/* ==========================================================================
   樱花影视 · 全站样式
   视觉方向：瑞士网格风，十二列对齐，细线分隔，无阴影无圆角装饰
   ========================================================================== */

/* ==========================================================================
   1. BASE — 变量、重置、排版基础
   ========================================================================== */

:root {
  --c-text: #0f1115;
  --c-text-2: #4a5158;
  --c-bg: #e8e6e1;
  --c-surface: #ffffff;
  --c-accent: #1f5fd0;
  --c-alert: #c0392b;
  --c-line: #c9c6c0;

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", "Cascadia Mono", Consolas, "Courier New", monospace;

  --w-page: 1120px;
  --w-article: 68ch;

  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --sp-7: 48px;
  --sp-8: 64px;
  --sp-9: 88px;

  --radius: 4px;
  --header-h: 68px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  background-color: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-feature-settings: "kern" 1;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 600;
  line-height: 1.35;
  color: var(--c-text);
}

p {
  margin: 0;
}

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

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

a:hover,
a:focus-visible {
  text-decoration: underline;
}

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

table {
  border-collapse: collapse;
  width: 100%;
}

button {
  font: inherit;
  color: inherit;
}

time {
  font-style: normal;
}

:focus-visible {
  outline: 2px solid var(--c-accent);
  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;
}

/* ==========================================================================
   2. LAYOUT — 骨架：页头、主导航、主内容区、页脚
   ========================================================================== */

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

/* --- 顶部线索说明条（仅首页） --- */

.notice-bar {
  border-bottom: 1px solid var(--c-line);
  background-color: var(--c-surface);
}

.notice-bar p {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 10px 24px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-text-2);
}

/* --- 页头 --- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--c-surface);
  border-bottom: 1px solid var(--c-line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-5);
  max-width: var(--w-page);
  min-height: var(--header-h);
  margin: 0 auto;
  padding: 0 24px;
}

.brand {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 2px;
  color: var(--c-text);
  text-decoration: none;
}

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

.brand-name {
  font-size: 19px;
  font-weight: 700;
  line-height: 1.2;
}

.brand-slogan {
  font-size: 13px;
  line-height: 1.4;
  color: var(--c-text-2);
}

/* --- 主导航 --- */

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

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--sp-6);
}

.nav-link {
  display: inline-block;
  padding: 6px 0;
  font-size: 15px;
  color: var(--c-text-2);
  border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--c-text);
  text-decoration: none;
  border-bottom-color: var(--c-line);
}

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

/* 汉堡按钮：桌面隐藏 */

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

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--c-text);
}

/* --- 主内容区 --- */

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

.home-main {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 0 24px var(--sp-9);
}

.inner-main {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 0 24px var(--sp-8);
}

/* --- 页脚 --- */

.site-footer {
  margin-top: var(--sp-8);
  background-color: var(--c-surface);
  border-top: 1px solid var(--c-line);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) 2fr;
  gap: var(--sp-6) var(--sp-7);
  max-width: var(--w-page);
  margin: 0 auto;
  padding: var(--sp-7) 24px var(--sp-5);
}

.footer-brand-name {
  font-size: 17px;
  font-weight: 700;
}

.footer-brand-text {
  margin-top: var(--sp-2);
  font-size: 14px;
  color: var(--c-text-2);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--sp-5);
}

.footer-group-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
}

.footer-list {
  margin-top: var(--sp-3);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-list a {
  font-size: 14px;
  color: var(--c-text-2);
}

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

.footer-copy {
  grid-column: 1 / -1;
  padding-top: var(--sp-4);
  border-top: 1px solid var(--c-line);
  font-size: 13px;
  color: var(--c-text-2);
}

/* ==========================================================================
   3. COMPONENTS — 通用组件：面包屑、页标题区、按钮、通用文本、区块头
   ========================================================================== */

/* --- 面包屑 --- */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: var(--sp-5) 0 0;
  font-size: 13px;
  color: var(--c-text-2);
}

.breadcrumb a {
  color: var(--c-text-2);
}

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

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

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

/* --- 页面标题区 --- */

.page-header {
  padding: var(--sp-5) 0 var(--sp-6);
  border-bottom: 1px solid var(--c-line);
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
}

.page-description {
  max-width: 62ch;
  margin-top: var(--sp-3);
  font-size: 16px;
  color: var(--c-text-2);
}

/* --- 通用按钮 --- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 22px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid var(--c-accent);
  border-radius: var(--radius);
  text-decoration: none;
}

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

.btn-primary {
  background-color: var(--c-accent);
  color: #ffffff;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background-color: #1a4fae;
  border-color: #1a4fae;
}

.btn-secondary {
  background-color: transparent;
  color: var(--c-accent);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  background-color: rgba(31, 95, 208, 0.08);
}

/* --- 通用文本与链接 --- */

.prose {
  max-width: var(--w-article);
}

.prose p {
  margin-bottom: var(--sp-4);
  color: var(--c-text-2);
}

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

.section-body p {
  max-width: var(--w-article);
  margin-bottom: var(--sp-4);
  color: var(--c-text-2);
}

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

.text-link,
.inline-link {
  font-size: 15px;
  font-weight: 600;
  color: var(--c-accent);
}

.inline-link {
  display: inline-block;
  margin-top: var(--sp-4);
}

/* --- 区块通用头 --- */

.section {
  padding: var(--sp-8) 0 0;
}

.section-head {
  padding-bottom: var(--sp-5);
  border-bottom: 1px solid var(--c-line);
}

.section-title {
  font-size: 24px;
  font-weight: 700;
}

.section-lead {
  max-width: 68ch;
  margin-top: var(--sp-3);
  font-size: 15px;
  color: var(--c-text-2);
}

.section-intro {
  max-width: 68ch;
  margin-top: var(--sp-3);
  font-size: 15px;
  color: var(--c-text-2);
}

.section-desc {
  max-width: 68ch;
  margin-top: var(--sp-3);
  font-size: 15px;
  color: var(--c-text-2);
}

/* 内页区块：标题与正文之间的间距 */

.inner-main .section {
  padding: var(--sp-7) 0 0;
}

.inner-main .section-title {
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--c-line);
}

/* --- 内容图片容器通用约束 --- */

figure {
  margin: 0;
}

.hero-media img,
.collection-media img,
.collection-figure img,
.channel-media img,
.guide-figure img,
.media-figure img,
.method-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background-color: var(--c-surface);
}

.hero-media figcaption,
.collection-media figcaption,
.channel-media figcaption,
.guide-figure-caption,
.media-caption,
.method-figure figcaption {
  margin-top: var(--sp-3);
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-text-2);
}

/* ==========================================================================
   4. PAGES — 各页面业务模块
   ========================================================================== */

/* --------------------------------------------------------------------------
   4.1 首页
   -------------------------------------------------------------------------- */

/* --- 首屏定位区 --- */

.hero {
  padding: var(--sp-8) 0 var(--sp-7);
  border-bottom: 1px solid var(--c-line);
}

.hero-grid {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: var(--sp-7);
  align-items: start;
}

.hero-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--c-accent);
}

.hero-title {
  margin-top: var(--sp-3);
  font-size: 40px;
  font-weight: 700;
  line-height: 1.25;
}

.hero-text {
  max-width: 60ch;
  margin-top: var(--sp-4);
  font-size: 16px;
  color: var(--c-text-2);
}

.hero-text + .hero-text {
  margin-top: var(--sp-3);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  margin-top: var(--sp-6);
}

.hero-media {
  margin: 0;
}

.hero-media img {
  aspect-ratio: 4 / 3;
}

/* --- 题材频道方向索引 --- */

.channel-index {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.channel-row {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) minmax(0, 200px) auto;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--c-line);
}

.channel-code {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
}

.channel-body {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.channel-name {
  font-size: 18px;
  font-weight: 600;
}

.channel-scope {
  font-size: 14px;
  color: var(--c-text-2);
}

.channel-audience {
  font-size: 14px;
  color: var(--c-text-2);
}

.channel-link {
  font-size: 14px;
  font-weight: 600;
  white-space: nowrap;
}

/* --- 专题片单入口 --- */

.collection-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-5);
  margin-top: var(--sp-5);
}

.collection-card {
  display: flex;
  flex-direction: column;
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.collection-media,
.collection-figure {
  margin: 0;
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.collection-media img,
.collection-figure img {
  border: 0;
  border-radius: 0;
}

.collection-body {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  padding: var(--sp-5);
}

.collection-name {
  font-size: 18px;
  font-weight: 600;
}

.collection-theme {
  font-size: 14px;
  color: var(--c-text-2);
}

.collection-order {
  font-size: 14px;
  color: var(--c-text-2);
}

.collection-link {
  margin-top: var(--sp-2);
  font-size: 14px;
  font-weight: 600;
}

/* --- 浏览顺序与准备条件 --- */

.flow-grid {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: var(--sp-6);
  margin-top: var(--sp-5);
}

.flow-subtitle {
  font-size: 18px;
  font-weight: 600;
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--c-line);
}

.flow-steps .step-list {
  margin-top: var(--sp-4);
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}

.flow-steps .step-item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: var(--sp-2) var(--sp-4);
  padding-bottom: var(--sp-4);
  border-bottom: 1px solid var(--c-line);
}

.flow-steps .step-item:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.flow-steps .step-no {
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--c-accent);
  line-height: 1.3;
}

.flow-steps .step-name {
  font-size: 16px;
  font-weight: 600;
}

.flow-steps .step-desc {
  font-size: 14px;
  color: var(--c-text-2);
}

.flow-side {
  display: flex;
  flex-direction: column;
  gap: var(--sp-5);
}

.flow-side .prep-list,
.flow-side .check-list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  margin-top: var(--sp-4);
}

.flow-side .prep-list li,
.flow-side .check-list li {
  position: relative;
  padding-left: var(--sp-5);
  font-size: 14px;
  color: var(--c-text-2);
}

.flow-side .prep-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  background-color: var(--c-accent);
}

.flow-side .check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-accent);
}

/* --- 字段口径与收录边界摘要 --- */

.fields-grid {
  display: grid;
  grid-template-columns: 6fr 6fr;
  gap: var(--sp-6);
  margin-top: var(--sp-5);
}

.fields-subtitle {
  font-size: 18px;
  font-weight: 600;
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--c-line);
}

.fields-table-wrap {
  min-width: 0;
}

.fields-table {
  margin-top: var(--sp-4);
  font-size: 14px;
}

.fields-table th,
.fields-table td {
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--c-line);
}

.fields-table th {
  font-weight: 600;
  color: var(--c-text);
  white-space: nowrap;
}

.fields-table td {
  color: var(--c-text-2);
}

.boundary-block {
  min-width: 0;
}

.boundary-text {
  margin-top: var(--sp-4);
  font-size: 14px;
  color: var(--c-text-2);
}

.boundary-list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  margin-top: var(--sp-4);
}

.boundary-list li {
  position: relative;
  padding-left: var(--sp-5);
  font-size: 14px;
  color: var(--c-text-2);
}

.boundary-list li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--c-alert);
}

.boundary-note {
  margin-top: var(--sp-5);
  padding: var(--sp-4);
  font-size: 14px;
  color: var(--c-text-2);
  background-color: rgba(192, 57, 43, 0.06);
  border-left: 3px solid var(--c-alert);
  border-radius: var(--radius);
}

/* --- 整理记录速览 --- */

.log-groups {
  margin-top: var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: var(--sp-6);
}

.log-month {
  font-size: 16px;
  font-weight: 700;
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--c-line);
}

.log-list {
  margin-top: var(--sp-3);
  display: flex;
  flex-direction: column;
}

.log-item {
  display: grid;
  grid-template-columns: 96px 120px minmax(0, 1fr);
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--c-line);
}

.log-item:last-child {
  border-bottom: 0;
}

.log-date {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
}

.log-channel {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
}

.log-text {
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 站内栏目索引 --- */

.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--sp-5);
  margin-top: var(--sp-5);
}

.sitemap-cell {
  min-width: 0;
}

.sitemap-name {
  font-size: 16px;
  font-weight: 600;
}

.sitemap-desc {
  margin-top: var(--sp-2);
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 首页相关内容条 --- */

.related-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-3) var(--sp-5);
  margin-top: var(--sp-7);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.related-links-label {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
}

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

/* --------------------------------------------------------------------------
   4.2 题材频道页
   -------------------------------------------------------------------------- */

.section-channel-basis .section-body {
  margin-top: var(--sp-4);
}

.channel-media {
  margin-top: var(--sp-5);
  aspect-ratio: 21 / 9;
  overflow: hidden;
}

.channel-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.channel-list .channel-row {
  display: grid;
  grid-template-columns: 72px repeat(3, minmax(0, 1fr));
  align-items: start;
  gap: var(--sp-4);
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--c-line);
}

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

.channel-list .channel-name {
  font-size: 16px;
  font-weight: 600;
}

.channel-direction {
  font-size: 14px;
  color: var(--c-text-2);
}

.channel-cross-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-6);
  margin-top: var(--sp-5);
}

.channel-cross-col {
  min-width: 0;
}

.subsection-title {
  font-size: 16px;
  font-weight: 600;
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--c-line);
}

.channel-cross-col p {
  margin-top: var(--sp-3);
  font-size: 15px;
  color: var(--c-text-2);
}

.channel-map-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.channel-map-row {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--c-line);
}

.channel-map-name {
  font-size: 15px;
}

.channel-map-link {
  font-size: 14px;
  font-weight: 600;
  white-space: nowrap;
}

/* --- 内页关联入口网格（频道 / 片单 / 指引 / 关于） --- */

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--sp-5);
  margin-top: var(--sp-5);
}

.related-item {
  min-width: 0;
  padding: var(--sp-5);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.related-name {
  font-size: 16px;
  font-weight: 600;
}

.related-text {
  margin-top: var(--sp-2);
  font-size: 14px;
  color: var(--c-text-2);
}

.related-link {
  display: inline-block;
  margin-top: var(--sp-3);
  font-size: 14px;
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   4.3 专题片单页
   -------------------------------------------------------------------------- */

.section-collection-intro .prose {
  margin-top: var(--sp-4);
}

.section-collection-list .collection-grid {
  margin-top: var(--sp-5);
}

.collection-code {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
}

.section-collection-list .collection-name {
  font-size: 17px;
}

.map-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.map-item {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) minmax(0, 160px) auto;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--c-line);
}

.map-code {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
}

.map-name {
  font-size: 15px;
}

.map-channel {
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 差异对比表 --- */

.compare-table-wrap {
  margin-top: var(--sp-5);
  overflow-x: auto;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background-color: var(--c-surface);
}

.compare-table {
  min-width: 640px;
  font-size: 14px;
}

.compare-caption {
  padding: var(--sp-3) var(--sp-4);
  text-align: left;
  font-size: 13px;
  color: var(--c-text-2);
  border-bottom: 1px solid var(--c-line);
}

.compare-table th,
.compare-table td {
  padding: 12px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--c-line);
}

.compare-table thead th {
  font-weight: 600;
  color: var(--c-text);
  background-color: rgba(201, 198, 192, 0.18);
}

.compare-table tbody th {
  font-weight: 600;
  color: var(--c-text);
}

.compare-table td {
  color: var(--c-text-2);
}

/* --------------------------------------------------------------------------
   4.4 浏览指引页
   -------------------------------------------------------------------------- */

.guide-prep .prep-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--sp-5);
  margin-top: var(--sp-5);
}

.guide-prep .prep-item {
  min-width: 0;
  padding: var(--sp-5);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.guide-prep .prep-name {
  font-size: 16px;
  font-weight: 600;
}

.guide-prep .prep-text {
  margin-top: var(--sp-2);
  font-size: 14px;
  color: var(--c-text-2);
}

.guide-figure {
  margin-top: var(--sp-5);
  aspect-ratio: 21 / 9;
  overflow: hidden;
}

.guide-steps .step-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.guide-steps .step-item {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: var(--sp-2) var(--sp-5);
  padding: var(--sp-5) 0;
  border-bottom: 1px solid var(--c-line);
}

.guide-steps .step-index {
  grid-row: 1 / span 3;
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  color: var(--c-accent);
  line-height: 1.2;
}

.guide-steps .step-name {
  font-size: 17px;
  font-weight: 600;
}

.guide-steps .step-text {
  font-size: 15px;
  color: var(--c-text-2);
}

.guide-steps .step-basis {
  font-size: 14px;
  color: var(--c-text-2);
}

.guide-steps .step-basis::before {
  content: "判断依据：";
  font-weight: 600;
  color: var(--c-text);
}

.guide-check .check-list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  margin-top: var(--sp-5);
}

.guide-check .check-item {
  position: relative;
  padding-left: var(--sp-5);
  font-size: 15px;
  color: var(--c-text-2);
}

.guide-check .check-item::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-mono);
  color: var(--c-accent);
}

.trouble-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-6);
  margin-top: var(--sp-5);
}

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

.trouble-col-title {
  font-size: 16px;
  font-weight: 600;
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--c-line);
}

.trouble-list {
  margin-top: var(--sp-3);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
}

.trouble-item {
  padding: var(--sp-4);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.trouble-text {
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- FAQ --- */

.guide-faq .faq-item {
  margin-top: var(--sp-3);
  padding: var(--sp-4) var(--sp-5);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.guide-faq .faq-item:first-of-type {
  margin-top: var(--sp-5);
}

.guide-faq .faq-question {
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.guide-faq .faq-question::before {
  content: "＋";
  display: inline-block;
  width: 1.2em;
  font-family: var(--font-mono);
  color: var(--c-accent);
}

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

.guide-faq .faq-answer {
  margin-top: var(--sp-3);
  padding-left: 1.2em;
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 指引页关联卡片 --- */

.guide-related .related-grid {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.guide-related .related-card {
  min-width: 0;
  padding: var(--sp-5);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

/* --------------------------------------------------------------------------
   4.5 字段说明页（左侧固定目录 + 右侧正文）
   -------------------------------------------------------------------------- */

.sidebar-left .page-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: var(--sp-7);
  margin-top: var(--sp-6);
}

.side-toc {
  align-self: start;
  position: sticky;
  top: calc(var(--header-h) + 16px);
  max-width: 260px;
}

.side-toc-title {
  font-size: 14px;
  font-weight: 700;
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--c-line);
}

.side-toc-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-top: var(--sp-3);
}

.toc-link {
  display: block;
  padding: 6px 0;
  font-size: 14px;
  color: var(--c-text-2);
}

.toc-link:hover,
.toc-link:focus-visible {
  color: var(--c-accent);
}

.toc-link.is-active {
  color: var(--c-accent);
  font-weight: 600;
}

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

.content-column .section:first-child {
  padding-top: 0;
}

.media-figure {
  margin-top: var(--sp-5);
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.field-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.field-item {
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--c-line);
}

.field-summary {
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.field-summary::before {
  content: "＋";
  display: inline-block;
  width: 1.2em;
  font-family: var(--font-mono);
  color: var(--c-accent);
}

.field-item[open] .field-summary::before {
  content: "－";
}

.field-note {
  margin-top: var(--sp-3);
  padding-left: 1.2em;
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 取值范围表 --- */

.range-table {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.range-row {
  display: grid;
  grid-template-columns: minmax(120px, 1fr) minmax(0, 1.6fr) minmax(0, 1.6fr);
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--c-line);
}

.range-head {
  font-weight: 600;
  background-color: rgba(201, 198, 192, 0.18);
}

.range-cell {
  font-size: 14px;
  color: var(--c-text-2);
  min-width: 0;
}

.range-head .range-cell {
  color: var(--c-text);
}

/* --- 收录边界双栏 --- */

.boundary-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-6);
  margin-top: var(--sp-5);
}

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

.column-title {
  font-size: 16px;
  font-weight: 600;
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--c-line);
}

.boundary-column .boundary-list {
  margin-top: var(--sp-3);
}

.boundary-in .boundary-list li::before {
  content: "✓";
  font-family: var(--font-mono);
  color: var(--c-accent);
}

.boundary-out .boundary-list li::before {
  content: "—";
  color: var(--c-alert);
}

/* --- 字段更新列表 --- */

.update-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.update-item {
  display: grid;
  grid-template-columns: minmax(120px, 1fr) minmax(0, 2.4fr) 110px;
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--c-line);
}

.update-field {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text);
}

.update-reason {
  font-size: 14px;
  color: var(--c-text-2);
  min-width: 0;
}

.update-date {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-text-2);
  text-align: right;
}

.update-note {
  margin-top: var(--sp-4);
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 字段页相关入口列表 --- */

.related-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--sp-4);
  margin-top: var(--sp-5);
}

.related-list .related-item {
  padding: var(--sp-4) var(--sp-5);
}

.related-list .related-item h3 {
  font-size: 16px;
  font-weight: 600;
}

.related-list .related-item p {
  margin-top: var(--sp-2);
  font-size: 14px;
  color: var(--c-text-2);
}

/* --------------------------------------------------------------------------
   4.6 关于本站页
   -------------------------------------------------------------------------- */

.about-position p {
  max-width: var(--w-article);
  margin-top: var(--sp-4);
  color: var(--c-text-2);
}

.about-audience-list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  margin-top: var(--sp-5);
  padding: var(--sp-5);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.about-audience-list li {
  font-size: 15px;
  color: var(--c-text-2);
}

.about-audience-list strong {
  color: var(--c-text);
}

/* --- 整理方式 --- */

.method-layout {
  display: grid;
  grid-template-columns: 7fr 3fr;
  gap: var(--sp-6);
  margin-top: var(--sp-5);
  align-items: start;
}

.method-text {
  min-width: 0;
}

.method-text p {
  margin-bottom: var(--sp-4);
  color: var(--c-text-2);
}

.method-text p:last-child {
  margin-bottom: 0;
}

.method-figure {
  min-width: 0;
  margin: 0;
}

.method-figure img {
  aspect-ratio: 4 / 3;
}

/* --- 原则列表 --- */

.principle-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
  counter-reset: principle;
}

.principle-item {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: var(--sp-2) var(--sp-4);
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--c-line);
  counter-increment: principle;
}

.principle-item::before {
  content: counter(principle, decimal-leading-zero);
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--c-accent);
  line-height: 1.4;
}

.principle-item h3 {
  font-size: 16px;
  font-weight: 600;
}

.principle-item p {
  font-size: 14px;
  color: var(--c-text-2);
}

/* --- 能力边界 --- */

.about-boundary > p {
  max-width: var(--w-article);
  margin-top: var(--sp-4);
  color: var(--c-text-2);
}

.about-boundary .boundary-list {
  margin-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.about-boundary .boundary-item {
  display: grid;
  grid-template-columns: minmax(160px, 1fr) minmax(0, 2.4fr);
  gap: var(--sp-2) var(--sp-5);
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--c-line);
}

.about-boundary .boundary-item h3 {
  font-size: 15px;
  font-weight: 600;
}

.about-boundary .boundary-item p {
  font-size: 14px;
  color: var(--c-text-2);
  min-width: 0;
}

.about-boundary .boundary-item h3::before {
  content: "—";
  margin-right: 8px;
  color: var(--c-alert);
}

/* --- 反馈路径 --- */

.feedback-layout {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-6);
  margin-top: var(--sp-5);
}

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

.feedback-col h3 {
  font-size: 16px;
  font-weight: 600;
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--c-line);
}

.feedback-list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  margin-top: var(--sp-3);
}

.feedback-list li {
  position: relative;
  padding-left: var(--sp-5);
  font-size: 14px;
  color: var(--c-text-2);
}

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

/* --------------------------------------------------------------------------
   4.7 404 页
   -------------------------------------------------------------------------- */

.error-main {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: var(--sp-8) 24px var(--sp-8);
}

.error-hero {
  padding-bottom: var(--sp-6);
  border-bottom: 1px solid var(--c-line);
}

.error-code {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-alert);
}

.error-hero h1 {
  margin-top: var(--sp-3);
  font-size: 32px;
  font-weight: 700;
}

.error-lead {
  max-width: 60ch;
  margin-top: var(--sp-3);
  color: var(--c-text-2);
}

.error-routes {
  padding-top: var(--sp-6);
}

.error-routes h2 {
  font-size: 22px;
  font-weight: 600;
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--c-line);
}

.error-route-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--sp-5);
  margin-top: var(--sp-5);
}

.error-route-item {
  min-width: 0;
  padding: var(--sp-5);
  background-color: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.error-route-link {
  font-size: 16px;
  font-weight: 600;
}

.error-route-text {
  margin-top: var(--sp-2);
  font-size: 14px;
  color: var(--c-text-2);
}

.error-note {
  margin-top: var(--sp-7);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}

.error-note h2 {
  font-size: 18px;
  font-weight: 600;
}

.error-note p {
  max-width: var(--w-article);
  margin-top: var(--sp-3);
  font-size: 14px;
  color: var(--c-text-2);
}

/* ==========================================================================
   5. RESPONSIVE — 1200 / 900 / 640 断点
   ========================================================================== */

@media (max-width: 1200px) {
  .home-main,
  .inner-main,
  .error-main,
  .header-inner,
  .footer-inner,
  .notice-bar p {
    padding-left: 20px;
    padding-right: 20px;
  }

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

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-6);
  }

  .hero-title {
    font-size: 32px;
  }

  .flow-grid,
  .fields-grid,
  .method-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-6);
  }

  .channel-list .channel-row {
    grid-template-columns: 64px minmax(0, 1fr);
    row-gap: var(--sp-3);
  }

  .channel-list .channel-row .channel-code {
    grid-row: 1 / span 3;
  }

  .channel-list .channel-field {
    grid-column: 2;
  }

  .map-item {
    grid-template-columns: 64px minmax(0, 1fr) auto;
    row-gap: var(--sp-2);
  }

  .map-item .map-channel {
    grid-column: 2;
  }

  .sidebar-left .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-6);
  }

  .side-toc {
    position: static;
    max-width: none;
  }

  .side-toc-list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--sp-2) var(--sp-5);
  }

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

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

@media (max-width: 640px) {
  :root {
    --header-h: 60px;
  }

  body {
    font-size: 15px;
  }

  .home-main,
  .inner-main,
  .error-main,
  .header-inner,
  .footer-inner,
  .notice-bar p {
    padding-left: 16px;
    padding-right: 16px;
  }

  /* --- 页头与移动导航 --- */

  .header-inner {
    flex-wrap: wrap;
    gap: var(--sp-3);
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    flex-basis: 100%;
  }

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

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

  .nav-list li {
    border-bottom: 1px solid var(--c-line);
  }

  .nav-list li:last-child {
    border-bottom: 0;
  }

  .nav-link {
    display: flex;
    align-items: center;
    min-height: 48px;
    padding: 0 4px;
    border-bottom: 0;
  }

  .nav-link:hover,
  .nav-link:focus-visible {
    border-bottom-color: transparent;
  }

  .nav-link.is-current {
    border-bottom-color: transparent;
    color: var(--c-accent);
  }

  /* --- 页面标题与首屏 --- */

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

  .hero {
    padding-top: var(--sp-6);
  }

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

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }

  .section {
    padding-top: var(--sp-7);
  }

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

  /* --- 频道索引：改为逐行卡片 --- */

  .channel-row {
    grid-template-columns: 64px minmax(0, 1fr);
    row-gap: var(--sp-2);
    align-items: start;
  }

  .channel-row .channel-code {
    grid-row: 1 / span 3;
  }

  .channel-row .channel-body,
  .channel-row .channel-audience,
  .channel-row .channel-link {
    grid-column: 2;
  }

  .channel-row .channel-link {
    justify-self: start;
  }

  /* --- 片单卡片：单列 --- */

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

  /* --- 浏览顺序 --- */

  .flow-steps .step-item {
    grid-template-columns: 32px minmax(0, 1fr);
  }

  .flow-steps .step-no {
    font-size: 18px;
  }

  /* --- 字段表 --- */

  .fields-table th,
  .fields-table td {
    padding: 8px 6px;
    font-size: 13px;
  }

  /* --- 整理记录 --- */

  .log-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  /* --- 站内栏目索引 --- */

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

  /* --- 频道总览：逐行卡片 --- */

  .channel-list .channel-row {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-2);
  }

  .channel-list .channel-row .channel-code {
    grid-row: auto;
  }

  .channel-list .channel-field {
    grid-column: 1;
  }

  /* --- 交叉说明与对比 --- */

  .channel-cross-grid,
  .trouble-columns,
  .boundary-columns,
  .feedback-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  /* --- 片单对应关系 --- */

  .map-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .map-item .map-channel {
    grid-column: 1;
  }

  /* --- 指引步骤 --- */

  .guide-steps .step-item {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-2);
  }

  .guide-steps .step-index {
    grid-row: auto;
    font-size: 20px;
  }

  /* --- 取值范围表 --- */

  .range-row {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-2);
    padding: var(--sp-4) 0;
  }

  .range-head {
    display: none;
  }

  .range-cell:first-child {
    font-weight: 600;
    color: var(--c-text);
  }

  /* --- 字段更新 --- */

  .update-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .update-date {
    text-align: left;
  }

  /* --- 关于页 --- */

  .principle-item {
    grid-template-columns: 36px minmax(0, 1fr);
  }

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

  /* --- 页脚 --- */

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

/* ==========================================================================
   6. ENHANCEMENT — 滚动淡入等非阻塞动效
   ========================================================================== */

@media (prefers-reduced-motion: no-preference) {
  .channel-row,
  .collection-card,
  .log-item,
  .guide-prep .prep-item,
  .related-item,
  .guide-related .related-card {
    transition: border-color 0.2s ease, background-color 0.2s ease;
  }

  .channel-row:hover {
    background-color: rgba(255, 255, 255, 0.6);
  }

  .collection-card:hover,
  .related-item:hover,
  .guide-related .related-card:hover,
  .guide-prep .prep-item:hover {
    border-color: var(--c-accent);
  }

  .js-reveal {
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.4s ease, transform 0.4s ease;
  }

  .js-reveal.is-visible {
    opacity: 1;
    transform: none;
  }
}