:root {
  --bg: #FBF9F4;
  --surface: #FFFFFF;
  --text: #23303B;
  --text-soft: #6B7A87;
  --brand: #2F6FB5;
  --accent: #E8A33D;
  --line: #E4E0D6;
  --radius: 8px;
  --shadow: 0 1px 2px rgba(35, 48, 59, 0.04), 0 6px 18px rgba(35, 48, 59, 0.05);
  --wrap: 1180px;
  --gap: 24px;
}

/* =========================================================
   base
   ========================================================= */

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC",
    Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
}

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

a {
  color: var(--brand);
  text-decoration: none;
}

a:hover,
a:focus-visible {
  color: #1f5793;
  text-decoration: underline;
}

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

dl,
dt,
dd,
figure,
p,
h1,
h2,
h3,
h4 {
  margin: 0;
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

button {
  font: inherit;
  color: inherit;
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

.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
   ========================================================= */

.site-body {
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 40;
}

.header-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

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

.inner-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 24px 24px 64px;
}

.home-main {
  width: 100%;
}

.site-factbar,
.fact-bar {
  background: #F2EEE4;
  border-bottom: 1px solid var(--line);
  color: var(--text-soft);
  font-size: 13px;
  line-height: 1.6;
}

.site-factbar,
.fact-bar .fact-text {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 8px 24px;
}

.fact-bar {
  padding: 0;
}

.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--line);
  margin-top: 48px;
}

.footer-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 40px 24px 20px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px 28px;
}

.footer-bottom {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 16px 24px 28px;
  border-top: 1px solid var(--line);
  color: var(--text-soft);
  font-size: 13px;
}

/* =========================================================
   components — 页头 / 导航
   ========================================================= */

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  color: var(--text);
  flex: 0 0 auto;
}

.brand:hover,
.brand:focus-visible {
  color: var(--text);
  text-decoration: none;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0;
}

.brand-tag {
  font-size: 12px;
  color: var(--text-soft);
  border-left: 1px solid var(--line);
  padding-left: 10px;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

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

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  color: var(--text);
  font-size: 15px;
  border-bottom: 2px solid transparent;
  border-radius: 0;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--brand);
  text-decoration: none;
  background: #F5F2EA;
}

.nav-link.is-current {
  color: var(--brand);
  font-weight: 700;
  border-bottom-color: var(--brand);
}

/* =========================================================
   components — 面包屑 / 页面标题区
   ========================================================= */

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: var(--text-soft);
  margin-bottom: 18px;
}

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

.breadcrumb a:hover,
.breadcrumb a:focus-visible {
  color: var(--brand);
}

.breadcrumb-sep {
  color: #B9C2C9;
}

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

.page-header {
  margin-bottom: 36px;
}

.page-title {
  font-size: 34px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}

.page-description {
  max-width: 760px;
  color: var(--text-soft);
  font-size: 16px;
}

/* =========================================================
   components — 通用区块头 / 标题
   ========================================================= */

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

.section-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.section-note,
.section-desc,
.section-lead,
.section-intro {
  color: var(--text-soft);
  font-size: 15px;
  max-width: 780px;
  margin-bottom: 16px;
}

.section {
  margin-bottom: 56px;
}

.column-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 6px;
}

.column-note {
  color: var(--text-soft);
  font-size: 14px;
  margin-bottom: 16px;
}

.subsection-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}

.aside-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
}

.aside-text {
  color: var(--text-soft);
  font-size: 15px;
  margin-bottom: 12px;
}

.aside-desc {
  color: var(--text-soft);
  font-size: 15px;
  margin-bottom: 16px;
}

.column-more,
.feedback-link,
.direction-link,
.topic-enter {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.column-more:hover,
.column-more:focus-visible,
.feedback-link:hover,
.feedback-link:focus-visible,
.direction-link:hover,
.direction-link:focus-visible,
.topic-enter:hover,
.topic-enter:focus-visible {
  color: #1f5793;
}

/* =========================================================
   components — 标签 / 元信息
   ========================================================= */

.tag {
  display: inline-flex;
  align-items: center;
  padding: 2px 10px;
  border-radius: var(--radius);
  font-size: 13px;
  line-height: 1.6;
  border: 1px solid var(--line);
  background: #F5F2EA;
  color: var(--text-soft);
}

.tag-topic {
  border-color: #CBD9EA;
  background: #EEF4FB;
  color: #2F6FB5;
}

.tag-status {
  border-color: #EFD9AE;
  background: #FBF3E3;
  color: #9A6A12;
}

/* =========================================================
   components — 页脚
   ========================================================= */

.footer-brand-name {
  display: block;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.footer-brand-desc {
  color: var(--text-soft);
  font-size: 14px;
  max-width: 320px;
}

.footer-group-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-list a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--text-soft);
  font-size: 14px;
}

.footer-list a:hover,
.footer-list a:focus-visible {
  color: var(--brand);
}

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

.hero-section {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding: 48px 24px;
}

.hero-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: 48px;
  align-items: center;
}

.hero-copy {
  min-width: 0;
}

.hero-title {
  font-size: 34px;
  font-weight: 700;
  margin-bottom: 16px;
}

.hero-lead {
  color: var(--text-soft);
  font-size: 16px;
  margin-bottom: 24px;
  max-width: 560px;
}

.hero-entry-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-entry {
  min-width: 0;
}

.entry-link {
  display: inline-flex;
  flex-direction: column;
  gap: 2px;
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FBF9F4;
  color: var(--text);
}

.entry-link:hover,
.entry-link:focus-visible {
  border-color: var(--brand);
  background: #EEF4FB;
  text-decoration: none;
}

.entry-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.entry-desc {
  font-size: 13px;
  color: var(--text-soft);
}

.hero-media {
  margin: 0;
  min-width: 0;
}

.hero-media img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: #F2EEE4;
}

.hero-caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-soft);
}

.topics-overview,
.overview-pair,
.ranking-pair,
.path-section,
.site-index {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 56px 24px 0;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--gap);
}

.topic-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.topic-card:hover,
.topic-card:focus-within {
  transform: translateY(-2px);
  border-color: #C6D5E6;
  box-shadow: var(--shadow);
}

.topic-name {
  font-size: 18px;
  font-weight: 700;
}

.topic-meta {
  margin: 0;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 10px;
  font-size: 13px;
}

.topic-meta dt {
  color: var(--text-soft);
}

.topic-meta dd {
  margin: 0;
  color: var(--text);
}

.topic-enter {
  margin-top: auto;
}

.pair-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

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

.pair-covers {
  background: transparent;
}

.cover-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.cover-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 10px;
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.cover-card:hover,
.cover-card:focus-within {
  transform: translateY(-2px);
  border-color: #C6D5E6;
}

.cover-card img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  border-radius: 6px;
  background: #F2EEE4;
  margin-bottom: 10px;
}

.cover-name {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
}

.cover-meta {
  font-size: 13px;
  color: var(--text-soft);
}

.pair-updates {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}

.update-brief-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 8px;
}

.update-brief-item {
  border-bottom: 1px dashed var(--line);
  padding-bottom: 12px;
}

.update-brief-item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.batch-no {
  display: inline-block;
  font-size: 12px;
  color: #9A6A12;
  background: #FBF3E3;
  border: 1px solid #EFD9AE;
  border-radius: var(--radius);
  padding: 1px 8px;
  margin-bottom: 6px;
}

.batch-desc {
  font-size: 14px;
  color: var(--text);
}

.batch-time {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  color: var(--text-soft);
}

.rank-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 8px;
}

.rank-item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 12px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px 14px;
}

.rank-no {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 16px;
  font-weight: 700;
  color: var(--accent);
  text-align: center;
}

.rank-name {
  font-size: 15px;
  font-weight: 700;
  min-width: 0;
}

.rank-topic {
  font-size: 13px;
  color: var(--text-soft);
  white-space: nowrap;
}

.rank-change {
  font-size: 13px;
  color: var(--text-soft);
  white-space: nowrap;
}

.pair-fields {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}

.field-brief-list {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 14px;
  margin-bottom: 10px;
}

.field-name {
  font-weight: 700;
  font-size: 14px;
  color: var(--text);
}

.field-desc {
  font-size: 14px;
  color: var(--text-soft);
}

.path-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--gap);
  margin-bottom: 28px;
}

.path-step {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.step-no {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 14px;
  font-weight: 700;
  color: var(--brand);
  background: #EEF4FB;
  border: 1px solid #CBD9EA;
  border-radius: var(--radius);
  padding: 2px 10px;
  align-self: flex-start;
}

.path-step .step-title {
  font-size: 18px;
  font-weight: 700;
}

.step-desc {
  font-size: 14px;
  color: var(--text-soft);
}

.path-step .step-link {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.path-step .step-link:hover,
.path-step .step-link:focus-visible {
  color: #1f5793;
}

.feedback-block {
  background: #F5F2EA;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}

.feedback-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feedback-desc {
  color: var(--text-soft);
  font-size: 15px;
  margin-bottom: 10px;
  max-width: 780px;
}

.index-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.index-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-height: 44px;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text);
}

.index-link:hover,
.index-link:focus-visible {
  border-color: var(--brand);
  background: #EEF4FB;
  text-decoration: none;
}

.index-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.index-desc {
  font-size: 13px;
  color: var(--text-soft);
}

/* =========================================================
   pages — 题材分类
   ========================================================= */

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

.basis-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}

.basis-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.basis-text {
  font-size: 14px;
  color: var(--text-soft);
}

.direction-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap);
}

.direction-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.direction-card:hover,
.direction-card:focus-within {
  transform: translateY(-2px);
  border-color: #C6D5E6;
  box-shadow: var(--shadow);
}

.direction-media {
  margin: 0;
}

.direction-media img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: #F2EEE4;
}

.direction-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  flex: 1 1 auto;
}

.direction-name {
  font-size: 18px;
  font-weight: 700;
}

.direction-meta {
  margin: 0;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 12px;
  font-size: 14px;
}

.direction-meta dt {
  color: var(--text-soft);
}

.direction-meta dd {
  margin: 0;
  color: var(--text);
}

.direction-link {
  margin-top: auto;
}

.field-table {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.field-row {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr) minmax(0, 1fr);
  gap: 0;
  border-bottom: 1px solid var(--line);
}

.field-row:last-child {
  border-bottom: 0;
}

.field-row-head {
  background: #F5F2EA;
  font-weight: 700;
}

.field-cell {
  padding: 12px 16px;
  font-size: 14px;
  color: var(--text);
  border-right: 1px solid var(--line);
}

.field-cell:last-child {
  border-right: 0;
}

.field-row-head .field-cell {
  color: var(--text);
}

.field-cell.field-meaning,
.field-cell.field-sample {
  color: var(--text-soft);
}

.advice-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.advice-text p {
  color: var(--text-soft);
  font-size: 15px;
  margin-bottom: 12px;
  max-width: 680px;
}

.advice-links {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.advice-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 15px;
  color: var(--text);
}

.advice-link:hover,
.advice-link:focus-visible {
  border-color: var(--brand);
  background: #EEF4FB;
  text-decoration: none;
}

/* =========================================================
   pages — 更新记录
   ========================================================= */

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.updates-layout .batch-bar {
  grid-column: 1 / -1;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.batch-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.batch-label {
  font-size: 13px;
  color: var(--text-soft);
}

.batch-value {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.batch-note {
  grid-column: 1 / -1;
  font-size: 13px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.update-list-section {
  min-width: 0;
}

.update-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 16px;
}

.update-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.update-cover {
  margin: 0;
}

.update-cover img {
  width: 96px;
  height: 96px;
  object-fit: cover;
  border-radius: 6px;
  background: #F2EEE4;
}

.update-body {
  min-width: 0;
}

.update-name {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 6px;
}

.update-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 6px;
}

.update-change {
  font-size: 14px;
  color: var(--text);
  margin-bottom: 4px;
}

.update-date {
  font-size: 13px;
  color: var(--text-soft);
}

.update-footnote {
  font-size: 14px;
  color: var(--text-soft);
}

.updates-aside {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  min-width: 0;
}

.rule-block {
  border-bottom: 1px dashed var(--line);
  padding-bottom: 12px;
  margin-bottom: 12px;
}

.rule-block:last-of-type {
  border-bottom: 0;
  padding-bottom: 0;
  margin-bottom: 16px;
}

.rule-name {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 6px;
}

.rule-text {
  font-size: 14px;
  color: var(--text-soft);
}

.aside-links {
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.aside-links-title {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 10px;
}

.aside-link-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.aside-link-list a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 14px;
}

/* =========================================================
   pages — 人气位次
   ========================================================= */

.ranking-layout {
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
}

.ranking-section {
  min-width: 0;
}

.ranking-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.ranking-row {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 16px;
  display: grid;
  grid-template-columns: 44px 72px minmax(0, 1fr);
  gap: 16px;
  align-items: center;
}

.rank-number {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 18px;
  font-weight: 700;
  color: var(--accent);
  text-align: center;
}

.rank-cover {
  margin: 0;
}

.rank-cover img {
  width: 72px;
  height: 72px;
  object-fit: cover;
  border-radius: 6px;
  background: #F2EEE4;
}

.rank-body {
  min-width: 0;
}

.ranking-row .rank-name {
  font-size: 16px;
  margin-bottom: 4px;
}

.rank-meta {
  font-size: 13px;
  color: var(--text-soft);
  margin-bottom: 4px;
}

.ranking-row .rank-change {
  font-size: 13px;
  color: var(--text-soft);
}

.ranking-section .section-note {
  font-size: 14px;
}

.ranking-aside {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.aside-block {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}

.method-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.method-item {
  border-top: 1px dashed var(--line);
  padding-top: 12px;
}

.method-item:first-child {
  border-top: 0;
  padding-top: 0;
}

.method-name {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
}

.method-desc {
  font-size: 14px;
  color: var(--text-soft);
}

.tip-list,
.misread-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tip-item,
.misread-item {
  font-size: 14px;
  color: var(--text-soft);
  padding-left: 14px;
  position: relative;
}

.tip-item::before,
.misread-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* =========================================================
   pages — 查阅指引
   ========================================================= */

.guide-steps,
.field-glossary,
.feedback-guide,
.guide-faq,
.guide-related {
  margin-bottom: 56px;
}

.step-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--gap);
  margin-bottom: 28px;
}

.step-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.step-index {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 14px;
  font-weight: 700;
  color: var(--brand);
  background: #EEF4FB;
  border: 1px solid #CBD9EA;
  border-radius: var(--radius);
  padding: 2px 10px;
  align-self: flex-start;
}

.step-item .step-title {
  font-size: 18px;
  font-weight: 700;
}

.step-item .step-desc {
  font-size: 14px;
  color: var(--text-soft);
}

.step-item .step-link {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.step-item .step-link:hover,
.step-item .step-link:focus-visible {
  color: #1f5793;
}

.guide-figure {
  margin: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.guide-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  background: #F2EEE4;
}

.guide-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--text-soft);
}

.field-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.field-list {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 8px 20px;
}

.field-list .field-row {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 16px;
  border-bottom: 1px dashed var(--line);
  padding: 14px 0;
}

.field-list .field-row:last-child {
  border-bottom: 0;
}

.field-example {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  min-width: 0;
}

.aside-links {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 12px;
}

.aside-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 14px;
}

.feedback-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.feedback-main,
.feedback-side {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  min-width: 0;
}

.feedback-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.feedback-item {
  font-size: 14px;
  color: var(--text-soft);
  padding-left: 14px;
  position: relative;
}

.feedback-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand);
}

.feedback-text {
  font-size: 14px;
  color: var(--text-soft);
  margin-bottom: 8px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 4px 18px;
}

.faq-question {
  display: flex;
  align-items: center;
  min-height: 48px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  margin-left: auto;
  font-size: 18px;
  color: var(--text-soft);
}

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

.faq-answer {
  padding: 0 0 14px;
  font-size: 15px;
  color: var(--text-soft);
}

.related-links {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.related-item a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 12px 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 15px;
  color: var(--text);
}

.related-item a:hover,
.related-item a:focus-visible {
  border-color: var(--brand);
  background: #EEF4FB;
  text-decoration: none;
}

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

.error-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 64px 24px 72px;
}

.error-panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 40px 32px;
  max-width: 720px;
}

.error-code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 10px;
}

.error-title {
  font-size: 34px;
  font-weight: 700;
  margin-bottom: 12px;
}

.error-desc {
  color: var(--text-soft);
  font-size: 16px;
  margin-bottom: 24px;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
}

.btn:hover,
.btn:focus-visible {
  text-decoration: none;
}

.btn-primary {
  background: var(--brand);
  border-color: var(--brand);
  color: #FFFFFF;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: #1f5793;
  border-color: #1f5793;
  color: #FFFFFF;
}

.btn-ghost {
  background: var(--surface);
  color: var(--brand);
  border-color: #CBD9EA;
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  background: #EEF4FB;
  color: #1f5793;
}

/* =========================================================
   responsive
   ========================================================= */

@media (max-width: 960px) {
  .header-inner {
    padding: 10px 18px;
    gap: 12px;
  }

  .nav-toggle {
    display: flex;
    margin-left: auto;
  }

  .site-nav {
    flex: 1 1 100%;
    margin-left: 0;
    order: 3;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    border-top: 1px solid var(--line);
    padding-top: 8px;
  }

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

  .nav-link {
    min-height: 48px;
    padding: 0 8px;
    border-bottom: 1px solid var(--line);
    border-left: 2px solid transparent;
    justify-content: flex-start;
  }

  .nav-link.is-current {
    border-bottom-color: var(--line);
    border-left-color: var(--brand);
  }

  .hero-section {
    padding: 32px 18px;
  }

  .hero-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
  }

  .hero-media img {
    height: 260px;
  }

  .topics-overview,
  .overview-pair,
  .ranking-pair,
  .path-section,
  .site-index {
    padding: 40px 18px 0;
  }

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

  .pair-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
  }

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

  .index-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .inner-main {
    padding: 20px 18px 56px;
  }

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

  .page-layout,
  .ranking-layout,
  .field-layout,
  .feedback-layout,
  .advice-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
  }

  .updates-layout .batch-bar {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .field-row {
    grid-template-columns: 140px minmax(0, 1fr) minmax(0, 1fr);
  }

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

  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding: 32px 18px 18px;
    gap: 24px;
  }

  .footer-bottom {
    padding: 14px 18px 24px;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }

  .site-factbar,
  .fact-bar .fact-text {
    padding: 8px 16px;
    font-size: 12px;
  }

  .header-inner {
    padding: 10px 16px;
  }

  .brand-name {
    font-size: 18px;
  }

  .brand-tag {
    display: none;
  }

  .hero-section {
    padding: 24px 16px;
  }

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

  .hero-media img {
    height: 200px;
  }

  .hero-entry-list {
    flex-direction: column;
  }

  .hero-entry {
    width: 100%;
  }

  .entry-link {
    width: 100%;
  }

  .topics-overview,
  .overview-pair,
  .ranking-pair,
  .path-section,
  .site-index {
    padding: 32px 16px 0;
  }

  .topic-grid,
  .basis-grid,
  .direction-grid,
  .path-list,
  .step-list,
  .index-grid,
  .related-links {
    grid-template-columns: minmax(0, 1fr);
  }

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

  .cover-card img {
    height: 130px;
  }

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

  .rank-item {
    grid-template-columns: 32px minmax(0, 1fr);
    row-gap: 4px;
  }

  .rank-item .rank-topic,
  .rank-item .rank-change {
    grid-column: 2;
  }

  .inner-main {
    padding: 16px 16px 48px;
  }

  .page-header {
    margin-bottom: 26px;
  }

  .updates-layout .batch-bar {
    grid-template-columns: minmax(0, 1fr);
  }

  .update-item {
    grid-template-columns: 72px minmax(0, 1fr);
    gap: 12px;
  }

  .update-cover img {
    width: 72px;
    height: 72px;
  }

  .ranking-row {
    grid-template-columns: 36px minmax(0, 1fr);
    row-gap: 8px;
  }

  .rank-cover {
    grid-column: 2;
  }

  .rank-cover img {
    width: 100%;
    height: 140px;
  }

  .rank-body {
    grid-column: 2;
  }

  .field-table {
    border-radius: var(--radius);
    overflow-x: auto;
  }

  .field-row {
    grid-template-columns: 110px minmax(0, 1fr);
    min-width: 0;
  }

  .field-cell.field-sample {
    grid-column: 2;
    border-top: 1px dashed var(--line);
    color: var(--text-soft);
  }

  .field-row-head .field-cell.field-sample {
    display: none;
  }

  .field-list .field-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }

  .error-panel {
    padding: 28px 20px;
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    padding: 28px 16px 16px;
  }

  .footer-bottom {
    padding: 12px 16px 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .topic-card,
  .cover-card,
  .direction-card {
    transition: none;
  }

  .topic-card:hover,
  .topic-card:focus-within,
  .cover-card:hover,
  .cover-card:focus-within,
  .direction-card:hover,
  .direction-card:focus-within {
    transform: none;
  }
}