/* ============================================================
   九九热在线视频 — 全站样式表
   分组：base / layout / components / pages / responsive
   ============================================================ */

/* ------------------------------------------------------------
   base：变量、重置、排版基线
   ------------------------------------------------------------ */
:root {
  --color-primary: #1f3a5f;
  --color-primary-soft: #2c4f7c;
  --color-accent: #e8a33d;
  --color-accent-soft: #fdf3e2;
  --color-bg: #f5f6f8;
  --color-surface: #ffffff;
  --color-text: #2c2c2c;
  --color-muted: #6b7280;
  --color-border: #e2e5ea;
  --color-border-strong: #cfd5dd;
  --radius-sm: 4px;
  --radius: 6px;
  --radius-lg: 8px;
  --shadow-card: 0 1px 2px rgba(31, 58, 95, 0.06);
  --shadow-hover: 0 6px 16px rgba(31, 58, 95, 0.12);
  --container: 1080px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

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

body {
  margin: 0;
  padding: 0;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-stack);
  font-size: 16px;
  line-height: 1.7;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--color-primary);
  line-height: 1.4;
  font-weight: 600;
}

h1 {
  font-size: 28px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 18px;
}

p {
  margin: 0 0 12px;
}

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

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

a:hover,
a:focus {
  color: var(--color-accent);
}

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

figure {
  margin: 0;
}

button {
  font-family: inherit;
}

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

/* ------------------------------------------------------------
   layout：全站骨架 —— 页头、导航、主容器、页脚
   ------------------------------------------------------------ */
.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  background-color: var(--color-primary);
  color: #ffffff;
  position: sticky;
  top: 0;
  z-index: 30;
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.12);
}

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

.brand-logo {
  display: flex;
  flex-direction: column;
  gap: 2px;
  color: #ffffff;
  flex: 0 0 auto;
}

.brand-logo:hover,
.brand-logo:focus {
  color: #ffffff;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.2;
}

.brand-slogan {
  font-size: 12px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.72);
  line-height: 1.3;
}

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

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

.nav-list li {
  display: block;
}

.nav-list a {
  display: block;
  padding: 9px 14px;
  min-height: 44px;
  display: flex;
  align-items: center;
  color: rgba(255, 255, 255, 0.86);
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border-bottom: 2px solid transparent;
}

.nav-list a:hover,
.nav-list a:focus {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.08);
}

.nav-list a.is-current {
  color: #ffffff;
  border-bottom-color: var(--color-accent);
}

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  padding: 0;
  background-color: transparent;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: var(--radius-sm);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background-color: #ffffff;
}

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

.home-main {
  display: block;
}

.inner-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 20px 20px 56px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-muted);
  padding: 6px 0 14px;
}

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

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

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

.page-header {
  padding: 4px 0 26px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 30px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.page-description {
  font-size: 16px;
  color: var(--color-muted);
  max-width: 76ch;
  margin-bottom: 14px;
}

.page-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-muted);
}

.meta-tag {
  display: inline-block;
  padding: 3px 10px;
  background-color: var(--color-accent-soft);
  color: #8a5a12;
  border: 1px solid #f0d9b0;
  border-radius: var(--radius-sm);
}

.meta-date {
  color: var(--color-muted);
}

.page-meta .meta-item {
  display: inline-block;
  padding: 3px 10px;
  background-color: #eef1f6;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-primary-soft);
  font-size: 13px;
  font-weight: 500;
}

.site-footer {
  background-color: var(--color-primary);
  color: rgba(255, 255, 255, 0.78);
  margin-top: 40px;
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 20px 26px;
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 28px 32px;
}

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

.footer-brand-name {
  font-size: 17px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.footer-brand-desc {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.7);
  margin: 0;
}

.footer-title {
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 12px;
}

.footer-list li {
  margin-bottom: 4px;
}

.footer-list a {
  display: inline-block;
  padding: 6px 0;
  min-height: 32px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.74);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.14);
}

.copyright {
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px 20px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}

/* ------------------------------------------------------------
   components：按钮、标签、卡片、列表、步骤、FAQ、时间线
   ------------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease,
    border-color 0.18s ease, transform 0.18s ease;
}

.btn-primary {
  background-color: var(--color-accent);
  color: #3a2708;
  border-color: var(--color-accent);
}

.btn-primary:hover,
.btn-primary:focus {
  background-color: #d9912a;
  border-color: #d9912a;
  color: #2f1f05;
}

.btn-ghost {
  background-color: transparent;
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.55);
}

.btn-ghost:hover,
.btn-ghost:focus {
  background-color: rgba(255, 255, 255, 0.12);
  color: #ffffff;
  border-color: #ffffff;
}

.link-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary-soft);
}

.link-more::after {
  content: "→";
  font-size: 14px;
}

.link-more:hover,
.link-more:focus {
  color: var(--color-accent);
}

.status-tag {
  display: inline-block;
  padding: 2px 9px;
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  white-space: nowrap;
}

.status-open,
.status-stable {
  background-color: #e8f3ec;
  color: #24683f;
  border-color: #cbe3d5;
}

.status-review,
.status-updated {
  background-color: var(--color-accent-soft);
  color: #8a5a12;
  border-color: #f0d9b0;
}

.status-new {
  background-color: #e9eef7;
  color: var(--color-primary-soft);
  border-color: #d3ddea;
}

.date-mark,
.topic-date {
  font-size: 13px;
  font-weight: 500;
  color: var(--color-muted);
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.card-text {
  font-size: 15px;
  color: var(--color-text);
  margin-bottom: 10px;
}

.card-meta {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-muted);
  margin: 0;
}

.meta-label {
  color: var(--color-primary-soft);
  font-weight: 600;
}

.section {
  padding: 34px 0;
}

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

.section-title {
  font-size: 22px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.section-desc {
  font-size: 15px;
  color: var(--color-muted);
  max-width: 78ch;
  margin: 0;
}

.section-intro {
  font-size: 15px;
  color: var(--color-muted);
  max-width: 78ch;
  margin: 0 0 20px;
}

.section-more,
.section-note,
.section-footnote {
  margin: 22px 0 0;
  font-size: 15px;
}

.section-note a,
.section-footnote a {
  font-weight: 600;
}

/* 编号步骤清单（通用） */
.step-list {
  display: grid;
  gap: 14px;
}

.step-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 16px 18px;
  box-shadow: var(--shadow-card);
}

.step-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.step-desc {
  font-size: 15px;
  color: var(--color-text);
  margin: 0;
}

/* ------------------------------------------------------------
   pages：首页
   ------------------------------------------------------------ */
.hero-section {
  background-color: var(--color-primary);
  color: #ffffff;
  padding: 44px 0 40px;
}

.hero-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 36px;
  align-items: center;
}

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

.hero-eyebrow {
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 14px;
  font-size: 13px;
  font-weight: 600;
  color: #3a2708;
  background-color: var(--color-accent);
  border-radius: var(--radius-sm);
}

.hero-title {
  font-size: 30px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 14px;
}

.hero-lead {
  font-size: 16px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.84);
  margin-bottom: 18px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 22px;
}

.tag-item {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 6px 14px;
  font-size: 14px;
  font-weight: 500;
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--radius);
}

.tag-item:hover,
.tag-item:focus {
  color: #ffffff;
  background-color: rgba(232, 163, 61, 0.28);
  border-color: var(--color-accent);
}

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

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

.hero-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.hero-figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.66);
}

.home-main .section {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
}

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

.channel-card {
  position: relative;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 18px 18px 20px;
  box-shadow: var(--shadow-card);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.channel-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.home-main .channel-card .status-tag {
  position: absolute;
  top: 16px;
  right: 16px;
}

.home-main .channel-card .card-title {
  padding-right: 78px;
}

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

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

.topic-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.topic-figure {
  margin: 0;
}

.topic-figure img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.home-main .topic-card .card-title {
  padding: 16px 16px 0;
}

.home-main .topic-card .card-text {
  padding: 0 16px;
  margin-bottom: 10px;
}

.home-main .topic-card .card-meta {
  padding: 0 16px;
}

.home-main .topic-card .date-mark {
  display: block;
  padding: 10px 16px 16px;
  border-top: 1px solid var(--color-border);
  margin-top: 12px;
}

.prep-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  counter-reset: prep;
}

.prep-item {
  position: relative;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
}

.prep-item::before {
  counter-increment: prep;
  content: counter(prep, decimal-leading-zero);
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 6px;
}

.prep-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.prep-text {
  font-size: 15px;
  color: var(--color-text);
  margin: 0;
}

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

.boundary-col {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
}

.col-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.boundary-list li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 15px;
  color: var(--color-text);
}

.boundary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  background-color: var(--color-accent);
  border-radius: 50%;
}

/* ------------------------------------------------------------
   pages：频道分类（侧栏在左）
   ------------------------------------------------------------ */
.page-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 30px;
  align-items: start;
}

.channel-index {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
  position: sticky;
  top: 84px;
}

.aside-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.aside-desc {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 14px;
}

.channel-index-list {
  border-top: 1px solid var(--color-border);
}

.channel-index-list li {
  border-bottom: 1px solid var(--color-border);
}

.channel-index-list a {
  display: block;
  padding: 10px 2px;
  min-height: 44px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-primary-soft);
}

.channel-index-list a:hover,
.channel-index-list a:focus {
  color: var(--color-accent);
}

.aside-note {
  margin: 14px 0 0;
  font-size: 13px;
  color: var(--color-muted);
}

.aside-note a {
  font-weight: 600;
}

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

.channel-visual {
  margin: 0 0 22px;
}

.channel-visual img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.channel-visual figcaption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-muted);
}

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

.section-channel-overview .channel-card {
  padding: 0;
  overflow: hidden;
}

.channel-card-media {
  margin: 0;
}

.channel-card-media img {
  width: 100%;
  height: 150px;
  object-fit: cover;
}

.channel-card-body {
  padding: 16px 16px 18px;
}

.channel-card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.channel-card-desc {
  font-size: 15px;
  color: var(--color-text);
  margin-bottom: 10px;
}

.channel-card-fields {
  font-size: 13px;
  font-weight: 500;
  color: var(--color-muted);
  margin: 0;
}

.section-channel-overview .status-tag {
  margin-top: 10px;
}

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

.path-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow-card);
}

.path-index {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 600;
  color: #3a2708;
  background-color: var(--color-accent);
  border-radius: var(--radius-sm);
}

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

.path-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.path-desc {
  font-size: 15px;
  color: var(--color-text);
  margin: 0 0 8px;
}

.path-link {
  font-size: 14px;
  font-weight: 600;
}

.section-channel-guide .step-list {
  counter-reset: chanstep;
}

.section-channel-guide .step-item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 6px 14px;
  align-items: start;
}

.step-num {
  grid-row: span 2;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 700;
  color: var(--color-primary);
  background-color: #eef1f6;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.section-channel-guide .step-title {
  margin-bottom: 4px;
}

/* ------------------------------------------------------------
   pages：专题片单
   ------------------------------------------------------------ */
.topic-hero-media {
  margin: 0 0 24px;
}

.topic-hero-media img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.topic-hero-media figcaption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-muted);
}

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

.topic-card-media {
  margin: 0;
}

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

.topic-card-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
}

.topic-card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.topic-card-scope {
  font-size: 15px;
  color: var(--color-text);
  margin-bottom: 8px;
}

.topic-card-direction {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.topic-card-meta {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.topic-status {
  display: inline-block;
  padding: 2px 9px;
  font-size: 13px;
  font-weight: 500;
  color: #8a5a12;
  background-color: var(--color-accent-soft);
  border: 1px solid #f0d9b0;
  border-radius: var(--radius-sm);
}

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

.route-item {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px 14px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 14px 18px;
  box-shadow: var(--shadow-card);
}

.route-topic {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
}

.route-arrow {
  color: var(--color-accent);
  font-weight: 700;
}

.route-channel {
  font-size: 15px;
  color: var(--color-text);
}

.route-channel a {
  font-weight: 600;
}

.section-topic-howto .step-list {
  counter-reset: topicstep;
}

.section-topic-howto .step-item {
  position: relative;
  padding-left: 52px;
}

.section-topic-howto .step-item::before {
  counter-increment: topicstep;
  content: counter(topicstep);
  position: absolute;
  left: 18px;
  top: 16px;
  width: 24px;
  height: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  color: #3a2708;
  background-color: var(--color-accent);
  border-radius: var(--radius-sm);
}

/* ------------------------------------------------------------
   pages：观看指引
   ------------------------------------------------------------ */
.guide-overview {
  padding: 0 0 34px;
}

.guide-overview-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  gap: 28px;
  align-items: start;
  margin-top: 18px;
}

.guide-figure {
  margin: 0;
}

.guide-figure img {
  width: 100%;
  height: 250px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.guide-figure figcaption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-muted);
}

.guide-overview-text {
  min-width: 0;
}

.guide-overview-text p {
  font-size: 15px;
}

.guide-quick-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.guide-quick-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 6px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary-soft);
  background-color: #eef1f6;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.guide-quick-links a:hover,
.guide-quick-links a:focus {
  color: #3a2708;
  background-color: var(--color-accent-soft);
  border-color: #f0d9b0;
}

.guide-prepare,
.guide-steps,
.guide-faq {
  padding: 30px 0;
  border-top: 1px solid var(--color-border);
}

.guide-prepare .step-list {
  counter-reset: guidestep;
}

.guide-prepare .step-item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 6px 14px;
  align-items: start;
}

.guide-prepare .step-index {
  grid-row: span 2;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 700;
  color: #3a2708;
  background-color: var(--color-accent);
  border-radius: var(--radius-sm);
}

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

.guide-prepare .step-title {
  margin-bottom: 4px;
}

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

.step-card {
  display: flex;
  flex-direction: column;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-top: 3px solid var(--color-accent);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
}

.step-badge {
  display: inline-block;
  margin-bottom: 10px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-muted);
}

.step-card-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.step-card p {
  font-size: 15px;
  margin-bottom: 12px;
}

.step-link {
  margin-top: auto;
  font-size: 14px;
  font-weight: 600;
}

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

.faq-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.faq-question {
  cursor: pointer;
  padding: 16px 44px 16px 18px;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  position: relative;
  list-style: none;
  min-height: 44px;
}

.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: 500;
  color: var(--color-accent);
}

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

.faq-answer {
  padding: 0 18px 16px;
  border-top: 1px solid var(--color-border);
}

.faq-answer p {
  font-size: 15px;
  margin: 14px 0 0;
}

/* ------------------------------------------------------------
   pages：收录边界与反馈
   ------------------------------------------------------------ */
.boundary-col-included {
  border-top: 3px solid #24683f;
}

.boundary-col-excluded {
  border-top: 3px solid #b4553f;
}

.boundary-col-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.boundary-item {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 15px;
  color: var(--color-text);
}

.boundary-col-included .boundary-item::before,
.boundary-col-excluded .boundary-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.boundary-col-included .boundary-item::before {
  background-color: #24683f;
}

.boundary-col-excluded .boundary-item::before {
  background-color: #b4553f;
}

.boundary-figure {
  margin: 22px 0 0;
}

.boundary-figure img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.figure-caption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-muted);
}

.feedback-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.feedback-col {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
}

.feedback-col-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 14px;
}

.feedback-col .step-list {
  counter-reset: fbstep;
}

.feedback-col .step-item {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  gap: 4px 12px;
  padding: 14px 0 0;
  border: 0;
  border-top: 1px solid var(--color-border);
  border-radius: 0;
  box-shadow: none;
  background-color: transparent;
}

.feedback-col .step-item:first-child {
  border-top: 0;
  padding-top: 0;
}

.feedback-col .step-index {
  grid-row: span 2;
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  color: var(--color-primary);
  background-color: #eef1f6;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.feedback-col .step-title {
  font-size: 17px;
  margin-bottom: 4px;
}

.feedback-list {
  margin: 0;
}

.feedback-item {
  font-size: 15px;
  color: var(--color-text);
  margin-bottom: 8px;
}

.feedback-note {
  margin: 16px 0 0;
  font-size: 14px;
  color: var(--color-muted);
}

.timeline-list {
  position: relative;
  padding-left: 20px;
  border-left: 2px solid var(--color-border);
  display: grid;
  gap: 18px;
}

.timeline-item {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 12px;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 10px;
  width: 10px;
  height: 10px;
  background-color: var(--color-surface);
  border: 2px solid var(--color-accent);
  border-radius: 50%;
}

.timeline-date {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
}

.timeline-tag {
  display: inline-block;
  padding: 2px 9px;
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background-color: #eef1f6;
  color: var(--color-primary-soft);
}

.timeline-tag-scope {
  background-color: #e8f3ec;
  border-color: #cbe3d5;
  color: #24683f;
}

.timeline-tag-topic {
  background-color: var(--color-accent-soft);
  border-color: #f0d9b0;
  color: #8a5a12;
}

.timeline-tag-guide {
  background-color: #e9eef7;
  border-color: #d3ddea;
  color: var(--color-primary-soft);
}

.timeline-tag-field {
  background-color: #f3eef8;
  border-color: #ded0ec;
  color: #5a3a80;
}

.timeline-body {
  flex: 1 1 260px;
  min-width: 0;
}

.timeline-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0 0 4px;
}

.timeline-desc {
  font-size: 15px;
  color: var(--color-text);
  margin: 0;
}

.changelog-note {
  margin: 22px 0 0;
  font-size: 15px;
}

.changelog-note a {
  font-weight: 600;
}

/* ------------------------------------------------------------
   pages：404
   ------------------------------------------------------------ */
.error-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 50px 20px 60px;
}

.error-panel {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 26px;
  box-shadow: var(--shadow-card);
}

.error-code {
  font-size: 40px;
  font-weight: 700;
  color: var(--color-accent);
  margin: 0 0 8px;
}

.error-panel h1 {
  font-size: 26px;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 16px;
  color: var(--color-muted);
  max-width: 70ch;
  margin-bottom: 20px;
}

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

.error-actions .btn-ghost {
  color: var(--color-primary);
  border-color: var(--color-border-strong);
}

.error-actions .btn-ghost:hover,
.error-actions .btn-ghost:focus {
  color: var(--color-primary);
  background-color: #eef1f6;
  border-color: var(--color-primary-soft);
}

.error-help {
  margin-top: 34px;
  padding-top: 26px;
  border-top: 1px solid var(--color-border);
}

.error-help h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.error-help p {
  font-size: 15px;
  color: var(--color-muted);
  max-width: 70ch;
  margin-bottom: 14px;
}

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

.error-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary-soft);
  background-color: #eef1f6;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.error-links a:hover,
.error-links a:focus {
  color: #3a2708;
  background-color: var(--color-accent-soft);
  border-color: #f0d9b0;
}

/* ------------------------------------------------------------
   responsive：≤1024px 与 ≤768px / 390px
   ------------------------------------------------------------ */
@media (max-width: 1024px) {
  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-layout {
    grid-template-columns: 230px minmax(0, 1fr);
    gap: 24px;
  }
}

@media (max-width: 768px) {
  h1,
  .page-title,
  .hero-title {
    font-size: 24px;
  }

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

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

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

  .nav-toggle {
    display: flex;
  }

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

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    border-top: 1px solid rgba(255, 255, 255, 0.16);
    padding-top: 6px;
  }

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

  .nav-list a {
    padding: 12px 4px;
    min-height: 44px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 0;
  }

  .nav-list a.is-current {
    color: var(--color-accent);
    border-bottom-color: rgba(255, 255, 255, 0.12);
  }

  .inner-main {
    padding: 16px 16px 44px;
  }

  .page-header {
    padding: 2px 0 20px;
    margin-bottom: 22px;
  }

  .hero-section {
    padding: 30px 0 28px;
  }

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

  .hero-figure {
    order: -1;
  }

  .hero-figure img {
    height: 210px;
  }

  .home-main .section {
    padding-left: 16px;
    padding-right: 16px;
  }

  .channel-grid,
  .topic-grid,
  .prep-list,
  .boundary-grid,
  .feedback-grid,
  .section-channel-overview .channel-grid,
  .section-topic-overview .topic-grid {
    grid-template-columns: minmax(0, 1fr);
  }

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

  .channel-index {
    position: static;
  }

  .guide-overview-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

  .guide-figure img,
  .channel-visual img,
  .topic-hero-media img,
  .boundary-figure img {
    height: 200px;
  }

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

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    padding: 32px 16px 20px;
  }

  .copyright {
    padding: 14px 16px;
  }

  .error-main {
    padding: 34px 16px 46px;
  }

  .error-panel {
    padding: 24px 18px;
  }

  .timeline-list {
    padding-left: 16px;
  }

  .timeline-item::before {
    left: -23px;
  }
}

@media (max-width: 420px) {
  .brand-slogan {
    font-size: 11px;
  }

  .hero-title {
    font-size: 22px;
  }

  .btn {
    width: 100%;
  }

  .hero-actions {
    flex-direction: column;
  }

  .error-actions {
    flex-direction: column;
  }

  .section-channel-guide .step-item,
  .guide-prepare .step-item,
  .feedback-col .step-item {
    grid-template-columns: minmax(0, 1fr);
  }

  .section-channel-guide .step-num,
  .guide-prepare .step-index,
  .feedback-col .step-index {
    grid-row: auto;
  }

  .section-topic-howto .step-item {
    padding-left: 46px;
  }
}

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

  .channel-card:hover,
  .topic-card:hover {
    transform: none;
  }
}