/* ============================================================
   base — 全局基础
   ============================================================ */
:root {
  --color-bg: #f5f2ec;
  --color-text: #1a1a1a;
  --color-card: #ffffff;
  --color-accent: #c8433a;
  --color-green: #2f5d50;
  --color-border: #e3ddd3;
  --color-muted: #6b655c;
  --color-header-bg: #1a1a1a;
  --color-header-text: #f5f2ec;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Cascadia Mono", Consolas, "Liberation Mono", monospace;
  --container-width: 1200px;
  --header-height: 64px;
  --header-height-scrolled: 48px;
  --radius: 6px;
  --radius-lg: 8px;
  --gap: 24px;
  --transition: 0.2s ease;
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  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 var(--transition), border-color var(--transition);
}

a:hover {
  color: #a8342c;
  text-decoration: underline;
}

ul,
ol {
  list-style-position: inside;
}

h1,
h2,
h3,
h4 {
  line-height: 1.3;
  font-weight: 700;
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

h4 {
  font-size: 16px;
}

p {
  max-width: 72ch;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  -webkit-clip-path: inset(50%);
  clip-path: inset(50%);
}

/* ============================================================
   layout — 全站骨架
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-header-bg);
  color: var(--color-header-text);
  height: var(--header-height);
  transition: height 0.2s ease;
}

.site-header.is-scrolled {
  height: var(--header-height-scrolled);
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  color: var(--color-header-text);
  text-decoration: none;
  flex-shrink: 0;
}

.brand:hover {
  color: var(--color-header-text);
  text-decoration: none;
}

.brand-name {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.brand-slogan {
  font-size: 13px;
  color: rgba(245, 242, 236, 0.7);
  font-weight: 400;
}

.site-nav {
  display: flex;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 4px;
  align-items: center;
}

.nav-list a {
  display: block;
  padding: 8px 14px;
  color: rgba(245, 242, 236, 0.85);
  font-size: 14px;
  font-weight: 500;
  border-radius: var(--radius);
  text-decoration: none;
  transition: background-color var(--transition), color var(--transition);
}

.nav-list a:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.08);
  text-decoration: none;
}

.nav-list a.is-current {
  color: #ffffff;
  background-color: var(--color-accent);
  font-weight: 700;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 44px;
  height: 44px;
  padding: 10px;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  align-items: center;
  border-radius: var(--radius);
}

.nav-toggle:hover {
  background-color: rgba(255, 255, 255, 0.08);
}

.nav-toggle-line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-header-text);
  border-radius: 1px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.site-main {
  flex: 1;
  width: 100%;
}

.site-main.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px 48px;
}

.site-footer {
  background-color: #1a1a1a;
  color: rgba(245, 242, 236, 0.8);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 24px 48px;
  display: grid;
  grid-template-columns: repeat(3, 1fr) 1.4fr;
  gap: 32px;
}

.footer-col h4 {
  color: #ffffff;
  font-size: 15px;
  margin-bottom: 14px;
  font-weight: 700;
}

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

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

.footer-col a {
  color: rgba(245, 242, 236, 0.75);
  font-size: 14px;
  text-decoration: none;
}

.footer-col a:hover {
  color: #ffffff;
  text-decoration: underline;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(245, 242, 236, 0.65);
}

.footer-brand strong {
  display: block;
  font-size: 20px;
  color: #ffffff;
  margin-bottom: 8px;
  font-weight: 800;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  margin-bottom: 20px;
  color: var(--color-muted);
  flex-wrap: wrap;
}

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

.breadcrumb a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

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

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 600;
}

/* 页面标题区 */
.page-header {
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 3px solid var(--color-text);
}

.page-title {
  font-size: 32px;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 8px;
}

.page-description {
  font-size: 16px;
  color: var(--color-muted);
  max-width: 72ch;
  line-height: 1.6;
}

/* ============================================================
   components — 通用组件
   ============================================================ */
/* 状态标签 */
.status {
  display: inline-block;
  padding: 3px 10px;
  font-size: 13px;
  font-weight: 600;
  border-radius: 999px;
  line-height: 1.5;
  white-space: nowrap;
}

.status-active {
  background-color: var(--color-green);
  color: #ffffff;
}

.status-new {
  background-color: var(--color-accent);
  color: #ffffff;
}

.status-normal {
  background-color: #e8e4dc;
  color: var(--color-text);
}

.status-moderate {
  background-color: #d9a441;
  color: #ffffff;
}

/* 数据表格 */
.table-wrapper,
.table-wrap,
.topic-table-wrap {
  width: 100%;
  overflow-x: auto;
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.data-table,
.board-table,
.topic-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  min-width: 640px;
}

.data-table th,
.data-table td,
.board-table th,
.board-table td,
.topic-table th,
.topic-table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.data-table th,
.board-table th,
.topic-table th {
  background-color: #efeae2;
  font-weight: 700;
  font-size: 14px;
  color: var(--color-text);
  white-space: nowrap;
}

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

.data-table tbody tr:hover,
.board-table tbody tr:hover,
.topic-table tbody tr:hover {
  background-color: #faf8f4;
}

/* 折叠面板 */
.accordion,
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

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

.accordion-item summary,
.faq-item summary {
  padding: 16px 20px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  transition: background-color var(--transition);
}

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

.accordion-item summary::after,
.faq-item summary::after {
  content: "+";
  font-size: 22px;
  font-weight: 400;
  color: var(--color-accent);
  flex-shrink: 0;
  transition: transform var(--transition);
}

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

.accordion-item summary:hover,
.faq-item summary:hover {
  background-color: #faf8f4;
}

.accordion-item p,
.faq-item p {
  padding: 4px 20px 18px;
  font-size: 15px;
  line-height: 1.7;
  color: #3a3733;
  max-width: 100%;
}

/* 图片容器 */
figure {
  margin: 0;
}

figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

figcaption {
  padding: 10px 0 0;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.5;
}

/* 双栏布局 */
.layout-shell {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 32px;
  align-items: start;
}

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

.sidebar-column {
  min-width: 0;
}

/* 侧栏卡片 */
.active-boards-card,
.source-note,
.side-tip {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 20px;
}

.active-boards-card h2,
.source-note h2,
.side-tip h2 {
  font-size: 18px;
  margin-bottom: 8px;
}

.active-boards-card .section-desc,
.source-note p,
.side-tip p {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 12px;
  line-height: 1.6;
}

.active-board-list {
  list-style: none;
}

.active-board-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--color-border);
}

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

.active-board-list a {
  font-weight: 700;
  font-size: 15px;
  display: block;
  margin-bottom: 4px;
}

.latest-topic {
  display: block;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.5;
}

.latest-time {
  display: block;
  font-size: 12px;
  color: var(--color-muted);
  margin-top: 2px;
  font-family: var(--font-mono);
}

.sidebar-more {
  margin-top: 12px;
  text-align: right;
}

.sidebar-more a {
  font-size: 14px;
  font-weight: 600;
}

/* ============================================================
   pages — 首页
   ============================================================ */
.home-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px 48px;
}

/* 首屏版块速览 */
.board-overview {
  margin-bottom: 56px;
}

.overview-intro {
  margin-bottom: 24px;
  border-left: 4px solid var(--color-accent);
  padding-left: 16px;
}

.overview-intro h1 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 8px;
}

.overview-desc {
  font-size: 16px;
  color: var(--color-muted);
  line-height: 1.6;
  max-width: 72ch;
}

.board-table {
  min-width: 720px;
}

.board-table td:last-child a {
  font-weight: 600;
  font-size: 14px;
}

.hero-figure {
  margin-top: 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
}

.hero-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.hero-figure figcaption {
  padding: 12px 16px;
}

.content-media-primary {
  margin-top: 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
}

.content-media-primary img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.content-media-primary figcaption {
  padding: 12px 16px;
}

/* 社区动态 */
.community-feed {
  margin-bottom: 56px;
}

.section-heading {
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-text);
}

.section-heading h2 {
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 4px;
}

.section-note {
  font-size: 14px;
  color: var(--color-muted);
}

.topic-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
}

.topic-item {
  border-bottom: 1px solid var(--color-border);
}

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

.topic-card {
  padding: 16px 20px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  justify-content: space-between;
  transition: background-color var(--transition);
}

.topic-card:hover {
  background-color: #faf8f4;
}

.topic-card h3 {
  font-size: 16px;
  font-weight: 600;
  flex: 1;
  min-width: 220px;
}

.topic-card h3 a {
  color: var(--color-text);
  text-decoration: none;
}

.topic-card h3 a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

.topic-meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--color-muted);
  font-family: var(--font-mono);
  flex-shrink: 0;
}

.topic-board {
  color: var(--color-accent);
  font-weight: 600;
}

.feed-footer {
  margin-top: 16px;
  text-align: right;
}

.feed-footer a {
  font-weight: 600;
  font-size: 15px;
}

/* 新手指南步骤条 */
.guide-steps-section {
  margin-bottom: 56px;
}

.step-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.step-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--color-accent);
  color: #ffffff;
  font-weight: 800;
  font-size: 16px;
  font-family: var(--font-mono);
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 6px;
}

.step-content p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

.guide-link {
  margin-top: 16px;
}

.guide-link a {
  font-weight: 600;
}

/* 规则摘要 */
.rules-teaser {
  margin-bottom: 56px;
}

.rules-link {
  margin-top: 16px;
}

.rules-link a {
  font-weight: 600;
}

/* 双卡片入口 */
.info-entry-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 24px;
}

.entry-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.entry-card h2 {
  font-size: 20px;
  font-weight: 800;
}

.entry-card p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.6;
  max-width: 100%;
}

.entry-card a {
  margin-top: auto;
  font-weight: 700;
  font-size: 15px;
  align-self: flex-start;
}

/* ============================================================
   pages — 版块目录 (boards.html)
   ============================================================ */
.board-list-section {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.board-list-section h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.board-list-section .section-desc {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 16px;
}

.board-table {
  min-width: 720px;
}

.board-figure {
  margin-top: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.board-figure img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.board-figure figcaption {
  padding: 10px 14px;
}

.board-tip-bar {
  margin-top: 24px;
  background-color: #efeae2;
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.board-tip-bar p {
  font-size: 15px;
  line-height: 1.6;
  max-width: 100%;
}

.board-tip-bar a {
  font-weight: 600;
}

/* ============================================================
   pages — 热门话题 (hot-topics.html)
   ============================================================ */
.page-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 32px;
  align-items: start;
}

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

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

.hot-topics-section {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.hot-topics-section h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.section-intro {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 16px;
}

.topic-table {
  min-width: 680px;
}

.side-media {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
  margin-bottom: 20px;
}

.side-media img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.side-media figcaption {
  padding: 10px 14px;
}

.source-links {
  list-style: none;
  margin-top: 8px;
}

.source-links li {
  margin-bottom: 6px;
}

.source-links a {
  font-size: 14px;
  font-weight: 600;
}

.discussion-prompt {
  margin-top: 24px;
  background-color: #efeae2;
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-green);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.discussion-prompt h2 {
  font-size: 18px;
  margin-bottom: 8px;
}

.discussion-prompt p {
  font-size: 15px;
  line-height: 1.6;
  max-width: 100%;
}

.discussion-prompt a {
  font-weight: 600;
}

/* ============================================================
   pages — 新手指南 (newbie-guide.html)
   ============================================================ */
.guide-steps {
  margin-bottom: 40px;
}

.guide-steps h2 {
  font-size: 24px;
  margin-bottom: 8px;
}

.guide-steps .section-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
}

.steps-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.guide-steps .step-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.guide-steps .step-number {
  width: 40px;
  height: 40px;
  font-size: 18px;
}

.guide-steps .step-content {
  flex: 1;
}

.guide-steps .step-content h3 {
  font-size: 18px;
  margin-bottom: 6px;
}

.guide-steps .step-content p {
  font-size: 15px;
  line-height: 1.6;
  margin-bottom: 8px;
  max-width: 100%;
}

.guide-steps .step-note {
  font-size: 14px;
  color: var(--color-muted);
  background-color: #f5f2ec;
  border-left: 3px solid var(--color-border);
  padding: 8px 12px;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.guide-media {
  margin: 32px 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
}

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

.guide-media figcaption {
  padding: 12px 16px;
}

.common-ops {
  margin-bottom: 40px;
}

.common-ops h2 {
  font-size: 24px;
  margin-bottom: 8px;
}

.common-ops .section-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
}

.ops-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.op-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.op-item h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.op-item p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text);
  margin-bottom: 8px;
  max-width: 100%;
}

.op-note {
  font-size: 13px;
  color: var(--color-muted);
  background-color: #f5f2ec;
  border-left: 3px solid var(--color-border);
  padding: 6px 10px;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.faq-section {
  margin-bottom: 24px;
}

.faq-section h2 {
  font-size: 24px;
  margin-bottom: 8px;
}

.faq-section .section-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 20px;
}

.faq-section .section-desc a {
  font-weight: 600;
}

/* ============================================================
   pages — 内容规则 (rules.html)
   ============================================================ */
.content-section {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  margin-bottom: 24px;
}

.content-section h2 {
  font-size: 20px;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-text);
}

.content-section > p {
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 16px;
  max-width: 100%;
}

.rule-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.rule-list li {
  padding: 12px 16px;
  background-color: #faf8f4;
  border-left: 3px solid var(--color-border);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.rule-list strong {
  display: block;
  font-size: 15px;
  margin-bottom: 4px;
}

.rule-list p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  max-width: 100%;
}

.content-figure {
  margin: 24px 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
}

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

.content-figure figcaption {
  padding: 12px 16px;
}

.related-links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 16px;
  padding: 16px 20px;
  background-color: #efeae2;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-top: 24px;
}

.related-links-label {
  font-size: 14px;
  font-weight: 700;
}

.related-links-item {
  font-size: 14px;
  font-weight: 600;
}

/* ============================================================
   pages — 版块介绍 (board-intro.html)
   ============================================================ */
.board-intro-section {
  margin-bottom: 48px;
}

.section-title {
  font-size: 24px;
  margin-bottom: 8px;
}

.section-lead {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
  max-width: 100%;
}

.board-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.board-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.board-card-media {
  border-bottom: 1px solid var(--color-border);
}

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

.board-card-body {
  padding: 20px;
  flex: 1;
}

.board-card-title {
  font-size: 19px;
  font-weight: 800;
  margin-bottom: 8px;
}

.board-card-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 12px;
  max-width: 100%;
}

.board-card-body h4 {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 4px;
  margin-top: 12px;
  color: var(--color-accent);
}

.board-card-body p {
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 8px;
  max-width: 100%;
}

.board-card-body em {
  font-style: normal;
  display: inline-block;
  background-color: #f5f2ec;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 2px 8px;
  font-size: 13px;
  margin: 2px 4px 2px 0;
  color: var(--color-text);
}

.board-choice-section {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-green);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
}

.board-choice-section .section-title {
  font-size: 20px;
  margin-bottom: 12px;
}

.choice-content p {
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 10px;
  max-width: 100%;
}

.choice-content a {
  font-weight: 600;
}

/* ============================================================
   pages — 站点说明 (about.html)
   ============================================================ */
.about-section {
  margin-bottom: 32px;
}

.about-media {
  margin-bottom: 20px;
}

.media-figure {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
}

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

.media-figure figcaption {
  padding: 12px 16px;
}

.about-section h2 {
  font-size: 22px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-text);
}

.about-section p {
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 12px;
  max-width: 72ch;
}

.about-section a {
  font-weight: 600;
}

.scope-list {
  list-style: none;
  margin-bottom: 12px;
}

.scope-list li {
  font-size: 15px;
  line-height: 1.7;
  padding: 8px 0;
  border-bottom: 1px solid var(--color-border);
}

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

/* ============================================================
   pages — 问题反馈 (feedback.html)
   ============================================================ */
.feedback-hero-media {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
  margin-bottom: 32px;
}

.feedback-hero-media img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.feedback-hero-media figcaption {
  padding: 12px 16px;
}

.feedback-path-section,
.feedback-prep-section,
.feedback-process-section {
  margin-bottom: 40px;
}

.feedback-path-section > h2,
.feedback-prep-section > h2,
.feedback-process-section > h2 {
  font-size: 22px;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-text);
}

.feedback-path-section > p,
.feedback-prep-section > p,
.feedback-process-section > p {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 16px;
  max-width: 100%;
}

.feedback-path-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  margin-bottom: 16px;
}

.feedback-path-item h3 {
  font-size: 17px;
  margin-bottom: 8px;
  color: var(--color-accent);
}

.feedback-path-item p {
  font-size: 15px;
  line-height: 1.6;
  margin-bottom: 6px;
  max-width: 100%;
}

.feedback-prep-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.feedback-prep-list li {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 14px;
  line-height: 1.6;
}

.feedback-process-steps {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 16px;
}

.feedback-process-steps li {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 16px;
}

.feedback-process-steps h3 {
  font-size: 15px;
  margin-bottom: 6px;
  color: var(--color-accent);
}

.feedback-process-steps p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-muted);
  max-width: 100%;
}

.feedback-entry-section {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-green);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
}

.feedback-entry-section h2 {
  font-size: 20px;
  margin-bottom: 10px;
}

.feedback-entry-section p {
  font-size: 15px;
  line-height: 1.7;
  max-width: 100%;
}

/* ============================================================
   pages — 404
   ============================================================ */
.error-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.error-panel {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 48px 40px;
  text-align: center;
  max-width: 560px;
  width: 100%;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 72px;
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 12px;
}

.error-panel h1 {
  font-size: 24px;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
  max-width: 100%;
}

.error-btn {
  display: inline-block;
  background-color: var(--color-accent);
  color: #ffffff;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 15px;
}

.error-btn:hover {
  background-color: #a8342c;
  color: #ffffff;
  text-decoration: none;
}

.error-alt {
  margin-top: 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.error-alt a {
  font-weight: 600;
}

/* ============================================================
   responsive — 响应式
   ============================================================ */
@media (max-width: 1024px) {
  .layout-shell,
  .page-layout {
    grid-template-columns: 1fr 300px;
    gap: 24px;
  }

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

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

@media (max-width: 900px) {
  .layout-shell,
  .page-layout {
    grid-template-columns: 1fr;
  }

  .sidebar-column,
  .content-side {
    order: 2;
  }

  .main-column,
  .content-main {
    order: 1;
  }

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

  .ops-list {
    grid-template-columns: 1fr;
  }

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

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

  .brand-slogan {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--color-header-bg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
  }

  .site-nav.is-open {
    max-height: 480px;
    overflow: visible;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    padding: 12px 16px;
    gap: 0;
  }

  .nav-list li {
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  }

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

  .nav-list a {
    padding: 12px 8px;
    border-radius: 0;
    font-size: 15px;
  }

  .nav-list a.is-current {
    background-color: transparent;
    color: var(--color-accent);
    font-weight: 700;
  }

  .site-main.inner-main {
    padding: 24px 16px 40px;
  }

  .home-main {
    padding: 24px 16px 40px;
  }

  .page-header {
    margin-bottom: 24px;
  }

  .page-title {
    font-size: 26px;
  }

  .page-description {
    font-size: 15px;
  }

  .breadcrumb {
    font-size: 13px;
  }

  .step-list {
    grid-template-columns: 1fr;
  }

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

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 16px 40px;
  }

  .footer-col {
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding-bottom: 16px;
  }

  .footer-col:last-child {
    border-bottom: none;
  }

  .footer-brand {
    border-bottom: none;
    padding-bottom: 0;
  }

  .topic-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .topic-card h3 {
    min-width: 0;
  }

  .topic-meta {
    flex-wrap: wrap;
    gap: 8px 16px;
  }

  .feedback-process-steps {
    grid-template-columns: 1fr;
  }

  .feedback-prep-list {
    grid-template-columns: 1fr;
  }

  .board-list-section,
  .hot-topics-section {
    padding: 16px;
  }

  .content-section {
    padding: 16px;
  }

  .hero-figure img {
    height: 180px;
  }

  .content-media-primary img {
    height: 160px;
  }

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

  .guide-media img {
    height: 180px;
  }

  .content-figure img {
    height: 160px;
  }

  .feedback-hero-media img {
    height: 160px;
  }

  .media-figure img {
    height: 180px;
  }

  .side-media img {
    height: 140px;
  }

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

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

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

@media (max-width: 480px) {
  .brand-name {
    font-size: 19px;
  }

  .header-inner {
    gap: 12px;
  }

  .nav-toggle {
    width: 40px;
    height: 40px;
  }

  .data-table,
  .board-table,
  .topic-table {
    font-size: 14px;
    min-width: 560px;
  }

  .data-table th,
  .data-table td,
  .board-table th,
  .board-table td,
  .topic-table th,
  .topic-table td {
    padding: 10px 12px;
  }

  .overview-intro h1 {
    font-size: 26px;
  }

  .section-heading h2 {
    font-size: 20px;
  }

  .step-item {
    padding: 16px;
  }

  .entry-card {
    padding: 20px;
  }

  .board-card-body {
    padding: 16px;
  }

  .feedback-path-item {
    padding: 16px;
  }

  .feedback-entry-section {
    padding: 20px;
  }

  .board-choice-section {
    padding: 20px;
  }
}

/* 减少动效偏好 */
@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;
  }
}