:root {
  --bg: #f5f6f8;
  --bg-strong: #ecedf0;
  --surface: rgba(255, 255, 255, 0.9);
  --surface-strong: rgba(255, 255, 255, 0.97);
  --line: rgba(0, 0, 0, 0.1);
  --line-strong: rgba(0, 0, 0, 0.2);
  --text: #1a1a1a;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.06);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.04);
  --radius-lg: 12px;
  --radius-md: 8px;
  --radius-sm: 6px;
  --radius-xs: 4px;
  --sidebar-width: 280px;
  --base-font-size: 15px;
  --transition: 120ms ease;
  --transition-slow: 200ms ease;
  --gap-xs: 4px;
  --gap-sm: 8px;
  --gap-md: 12px;
  --gap-lg: 20px;
  --gap-xl: 28px;
  --z-progress: 50;
  --z-hamburger: 40;
  --z-sidebar: 35;
  --z-overlay: 34;
  --z-back-to-top: 30;
  --z-dropdown: 25;
  --badge-color: var(--accent);
  --badge-bg: var(--accent-soft);
  --color-on-accent: #fff;
  --color-can: #16a34a;
  --color-can-bg: rgba(34, 197, 94, 0.04);
  --color-can-border: rgba(34, 197, 94, 0.2);
  --color-cannot: #dc2626;
  --color-cannot-bg: rgba(239, 68, 68, 0.04);
  --color-cannot-border: rgba(239, 68, 68, 0.15);
  color-scheme: light;
  font-family: "IBM Plex Sans KR", -apple-system, BlinkMacSystemFont, sans-serif;
}

:root[data-theme="dark"] {
  --bg: #111113;
  --bg-strong: #1a1a1e;
  --surface: rgba(26, 26, 30, 0.92);
  --surface-strong: rgba(30, 30, 34, 0.97);
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.16);
  --text: #e8e8ec;
  --muted: #9ca3af;
  --accent: #60a5fa;
  --accent-strong: #93c5fd;
  --accent-soft: rgba(96, 165, 250, 0.1);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.2);
  --badge-color: #60a5fa;
  --badge-bg: rgba(96, 165, 250, 0.1);
  --color-on-accent: #fff;
  --color-can: #4ade80;
  --color-can-bg: rgba(34, 197, 94, 0.06);
  --color-can-border: rgba(34, 197, 94, 0.15);
  --color-cannot: #f87171;
  --color-cannot-bg: rgba(239, 68, 68, 0.06);
  --color-cannot-border: rgba(239, 68, 68, 0.12);
  color-scheme: dark;
}

:root[data-font-size="small"] {
  --base-font-size: 14px;
}

:root[data-font-size="medium"] {
  --base-font-size: 16px;
}

:root[data-font-size="large"] {
  --base-font-size: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: var(--base-font-size);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100dvh;
  color: var(--text);
  background: var(--bg);
}

a {
  color: inherit;
}

/* Skip to content */
.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  z-index: 100;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--color-on-accent);
  font-weight: 600;
  text-decoration: none;
}

.skip-link:focus-visible {
  top: 16px;
}

/* Scroll progress bar */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: var(--z-progress);
  width: 0%;
  height: 3px;
  background: var(--accent);
  transition: width 60ms linear;
  will-change: width;
}

/* Hamburger menu button */
.hamburger {
  display: none;
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: var(--z-hamburger);
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
  color: var(--muted);
  cursor: pointer;
}

.hamburger svg {
  width: 22px;
  height: 22px;
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(260px, var(--sidebar-width)) minmax(0, 1fr);
  min-height: 100dvh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  padding: 24px 16px 20px;
  border-right: 1px solid var(--line);
  background: var(--surface-strong);
}

.brand {
  padding: 4px 4px 14px;
}

.brand-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
}

.eyebrow-link {
  color: var(--muted);
  font-weight: 500;
  text-decoration: none;
  transition: color var(--transition);
}

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

.eyebrow,
.hero-kicker,
.article-category,
.meta-label,
.overview-index {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.brand h1 {
  margin: 6px 0 8px;
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.2;
}

.brand h1 a {
  text-decoration: none;
  color: inherit;
}

.hero-copy,
.article-summary,
.callout p,
.source-list,
.sidebar-footer,
.search-box span {
  color: var(--muted);
}

.search-box {
  display: grid;
  gap: 10px;
  margin-bottom: 18px;
}

.search-control {
  position: relative;
}

.search-box input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 10px 36px 10px 14px;
  background: var(--bg);
  font: inherit;
  font-size: 0.88rem;
  color: var(--text);
  outline: none;
  transition: border-color var(--transition);
}

.search-box input:hover {
  border-color: var(--line-strong);
}

.search-box input:focus,
.search-box input:focus-visible {
  border-color: var(--accent);
}

.search-clear {
  position: absolute;
  right: 8px;
  top: 50%;
  width: 36px;
  height: 36px;
  transform: translateY(-50%);
  border: 1px solid var(--line);
  border-radius: 9999px;
  background: var(--surface);
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 0;
  font-size: 0.95rem;
  transition: border-color var(--transition), color var(--transition), background var(--transition);
}

.search-clear:hover,
.search-clear:focus-visible {
  border-color: var(--line-strong);
  color: var(--text);
  background: var(--surface-strong);
}

.search-clear[hidden] {
  display: none;
}

.toc-panel {
  display: flex;
  flex: 1;
  min-height: 0;
  flex-direction: column;
}

.settings-head h2 {
  margin: 8px 0 0;
  font-size: 1.05rem;
}

.setting-group {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.setting-group label {
  font-size: 0.92rem;
  color: var(--muted);
}

.setting-label {
  font-size: 0.92rem;
  color: var(--muted);
}

.setting-group select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius-xs);
  padding: 8px 12px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
  font-size: 0.88rem;
  outline: none;
}

.theme-toggle {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.theme-option {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius-xs);
  background: var(--bg);
  color: var(--muted);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), color var(--transition);
}

.theme-option svg {
  width: 16px;
  height: 16px;
}

.theme-option:hover,
.theme-option:focus-visible {
  border-color: var(--line-strong);
}

.theme-option.is-active,
.theme-option[aria-pressed="true"] {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.font-size-toggle {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.font-size-option {
  display: grid;
  grid-template-columns: 18px 1fr;
  align-items: center;
  justify-items: center;
  gap: 5px;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius-xs);
  background: var(--bg);
  color: var(--muted);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), color var(--transition);
}

.font-size-option span:first-child {
  justify-self: center;
  font-size: 0.95rem;
}

.font-size-option:hover,
.font-size-option:focus-visible {
  border-color: var(--line-strong);
}

.font-size-option.is-active,
.font-size-option[aria-pressed="true"] {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-strong);
}

:root[data-theme="dark"] .search-box input,
:root[data-theme="dark"] .setting-group select,
:root[data-theme="dark"] .display-settings-menu,
:root[data-theme="dark"] .icon-button,
:root[data-theme="dark"] .theme-option,
:root[data-theme="dark"] .font-size-option,
:root[data-theme="dark"] .search-clear {
  background: var(--bg-strong);
}

/* Nav list & groups */
.nav-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
  padding-right: 4px;
  /* Visually hide scrollbar — wheel scroll still works */
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none; /* IE/Edge legacy */
}

.nav-list::-webkit-scrollbar {
  width: 0;
  height: 0;
  display: none; /* Chrome/Safari */
}

.nav-group-label {
  width: 100%;
  margin: 16px 0 4px;
  padding: 4px 8px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: none;
  border-radius: var(--radius-xs);
  background: none;
  user-select: none;
  transition: background var(--transition);
}

.nav-group-label:hover {
  background: var(--accent-soft);
}

.nav-group-label::after {
  content: "";
  width: 8px;
  height: 8px;
  border-right: 1.5px solid var(--muted);
  border-bottom: 1.5px solid var(--muted);
  transform: rotate(45deg);
  transition: transform 200ms ease;
  flex-shrink: 0;
  opacity: 0.5;
}

.nav-group-label.is-collapsed::after {
  transform: rotate(-45deg);
}

.nav-group-label:first-child {
  margin-top: 0;
}

.nav-group {
  display: grid;
  gap: 4px;
}

.nav-group.is-collapsed {
  display: none;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 40px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--muted);
  font-size: 0.85rem;
  transition: background var(--transition), color var(--transition);
}

.nav-item-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.55;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
}

.nav-item-icon svg {
  width: 100%;
  height: 100%;
}

.nav-item.is-active .nav-item-icon {
  color: var(--accent);
}

.nav-item-text {
  display: block;
  min-width: 0;
  line-height: 1.4;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-item-read {
  display: none;
  width: 14px;
  height: 14px;
  color: var(--accent);
  margin-left: auto;
  flex-shrink: 0;
}

.nav-item.is-read .nav-item-read {
  display: inline-block;
}

.nav-item:hover,
.nav-item:focus-visible {
  background: var(--accent-soft);
  color: var(--text);
}

.nav-item.is-active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 500;
}

.nav-item.is-active .nav-item-icon {
  opacity: 1;
}

:root[data-theme="dark"] .channel-banner {
  background: var(--bg-strong);
}

.sidebar-footer {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 0.92rem;
  flex-shrink: 0;
}

.sidebar-footer a {
  color: var(--accent-strong);
  font-weight: 600;
  text-decoration: none;
}

.channel-banner {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg);
  text-decoration: none;
  color: var(--muted);
  transition: border-color var(--transition), color var(--transition);
}

.channel-banner:hover,
.channel-banner:focus-visible {
  border-color: var(--accent);
  color: var(--text);
}

.channel-banner strong {
  font-size: 0.82rem;
  font-weight: 600;
}

.content {
  padding: 28px 32px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 20px;
  margin-bottom: 16px;
}

.topbar-copy {
  flex: 1;
  min-width: 0;
  max-width: 840px;
}

.topbar-actions {
  display: inline-flex;
  gap: 10px;
  align-items: flex-start;
}

.official-link {
  align-self: center;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
  color: var(--muted);
  text-decoration: none;
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  font-weight: 600;
  white-space: nowrap;
  transition: border-color var(--transition), color var(--transition);
}

.official-link:hover,
.official-link:focus-visible {
  border-color: var(--line-strong);
  color: var(--text);
}
.display-settings-wrap {
  position: relative;
  flex-shrink: 0;
  margin-top: 2px;
}

.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
  color: var(--muted);
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition);
}

.icon-button:hover,
.icon-button:focus-visible {
  border-color: var(--line-strong);
  color: var(--text);
}

.icon-button svg {
  width: 20px;
  height: 20px;
}

.display-settings-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: var(--z-dropdown);
  width: min(260px, calc(100vw - 32px));
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface-strong);
  box-shadow: var(--shadow);
}

.hero {
  display: grid;
  gap: 20px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface-strong);
}

:root[data-theme="dark"] body {
  background: var(--bg);
}

:root[data-theme="dark"] .sidebar {
  background: var(--surface-strong);
}

:root[data-theme="dark"] .hero {
  background: var(--surface-strong);
}

.hero h2 {
  margin: 8px 0 0;
  max-width: 22ch;
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero-copy {
  max-width: 760px;
  margin-top: 18px;
  font-size: 1.02rem;
  line-height: 1.8;
}

/* Hero top layout */
.hero-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.hero-doc-link {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--color-on-accent);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background var(--transition), border-color var(--transition);
}

.hero-doc-link svg {
  stroke: var(--color-on-accent);
}

.hero-doc-link:hover,
.hero-doc-link:focus-visible {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
}

/* Infographic sections */
.infographic {
  display: grid;
  gap: 20px;
  margin-top: 24px;
}

.info-section {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface-strong);
  padding: 24px;
}

.info-section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 16px;
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
}

.info-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.info-icon--blue {
  background: var(--accent-soft);
  color: var(--accent);
}

.info-desc {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--muted);
  margin: 0;
  overflow-wrap: anywhere;
}

.info-desc strong {
  color: var(--text);
  font-weight: 600;
}

.info-desc--spaced {
  margin-bottom: 16px;
}

.info-desc--top-spaced {
  margin-top: 14px;
}

/* Doc links nav */
.doc-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.doc-link-item {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-xs);
  background: var(--bg);
  color: var(--muted);
  text-decoration: none;
  font-size: 0.78rem;
  font-weight: 600;
  white-space: nowrap;
  transition: border-color var(--transition), color var(--transition), background var(--transition);
}

.doc-link-item:hover,
.doc-link-item:focus-visible {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

:root[data-theme="dark"] .doc-link-item {
  background: var(--bg-strong);
}

:root[data-theme="dark"] .feature-highlight {
  background: var(--bg-strong);
}

/* Official document audit */
.official-audit {
  margin-top: 28px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.latest-updates,
.infographic-explainer {
  margin-top: 28px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.section-heading {
  max-width: 760px;
}

.section-heading h2 {
  margin: 4px 0 10px;
  font-size: clamp(1.45rem, 2vw, 2rem);
  line-height: 1.35;
}

.section-heading p:last-child {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
  overflow-wrap: anywhere;
}

.official-audit-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.latest-updates-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.update-card {
  min-width: 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
}

.update-card-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 0.74rem;
  color: var(--muted);
}

.update-card-meta span {
  font-family: "JetBrains Mono", monospace;
  color: var(--accent);
  font-weight: 700;
}

.update-card-meta a {
  color: var(--accent-strong);
  font-weight: 600;
  text-decoration: none;
}

.update-card h3 {
  margin: 0 0 8px;
  font-size: 0.96rem;
  line-height: 1.45;
}

.update-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

.infographic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.infographic-card {
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background:
    linear-gradient(180deg, var(--accent-soft), transparent 46%),
    var(--surface-strong);
}

.infographic-card-step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  padding: 6px 10px;
  border-radius: var(--radius-xs);
  background: var(--bg);
  color: var(--accent);
  font-family: "JetBrains Mono", monospace;
  font-size: 0.75rem;
  font-weight: 700;
}

.infographic-card h3 {
  margin: 12px 0 8px;
  font-size: 1rem;
  line-height: 1.45;
}

.infographic-card p {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

.infographic-card ul {
  margin: 0;
  padding-left: 18px;
  color: var(--text);
  font-size: 0.81rem;
  line-height: 1.7;
}

.official-audit-card {
  min-width: 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
}

.official-audit-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
  color: var(--accent);
  font-size: 0.72rem;
}

.official-audit-meta span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-xs);
  background: var(--accent-soft);
  font-family: "JetBrains Mono", monospace;
  font-weight: 700;
}

.official-audit-meta strong {
  font-weight: 700;
}

.official-audit-card h3 {
  margin: 0 0 8px;
  font-size: 0.95rem;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.official-audit-card p {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.83rem;
  line-height: 1.65;
  overflow-wrap: anywhere;
}

.official-audit-card small {
  color: var(--muted-strong);
  font-size: 0.72rem;
  font-weight: 700;
}

:root[data-theme="dark"] .official-audit-card {
  background: var(--bg-strong);
}

:root[data-theme="dark"] .update-card,
:root[data-theme="dark"] .infographic-card {
  background:
    linear-gradient(180deg, rgba(37, 99, 235, 0.18), transparent 42%),
    var(--bg-strong);
}

/* Codex features grid */
.codex-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 10px;
  margin-top: 16px;
}

.codex-feature {
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg);
  transition: border-color var(--transition);
}

.codex-feature:hover {
  border-color: var(--accent);
}

.codex-feature strong {
  display: block;
  font-size: 0.82rem;
  color: var(--accent);
  margin-bottom: 4px;
}

.codex-feature span {
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.5;
}

:root[data-theme="dark"] .codex-feature {
  background: var(--bg-strong);
}

/* Feature highlights */
.feature-highlights {
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.feature-highlight {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
  transition: background var(--transition);
}

.feature-highlight:last-child {
  border-bottom: none;
}

.feature-highlight:hover {
  background: var(--accent-soft);
}

.feature-highlight-icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  margin-top: 2px;
}

.feature-highlight strong {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 2px;
}

.feature-highlight p {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--muted);
}

.feature-highlight code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.78rem;
  padding: 1px 5px;
  border-radius: var(--radius-xs);
  background: var(--bg-strong);
  color: var(--accent);
}

/* Noscript fallback */
.noscript-fallback {
  padding: 40px 20px;
  text-align: center;
  color: var(--muted);
}

.noscript-link {
  color: var(--accent);
  font-weight: 600;
}

/* Comparison table */
.compare-table {
  display: grid;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.compare-row {
  display: grid;
  grid-template-columns: 1fr 1.4fr 1.4fr;
  border-bottom: 1px solid var(--line);
}

.compare-row:last-child {
  border-bottom: none;
}

.compare-row--header {
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.compare-cell {
  padding: 10px 14px;
  font-size: 0.85rem;
  line-height: 1.5;
}

.compare-cell--label {
  font-weight: 600;
  color: var(--text);
  background: var(--bg);
}

.compare-cell--codex {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.compare-cell--chatgpt,
.compare-cell--cli {
  background: var(--bg);
  color: var(--muted);
}

.compare-row--header .compare-cell--codex {
  color: var(--accent);
}

.compare-row--header .compare-cell--chatgpt,
.compare-row--header .compare-cell--cli {
  color: var(--muted);
}

:root[data-theme="dark"] .compare-cell--label,
:root[data-theme="dark"] .compare-cell--chatgpt,
:root[data-theme="dark"] .compare-cell--cli {
  background: var(--bg-strong);
}

:root[data-theme="dark"] .info-section {
  background: var(--surface-strong);
}

/* Capability grid */
.capability-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.capability-card {
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  border: 1px solid var(--line);
}

.capability-card--can {
  background: var(--color-can-bg);
  border-color: var(--color-can-border);
}

.capability-card--cannot {
  background: var(--color-cannot-bg);
  border-color: var(--color-cannot-border);
}

.capability-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  font-size: 0.9rem;
  font-weight: 700;
}

.capability-title--can {
  color: var(--color-can);
}

.capability-title--cannot {
  color: var(--color-cannot);
}

.capability-title--can svg { stroke: var(--color-can); }
.capability-title--cannot svg { stroke: var(--color-cannot); }

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

.capability-list li {
  position: relative;
  padding: 4px 0 4px 20px;
  font-size: 0.84rem;
  line-height: 1.6;
  color: var(--text);
}

.capability-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.capability-card--can .capability-list li::before {
  background: var(--color-can);
}

.capability-card--cannot .capability-list li::before {
  background: var(--color-cannot);
}

/* Environment cards */
.env-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 20px;
}

.env-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  background: var(--bg);
}

.env-card-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
  font-size: 0.9rem;
  color: var(--accent);
}

.env-card > p {
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--muted);
  margin: 0 0 12px;
}

.env-card > p strong {
  color: var(--text);
}

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

.env-detail-list li {
  position: relative;
  padding: 3px 0 3px 18px;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text);
}

.env-detail-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}

.env-detail-list li strong {
  color: var(--accent-strong);
}

:root[data-theme="dark"] .env-card {
  background: var(--bg-strong);
}

/* Environment FAQ */
.env-faq {
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.env-faq-item {
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
}

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

.env-faq-item h4 {
  margin: 0 0 6px;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text);
}

.env-faq-item p {
  margin: 0;
  font-size: 0.84rem;
  line-height: 1.7;
  color: var(--muted);
}

.env-faq-item p strong {
  color: var(--text);
}

.env-faq-item code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.82rem;
  padding: 1px 5px;
  border-radius: var(--radius-xs);
  background: var(--bg-strong);
  color: var(--accent);
}

@media (max-width: 640px) {
  .env-cards {
    grid-template-columns: 1fr;
  }

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

  .hero-doc-link {
    width: 100%;
    justify-content: center;
  }

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

  .compare-cell--label {
    font-size: 0.78rem;
    padding: 8px 14px 4px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
  }

  .compare-cell--codex,
  .compare-cell--chatgpt,
  .compare-cell--cli {
    padding: 4px 14px 8px;
  }

  .compare-row--header {
    display: none;
  }

  .compare-cell--codex::before {
    content: "App: ";
    font-weight: 600;
  }

  .compare-cell--chatgpt::before {
    content: "ChatGPT: ";
    font-weight: 600;
  }

  .compare-cell--cli::before {
    content: "CLI: ";
    font-weight: 600;
  }

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

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

  .doc-links {
    gap: 6px;
  }

  .feature-highlight {
    padding: 12px 14px;
    gap: 10px;
  }

  .feature-highlight-icon {
    width: 24px;
    height: 24px;
  }
}

@media (max-width: 420px) {
  .codex-features {
    grid-template-columns: 1fr;
  }

  .doc-link-item {
    white-space: normal;
    font-size: 0.72rem;
  }
}

/* Overview — typography-based inline keywords */
.overview-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
  padding: 0;
}

.overview-keyword {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: none;
  border-radius: var(--radius-xs);
  background: var(--bg-strong);
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.overview-keyword:hover,
.overview-keyword:focus-visible {
  background: var(--accent-soft);
  color: var(--accent);
}

.overview-keyword .overview-index {
  font-size: 0.7rem;
  font-weight: 700;
}

:root[data-theme="dark"] .overview-keyword {
  background: var(--surface-strong);
}

/* Article list */
.article-list {
  display: grid;
  gap: 20px;
  margin-top: 28px;
}

.article-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface-strong);
  padding: 24px;
  cursor: pointer;
  transition: border-color var(--transition);
}

.article-card:hover,
.article-card:focus-visible {
  border-color: var(--accent);
}

.article-head {
  display: flex;
  gap: 16px;
  justify-content: space-between;
  align-items: start;
}

.article-title {
  margin: 6px 0 8px;
  font-size: clamp(1.2rem, 1.8vw, 1.5rem);
  line-height: 1.4;
}

.article-summary {
  font-size: 0.9rem;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

.article-badge {
  flex-shrink: 0;
  padding: 4px 10px;
  border-radius: var(--radius-xs);
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--badge-bg);
  color: var(--badge-color);
  letter-spacing: 0.02em;
}

/* Callout */
.callout {
  margin-top: 18px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: var(--surface-strong);
  border-radius: var(--radius-sm);
}

.callout strong,
.article-columns h4,
.source-block h4 {
  display: block;
  margin-bottom: 10px;
}

.article-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.bullet-list,
.article-steps,
.article-checklist {
  margin: 0;
  padding-left: 20px;
  line-height: 1.75;
  overflow-wrap: anywhere;
}

.article-steps,
.article-checklist {
  list-style-position: outside;
}

.article-columns > section {
  min-width: 0;
}

.source-list {
  margin: 0;
  padding-left: 20px;
  line-height: 1.75;
}

.source-block {
  margin-top: 22px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.source-list a {
  color: var(--accent-strong);
  font-weight: 600;
  text-decoration: none;
}

/* External link icon for source links */
.source-list a::after {
  content: " ↗";
  font-size: 0.8em;
}

.source-list code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.88rem;
}

/* Search highlight */
mark {
  background: var(--accent-soft);
  color: inherit;
  border-radius: var(--radius-xs);
  padding: 0 2px;
}

.empty-state {
  padding: 36px 24px;
  text-align: center;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-md);
  color: var(--muted);
  background: var(--surface);
}

/* Back to top button */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: var(--z-back-to-top);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
  color: var(--muted);
  cursor: pointer;
  transition: opacity var(--transition), color var(--transition);
  opacity: 0;
  pointer-events: none;
}

.back-to-top[data-visible="true"] {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover,
.back-to-top:focus-visible {
  color: var(--text);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

:root[data-theme="dark"] .back-to-top {
  background: var(--surface-strong);
}

/* Responsive */
/* ─── Detail link ─── */
.article-detail-link {
  margin-top: 20px;
  text-align: right;
}

.detail-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 8px 16px;
  background: var(--accent);
  color: var(--color-on-accent);
  border-radius: var(--radius-xs);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 600;
  transition: background var(--transition);
}

.detail-link:hover,
.detail-link:focus-visible {
  background: var(--accent-strong);
}

@media (max-width: 1180px) {
  .article-columns {
    grid-template-columns: 1fr;
  }
}

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

  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    z-index: var(--z-sidebar);
    width: min(320px, 85vw);
    height: 100vh;
    border-right: 1px solid var(--line);
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
  }

  .sidebar.is-open {
    transform: translateX(0);
  }

  .sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: var(--z-overlay);
    background: rgba(0, 0, 0, 0.4);
  }

  .sidebar-overlay.is-visible {
    display: block;
  }

  .content {
    padding: 72px 18px 18px;
  }

  .hero,
  .article-card {
    padding: 22px;
  }
}

@media (max-width: 640px) {
  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .topbar-copy {
    width: 100%;
  }

  .topbar-actions {
    width: 100%;
    justify-content: space-between;
    gap: 8px;
  }

  .official-link {
    width: 100%;
  }

  .display-settings-wrap {
    align-self: flex-end;
  }

  .article-head {
    flex-direction: column;
  }

  .hero h2 {
    max-width: none;
  }
}

/* ─── Custom scrollbar ─── */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--line-strong);
  border-radius: var(--radius-xs);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--muted);
}

/* ─── Reduced motion ─── */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

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

button:focus-visible,
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}

/* ─── Print styles ─── */
@media print {
  .sidebar,
  .hamburger,
  .scroll-progress,
  .back-to-top,
  .sidebar-overlay,
  .topbar,
  .display-settings-wrap,
  .page-toc {
    display: none !important;
  }

  .app-shell {
    display: block;
  }

  .content,
  .page-content {
    padding: 0;
    max-width: 100%;
  }

  body {
    background: #fff;
    color: #000;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
    color: #666;
  }

  a[href^="#"]::after,
  a[href^="javascript"]::after {
    content: "";
  }

  .page-body {
    display: block;
  }

  .article-card,
  .takeaway-box,
  .callout,
  .info-card,
  .info-section,
  .env-card,
  .capability-card {
    page-break-inside: avoid;
  }

  .infographic,
  .compare-table,
  .capability-grid,
  .env-cards,
  .feature-highlights,
  .codex-features {
    break-inside: avoid;
  }

  .doc-links {
    display: none;
  }

  .feature-highlight {
    background: #fff !important;
    border-color: #ddd !important;
  }

  .codex-feature {
    background: #fafafa !important;
    border-color: #ddd !important;
  }

  .compare-cell--codex {
    background: #f0f7ff !important;
    color: #1a1a1a !important;
  }

  .capability-card--can {
    background: #f0fdf4 !important;
    border-color: #86efac !important;
  }

  .capability-card--cannot {
    background: #fef2f2 !important;
    border-color: #fca5a5 !important;
  }

  .page-badge {
    background: #eee !important;
    color: #333 !important;
  }
}

/* ─── Selection color ─── */
::selection {
  background: var(--accent-soft);
  color: var(--text);
}