/* ==========================================================================
   樱花高清电视剧 · 全站样式
   base / layout / components / pages / responsive
   ========================================================================== */

/* --------------------------------------------------------------------------
   base · 变量与基础元素
   -------------------------------------------------------------------------- */

:root {
  --brand: #2f6f8f;
  --brand-dark: #1f4a61;
  --accent: #e8a33d;
  --ink: #24303a;
  --ink-soft: #4c5b66;
  --muted: #6d7c87;
  --surface: #f4f7f9;
  --surface-alt: #eef3f6;
  --line: #d8e1e7;
  --white: #ffffff;
  --radius: 8px;
  --radius-sm: 4px;
  --shadow-card: 0 1px 2px rgba(31, 74, 97, 0.06);
  --shadow-lift: 0 8px 18px rgba(31, 74, 97, 0.12);
  --container: 1120px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", "WenQuanYi Micro Hei", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, "Courier New", monospace;
}

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

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--white);
}

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--brand-dark);
  font-weight: 700;
}

h1 {
  font-size: 32px;
  line-height: 1.3;
}

h2 {
  font-size: 22px;
  line-height: 1.4;
}

h3 {
  font-size: 17px;
  line-height: 1.5;
}

p {
  margin: 0 0 12px;
}

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

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

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

a:hover,
a:focus-visible {
  color: var(--brand-dark);
  text-decoration: underline;
}

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

figure {
  margin: 0;
}

figcaption {
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

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

caption {
  text-align: left;
}

button {
  font-family: inherit;
}

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

/* --------------------------------------------------------------------------
   layout · 骨架（页头 / 导航 / 主容器 / 面包屑 / 页脚）
   -------------------------------------------------------------------------- */

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: var(--brand);
  border-bottom: 1px solid var(--brand-dark);
}

.header-inner {
  position: relative;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
  min-height: 64px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  flex: 0 0 auto;
  min-height: 44px;
}

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

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--white);
  object-fit: contain;
  padding: 3px;
}

.brand-text {
  font-size: 18px;
  font-weight: 700;
  white-space: nowrap;
}

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

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

.nav-item {
  display: block;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.86);
  border-bottom: 3px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--white);
  border-bottom-color: rgba(255, 255, 255, 0.5);
  text-decoration: none;
}

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

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: var(--radius-sm);
  background: transparent;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--white);
  border-radius: 1px;
}

.site-main {
  flex: 1 1 auto;
  width: 100%;
  min-width: 0;
}

.page-layout {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 20px 56px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 36px;
  align-items: start;
}

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  max-width: var(--container);
  margin: 0 auto;
  padding: 18px 20px 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

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

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

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

.page-header {
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px 20px 4px;
}

.page-title {
  font-size: 32px;
  line-height: 1.3;
  color: var(--brand-dark);
}

.page-description {
  margin-top: 12px;
  max-width: 760px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.site-footer {
  background: var(--brand-dark);
  color: rgba(255, 255, 255, 0.78);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 20px 28px;
  display: grid;
  grid-template-columns: minmax(220px, 1.4fr) repeat(5, minmax(120px, 1fr));
  gap: 28px 20px;
  align-items: start;
}

.footer-brand-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 8px;
}

.footer-text {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.7);
}

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

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

.footer-list a {
  display: inline-block;
  padding: 2px 0;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.76);
}

.footer-list a:hover,
.footer-list a:focus-visible {
  color: var(--white);
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.16);
}

.footer-copy {
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px 20px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.62);
}

/* --------------------------------------------------------------------------
   components · 通用按钮 / 链接 / 标题块 / 侧栏 / 表格 / 列表
   -------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

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

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

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--brand-dark);
  border-color: var(--brand-dark);
  color: var(--white);
}

.btn-ghost {
  background: transparent;
  border-color: var(--brand);
  color: var(--brand);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  background: var(--surface);
  border-color: var(--brand-dark);
  color: var(--brand-dark);
}

.btn-plain {
  background: transparent;
  border-color: var(--line);
  color: var(--ink-soft);
}

.btn-plain:hover,
.btn-plain:focus-visible {
  background: var(--surface);
  border-color: var(--brand);
  color: var(--brand-dark);
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 32px;
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.text-link::after {
  content: "→";
  font-weight: 400;
}

.text-link:hover,
.text-link:focus-visible {
  color: var(--brand-dark);
  text-decoration: underline;
}

.section-head {
  margin-bottom: 20px;
}

.section-title {
  font-size: 22px;
  line-height: 1.4;
  color: var(--brand-dark);
}

.section-desc,
.section-lead {
  margin-top: 8px;
  max-width: 760px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.section-foot,
.section-more {
  margin-top: 20px;
}

.sub-title,
.subsection-title {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 10px;
}

/* 侧栏 */

.site-aside,
.page-aside,
.layout-aside {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.aside-nav,
.aside-block {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
}

.aside-title {
  font-size: 15px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.aside-list,
.aside-anchor-list,
.aside-link-list,
.aside-steps {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.aside-item {
  display: block;
}

.aside-link {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-soft);
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.aside-link:hover,
.aside-link:focus-visible {
  background: var(--white);
  color: var(--brand-dark);
  border-left-color: var(--brand);
  text-decoration: none;
}

.aside-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* 表格 */

.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.data-table,
.fields-table {
  width: 100%;
  min-width: 560px;
  font-size: 15px;
  line-height: 1.7;
}

.table-caption,
.data-table-caption {
  padding: 12px 14px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.data-table th,
.data-table td,
.fields-table th,
.fields-table td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

.data-table thead th,
.fields-table thead th {
  background: var(--brand);
  color: var(--white);
  font-weight: 700;
  white-space: nowrap;
}

.data-table tbody tr:nth-child(even),
.fields-table tbody tr:nth-child(even) {
  background: var(--surface);
}

.data-table tbody tr:last-child td,
.fields-table tbody tr:last-child td {
  border-bottom: 0;
}

/* 列表型条目（收录边界等） */

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

.scope-item {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.scope-item::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 11px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.scope-foot,
.scope-note {
  margin-top: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* --------------------------------------------------------------------------
   pages · 首页
   -------------------------------------------------------------------------- */

.home-main {
  display: block;
}

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

.hero-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 44px 20px 40px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: 40px;
  align-items: center;
}

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

.hero-eyebrow {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 12px;
  font-size: 13px;
  font-weight: 700;
  color: var(--brand-dark);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.hero-title {
  font-size: 32px;
  line-height: 1.3;
  color: var(--brand-dark);
}

.hero-text {
  margin-top: 16px;
  max-width: 560px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.hero-actions {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

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

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

.hero-media figcaption {
  margin-top: 10px;
}

.channels,
.collections,
.fields,
.path,
.updates {
  padding: 40px 0;
  border-bottom: 1px solid var(--line);
}

.updates {
  border-bottom: 0;
}

/* 五个题材频道逐行 */

.channel-rows {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.channel-row {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr) minmax(0, 1fr);
  gap: 20px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

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

.channel-row:nth-child(even) {
  background: var(--surface);
}

.channels .channel-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--brand-dark);
}

.channels .channel-focus,
.channels .channel-scope {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.channels .channel-scope {
  color: var(--muted);
}

/* 专题片单三列 */

.collection-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.collection-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.collection-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
  border-color: var(--brand);
}

.collections .collection-media,
.collection-list .collection-cover {
  overflow: hidden;
  border-radius: var(--radius-sm);
  background: var(--surface-alt);
}

.collections .collection-media img,
.collection-list .collection-cover img {
  width: 100%;
  height: 168px;
  object-fit: cover;
}

.collection-name {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
}

.collection-range,
.collection-scope,
.collection-audience {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.collection-audience {
  color: var(--muted);
}

.collection-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 32px;
  margin-top: auto;
  font-size: 14px;
  font-weight: 700;
  color: var(--brand);
}

/* 条目字段与收录边界摘要 */

.fields-columns {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

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

.fields-table-wrap .fields-table {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.scope-note {
  min-width: 0;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

/* 观看路径三步（首页） */

.path .path-steps {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.path .path-step {
  display: grid;
  grid-template-columns: 48px 160px minmax(0, 1fr);
  gap: 16px;
  align-items: center;
  padding: 16px 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
}

.path .step-no {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--accent);
}

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

.path .step-text {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* 收录范围调整记录 */

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

.update-item {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.update-tag {
  display: inline-block;
  padding: 3px 10px;
  font-size: 13px;
  font-weight: 700;
  color: var(--brand-dark);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 999px;
  text-align: center;
}

.update-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* --------------------------------------------------------------------------
   pages · 内页公共
   -------------------------------------------------------------------------- */

.inner-main {
  display: block;
}

.inner-main .page-layout {
  padding-top: 26px;
}

.channel-table,
.channel-detail,
.channel-bridge,
.collection-list,
.collection-detail,
.collection-map,
.field-table,
.field-scope,
.out-of-scope,
.related-links,
.find-back,
.feedback,
.faq {
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.inner-main .page-layout > .site-main > section:last-child,
.inner-main section:last-child {
  border-bottom: 0;
}

/* 题材频道 */

.channel-figure {
  margin-bottom: 22px;
}

.channel-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-alt);
}

.channel-figure figcaption {
  margin-top: 10px;
}

.channel-compare-table {
  min-width: 640px;
}

.channel-block {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 18px;
}

.channel-block:last-child {
  margin-bottom: 0;
}

.channel-detail .channel-name {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 12px;
}

.channel-media {
  margin-bottom: 14px;
}

.channel-media img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--surface-alt);
}

.channel-orientation,
.channel-scope {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.channel-scope {
  color: var(--muted);
}

.bridge-columns {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

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

.bridge-col-side {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

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

.link-list a {
  display: block;
  padding: 10px 12px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--brand-dark);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

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

/* 专题片单 */

.collection-list .collection-grid {
  margin-top: 4px;
}

.collection-list .collection-card {
  padding: 16px;
}

.collection-list .collection-name {
  margin-bottom: 2px;
}

.detail-block {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 18px;
}

.detail-block:last-child {
  margin-bottom: 0;
}

.detail-name {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 10px;
}

.detail-scope,
.detail-boundary {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.detail-boundary {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  color: var(--muted);
}

.map-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
  align-items: start;
}

.map-column {
  min-width: 0;
  padding: 20px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.map-title {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 10px;
}

.map-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.map-channel-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 12px;
}

/* 条目字段说明 */

.field-figure {
  margin-bottom: 22px;
}

.field-figure-img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-alt);
}

.field-figure-caption {
  margin-top: 10px;
}

.scope-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
  align-items: start;
}

.scope-col {
  min-width: 0;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.scope-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

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

.related-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.related-item a {
  font-size: 16px;
  font-weight: 700;
  color: var(--brand-dark);
}

.related-desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* 观看路径指引 */

.path-figure {
  margin-bottom: 22px;
}

.path-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-alt);
}

.path-figure figcaption {
  margin-top: 10px;
}

.step-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.step-item {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
}

.step-index {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.4;
}

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

.step-title {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 6px;
}

.step-body .step-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.two-column {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
  align-items: start;
}

.column-block {
  min-width: 0;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.column-title {
  font-size: 17px;
  line-height: 1.5;
  color: var(--brand-dark);
  margin-bottom: 10px;
}

.column-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.feedback-block {
  padding: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius);
}

.feedback-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.feedback-more {
  margin-top: 14px;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

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

.faq-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-question {
  position: relative;
  padding: 16px 48px 16px 18px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
  color: var(--brand-dark);
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  font-weight: 400;
  color: var(--brand);
}

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

.faq-question:hover {
  background: var(--surface);
}

.faq-answer {
  margin: 0;
  padding: 14px 18px 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
}

/* --------------------------------------------------------------------------
   pages · 404
   -------------------------------------------------------------------------- */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
}

.error-block {
  width: 100%;
  max-width: 640px;
  padding: 40px 32px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: left;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--accent);
  margin-bottom: 12px;
}

.error-title {
  font-size: 32px;
  line-height: 1.3;
  color: var(--brand-dark);
}

.error-text {
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.error-actions {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* --------------------------------------------------------------------------
   responsive · 960px
   -------------------------------------------------------------------------- */

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

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    background: var(--brand-dark);
    border-top: 1px solid rgba(255, 255, 255, 0.14);
    padding: 8px 20px 14px;
  }

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

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

  .nav-link {
    width: 100%;
    padding: 0 12px;
    border-bottom: 0;
    border-left: 3px solid transparent;
  }

  .nav-link:hover,
  .nav-link:focus-visible {
    border-bottom-color: transparent;
    border-left-color: rgba(255, 255, 255, 0.5);
  }

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

  .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding: 24px 20px 44px;
  }

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

  .footer-brand {
    grid-column: 1 / -1;
  }

  .hero-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding: 32px 20px 34px;
  }

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

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

  .fields-columns,
  .bridge-columns,
  .map-columns,
  .scope-columns,
  .two-column {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

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

  .channel-row {
    grid-template-columns: 140px minmax(0, 1fr);
    gap: 8px 16px;
  }

  .channels .channel-scope {
    grid-column: 2 / 3;
  }

  .path .path-step {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 8px 14px;
  }

  .path .step-name {
    grid-column: 2 / 3;
  }

  .path .step-text {
    grid-column: 2 / 3;
  }

  .update-item {
    grid-template-columns: 110px minmax(0, 1fr);
  }
}

/* --------------------------------------------------------------------------
   responsive · 640px
   -------------------------------------------------------------------------- */

@media (max-width: 640px) {
  h1,
  .page-title,
  .hero-title,
  .error-title {
    font-size: 24px;
    line-height: 1.35;
  }

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

  .header-inner {
    min-height: 58px;
  }

  .brand-text {
    font-size: 16px;
  }

  .breadcrumb,
  .page-header,
  .page-layout,
  .hero-inner,
  .footer-inner,
  .footer-copy {
    padding-left: 16px;
    padding-right: 16px;
  }

  .page-header {
    padding-top: 12px;
  }

  .channels,
  .collections,
  .fields,
  .path,
  .updates,
  .channel-table,
  .channel-detail,
  .channel-bridge,
  .collection-list,
  .collection-detail,
  .collection-map,
  .field-table,
  .field-scope,
  .out-of-scope,
  .related-links,
  .find-back,
  .feedback,
  .faq {
    padding: 26px 0;
  }

  .hero-inner {
    padding-top: 26px;
    padding-bottom: 28px;
  }

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

  .hero-actions {
    gap: 10px;
  }

  .hero-actions .btn {
    flex: 1 1 160px;
  }

  .channel-rows {
    border: 0;
    border-radius: 0;
    overflow: visible;
    gap: 12px;
  }

  .channel-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--white);
  }

  .channel-row:nth-child(even) {
    background: var(--white);
  }

  .channels .channel-scope {
    grid-column: auto;
  }

  .collection-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .collections .collection-media img,
  .collection-list .collection-cover img {
    height: 180px;
  }

  .path .path-step {
    grid-template-columns: 40px minmax(0, 1fr);
    padding: 14px;
  }

  .update-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
  }

  .update-tag {
    justify-self: start;
  }

  .data-table,
  .fields-table,
  .channel-compare-table {
    min-width: 520px;
  }

  .channel-figure img,
  .field-figure-img,
  .path-figure img {
    height: 190px;
  }

  .channel-media img {
    height: 170px;
  }

  .error-main {
    padding: 40px 16px;
  }

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

  .error-code {
    font-size: 34px;
  }

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

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    padding-top: 30px;
    padding-bottom: 22px;
  }

  .footer-brand {
    grid-column: auto;
  }

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