3e0d8;
    flex-direction: column;
    padding: 8px 16px;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  }

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

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

  .nav-list a {
    display: block;
    padding: 12px 8px;
    border-bottom: 1px solid #f7f6f2;
    font-size: 15px;
  }

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

  .site-header {
    position: relative;
  }

  .inner-main {
    padding: 20px 16px 40px;
  }

  .home-main {
    padding: 0 16px 40px;
  }

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

  .hero-split {
    padding: 24px 0;
  }

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

  .data-tool-strip {
    grid-template-columns: 1fr;
    padding: 20px;
    gap: 12px;
  }

  .data-tool-icon {
    width: 44px;
    height: 44px;
    font-size: 20px;
  }

  .data-tool-strip .btn-secondary {
    grid-column: 1;
  }

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

  .home-columns {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .sidebar-home {
    order: 2;
  }

  .recent-topics {
    order: 1;
  }

  .guide-entry-strip {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

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

  .footer-bottom {
    padding: 16px 16px 24px;
  }

  /* 内页侧栏布局切换 */
  .layout-shell.sidebar-left,
  .page-layout.sidebar-left,
  .page-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .layout-shell.sidebar-left .campus-aside,
  .layout-shell.sidebar-left .help-sidebar,
  .layout-shell.sidebar-left .sidebar.sidebar-left-col,
  .page-layout.sidebar-left .page-sidebar,
  .page-layout.sidebar-left .topic-tree {
    grid-column: 1;
    order: 2;
    position: static;
  }

  .layout-shell.sidebar-left .campus-main,
  .layout-shell.sidebar-left .help-content,
  .layout-shell.sidebar-left .main-col,
  .page-layout.sidebar-left .learning-path,
  .page-layout.sidebar-left .inner-main {
    grid-column: 1;
    order: 1;
  }

  .page-layout .main-content {
    grid-column: 1;
  }

  .page-layout .aside-content {
    grid-column: 1;
  }

  .campus-aside,
  .help-sidebar,
  .sidebar.sidebar-left-col,
  .page-sidebar,
  .topic-tree {
    position: static;
  }

  .exp-card-grid {
    grid-template-columns: 1fr;
  }

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

  .rule-entry-img {
    height: 120px;
  }

  .about-intro {
    grid-template-columns: 1fr;
  }

  .content-media img {
    max-height: 200px;
  }

  .data-figure img,
  .step-figure img {
    max-height: 220px;
  }

  .hero-figure img {
    max-height: 220px;
  }

  .aside-content {
    order: 2;
  }

  .main-content {
    order: 1;
  }
}

@media (max-width: 480px) {
  .header-inner {
    padding: 0 12px;
  }

  .brand {
    font-size: 17px;
  }

  .nav-list {
    top: 52px;
    padding: 8px 12px;
  }

  .inner-main,
  .home-main {
    padding-left: 12px;
    padding-right: 12px;
  }

  .topic-item {
    padding: 14px 16px;
  }

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

  .topic-status {
    font-size: 12px;
  }

  .board-card img {
    height: 140px;
  }

  .hero-quick-links {
    padding: 16px 18px;
  }

  .data-tool-strip {
    padding: 16px;
  }

  .guide-entry-strip {
    padding: 20px;
  }

  .footer-columns {
    padding-left: 12px;
    padding-right: 12px;
  }

  .footer-bottom {
    padding-left: 12px;
    padding-right: 12px;
  }

  .about-section {
    padding: 20px;
  }

  .help-section,
  .learn-goal,
  .prepare-condition,
  .operate-steps,
  .finish-check,
  .featured-entry {
    padding: 20px;
  }

  .rule-entry {
    padding: 20px;
  }

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

/* 程序验收反馈：移动端正文优先 */
@media (max-width: 768px) {
  .site-main :is(.page-content, .main-content, .content-main) {
    order: 1;
  }

  .site-main :is(aside, .sidebar) {
    order: 2;
  }
}