/* ==========================================================================
   动漫之家 · uoctbf.cn
   全站样式表
   分组：base / layout / components / pages / responsive
   ========================================================================== */

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

:root {
  --paper: #f7f6f2;
  --ink: #1c1e22;
  --ink-soft: #4b4f57;
  --ink-mute: #6f747d;
  --teal: #2f6f7a;
  --teal-deep: #245661;
  --batch: #b4531f;
  --rule: #d8d5cd;
  --rule-soft: #e6e3db;
  --surface: #ffffff;
  --surface-alt: #f1efe9;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", Menlo, Consolas, "Courier New", monospace;
  --shell: 1120px;
  --gutter: 24px;
  --radius: 6px;
  --header-h: 62px;
}

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

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

body.site-body {
  margin: 0;
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.35;
}

p {
  margin: 0;
}

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

dl,
dd,
dt,
figure,
figcaption {
  margin: 0;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
  border: 0;
}

a {
  color: var(--teal);
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

a:hover,
a:focus-visible {
  color: var(--teal-deep);
}

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

button {
  font: inherit;
  color: inherit;
}

strong {
  font-weight: 700;
}

/* ==========================================================================
   layout · 全站骨架
   ========================================================================== */

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

.site-header.is-solid {
  background-color: var(--surface);
  box-shadow: 0 1px 0 rgba(28, 30, 34, 0.06);
}

.site-home .site-header {
  background-color: transparent;
  border-bottom-color: transparent;
}

.site-home .site-header.is-solid {
  background-color: var(--surface);
  border-bottom-color: var(--rule);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  max-width: var(--shell);
  min-height: var(--header-h);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  height: 40px;
  padding: 0 2px;
  color: var(--ink);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

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

.site-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: flex-end;
}

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

.nav-list > li {
  display: block;
}

.nav-list a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  color: var(--ink-soft);
  font-size: 15px;
  border-radius: var(--radius);
}

.nav-list a:hover,
.nav-list a:focus-visible {
  color: var(--teal);
  background-color: rgba(47, 111, 122, 0.08);
}

.nav-list a.is-current {
  color: var(--teal-deep);
  font-weight: 700;
  background-color: rgba(47, 111, 122, 0.1);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0 10px;
  background-color: transparent;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--ink);
  border-radius: 1px;
}

.site-main {
  display: block;
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter) 64px;
}

.inner-main {
  padding-top: 20px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 0 18px;
  color: var(--ink-mute);
  font-size: 14px;
  line-height: 1.6;
}

.breadcrumb a {
  color: var(--ink-mute);
}

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

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

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

.page-header {
  padding: 0 0 26px;
  margin-bottom: 30px;
  border-bottom: 1px solid var(--rule);
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--ink);
}

.page-description {
  max-width: 860px;
  margin-top: 12px;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.8;
}

.site-footer {
  background-color: var(--surface);
  border-top: 1px solid var(--rule);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(180px, 1.2fr) repeat(3, minmax(150px, 1fr));
  gap: 20px 32px;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 30px var(--gutter) 24px;
}

.footer-brand {
  color: var(--ink);
  font-size: 16px;
  font-weight: 700;
}

.footer-group {
  display: block;
}

.footer-group-title {
  margin-bottom: 8px;
  color: var(--ink-mute);
  font-size: 13px;
  font-weight: 700;
}

.footer-group ul {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
}

.footer-group a {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  color: var(--ink-soft);
  font-size: 14px;
}

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

.footer-copy {
  grid-column: 1 / -1;
  padding-top: 16px;
  border-top: 1px solid var(--rule-soft);
  color: var(--ink-mute);
  font-size: 13px;
}

/* ==========================================================================
   components · 通用组件
   ========================================================================== */

.section-head {
  max-width: 820px;
  margin-bottom: 22px;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
}

.section-desc,
.section-lead,
.section-intro {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 15px;
  line-height: 1.8;
}

.section-more {
  margin-top: 16px;
  font-size: 15px;
}

.text-link {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  color: var(--teal);
  font-weight: 700;
  border-bottom: 1px solid rgba(47, 111, 122, 0.35);
}

.text-link:hover,
.text-link:focus-visible {
  color: var(--teal-deep);
  border-bottom-color: var(--teal-deep);
}

.source-note {
  margin-top: 14px;
  padding-left: 12px;
  border-left: 3px solid var(--rule);
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.7;
}

.source-note a {
  color: var(--teal);
}

.column-title {
  margin-bottom: 14px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

/* 封面条目卡 */
.cover-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 18px;
}

.cover-card {
  display: flex;
  flex-direction: column;
  padding: 12px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.cover-card:hover,
.cover-card:focus-within {
  border-color: var(--teal);
  box-shadow: 0 2px 10px rgba(28, 30, 34, 0.08);
}

.cover-card img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  background-color: var(--surface-alt);
  border-radius: 4px;
}

.cover-figure {
  display: block;
  margin-bottom: 10px;
}

.cover-name {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink);
}

.cover-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 10px;
  margin-top: 6px;
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.6;
}

.cover-topic,
.cover-status {
  display: inline-block;
}

.cover-topic {
  color: var(--teal);
}

.cover-status {
  color: var(--batch);
}

/* 更新批次条 */
.batch-list,
.batch-items {
  display: block;
}

.batch-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 12px;
  padding: 12px 0;
  border-top: 1px solid var(--rule-soft);
}

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

.batch-no {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--batch);
}

.batch-desc {
  flex: 1 1 220px;
  min-width: 200px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.7;
}

/* 位次顺序列表 */
.rank-list {
  display: block;
}

.rank-item {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 0;
  border-top: 1px solid var(--rule-soft);
}

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

.rank-no,
.rank-number {
  flex: 0 0 auto;
  min-width: 26px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--teal);
}

.rank-name,
.rank-title {
  flex: 1 1 auto;
  min-width: 120px;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.rank-topic {
  flex: 0 0 auto;
  color: var(--ink-mute);
  font-size: 13px;
}

/* 步骤指引 */
.step-list {
  display: grid;
  gap: 16px;
}

.step-item {
  display: block;
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-left: 3px solid var(--teal);
  border-radius: var(--radius);
}

.step-index {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--teal);
}

.step-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.step-item p {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.step-body {
  display: block;
}

/* 字段摘要字典 */
.field-summary {
  display: block;
}

.field-summary dt {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--teal-deep);
}

.field-summary dt:first-of-type {
  margin-top: 0;
}

.field-summary dd {
  margin-top: 4px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

/* ==========================================================================
   pages · 首页
   ========================================================================== */

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

.hero-section {
  padding: 34px 0 44px;
  border-bottom: 1px solid var(--rule);
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 40px;
  align-items: start;
}

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

.hero-kicker {
  display: inline-block;
  padding: 3px 10px;
  margin-bottom: 14px;
  background-color: rgba(47, 111, 122, 0.1);
  color: var(--teal-deep);
  font-size: 13px;
  font-weight: 700;
  border-radius: 4px;
}

.hero-title {
  font-size: 34px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.hero-summary {
  margin-top: 16px;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  margin-top: 22px;
}

.action-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 18px;
  background-color: var(--surface);
  color: var(--teal-deep);
  font-size: 15px;
  font-weight: 700;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

.action-link:hover,
.action-link:focus-visible {
  background-color: var(--teal);
  border-color: var(--teal);
  color: #ffffff;
}

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

.hero-figure {
  display: block;
  margin-bottom: 20px;
}

.hero-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background-color: var(--surface-alt);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.hero-figure figcaption {
  margin-top: 8px;
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.6;
}

.hero-steps {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.hero-steps .step-item {
  padding: 12px;
}

.hero-steps .step-item p {
  font-size: 13px;
}

.topics-overview,
.updates-and-covers,
.ranking-and-fields,
.guide-steps,
.column-index {
  padding: 44px 0;
  border-bottom: 1px solid var(--rule);
}

.column-index {
  border-bottom: 0;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.topic-card {
  display: flex;
  flex-direction: column;
  padding: 18px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-top: 3px solid var(--teal);
  border-radius: var(--radius);
}

.topic-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.topic-scope {
  margin-top: 10px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.topic-types {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--rule);
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.7;
}

.updates-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: 34px;
  align-items: start;
}

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

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

.batches-column {
  min-width: 0;
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.ranking-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 34px;
  align-items: start;
}

.rank-column,
.fields-column {
  min-width: 0;
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

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

.index-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
}

.index-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.index-item:hover,
.index-item:focus-visible {
  border-color: var(--teal);
  background-color: rgba(47, 111, 122, 0.06);
}

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

.index-desc {
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.65;
}

/* ==========================================================================
   pages · 题材分类
   ========================================================================== */

.topic-groups {
  padding-bottom: 10px;
}

.topic-groups > .section-title {
  margin-bottom: 8px;
}

.topic-group {
  padding: 26px 0;
  border-top: 1px solid var(--rule);
}

.topic-group:first-of-type {
  border-top: 0;
  padding-top: 6px;
}

.topic-group-head {
  max-width: 780px;
  margin-bottom: 18px;
}

.topic-group-head .topic-name {
  font-size: 19px;
}

.topic-group .cover-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.topic-diff {
  padding: 34px 0;
  border-top: 1px solid var(--rule);
}

.topic-diff > .section-title {
  margin-bottom: 8px;
}

.diff-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.diff-item {
  padding: 16px 18px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.diff-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.diff-text {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.next-links {
  padding: 34px 0 8px;
  border-top: 1px solid var(--rule);
}

.next-links > .section-title {
  margin-bottom: 8px;
}

.next-links-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 18px;
}

.next-link-card {
  display: flex;
  flex-direction: column;
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-left: 3px solid var(--teal);
  border-radius: var(--radius);
}

.next-link-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.next-link-text {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.next-link-anchor {
  margin-top: 12px;
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 12px;
  color: var(--teal-deep);
  font-size: 14px;
  font-weight: 700;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

.next-link-anchor:hover,
.next-link-anchor:focus-visible {
  background-color: var(--teal);
  border-color: var(--teal);
  color: #ffffff;
}

.next-links-note {
  margin-top: 18px;
  color: var(--ink-mute);
  font-size: 14px;
}

/* ==========================================================================
   pages · 最近更新
   ========================================================================== */

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 300px);
  gap: 34px;
  align-items: start;
}

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

.field-note,
.batch-list,
.filter-entry,
.feedback-note {
  padding: 26px 0;
  border-top: 1px solid var(--rule);
}

.field-note {
  border-top: 0;
  padding-top: 6px;
}

.field-note > .section-title,
.batch-list > .section-title,
.filter-entry > .section-title,
.feedback-note > .section-title {
  margin-bottom: 8px;
}

.field-note-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.field-note-item {
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.field-note-name {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--teal-deep);
}

.field-note-desc {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.batch-card {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 16px;
  padding: 16px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.batch-items {
  display: grid;
  gap: 14px;
  margin-top: 16px;
}

.batch-thumb {
  display: block;
  width: 84px;
}

.batch-thumb img {
  width: 84px;
  height: 112px;
  object-fit: cover;
  background-color: var(--surface-alt);
  border-radius: 4px;
}

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

.batch-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 12px;
}

.batch-code {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--batch);
}

.batch-topic {
  color: var(--teal);
  font-size: 13px;
}

.batch-entry-name {
  margin-top: 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.batch-text {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.filter-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.filter-link-item a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  background-color: var(--surface);
  color: var(--teal-deep);
  font-size: 15px;
  font-weight: 700;
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.filter-link-item a:hover,
.filter-link-item a:focus-visible {
  border-color: var(--teal);
  background-color: rgba(47, 111, 122, 0.08);
}

.feedback-steps {
  display: grid;
  gap: 14px;
  margin-top: 16px;
}

.feedback-step {
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-left: 3px solid var(--batch);
  border-radius: var(--radius);
}

.feedback-step .step-index {
  color: var(--batch);
}

.step-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.step-desc {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.next-links-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.next-link-item a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  background-color: var(--surface);
  color: var(--teal-deep);
  font-size: 15px;
  font-weight: 700;
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.next-link-item a:hover,
.next-link-item a:focus-visible {
  border-color: var(--teal);
  background-color: rgba(47, 111, 122, 0.08);
}

/* ==========================================================================
   pages · 人气位次
   ========================================================================== */

.metric-note,
.rank-list-section,
.relation-note,
.feedback-note {
  padding: 30px 0;
  border-top: 1px solid var(--rule);
}

.metric-note {
  border-top: 0;
  padding-top: 6px;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 18px;
}

.metric-item {
  padding: 16px 18px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.metric-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--teal-deep);
}

.metric-item p {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.rank-list-section .rank-list {
  margin-top: 18px;
}

.rank-list-section .rank-item {
  display: grid;
  grid-template-columns: 34px 72px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 16px 0;
  border-top: 1px solid var(--rule-soft);
}

.rank-list-section .rank-item:first-child {
  border-top: 0;
}

.rank-list-section .rank-number {
  padding-top: 2px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--teal);
}

.rank-cover {
  display: block;
  width: 72px;
}

.rank-cover img {
  width: 72px;
  height: 96px;
  object-fit: cover;
  background-color: var(--surface-alt);
  border-radius: 4px;
}

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

.rank-list-section .rank-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.rank-list-section .rank-topic {
  margin-top: 4px;
  color: var(--teal);
  font-size: 13px;
}

.rank-desc {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.relation-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.relation-item {
  padding: 16px 18px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.relation-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.relation-item p {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.relation-note > .section-lead a,
.feedback-note > .section-lead a {
  color: var(--teal);
  font-weight: 700;
  border-bottom: 1px solid rgba(47, 111, 122, 0.35);
}

.relation-note > .section-lead a:hover,
.feedback-note > .section-lead a:hover {
  color: var(--teal-deep);
  border-bottom-color: var(--teal-deep);
}

.feedback-note .step-list {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 18px;
}

/* ==========================================================================
   pages · 条目字段说明
   ========================================================================== */

.field-dictionary,
.reading-path,
.faq-list,
.correction-note {
  padding: 30px 0;
  border-top: 1px solid var(--rule);
}

.field-dictionary {
  border-top: 0;
  padding-top: 6px;
}

.field-dictionary > h2,
.reading-path > h2,
.faq-list > h2,
.correction-note > h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
}

.field-figure {
  display: block;
  margin: 18px 0;
}

.field-figure img {
  width: 100%;
  max-width: 720px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background-color: var(--surface-alt);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.field-figure figcaption {
  max-width: 720px;
  margin-top: 8px;
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.65;
}

.field-list {
  display: grid;
  gap: 12px;
}

.field-item {
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.field-name {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 10px 16px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--teal-deep);
  cursor: pointer;
  list-style: none;
}

.field-name::-webkit-details-marker {
  display: none;
}

.field-name::after {
  content: "展开";
  margin-left: auto;
  padding-left: 12px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 400;
  color: var(--ink-mute);
}

.field-item[open] .field-name::after {
  content: "收起";
}

.field-item[open] .field-name {
  border-bottom: 1px solid var(--rule-soft);
}

.field-body {
  padding: 12px 16px 16px;
}

.field-meaning {
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.field-rule {
  margin-top: 8px;
  padding-left: 12px;
  border-left: 3px solid var(--teal);
  color: var(--ink-mute);
  font-size: 13px;
  line-height: 1.7;
}

.reading-path .path-steps {
  margin-top: 18px;
}

.path-step {
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-left: 3px solid var(--teal);
  border-radius: var(--radius);
}

.path-step .step-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.path-step .step-desc {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.path-step .step-desc a {
  color: var(--teal);
  font-weight: 700;
}

.faq-list .faq-item {
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.faq-list .faq-item + .faq-item {
  margin-top: 12px;
}

.faq-question {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 12px 16px;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "＋";
  margin-left: auto;
  padding-left: 12px;
  font-size: 16px;
  font-weight: 400;
  color: var(--teal);
}

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

.faq-item[open] .faq-question {
  border-bottom: 1px solid var(--rule-soft);
}

.faq-answer {
  padding: 12px 16px 16px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

.correction-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.correction-card {
  padding: 16px 18px;
  background-color: var(--surface);
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.correction-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.correction-list {
  margin-top: 10px;
}

.correction-list li {
  position: relative;
  padding-left: 16px;
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.75;
}

.correction-list li:first-child {
  margin-top: 0;
}

.correction-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 5px;
  height: 5px;
  background-color: var(--teal);
  border-radius: 50%;
}

/* ==========================================================================
   pages · 404
   ========================================================================== */

.error-main {
  padding-top: 40px;
  padding-bottom: 72px;
}

.error-hero {
  padding: 26px 0 34px;
  border-bottom: 1px solid var(--rule);
}

.error-code {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--batch);
}

.error-hero h1 {
  margin-top: 10px;
  font-size: 32px;
  font-weight: 700;
  color: var(--ink);
}

.error-text {
  max-width: 720px;
  margin-top: 14px;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.8;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

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

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

.btn-primary:hover,
.btn-primary:focus-visible {
  background-color: var(--teal-deep);
  border-color: var(--teal-deep);
  color: #ffffff;
}

.btn-ghost {
  background-color: var(--surface);
  border-color: var(--rule);
  color: var(--teal-deep);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--teal);
  background-color: rgba(47, 111, 122, 0.08);
}

.error-paths {
  padding: 30px 0 0;
}

.error-paths h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
}

.error-path-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.error-path-list a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  background-color: var(--surface);
  color: var(--teal-deep);
  font-size: 15px;
  font-weight: 700;
  border: 1px solid var(--rule-soft);
  border-radius: var(--radius);
}

.error-path-list a:hover,
.error-path-list a:focus-visible {
  border-color: var(--teal);
  background-color: rgba(47, 111, 122, 0.08);
}

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

@media (max-width: 960px) {
  :root {
    --gutter: 20px;
  }

  .hero-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

  .hero-title {
    font-size: 30px;
  }

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

  .updates-layout,
  .ranking-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

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

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

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

  .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

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

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

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

@media (max-width: 640px) {
  :root {
    --gutter: 16px;
  }

  body.site-body {
    font-size: 15px;
  }

  .header-inner {
    position: relative;
    min-height: 56px;
    gap: 12px;
  }

  .brand {
    font-size: 18px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: block;
    padding: 8px var(--gutter) 14px;
    background-color: var(--surface);
    border-bottom: 1px solid var(--rule);
    box-shadow: 0 6px 14px rgba(28, 30, 34, 0.08);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

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

  .nav-list a {
    min-height: 46px;
    padding: 0 12px;
    font-size: 16px;
    border-radius: 4px;
  }

  .site-main {
    padding-bottom: 48px;
  }

  .page-header {
    padding-bottom: 20px;
    margin-bottom: 24px;
  }

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

  .page-description {
    margin-top: 10px;
    font-size: 15px;
  }

  .hero-section {
    padding: 24px 0 32px;
  }

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

  .hero-summary {
    font-size: 15px;
  }

  .hero-actions {
    gap: 10px;
  }

  .action-link {
    flex: 1 1 100%;
    justify-content: center;
  }

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

  .topics-overview,
  .updates-and-covers,
  .ranking-and-fields,
  .guide-steps,
  .column-index {
    padding: 30px 0;
  }

  .section-title {
    font-size: 19px;
  }

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

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

  .cover-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .batches-column,
  .rank-column,
  .fields-column {
    padding: 16px;
  }

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

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

  .diff-list,
  .next-links-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .batch-card {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
  }

  .batch-thumb,
  .batch-thumb img {
    width: 100%;
  }

  .batch-thumb img {
    height: auto;
    aspect-ratio: 3 / 4;
    max-width: 200px;
  }

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

  .rank-list-section .rank-item {
    grid-template-columns: 28px 60px minmax(0, 1fr);
    gap: 12px;
  }

  .rank-cover,
  .rank-cover img {
    width: 60px;
  }

  .rank-cover img {
    height: 80px;
  }

  .feedback-note .step-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .error-main {
    padding-top: 26px;
    padding-bottom: 52px;
  }

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

  .error-actions .btn {
    flex: 1 1 100%;
    justify-content: center;
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
    padding: 24px var(--gutter) 20px;
  }

  .footer-group ul {
    gap: 4px 16px;
  }
}