:root {
  --paper: #FAF7F2;
  --ink: #1E2A44;
  --indigo: #3548B8;
  --coral: #F2555A;
  --indigo-soft: #EDF0FA;
  --rule: #D8D3C9;
  --ink-soft: #5A6478;
  --ink-mute: #7C8698;
  --header-h: 72px;
  --header-h-shrink: 60px;
  --wrap: 1120px;
  --prose: 760px;
  --radius: 6px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", sans-serif;
  --font-mono: "SFMono-Regular", "SF Mono", Consolas, "Liberation Mono", Menlo, "Courier New", monospace;
}

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

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

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

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

a {
  color: var(--indigo);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--coral);
  text-decoration-thickness: 2px;
}

h1,
h2,
h3,
h4 {
  color: var(--ink);
  line-height: 1.35;
  margin: 0 0 0.5em;
  font-weight: 700;
}

h1 {
  font-size: 34px;
}

h2 {
  font-size: 26px;
}

h3 {
  font-size: 19px;
}

p {
  margin: 0 0 1em;
}

ul,
ol {
  margin: 0 0 1em;
  padding-left: 1.4em;
}

li {
  margin: 0 0 6px;
}

figure {
  margin: 0;
}

figcaption {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.6;
  margin-top: 8px;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}

/* =========================================================
   layout — shell, wrappers, header, footer
   ========================================================= */

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: var(--paper);
  border-bottom: 1px solid var(--rule);
  height: var(--header-h);
  transition: height 0.2s ease;
}

.site-header.is-shrunk {
  height: var(--header-h-shrink);
}

.header-inner {
  max-width: var(--wrap);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  line-height: 1.2;
}

.brand:hover {
  color: var(--indigo);
  text-decoration: none;
}

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

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-list li {
  margin: 0;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  font-size: 15px;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  line-height: 1.2;
}

.nav-link:hover {
  color: var(--coral);
  text-decoration: none;
  border-bottom-color: var(--coral);
}

.nav-link.is-current {
  color: var(--indigo);
  border-bottom-color: var(--coral);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  width: 44px;
  height: 44px;
  padding: 0;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  margin-left: auto;
}

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

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

.inner-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px 64px;
}

.home-main {
  width: 100%;
}

.site-footer {
  border-top: 1px solid var(--rule);
  padding: 40px 24px 24px;
  margin-top: 48px;
}

.footer-top {
  max-width: var(--wrap);
  margin: 0 auto 28px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr);
  gap: 24px 40px;
  align-items: end;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--rule);
}

.footer-brand-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 4px;
}

.footer-slogan {
  margin: 0;
  font-size: 14px;
  color: var(--indigo);
  font-weight: 600;
}

.footer-position {
  margin: 0;
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.footer-nav {
  max-width: var(--wrap);
  margin: 0 auto 28px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px 32px;
}

.footer-col-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
}

.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-col li {
  margin: 0 0 6px;
}

.footer-col a {
  font-size: 14px;
  color: var(--ink-soft);
  text-decoration: none;
}

.footer-col a:hover {
  color: var(--coral);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.footer-bottom {
  max-width: var(--wrap);
  margin: 0 auto;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
}

.footer-copy {
  margin: 0;
  font-size: 13px;
  color: var(--ink-mute);
}

/* breadcrumb + page header (shared inner-page skeleton) */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--ink-mute);
  padding: 20px 0 0;
  margin: 0;
}

.breadcrumb a {
  color: var(--ink-soft);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--coral);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

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

.breadcrumb-current {
  color: var(--ink);
  font-weight: 600;
}

.page-header {
  padding: 16px 0 8px;
}

.page-title {
  font-size: 34px;
  font-weight: 700;
  color: var(--ink);
  margin: 0;
  line-height: 1.35;
}

.page-layout {
  display: grid;
  gap: 40px;
  align-items: start;
}

.sidebar-left .page-layout,
.page-layout.sidebar-left {
  grid-template-columns: 240px minmax(0, 1fr);
}

/* generic section rhythm (inner pages) */

.content-section,
.content-block {
  margin: 0 0 48px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--rule);
}

.content-block:last-child,
.content-section:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.section-title {
  font-size: 26px;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

.section-intro,
.section-note,
.section-desc,
.section-lead {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0 0 20px;
  max-width: var(--prose);
}

.section-link {
  display: inline-block;
  font-size: 15px;
  font-weight: 600;
  color: var(--indigo);
  margin-top: 8px;
}

/* =========================================================
   components — buttons, lists, tables, FAQ, steps
   ========================================================= */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  text-decoration: none;
  line-height: 1.2;
  border: 1px solid transparent;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn-primary {
  background-color: var(--coral);
  color: #fff;
  border-color: var(--coral);
}

.btn-primary:hover {
  background-color: #D93F44;
  border-color: #D93F44;
  color: #fff;
  text-decoration: none;
}

.btn-outline {
  background-color: transparent;
  color: var(--indigo);
  border-color: var(--indigo);
}

.btn-outline:hover {
  background-color: var(--indigo-soft);
  color: var(--indigo);
  text-decoration: none;
}

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

.btn-ghost:hover {
  color: var(--ink);
  border-color: var(--ink-soft);
  text-decoration: none;
}

/* numbered index rows (home) */

.numbered-index {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.index-row {
  display: grid;
  grid-template-columns: 48px 120px minmax(0, 1fr) 96px auto;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.index-no {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  color: var(--indigo);
}

.index-genre {
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
}

.index-feature {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.index-status {
  font-size: 13px;
  color: var(--indigo);
  background-color: var(--indigo-soft);
  border-radius: 4px;
  padding: 2px 8px;
  text-align: center;
  white-space: nowrap;
}

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

/* entry rows (catalog) */

.entry-list {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.entry-row {
  display: grid;
  grid-template-columns: 44px 140px minmax(0, 1fr) 90px auto;
  align-items: baseline;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.entry-no {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--indigo);
}

.entry-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
}

.entry-feature {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.entry-status {
  font-size: 13px;
  color: var(--indigo);
  background-color: var(--indigo-soft);
  border-radius: 4px;
  padding: 2px 8px;
  text-align: center;
  white-space: nowrap;
}

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

/* topic tags */

.topic-tag {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 14px;
  font-size: 14px;
  color: var(--indigo);
  background-color: var(--indigo-soft);
  border-radius: 4px;
  text-decoration: none;
  line-height: 1.4;
}

.topic-tag:hover {
  background-color: var(--coral);
  color: #fff;
  text-decoration: none;
}

/* tables */

.table-scroll,
.table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 0 0 16px;
}

.compare-table,
.device-table,
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  line-height: 1.7;
}

.table-caption {
  caption-side: top;
  text-align: left;
  font-size: 14px;
  color: var(--ink-mute);
  padding: 0 0 10px;
}

.compare-table th,
.compare-table td,
.device-table th,
.device-table td,
.data-table th,
.data-table td {
  border: 1px solid var(--rule);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}

.compare-table thead th,
.device-table thead th,
.data-table thead th {
  background-color: var(--indigo-soft);
  color: var(--ink);
  font-weight: 700;
}

.compare-table tbody th,
.device-table tbody th,
.data-table tbody th {
  background-color: #F3EFE8;
  font-weight: 600;
  color: var(--ink);
}

.table-note {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
}

/* FAQ */

.faq-list {
  border-top: 1px solid var(--rule);
}

.faq-item {
  border-bottom: 1px solid var(--rule);
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 14px 32px 14px 0;
  position: relative;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.6;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 14px;
  font-size: 20px;
  font-weight: 400;
  color: var(--indigo);
  line-height: 1.4;
}

.faq-item[open] summary::after {
  content: "−";
  color: var(--coral);
}

.faq-item summary:hover {
  color: var(--indigo);
}

.faq-answer,
.faq-item > p {
  padding: 0 32px 16px 0;
  margin: 0;
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
}

.faq-answer p {
  margin: 0 0 10px;
}

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

/* steps */

.step-list {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  counter-reset: step;
}

.step-item {
  position: relative;
  padding: 14px 0 14px 52px;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.step-item:last-child {
  border-bottom: none;
}

.step-no,
.step-index {
  position: absolute;
  left: 0;
  top: 14px;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  color: var(--indigo);
  background-color: var(--indigo-soft);
  border-radius: 50%;
}

.step-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 4px;
  line-height: 1.5;
}

.step-desc {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.step-result {
  font-size: 14px;
  color: var(--ink-mute);
  margin: 6px 0 0;
  line-height: 1.7;
}

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

/* related links */

.related-links {
  margin: 32px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 20px;
}

.related-links-label {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
}

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

.related-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px 24px;
}

.related-item {
  margin: 0;
  padding: 8px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 15px;
}

/* point list (copyright) */

.point-list {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
}

.point-list li {
  position: relative;
  padding: 8px 0 8px 20px;
  border-bottom: 1px solid var(--rule);
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.point-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 18px;
  width: 6px;
  height: 6px;
  background-color: var(--coral);
  border-radius: 50%;
}

/* =========================================================
   pages — home
   ========================================================= */

.hero {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 48px 24px 40px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 40px;
  align-items: center;
}

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

.hero-text h1 {
  font-size: 34px;
  margin: 0 0 16px;
}

.hero-lead {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 10px;
}

.hero-sub {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0 0 24px;
}

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

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

.hero-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.home-main > section {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 40px 24px;
  border-top: 1px solid var(--rule);
}

.home-main > section.hero {
  border-top: none;
}

.home-main > section h2 {
  margin: 0 0 8px;
}

.topic-quicklinks .quicklink-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.quicklink-list li {
  margin: 0;
}

.genre-band-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 18px;
}

.genre-band-item {
  margin: 0;
  min-width: 0;
}

.genre-band-item a {
  display: block;
  color: var(--ink);
  text-decoration: none;
}

.genre-band-item img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
  margin-bottom: 10px;
}

.genre-band-name {
  display: block;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 4px;
}

.genre-band-desc {
  display: block;
  font-size: 13px;
  color: var(--ink-mute);
  line-height: 1.6;
}

.genre-band-item a:hover .genre-band-name {
  color: var(--coral);
}

.deep-entry {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 32px;
  align-items: start;
}

.deep-entry-media {
  min-width: 0;
}

.deep-entry-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.deep-entry-body {
  min-width: 0;
}

.deep-entry-body h2 {
  margin: 0 0 12px;
}

.deep-entry-body p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.85;
  margin: 0 0 14px;
}

.deep-entry-facts {
  margin: 20px 0 0;
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 8px 16px;
  border-top: 1px solid var(--rule);
  padding-top: 16px;
}

.deep-entry-facts dt {
  font-size: 14px;
  font-weight: 700;
  color: var(--indigo);
  margin: 0;
}

.deep-entry-facts dd {
  font-size: 14px;
  color: var(--ink-soft);
  margin: 0;
  line-height: 1.7;
}

.pick-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.pick-item {
  padding: 20px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.pick-item h3 {
  margin: 0 0 8px;
}

.pick-item p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0 0 8px;
}

.pick-audience {
  font-size: 14px;
  color: var(--ink-mute);
}

.pick-link {
  font-size: 15px;
  font-weight: 600;
}

.brief-list {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.brief-item {
  margin: 0;
  padding: 16px 0 0;
  border-top: 2px solid var(--indigo);
  min-width: 0;
}

.brief-item h3 {
  margin: 0 0 8px;
}

.brief-item p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.serial-brief-list {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.serial-brief-item {
  margin: 0;
  padding: 14px 0;
  border-top: 1px solid var(--rule);
  min-width: 0;
}

.serial-brief-item h3 {
  margin: 0 0 8px;
  font-size: 17px;
}

.serial-brief-item p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.faq-excerpt .faq-list {
  margin-bottom: 8px;
}

/* =========================================================
   pages — catalog
   ========================================================= */

.page-catalog .page-hero {
  margin: 0 0 40px;
}

.page-hero {
  margin: 0 0 40px;
}

.page-hero-inner {
  min-width: 0;
}

.page-hero-kicker {
  font-size: 14px;
  font-weight: 700;
  color: var(--coral);
  margin: 0 0 8px;
  letter-spacing: 0;
}

.page-hero-lead {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 8px;
  max-width: var(--prose);
}

.page-hero-scope {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.page-hero-media {
  margin: 20px 0 0;
  min-width: 0;
}

.page-hero-media img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.topic-index {
  padding: 20px;
  background-color: var(--indigo-soft);
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.aside-title {
  font-size: 17px;
  margin: 0 0 8px;
}

.aside-note {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin: 0 0 14px;
}

.topic-index-list {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
}

.topic-index-list li {
  margin: 0 0 4px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 8px;
  padding: 6px 0;
  border-bottom: 1px solid rgba(53, 72, 184, 0.15);
}

.topic-index-list a {
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
}

.topic-index-list a:hover {
  color: var(--coral);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.topic-index-count {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-mute);
}

.aside-status-note {
  border-top: 1px solid rgba(53, 72, 184, 0.25);
  padding-top: 14px;
}

.aside-subtitle {
  font-size: 15px;
  margin: 0 0 6px;
}

.aside-status-note p {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin: 0 0 8px;
}

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

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

.catalog-section {
  margin: 0 0 40px;
}

.catalog-section-head {
  margin-bottom: 12px;
}

.catalog-section-index {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--indigo);
  margin: 0 0 4px;
}

.catalog-section-title {
  font-size: 22px;
  margin: 0 0 6px;
}

.catalog-section-desc {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
  max-width: var(--prose);
}

.catalog-section-media {
  margin: 16px 0;
}

.catalog-section-media img {
  width: 100%;
  aspect-ratio: 16 / 6;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.catalog-elements {
  margin: 0 0 40px;
}

.catalog-roadmap {
  margin: 0 0 24px;
}

.roadmap-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.roadmap-item {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr) auto;
  gap: 16px;
  align-items: baseline;
  padding: 12px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.roadmap-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

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

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

/* =========================================================
   pages — topics
   ========================================================= */

.page-topics .page-title-block {
  padding: 20px 0 0;
}

.page-title-block .page-lead {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 8px;
  max-width: var(--prose);
}

.page-title-block .page-scope {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.layout-shell {
  display: grid;
  gap: 40px;
}

.topics-layout {
  grid-template-columns: minmax(0, 1fr) 280px;
}

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

.topics-main .breadcrumb {
  padding-top: 0;
}

.topic-intro {
  margin: 0 0 40px;
}

.topic-intro-text {
  font-size: 16px;
  color: var(--ink);
  line-height: 1.85;
  margin: 0 0 10px;
  max-width: var(--prose);
}

.topic-intro-note {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.topic-threads {
  margin: 0 0 40px;
}

.thread-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: thread;
}

.thread-item {
  position: relative;
  padding: 16px 0 16px 40px;
  border-bottom: 1px solid var(--rule);
  margin: 0;
  counter-increment: thread;
}

.thread-item::before {
  content: counter(thread, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  color: var(--indigo);
}

.thread-name {
  font-size: 17px;
  margin: 0 0 6px;
}

.thread-text {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.topic-articles {
  margin: 0 0 40px;
}

.topic-entry {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 28px;
  align-items: start;
  padding: 24px 0;
  border-bottom: 1px solid var(--rule);
}

.topic-entry:last-child {
  border-bottom: none;
}

.topic-entry-media {
  min-width: 0;
}

.topic-entry-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.topic-entry-body {
  min-width: 0;
}

.topic-entry-title {
  font-size: 20px;
  margin: 0 0 10px;
}

.topic-entry-text {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.85;
  margin: 0 0 12px;
}

.topic-entry-meta {
  margin: 16px 0 0;
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 6px 16px;
  border-top: 1px solid var(--rule);
  padding-top: 14px;
}

.topic-entry-meta dt {
  font-size: 14px;
  font-weight: 700;
  color: var(--indigo);
  margin: 0;
}

.topic-entry-meta dd {
  font-size: 14px;
  color: var(--ink-soft);
  margin: 0;
  line-height: 1.7;
}

.topic-next {
  margin: 0 0 24px;
}

.topic-next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 10px 24px;
}

.topic-next-list li {
  margin: 0;
  padding: 10px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 15px;
}

.page-sidebar {
  min-width: 0;
}

.sidebar-block {
  margin: 0 0 32px;
}

.sidebar-title {
  font-size: 17px;
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--indigo);
}

.sidebar-group {
  margin: 0 0 16px;
}

.sidebar-group-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-mute);
  margin: 0 0 6px;
}

.sidebar-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar-list li {
  margin: 0 0 4px;
  padding: 6px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 14px;
  line-height: 1.7;
}

.sidebar-list a {
  text-decoration: none;
}

.sidebar-list a:hover {
  color: var(--coral);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

/* =========================================================
   pages — selection guide
   ========================================================= */

.page-selection-guide .page-hero {
  margin: 0 0 40px;
}

.page-hero .page-lede {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 8px;
  max-width: var(--prose);
}

.page-hero .page-scope {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.self-question {
  margin: 0 0 48px;
}

.question-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: question;
}

.question-item {
  position: relative;
  padding: 14px 0 14px 48px;
  border-bottom: 1px solid var(--rule);
  margin: 0;
  counter-increment: question;
}

.question-item::before {
  content: counter(question, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 16px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  color: var(--indigo);
}

.question-text {
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 4px;
  line-height: 1.7;
}

.question-hint {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.75;
  margin: 0;
}

.compare-section {
  margin: 0 0 48px;
}

.compare-figure {
  margin: 0 0 20px;
}

.compare-figure img {
  width: 100%;
  aspect-ratio: 16 / 6;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.check-flow {
  margin: 0 0 48px;
}

.pitfall-section {
  margin: 0 0 48px;
}

.pitfall-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.pitfall-item {
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.pitfall-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--coral);
  margin: 0 0 6px;
}

.pitfall-desc {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.related-section {
  margin: 0;
}

/* =========================================================
   pages — reading guide
   ========================================================= */

.page-reading-guide .page-head {
  margin: 0 0 40px;
}

.page-head .page-lead {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 8px;
  max-width: var(--prose);
}

.page-head .page-scope {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.guide-prepare {
  margin: 0 0 48px;
}

.prepare-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.prepare-item {
  margin: 0;
  padding: 16px 0 0;
  border-top: 2px solid var(--indigo);
  min-width: 0;
}

.prepare-name {
  font-size: 17px;
  margin: 0 0 6px;
}

.prepare-desc {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.guide-steps {
  margin: 0 0 48px;
}

.steps-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 32px;
  align-items: start;
}

.steps-layout .step-list {
  margin-bottom: 0;
}

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

.steps-figure img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.guide-device {
  margin: 0 0 48px;
}

.guide-glossary {
  margin: 0 0 48px;
}

.glossary-list {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 0 32px;
}

.glossary-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.glossary-term {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 4px;
}

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

.glossary-where {
  display: block;
  font-size: 13px;
  color: var(--ink-mute);
  margin-top: 4px;
}

/* =========================================================
   pages — serial status
   ========================================================= */

.page-serial-status .page-hero {
  margin: 0 0 40px;
}

.page-serial-status .page-hero .page-lead {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 8px;
  max-width: var(--prose);
}

.page-serial-status .page-hero .page-scope {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.status-types {
  margin: 0 0 48px;
}

.status-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  margin: 0 0 24px;
}

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

.status-name {
  font-size: 19px;
  margin: 0 0 10px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--coral);
}

.status-definition {
  font-size: 15px;
  color: var(--ink);
  line-height: 1.8;
  margin: 0 0 12px;
}

.status-applies {
  list-style: none;
  margin: 0;
  padding: 0;
}

.status-applies li {
  position: relative;
  padding: 6px 0 6px 18px;
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin: 0;
  border-bottom: 1px solid rgba(53, 72, 184, 0.15);
}

.status-applies li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 15px;
  width: 5px;
  height: 5px;
  background-color: var(--indigo);
  border-radius: 50%;
}

.status-figure {
  margin: 0;
}

.status-figure img {
  width: 100%;
  aspect-ratio: 16 / 6;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.status-steps {
  margin: 0 0 48px;
}

.status-steps .step-item {
  padding-left: 56px;
}

.status-change {
  margin: 0 0 48px;
}

.section-paragraph {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.85;
  margin: 0 0 14px;
  max-width: var(--prose);
}

.change-points {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.change-point {
  margin: 0;
  padding: 14px 0 0;
  border-top: 2px solid var(--indigo);
  min-width: 0;
}

.change-point-name {
  font-size: 16px;
  margin: 0 0 6px;
}

.change-point p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

.status-misread {
  margin: 0 0 48px;
}

.misread-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.misread-item {
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
}

.misread-wrong {
  font-size: 15px;
  color: var(--coral);
  font-weight: 600;
  margin: 0 0 6px;
  line-height: 1.7;
}

.misread-right {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0;
}

/* =========================================================
   pages — copyright
   ========================================================= */

.page-copyright .page-hero {
  margin: 0 0 28px;
}

.page-copyright .page-hero .page-lead {
  font-size: 17px;
  color: var(--ink);
  line-height: 1.75;
  margin: 0 0 8px;
  max-width: var(--prose);
}

.page-copyright .page-hero .page-scope {
  font-size: 14px;
  color: var(--ink-mute);
  line-height: 1.7;
  margin: 0;
  max-width: var(--prose);
}

.page-media {
  margin: 0 0 40px;
}

.page-media img {
  width: 100%;
  aspect-ratio: 16 / 6;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}

.narrow-text {
  display: block;
  max-width: var(--prose);
}

.narrow-text .content-block h2 {
  font-size: 22px;
  margin: 0 0 12px;
}

.narrow-text .content-block p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.85;
  margin: 0 0 14px;
}

.narrow-text .step-list {
  margin-top: 6px;
}

.narrow-text .step-item {
  padding: 12px 0 12px 44px;
}

.narrow-text .step-name {
  font-size: 16px;
}

.related-block {
  border-bottom: none;
}

/* =========================================================
   pages — faq
   ========================================================= */

.page-faq .page-hero {
  margin: 0 0 40px;
}

.faq-group {
  margin: 0 0 40px;
}

.faq-group .faq-list {
  margin-top: 4px;
}

.faq-next {
  margin: 0 0 24px;
}

.next-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.next-card {
  margin: 0;
  padding: 16px 0 0;
  border-top: 2px solid var(--indigo);
  min-width: 0;
}

.next-card-title {
  font-size: 17px;
  margin: 0 0 6px;
}

.next-card-title a {
  text-decoration: none;
}

.next-card-title a:hover {
  color: var(--coral);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.next-card-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.75;
  margin: 0;
}

/* =========================================================
   pages — 404
   ========================================================= */

.site-error .error-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 64px 24px 48px;
}

.error-panel {
  max-width: var(--prose);
  padding: 0 0 32px;
  border-bottom: 1px solid var(--rule);
}

.error-code {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--coral);
  margin: 0 0 8px;
}

.error-title {
  font-size: 34px;
  margin: 0 0 12px;
}

.error-lead {
  font-size: 16px;
  color: var(--ink-soft);
  line-height: 1.8;
  margin: 0 0 24px;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0;
}

.error-suggest {
  margin: 32px 0 0;
}

.error-suggest-title {
  font-size: 22px;
  margin: 0 0 14px;
}

.error-suggest-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px 24px;
}

.error-suggest-list li {
  margin: 0;
  padding: 10px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 15px;
}

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

@media (max-width: 1079px) {
  .hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding-top: 32px;
  }

  .hero-media {
    order: 2;
  }

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

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

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

  .page-sidebar {
    margin-top: 8px;
  }

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

  .topic-index {
    display: block;
  }

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

  .steps-figure img {
    aspect-ratio: 16 / 9;
  }

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

@media (max-width: 900px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--paper);
    border-bottom: 1px solid var(--rule);
    padding: 8px 24px 16px;
    margin-left: 0;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.18s ease;
  }

  .nav-list.is-open {
    max-height: 520px;
    overflow: auto;
  }

  .nav-link {
    width: 100%;
    padding: 0 4px;
    border-bottom: 1px solid var(--rule);
    border-left: 2px solid transparent;
  }

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

  .footer-top {
    grid-template-columns: minmax(0, 1fr);
    align-items: start;
  }

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

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

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

  .index-row,
  .entry-row {
    grid-template-columns: 44px minmax(0, 1fr) auto;
    row-gap: 6px;
  }

  .index-genre,
  .entry-name {
    grid-column: 2 / 3;
  }

  .index-feature,
  .entry-feature {
    grid-column: 2 / 4;
    grid-row: 2;
  }

  .index-status,
  .entry-status {
    grid-column: 3 / 4;
    grid-row: 1;
    justify-self: end;
  }

  .index-link,
  .entry-link {
    grid-column: 3 / 4;
    grid-row: 2;
    justify-self: end;
    align-self: end;
  }

  .roadmap-item {
    grid-template-columns: 120px minmax(0, 1fr);
    row-gap: 6px;
  }

  .roadmap-link {
    grid-column: 2 / 3;
  }
}

@media (max-width: 719px) {
  body {
    font-size: 15.5px;
  }

  h1,
  .page-title,
  .hero-text h1,
  .error-title {
    font-size: 26px;
  }

  h2,
  .section-title {
    font-size: 21px;
  }

  h3 {
    font-size: 17px;
  }

  .header-inner {
    padding: 0 16px;
    gap: 12px;
  }

  .brand {
    font-size: 18px;
    white-space: normal;
    line-height: 1.25;
  }

  .inner-main {
    padding: 0 16px 48px;
  }

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

  .hero {
    padding-top: 24px;
  }

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

  .hero-actions .btn {
    width: 100%;
  }

  .quicklink-list {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 6px;
    -webkit-overflow-scrolling: touch;
  }

  .quicklink-list li {
    flex: 0 0 auto;
  }

  .genre-band-list {
    grid-template-columns: repeat(6, 168px);
    overflow-x: auto;
    padding-bottom: 8px;
    -webkit-overflow-scrolling: touch;
  }

  .genre-band-item img {
    aspect-ratio: 3 / 4;
  }

  .deep-entry-facts,
  .topic-entry-meta {
    grid-template-columns: 84px minmax(0, 1fr);
  }

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

  .topic-entry-media {
    order: 0;
  }

  .entry-row,
  .index-row {
    grid-template-columns: 40px minmax(0, 1fr);
    row-gap: 4px;
    padding: 12px 0;
  }

  .index-feature,
  .entry-feature {
    grid-column: 2 / 3;
    grid-row: auto;
  }

  .index-status,
  .entry-status {
    grid-column: 2 / 3;
    grid-row: auto;
    justify-self: start;
  }

  .index-link,
  .entry-link {
    grid-column: 2 / 3;
    grid-row: auto;
    justify-self: start;
  }

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

  .roadmap-link {
    grid-column: 1 / 2;
  }

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

  .site-footer {
    padding: 32px 16px 20px;
  }

  .compare-table,
  .device-table,
  .data-table {
    font-size: 14px;
  }

  .compare-table th,
  .compare-table td,
  .device-table th,
  .device-table td,
  .data-table th,
  .data-table td {
    padding: 8px 10px;
  }

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

  .step-no,
  .step-index {
    width: 32px;
    height: 32px;
    font-size: 14px;
  }

  .status-steps .step-item {
    padding-left: 46px;
  }

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

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

  .error-main {
    padding: 40px 16px 32px;
  }

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

  .error-actions .btn {
    width: 100%;
  }
}

@media (max-width: 380px) {
  .brand {
    font-size: 16px;
  }

  .genre-band-list {
    grid-template-columns: repeat(6, 152px);
  }
}