/* ============================================================
   base — reset, variables, typography
   ============================================================ */
:root {
  --bg-main: #ffffff;
  --bg-sub: #f5f6f8;
  --bg-code: #101820;
  --text-main: #1c232b;
  --text-sub: #5a6670;
  --line: #e3e7ea;
  --accent: #2a6b9a;
  --accent-soft: #e8f1f7;
  --tag-bg: #f5f6f8;
  --status-live: #1e7f4f;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --container: 1200px;
  --gap: 24px;
  --gap-lg: 40px;
  --gap-xl: 64px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --shadow-sm: 0 1px 2px rgba(16, 24, 32, 0.04);
  --shadow-md: 0 2px 8px rgba(16, 24, 32, 0.06);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  line-height: 1.75;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg-main);
  color: var(--text-main);
  line-height: 1.75;
}

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

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

a:hover {
  text-decoration: underline;
}

ul,
ol {
  list-style: none;
}

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

h1 {
  font-size: 24px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 18px;
}

p {
  color: var(--text-main);
}

/* ============================================================
   layout — shared shell
   ============================================================ */
.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-header {
  background: var(--bg-main);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gap);
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
}

.site-nav {
  display: block;
}

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

.nav-list a {
  display: block;
  padding: 8px 16px;
  color: var(--text-sub);
  font-size: 15px;
  line-height: 1.4;
  border-radius: var(--radius-sm);
  border-bottom: 2px solid transparent;
}

.nav-list a:hover {
  color: var(--accent);
  text-decoration: none;
  background: var(--accent-soft);
}

.nav-list a.is-current {
  color: var(--accent);
  font-weight: 600;
  border-bottom-color: var(--accent);
}

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

.inner-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--gap) var(--gap) var(--gap-xl);
}

/* breadcrumb */
.breadcrumb {
  font-size: 14px;
  color: var(--text-sub);
  padding: 16px 0 8px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

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

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

.breadcrumb-sep {
  color: var(--line);
  margin: 0 2px;
}

.breadcrumb-current {
  color: var(--text-main);
  font-weight: 500;
}

/* page header */
.page-header {
  padding: 16px 0 32px;
}

.page-title {
  font-size: 24px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 8px;
}

.page-description {
  color: var(--text-sub);
  font-size: 16px;
  max-width: 720px;
}

/* ============================================================
   components — shared
   ============================================================ */
/* buttons */
.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 15px;
  line-height: 1.2;
  padding: 12px 28px;
  border-radius: var(--radius-md);
  min-height: 44px;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  border: 1px solid var(--accent);
}

.btn-primary:hover {
  background: #245a82;
  text-decoration: none;
}

.btn-secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.btn-secondary:hover {
  background: var(--accent-soft);
  text-decoration: none;
}

/* section titles */
.section-title {
  font-size: 22px;
  margin-bottom: 8px;
}

.section-desc {
  color: var(--text-sub);
  margin-bottom: 24px;
  max-width: 640px;
}

.section-note {
  color: var(--text-sub);
  font-size: 15px;
  margin-bottom: 16px;
}

/* status badges */
.status-badge,
.status-live,
.status-end {
  display: inline-flex;
  align-items: center;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  line-height: 1.6;
  white-space: nowrap;
}

.status-live,
.status-badge {
  background: rgba(30, 127, 79, 0.12);
  color: var(--status-live);
}

.status-badge.status-live {
  background: rgba(30, 127, 79, 0.12);
  color: var(--status-live);
}

.status-end {
  background: var(--tag-bg);
  color: var(--text-sub);
}

/* related links strip */
.related-links {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gap) 48px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.related-links-label {
  color: var(--text-sub);
  font-size: 14px;
  font-weight: 600;
}

.related-links-item {
  color: var(--accent);
  font-size: 14px;
  padding: 6px 12px;
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
}

.related-links-item:hover {
  text-decoration: none;
  background: #dbe8f2;
}

/* footer */
.site-footer {
  background: var(--bg-main);
  border-top: 1px solid var(--line);
}

.footer-columns {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gap) 24px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
}

.footer-logo {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
}

.footer-brand p {
  color: var(--text-sub);
  font-size: 14px;
  margin-bottom: 8px;
  max-width: 320px;
}

.footer-boundary {
  font-size: 13px;
  color: var(--text-sub);
  opacity: 0.8;
}

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

.footer-links ul,
.footer-meta ul {
  display: grid;
  gap: 8px;
}

.footer-links a,
.footer-meta a {
  color: var(--text-sub);
  font-size: 14px;
}

.footer-links a:hover,
.footer-meta a:hover {
  color: var(--accent);
}

.copyright {
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-sub);
  opacity: 0.8;
}

/* ============================================================
   components — index
   ============================================================ */
.home-main {
  width: 100%;
}

/* hero */
.hero {
  background: var(--bg-sub);
  border-bottom: 1px solid var(--line);
}

.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gap) 48px;
  gap: 48px;
}

.hero-content h1 {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 16px;
}

.hero-lead {
  color: var(--text-sub);
  font-size: 17px;
  margin-bottom: 24px;
  max-width: 520px;
}

.hero-media {
  position: relative;
}

.hero-figure {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  aspect-ratio: 4 / 3;
}

.hero-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* channel filter */
.channel-filter {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gap) 8px;
}

.filter-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 16px;
}

.filter-tag {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--bg-sub);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-main);
  min-height: 40px;
  transition: all 0.2s ease;
}

.filter-tag:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

/* video row list */
.video-row-list {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px var(--gap) 8px;
}

.video-row-list h2 {
  margin-bottom: 4px;
}

.video-list {
  margin-top: 24px;
  display: grid;
  gap: 12px;
}

.video-row {
  display: grid;
  grid-template-columns: 140px 1fr;
  align-items: center;
  gap: 20px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--bg-main);
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.video-row:hover {
  box-shadow: var(--shadow-md);
  border-color: #d0d7dd;
}

.row-thumb {
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--bg-sub);
}

.row-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.video-name {
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
}

.video-channel {
  color: var(--accent);
  font-size: 13px;
  font-weight: 500;
}

.video-tags {
  color: var(--text-sub);
  font-size: 13px;
}

.video-row .status-live {
  align-self: flex-start;
}

/* daily schedule */
.daily-schedule {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gap);
}

.daily-schedule .section-note {
  margin-bottom: 20px;
}

.daily-picks {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.daily-card {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.daily-card h3 {
  font-size: 18px;
}

.daily-card p {
  color: var(--text-sub);
  font-size: 14px;
  flex: 1;
}

.daily-card a {
  font-size: 14px;
  font-weight: 600;
}

.daily-card .status-badge {
  align-self: flex-start;
}

/* topic crossline */
.topic-crossline {
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px var(--gap) 48px;
}

.topic-track {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.topic-card {
  background: var(--bg-main);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: var(--shadow-md);
}

.topic-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.topic-card h3 {
  font-size: 16px;
  padding: 12px 16px 2px;
}

.topic-tag {
  display: inline-block;
  color: var(--accent);
  font-size: 13px;
  padding: 0 16px;
}

.topic-card p {
  color: var(--text-sub);
  font-size: 14px;
  padding: 4px 16px 16px;
}

/* guide preview */
.guide-preview {
  background: var(--bg-sub);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.guide-preview {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gap);
}

.guide-preview h2 {
  margin-bottom: 12px;
}

.guide-preview p {
  color: var(--text-sub);
  max-width: 640px;
  margin-bottom: 20px;
}

/* faq preview */
.faq-preview {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gap) 16px;
}

.faq-preview h2 {
  margin-bottom: 16px;
}

.faq-preview .faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  background: var(--bg-main);
}

.faq-preview summary {
  padding: 16px 20px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

.faq-preview .faq-item p {
  padding: 0 20px 16px;
  color: var(--text-sub);
  font-size: 14px;
}

.link-more {
  display: inline-block;
  margin-top: 8px;
  font-weight: 600;
  color: var(--accent);
}

/* boundary note */
.boundary-note {
  max-width: var(--container);
  margin: 0 auto;
  padding: 24px var(--gap) 48px;
}

.boundary-note p {
  background: var(--bg-sub);
  border-left: 3px solid var(--accent);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-sub);
  font-size: 14px;
}

/* ============================================================
   components — inner page shared
   ============================================================ */
.section-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

/* content media inline */
.content-media-inline {
  margin: 24px 0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.content-media-inline img {
  width: 100%;
  max-height: 320px;
  object-fit: cover;
}

.content-media-inline figcaption {
  background: var(--bg-sub);
  padding: 8px 16px;
  font-size: 13px;
  color: var(--text-sub);
  text-align: center;
}

/* ============================================================
   components — tangxin-vlog page
   ============================================================ */
.channel-filter .filter-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 20px 0;
}

.filter-btn {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--bg-sub);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-main);
  cursor: pointer;
  min-height: 40px;
  transition: all 0.2s ease;
}

.filter-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

.filter-btn.is-active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.channel-overview {
  margin: 24px 0;
}

.channel-card {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 20px;
  background: var(--bg-main);
}

.channel-media {
  border-radius: var(--radius-sm);
  overflow: hidden;
  aspect-ratio: 16 / 9;
}

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

.channel-info h3 {
  font-size: 20px;
  margin-bottom: 8px;
}

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

/* tag manager */
.tag-manager {
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.tag-input-area {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 16px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent-soft);
  border-radius: 999px;
  padding: 4px 6px 4px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
}

.tag-remove {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: none;
  background: transparent;
  color: var(--accent);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.tag-remove:hover {
  background: rgba(42, 107, 154, 0.12);
}

.tag-entry {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.tag-input {
  flex: 1;
  min-width: 220px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-family: inherit;
  background: var(--bg-main);
}

.tag-input:focus {
  outline: none;
  border-color: var(--accent);
}

.tag-hint {
  color: var(--text-sub);
  font-size: 13px;
}

/* video list */
.video-row-list {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.video-row-item {
  display: grid;
  grid-template-columns: 160px 1fr auto;
  gap: 16px;
  align-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--bg-main);
}

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

.row-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.row-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 4px;
}

.meta-channel {
  color: var(--accent);
  font-size: 13px;
  font-weight: 500;
}

.meta-tag {
  color: var(--text-sub);
  font-size: 13px;
  background: var(--tag-bg);
  padding: 2px 10px;
  border-radius: 999px;
}

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

.row-status {
  display: flex;
  align-items: center;
}

.list-footnote {
  margin-top: 24px;
  color: var(--text-sub);
  font-size: 14px;
  display: flex;
  gap: 16px;
}

.list-footnote a {
  font-weight: 600;
}

/* ============================================================
   components — topic page
   ============================================================ */
.topic-grid-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.topic-card {
  background: var(--bg-main);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: var(--shadow-md);
}

.topic-card-media {
  aspect-ratio: 16 / 10;
  overflow: hidden;
}

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

.topic-card-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.topic-card-title {
  font-size: 18px;
  font-weight: 600;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.topic-tags .tag {
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 999px;
}

.topic-card-desc {
  color: var(--text-sub);
  font-size: 14px;
  flex: 1;
}

.topic-card-link {
  font-size: 14px;
  font-weight: 600;
  align-self: flex-start;
}

/* topic detail */
.topic-detail {
  margin-top: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.topic-detail-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 40px;
  margin-top: 24px;
}

.topic-detail-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 20px;
}

.topic-detail-figure img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
}

.topic-detail-figure figcaption {
  background: var(--bg-sub);
  padding: 8px 16px;
  font-size: 13px;
  color: var(--text-sub);
}

.topic-detail-subhead {
  font-size: 19px;
  margin: 20px 0 8px;
}

.topic-detail-main p {
  color: var(--text-sub);
  margin-bottom: 8px;
}

.topic-detail-list {
  list-style: disc;
  padding-left: 20px;
  display: grid;
  gap: 6px;
}

.topic-detail-list li {
  color: var(--text-sub);
}

.topic-more-link {
  margin-top: 16px;
}

.topic-more-link a {
  font-weight: 600;
}

.topic-detail-aside {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 24px;
  align-self: flex-start;
  border: 1px solid var(--line);
}

.aside-title {
  font-size: 17px;
  margin-bottom: 16px;
}

.related-topics {
  display: grid;
  gap: 12px;
}

.related-topics a {
  display: block;
  padding: 10px 12px;
  background: var(--bg-main);
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-main);
}

.related-topics a:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

/* related section */
.related {
  margin-top: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.related-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg-main);
}

.related-card-media {
  aspect-ratio: 16 / 10;
  overflow: hidden;
}

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

.related-card-body {
  padding: 16px;
}

.related-card-title {
  font-size: 16px;
  margin-bottom: 8px;
}

.related-more {
  margin-top: 20px;
  text-align: center;
}

.related-more a {
  font-weight: 600;
}

/* ============================================================
   components — guide page
   ============================================================ */
.access-steps {
  margin-bottom: 48px;
}

.steps-list {
  counter-reset: step;
  display: grid;
  gap: 20px;
  margin-top: 24px;
}

.step-item {
  counter-increment: step;
}

.step-card {
  display: grid;
  grid-template-columns: 1fr 200px;
  gap: 24px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 24px;
  background: var(--bg-main);
  position: relative;
}

.step-card h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.step-card h3::before {
  content: counter(step) ".";
  color: var(--accent);
  margin-right: 8px;
}

.step-card p {
  color: var(--text-sub);
  font-size: 15px;
}

.step-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

/* verification list */
.verification-list {
  margin-bottom: 48px;
}

.check-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.check-item {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1px solid var(--line);
}

.check-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.check-item h3::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
}

.check-item p {
  color: var(--text-sub);
  font-size: 14px;
}

/* notice */
.notice {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 32px;
  border: 1px solid var(--line);
}

.notice h2 {
  margin-bottom: 8px;
}

.notice > p {
  color: var(--text-sub);
  margin-bottom: 16px;
}

.notice ul {
  list-style: disc;
  padding-left: 20px;
  display: grid;
  gap: 8px;
}

.notice li {
  color: var(--text-sub);
  font-size: 15px;
}

/* ============================================================
   components — faq page
   ============================================================ */
.faq-group {
  margin-bottom: 48px;
}

.faq-list {
  margin-top: 24px;
  display: grid;
  gap: 12px;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--bg-main);
}

.faq-item summary {
  padding: 18px 20px;
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 22px;
  color: var(--accent);
  flex-shrink: 0;
  font-weight: 400;
}

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

.faq-item[open] summary {
  border-bottom: 1px solid var(--line);
}

.faq-item > p {
  padding: 16px 20px;
  color: var(--text-sub);
  font-size: 15px;
}

/* feedback guide */
.feedback-guide {
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.guide-columns {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.guide-card {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--line);
}

.guide-card h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.guide-card p {
  color: var(--text-sub);
  font-size: 14px;
  margin-bottom: 16px;
}

.text-link {
  font-weight: 600;
}

.more-about {
  margin-top: 20px;
}

.more-about a {
  font-weight: 600;
}

/* ============================================================
   components — feedback page
   ============================================================ */
.feedback-types {
  margin-bottom: 48px;
}

.section-intro {
  color: var(--text-sub);
  margin-bottom: 24px;
  max-width: 640px;
}

.feedback-type-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feedback-type-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 24px;
  background: var(--bg-main);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.type-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.type-card-head h3 {
  font-size: 18px;
}

.type-tag {
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 999px;
  white-space: nowrap;
}

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

.type-suggestion {
  color: var(--text-main);
  font-size: 14px;
  background: var(--bg-sub);
  padding: 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--accent);
}

/* prepare list */
.prepare-list {
  margin-bottom: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.prepare-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.prepare-item {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--line);
}

.prepare-item h3 {
  font-size: 16px;
  margin-bottom: 12px;
}

.check-list {
  display: grid;
  gap: 8px;
}

.check-list li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 14px;
  color: var(--text-sub);
}

.check-list li::before {
  content: "✓";
  color: var(--status-live);
  font-weight: 700;
  flex-shrink: 0;
}

/* process */
.process {
  margin-bottom: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

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

.process-step {
  background: var(--bg-main);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 20px;
  position: relative;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 50%;
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 12px;
}

.process-step h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.process-step p {
  color: var(--text-sub);
  font-size: 14px;
}

/* other help */
.other-help {
  margin-bottom: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.help-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.help-links p {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 16px;
}

.help-links a {
  font-weight: 600;
}

/* ============================================================
   components — about page
   ============================================================ */
.about-content {
  margin-bottom: 48px;
}

.about-intro {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
}

.about-text h2 {
  margin-bottom: 16px;
}

.about-text p {
  color: var(--text-sub);
  margin-bottom: 12px;
}

.about-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
}

.about-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

/* site map */
.site-map {
  margin-bottom: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.map-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.map-item {
  background: var(--bg-sub);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.map-item h3 {
  font-size: 17px;
}

.map-item p {
  color: var(--text-sub);
  font-size: 14px;
  flex: 1;
}

.map-item a {
  font-weight: 600;
  font-size: 14px;
  align-self: flex-start;
}

/* editorial principles */
.editorial-principles {
  margin-bottom: 48px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.principle-item {
  background: var(--bg-main);
  border-left: 3px solid var(--accent);
  padding: 20px 24px;
  margin-bottom: 16px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--bg-sub);
}

.principle-item h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.principle-item p {
  color: var(--text-sub);
  font-size: 15px;
}

/* contact note */
.contact-note {
  border-top: 1px solid var(--line);
  padding-top: 40px;
}

.contact-note h2 {
  margin-bottom: 12px;
}

.contact-note p {
  color: var(--text-sub);
  max-width: 640px;
  margin-bottom: 24px;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.contact-links a {
  font-weight: 600;
  background: var(--accent-soft);
  padding: 10px 20px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   components — 404
   ============================================================ */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px var(--gap);
}

.error-panel {
  text-align: center;
  max-width: 560px;
  width: 100%;
}

.error-code {
  font-size: 80px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-panel h1 {
  font-size: 28px;
  margin-bottom: 16px;
}

.error-desc {
  color: var(--text-sub);
  margin-bottom: 12px;
}

.error-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
  flex-wrap: wrap;
}

/* ============================================================
   responsive
   ============================================================ */
@media (min-width: 1025px) {
  h1 {
    font-size: 32px;
  }
}

@media (max-width: 1024px) {
  .topic-grid-list {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .topic-detail-layout {
    grid-template-columns: 1fr;
  }

  .topic-detail-aside {
    display: none;
  }

  .footer-columns {
    grid-template-columns: 1fr 1fr;
  }

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

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

  .feedback-type-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .about-intro {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .header-inner {
    min-height: 56px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--bg-main);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 8px 0;
    gap: 0;
  }

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

  .nav-list a {
    padding: 14px 24px;
    border-radius: 0;
    border-bottom: none;
    border-left: 3px solid transparent;
  }

  .nav-list a.is-current {
    border-left-color: var(--accent);
    background: var(--accent-soft);
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px var(--gap);
  }

  .hero-content h1 {
    font-size: 26px;
  }

  .video-row {
    grid-template-columns: 100px 1fr;
    gap: 12px;
  }

  .daily-picks {
    grid-template-columns: 1fr;
  }

  .topic-track {
    grid-template-columns: 1fr;
  }

  .step-card {
    grid-template-columns: 1fr;
  }

  .step-card img {
    order: -1;
  }

  .check-grid {
    grid-template-columns: 1fr;
  }

  .guide-columns {
    grid-template-columns: 1fr;
  }

  .video-row-item {
    grid-template-columns: 1fr;
  }

  .row-status {
    grid-column: 1;
  }

  .channel-card {
    grid-template-columns: 1fr;
  }

  .footer-columns {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px var(--gap) 16px;
  }

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

  .topic-grid-list {
    grid-template-columns: 1fr;
  }

  .related-grid {
    grid-template-columns: 1fr;
  }

  .process-steps {
    grid-template-columns: 1fr;
  }

  .feedback-type-grid {
    grid-template-columns: 1fr;
  }

  .prepare-grid {
    grid-template-columns: 1fr;
  }

  .help-links {
    grid-template-columns: 1fr;
  }

  .map-grid {
    grid-template-columns: 1fr;
  }

  .inner-main {
    padding: 16px var(--gap) 48px;
  }

  .page-header {
    padding: 8px 0 24px;
  }

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

  .related-links {
    padding: 0 var(--gap) 32px;
  }

  .error-main {
    padding: 48px var(--gap);
  }

  .error-code {
    font-size: 56px;
  }
}

@media (max-width: 480px) {
  .header-inner,
  .inner-main,
  .hero,
  .channel-filter,
  .video-row-list,
  .daily-schedule,
  .topic-crossline,
  .guide-preview,
  .faq-preview,
  .boundary-note,
  .footer-columns,
  .related-links {
    padding-left: 16px;
    padding-right: 16px;
  }

  .video-row {
    grid-template-columns: 1fr;
  }

  .row-thumb {
    max-width: 240px;
  }

  .video-row-item {
    grid-template-columns: 1fr;
  }

  .row-content {
    grid-column: 1;
  }

  .row-status {
    grid-column: 1;
  }
}

/* reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
  }
}