:root {
  color-scheme: light;
  --demo-square-reference-font: "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans CJK KR", sans-serif;
  --demo-desquare-reference-font: var(--demo-square-reference-font);
  --demo-serif: ui-serif, Georgia, "Times New Roman", serif;
  --demo-sans: system-ui, -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --demo-display: var(--demo-sans);
  --demo-mono: "SFMono-Regular", "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;

  --demo-bg: #ffffff;
  --demo-bg-2: #ffffff;
  --demo-ink: #1c1a16;
  --demo-ink-soft: #3a3730;
  --demo-muted: #6a675d;
  --demo-muted-soft: #767263;
  --demo-rule: rgba(28, 26, 22, 0.08);
  --demo-rule-strong: rgba(28, 26, 22, 0.16);
  --demo-panel: #faf8f4;
  --demo-panel-soft: rgba(250, 248, 244, 0.86);
  --demo-surface: #ffffff;
  --demo-surface-muted: #f4f1eb;
  --demo-border: rgba(28, 26, 22, 0.12);
  --demo-border-strong: rgba(28, 26, 22, 0.22);
  --demo-accent: #2447a8;
  --demo-accent-soft: rgba(36, 71, 168, 0.1);
  --demo-accent-2: #44517e;
  --demo-accent-2-soft: rgba(68, 81, 126, 0.1);
  --demo-seal: #d62839;
  --demo-seal-soft: rgba(214, 40, 57, 0.1);
  --demo-grid-line: rgba(36, 71, 168, 0.07);
  --demo-grid-bg: #fffefa;
  --demo-dark: #1c202f;
  --demo-dark-ink: #ece6d4;
  --demo-dark-muted: rgba(236, 230, 212, 0.6);
  --demo-shadow-sm: 0 1px 2px rgba(28, 26, 22, 0.04);
  --demo-shadow-md: 0 1px 0 rgba(28, 26, 22, 0.03), 0 8px 22px rgba(28, 26, 22, 0.07);
  --demo-shadow-lg: 0 2px 0 rgba(28, 26, 22, 0.03), 0 16px 36px rgba(28, 26, 22, 0.09);
  /* Editor pages historically consume these aliases. */
  --demo-line: var(--demo-border);
  --demo-shadow: var(--demo-shadow-md);
  --demo-radius-xs: 4px;
  --demo-radius-sm: 8px;
  --demo-radius: 10px;
  --demo-radius-lg: 14px;
  --demo-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --demo-content-max: 1180px;
}

* {
  box-sizing: border-box;
}

/* `hidden` must win over component display rules (display: grid/flex on a
 * class beats the UA [hidden] rule and leaves "hidden" panels on screen). */
[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: var(--demo-sans);
  font-feature-settings: "ss01", "ss02";
  color: var(--demo-ink);
  background: linear-gradient(180deg, var(--demo-bg) 0%, var(--demo-bg-2) 100%);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.6;
  word-break: keep-all;
  overflow-wrap: break-word;
  position: relative;
}

a {
  color: inherit;
}

::selection {
  background: rgba(36, 71, 168, 0.16);
}

:focus-visible {
  outline: 2px solid var(--demo-accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.demo-visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.demo-shell {
  position: relative;
  z-index: 1;
  max-width: var(--demo-content-max);
  margin: 0 auto;
  padding: 1rem 1.5rem 6rem;
}

/* ── Topbar / masthead ─────────────────────────────────── */
.demo-topbar {
  position: sticky;
  top: 0.75rem;
  z-index: 20;
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding: 0.6rem 0;
  border: 0;
  border-bottom: 1px solid #ebe6dd;
  border-radius: 0;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  transition: background 200ms var(--demo-ease), border-color 200ms var(--demo-ease), box-shadow 200ms var(--demo-ease);
}

.demo-topbar[data-scrolled="true"] {
  background: rgba(255, 255, 255, 0.96);
}

.demo-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.25rem 0.55rem 0.25rem 0.3rem;
  border-radius: 999px;
  text-decoration: none;
  transition: background 180ms var(--demo-ease);
}

.demo-brand:hover {
  background: rgba(28, 26, 22, 0.04);
}

/* 낙관(seal stamp) badge */
.demo-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  inline-size: 2.1rem;
  block-size: 2.1rem;
  border-radius: 7px;
  background: #d62839;
  color: #fff;
  transform: rotate(-4deg);
  font-family: var(--demo-display);
  font-weight: 800;
  font-size: 1.02rem;
  letter-spacing: 0;
  box-shadow:
    inset 0 0 0 1.5px rgba(253, 246, 236, 0.28),
    inset 0 0 0 3px rgba(169, 46, 32, 0.6),
    0 1px 3px rgba(28, 26, 22, 0.14);
}

.demo-brand-text {
  display: grid;
  gap: 0.05rem;
  line-height: 1.15;
}

.demo-brand-text strong {
  font-family: var(--demo-sans);
  font-weight: 750;
  font-size: 1rem;
  letter-spacing: -0.01em;
}

.demo-brand-text span {
  font-size: 0.72rem;
  color: var(--demo-muted);
  letter-spacing: 0.02em;
}

.demo-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.15rem;
  align-items: center;
}

.demo-nav a {
  display: inline-flex;
  align-items: center;
  min-block-size: 2.1rem;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  text-decoration: none;
  background: transparent;
  position: relative;
  color: var(--demo-ink-soft);
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  transition: background 160ms var(--demo-ease), color 160ms var(--demo-ease);
}

.demo-nav a:hover,
.demo-nav a:focus-visible {
  background: rgba(28, 26, 22, 0.05);
  color: var(--demo-ink);
}

/* AI 에이전트용 설명서 — 공개 페이지와 같은 점선 알약 */
.demo-nav a[data-demo-nav-ai] {
  margin-inline-start: 0.3rem;
  border: 1px dashed var(--demo-ink-soft);
  font-size: 0.85rem;
}

/* 공개 페이지(site.css .k-nav)와 같은 표시: 지금 페이지는 적색 밑줄, 작업실은 테두리 알약 */
.demo-nav a[aria-current="page"] {
  color: var(--demo-ink);
  background: transparent;
}

.demo-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  inset-inline: 0.65rem;
  inset-block-end: 0.2rem;
  block-size: 3px;
  border-radius: 3px;
  background: var(--demo-seal);
  transform: rotate(-1deg);
}

.demo-nav a[data-demo-category="Create"] {
  margin-inline-start: 0.3rem;
  border: 1px solid var(--demo-ink);
}

.demo-nav a[data-demo-category="Create"][aria-current="page"]::after {
  display: none;
}

.demo-debug-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-block-size: 2.1rem;
  padding: 0.4rem 0.8rem 0.4rem 0.6rem;
  border: 1px solid var(--demo-border);
  border-radius: 999px;
  background: transparent;
  color: var(--demo-muted);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  user-select: none;
  transition: background 160ms var(--demo-ease), border-color 160ms var(--demo-ease), color 160ms var(--demo-ease);
}

.demo-debug-toggle:hover {
  background: rgba(28, 26, 22, 0.03);
  border-color: var(--demo-border-strong);
  color: var(--demo-ink);
}

.demo-debug-toggle input {
  margin: 0;
  accent-color: var(--demo-accent);
}

.demo-debug-toggle span {
  line-height: 1;
}

/* ── Context (prev / next) ─────────────────────────────── */
.demo-context {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.25rem;
  align-items: center;
  margin: 0 0 1.5rem;
  padding: 1rem 1.25rem;
  border: 1px solid var(--demo-border);
  border-radius: var(--demo-radius);
  background: var(--demo-panel-soft);
  backdrop-filter: blur(6px);
  box-shadow: var(--demo-shadow-sm);
}

.demo-context-current {
  display: grid;
  gap: 0.2rem;
  min-width: 0;
}

.demo-context-kicker {
  color: var(--demo-accent-2);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.demo-context-current strong {
  font-family: var(--demo-display);
  font-weight: 750;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
}

.demo-context-current p {
  margin: 0.1rem 0 0;
  color: var(--demo-muted);
  font-size: 0.88rem;
  line-height: 1.55;
}

.demo-context-links {
  display: flex;
  gap: 0.5rem;
}

.demo-context-link {
  display: grid;
  align-content: center;
  gap: 0.2rem;
  min-inline-size: 9rem;
  padding: 0.6rem 0.85rem;
  border: 1px solid var(--demo-border);
  border-radius: var(--demo-radius-sm);
  background: var(--demo-surface);
  text-decoration: none;
  transition: border-color 180ms var(--demo-ease), transform 180ms var(--demo-ease), box-shadow 180ms var(--demo-ease);
}

.demo-context-link:hover,
.demo-context-link:focus-visible {
  border-color: var(--demo-border-strong);
  transform: translateY(-1px);
  box-shadow: var(--demo-shadow-sm);
}

.demo-context-link span {
  color: var(--demo-accent);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.demo-context-link strong {
  font-family: var(--demo-display);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: -0.015em;
}

/* ── Hero ──────────────────────────────────────────────── */
/* 페이지 히어로는 지면 위에 직접 놓는다 — 프레임은 활자 견본 전용. */
.demo-hero {
  position: relative;
  display: grid;
  gap: 1.35rem;
  padding: 2.25rem 0.25rem 2.25rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--demo-rule-strong);
}

.demo-hero > * {
  position: relative;
}

.demo-kicker {
  display: inline-flex;
  gap: 0.5rem;
  align-items: center;
  font-family: var(--demo-sans);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--demo-accent);
}

.demo-kicker::before {
  content: "";
  display: inline-block;
  inline-size: 1.75rem;
  block-size: 1px;
  background: currentColor;
  opacity: 0.7;
}

.demo-title {
  margin: 0;
  max-width: 18ch;
  font-family: var(--demo-display);
  font-weight: 800;
  font-size: clamp(2rem, 5vw, 3.6rem);
  line-height: 1.12;
  letter-spacing: -0.035em;
  color: var(--demo-ink);
}

.demo-title em {
  font-style: normal;
  color: var(--demo-seal);
}

.demo-copy {
  max-width: 62ch;
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--demo-ink-soft);
}

.demo-copy code {
  margin: 0 0.05em;
}

.demo-button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-block-size: 2.75rem;
  padding: 0.75rem 1.35rem;
  border: 0;
  border-radius: 999px;
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 650;
  letter-spacing: 0.01em;
  cursor: pointer;
  text-decoration: none;
  transition: transform 180ms var(--demo-ease), background 180ms var(--demo-ease), box-shadow 180ms var(--demo-ease);
}

.demo-button:hover {
  transform: translateY(-1px);
}

.demo-button-primary {
  background: var(--demo-dark);
  color: var(--demo-dark-ink);
}

.demo-button-primary:hover {
  background: #12141f;
  box-shadow: var(--demo-shadow-sm);
}

.demo-button-ghost {
  background: var(--demo-surface);
  color: var(--demo-ink);
  border: 1px solid var(--demo-border-strong);
}

.demo-button-ghost:hover {
  background: var(--demo-surface-muted);
}

.demo-button svg {
  inline-size: 1rem;
  block-size: 1rem;
  fill: currentColor;
}

/* Section section — labeled rhythm */
.demo-section {
  display: grid;
  gap: 1.5rem;
  margin-top: 3.25rem;
}

.demo-section-head {
  display: grid;
  gap: 0.6rem;
  max-width: 56ch;
}

.demo-section-head .demo-kicker {
  color: var(--demo-accent-2);
}

.demo-section-title {
  margin: 0;
  font-family: var(--demo-display);
  font-weight: 800;
  font-size: clamp(1.6rem, 3.4vw, 2.25rem);
  line-height: 1.18;
  letter-spacing: -0.035em;
  color: var(--demo-ink);
}

.demo-section-title em {
  font-style: normal;
  color: var(--demo-seal);
}

.demo-section-lead {
  margin: 0;
  color: var(--demo-muted);
  font-size: 1rem;
  line-height: 1.75;
}

/* Grid primitives (shared) */
.demo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 0;
}

.demo-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.demo-compare-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.demo-compare-grid-soft {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.demo-stack {
  display: grid;
  gap: 1.25rem;
  margin-top: 0;
}

.demo-shell > .demo-stack {
  margin-top: 0;
}

/* ── Cards & Panels ────────────────────────────────────── */

.demo-panel {
  position: relative;
  padding: 1.5rem 1.5rem 1.6rem;
  border-radius: var(--demo-radius);
  border: 1px solid var(--demo-border);
  background: var(--demo-panel);
  box-shadow: var(--demo-shadow-sm);
  transition: border-color 200ms var(--demo-ease), box-shadow 200ms var(--demo-ease), transform 200ms var(--demo-ease);
}

.demo-panel {
  padding: 1.65rem 1.75rem 1.75rem;
}

.demo-panel h2,
.demo-panel h3 {
  margin: 0 0 0.8rem;
  font-family: var(--demo-display);
  font-weight: 750;
  letter-spacing: -0.025em;
  color: var(--demo-ink);
  line-height: 1.25;
}

.demo-panel h2 {
  font-size: 1.3rem;
}

.demo-panel h3 {
  font-size: 1.08rem;
  margin-top: 0.75rem;
}

.demo-panel p,
.demo-note,
.demo-meta,
.demo-caption {
  margin: 0;
  line-height: 1.65;
  color: var(--demo-muted);
}

.demo-meta {
  font-size: 0.92rem;
}

.demo-caption {
  font-size: 0.82rem;
  color: var(--demo-muted-soft);
  padding-top: 0.2rem;
}

.demo-note {
  font-size: 0.9rem;
  padding: 0.75rem 0.9rem;
  margin-top: 0.75rem;
  border-left: 2px solid var(--demo-accent-2);
  background: var(--demo-accent-2-soft);
  border-radius: 0 var(--demo-radius-xs) var(--demo-radius-xs) 0;
  color: var(--demo-ink-soft);
}

/* ── Pills, chips, labels ──────────────────────────────── */
.demo-pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.demo-pill {
  display: inline-flex;
  align-items: center;
  min-block-size: 1.9rem;
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--demo-border);
  border-radius: 999px;
  background: rgba(255, 255, 251, 0.55);
  color: var(--demo-ink-soft);
  font-size: 0.78rem;
  font-weight: 550;
  letter-spacing: -0.005em;
}

.demo-pill code {
  background: transparent;
  padding: 0;
  font-size: 0.82em;
  color: var(--demo-accent);
}

.demo-label {
  display: inline-block;
  padding: 0.15rem 0;
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--demo-accent);
  font-weight: 700;
}

.demo-inline-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

/* ── Samples ───────────────────────────────────────────── */
.demo-sample {
  display: grid;
  gap: 0.75rem;
  padding: 1.15rem 1.2rem;
  border-radius: var(--demo-radius-sm);
  background: var(--demo-surface);
  border: 1px solid var(--demo-border);
  transition: border-color 180ms var(--demo-ease);
}

.demo-sample:hover {
  border-color: var(--demo-border-strong);
}

.demo-sample[data-tight="true"] {
  max-inline-size: 14rem;
}

.demo-sample font-kku,
.demo-sample .font-kku {
  display: block;
}

.demo-sample-tone-default {
  background: #fbf8ef;
}

.demo-sample-tone-gothic {
  background: #f5f7f3;
}

.demo-sample-tone-detail {
  background: #f8f3e8;
  border-color: rgba(36, 71, 168, 0.2);
}

.demo-sample .demo-reference-text {
  font-size: clamp(1.5rem, 4.4vw, 2.75rem);
}

.demo-reference-text {
  display: block;
  color: var(--demo-ink);
  font-size: clamp(2rem, 7vw, 4.25rem);
  line-height: 1.18;
}

/* 기준 표본은 변형 없이 원본 그대로 (위 .demo-specimen-ref-glyph 주석 참조) */
.demo-reference-text--square {
  font-family: var(--demo-square-reference-font);
  font-weight: 400;
  line-height: 1.05;
}

.demo-reference-text--desquare {
  font-family: var(--demo-desquare-reference-font);
  font-weight: 500;
  line-height: 1.05;
}

/* ── Toolbar & forms ───────────────────────────────────── */
.demo-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1rem;
}

.demo-toolbar label {
  display: grid;
  gap: 0.4rem;
  flex: 1 1 12rem;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--demo-muted);
}

.demo-toolbar label:first-child {
  flex-basis: 100%;
}

.demo-toolbar input,
.demo-toolbar select,
.demo-toolbar textarea,
.demo-toolbar button {
  font: inherit;
  letter-spacing: normal;
  text-transform: none;
}

.demo-toolbar input,
.demo-toolbar select,
.demo-toolbar textarea {
  min-inline-size: 10rem;
  padding: 0.65rem 0.85rem;
  border-radius: var(--demo-radius-sm);
  border: 1px solid var(--demo-border);
  background: var(--demo-surface);
  color: var(--demo-ink);
  font-size: 0.95rem;
  font-weight: 500;
  transition: border-color 160ms var(--demo-ease), box-shadow 160ms var(--demo-ease);
}

.demo-toolbar input:hover,
.demo-toolbar select:hover,
.demo-toolbar textarea:hover {
  border-color: var(--demo-border-strong);
}

.demo-toolbar input:focus,
.demo-toolbar select:focus,
.demo-toolbar textarea:focus {
  outline: none;
  border-color: var(--demo-accent);
  box-shadow: 0 0 0 3px var(--demo-accent-soft);
}

.demo-toolbar textarea {
  inline-size: 100%;
  min-inline-size: 100%;
  min-block-size: 7rem;
  resize: vertical;
  font-family: var(--demo-sans);
  line-height: 1.6;
}

.demo-toolbar button {
  align-self: end;
  min-block-size: 2.75rem;
  padding: 0.7rem 1.25rem;
  border: 0;
  border-radius: var(--demo-radius-sm);
  background: var(--demo-dark);
  color: var(--demo-dark-ink);
  font-size: 0.88rem;
  font-weight: 650;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: background 180ms var(--demo-ease), transform 180ms var(--demo-ease), box-shadow 180ms var(--demo-ease);
}

.demo-toolbar button:hover {
  background: #12141f;
  transform: translateY(-1px);
  box-shadow: var(--demo-shadow-sm);
}

.demo-toolbar button:active {
  transform: translateY(0);
}

/* ── Code panel ────────────────────────────────────────── */
.demo-code-panel {
  display: grid;
  gap: 0.6rem;
  padding: 1rem 1.1rem 1.1rem;
  border-radius: var(--demo-radius-sm);
  border: 1px solid rgba(10, 14, 28, 0.6);
  background: linear-gradient(180deg, #1e2436 0%, #171b2a 100%);
  color: #ece6d4;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 10px 22px rgba(10, 14, 28, 0.2);
}

.demo-code-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: rgba(236, 230, 212, 0.6);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
}

.demo-code-meta::before {
  content: "";
  inline-size: 8px;
  block-size: 8px;
  border-radius: 50%;
  background: rgba(36, 71, 168, 0.6);
  box-shadow: 0 0 0 3px rgba(36, 71, 168, 0.12);
}

code {
  padding: 0.14em 0.38em;
  border-radius: 0.3em;
  background: rgba(36, 71, 168, 0.1);
  color: var(--demo-accent);
  font-family: var(--demo-mono);
  font-size: 0.86em;
  font-weight: 550;
}

.demo-code-panel code {
  background: rgba(255, 255, 255, 0.06);
  color: #f4e9d0;
}

.demo-code-block {
  margin: 0;
  white-space: pre-wrap;
  font-family: var(--demo-mono);
  font-size: 0.9rem;
  line-height: 1.8;
  color: #ece6d4;
}

.demo-code-block-scroll {
  overflow: auto;
  white-space: pre;
  max-block-size: 22rem;
  padding-right: 0.5rem;
}

.demo-code-block-scroll::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

.demo-code-block-scroll::-webkit-scrollbar-thumb {
  background: rgba(236, 230, 212, 0.15);
  border-radius: 999px;
}

/* inline bash-style sample (used in text-mode / sprite-demo) */
pre.demo-code {
  margin: 0.75rem 0 0;
  padding: 1rem 1.2rem;
  border-radius: var(--demo-radius-sm);
  border: 1px solid rgba(10, 14, 28, 0.6);
  background: linear-gradient(180deg, #1e2436 0%, #171b2a 100%);
  color: #ece6d4;
  font-family: var(--demo-mono);
  font-size: 0.88rem;
  line-height: 1.75;
  overflow-x: auto;
  white-space: pre;
}

pre.demo-code code,
pre.demo-code::before {
  padding: 0;
}

/* ── Preset row ────────────────────────────────────────── */
.demo-preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.demo-preset-button {
  display: inline-flex;
  align-items: center;
  min-block-size: 2.3rem;
  padding: 0.5rem 0.95rem;
  border: 1px solid var(--demo-border);
  border-radius: 999px;
  background: var(--demo-surface);
  color: var(--demo-ink);
  font: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color 160ms var(--demo-ease), background 160ms var(--demo-ease), transform 160ms var(--demo-ease);
}

.demo-preset-button:hover {
  border-color: var(--demo-border-strong);
  background: rgba(36, 71, 168, 0.04);
  transform: translateY(-1px);
}

/* ── Metrics ───────────────────────────────────────────── */
.demo-metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.65rem;
}

.demo-metric-card {
  display: grid;
  gap: 0.2rem;
  padding: 1rem 1.1rem;
  border-radius: var(--demo-radius-sm);
  border: 1px solid var(--demo-border);
  background: var(--demo-surface);
  transition: border-color 160ms var(--demo-ease), transform 160ms var(--demo-ease);
}

.demo-metric-card:hover {
  border-color: var(--demo-border-strong);
  transform: translateY(-1px);
}

.demo-metric-card strong {
  font-family: var(--demo-display);
  font-weight: 750;
  font-size: 1.6rem;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--demo-ink);
  font-variant-numeric: tabular-nums;
}

.demo-metric-card span {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--demo-accent);
}

.demo-metric-card small {
  color: var(--demo-muted);
  font-size: 0.78rem;
  line-height: 1.45;
}

/* ── Topology chips ────────────────────────────────────── */
.demo-topology-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.demo-topology-chip {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  min-block-size: 1.9rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--demo-border);
  background: var(--demo-surface);
  color: var(--demo-muted);
  font-family: var(--demo-mono);
  font-size: 0.78rem;
}

.demo-topology-chip strong {
  font-family: var(--demo-mono);
  font-weight: 600;
  color: var(--demo-ink);
  letter-spacing: 0;
}

/* ── Rule cards ────────────────────────────────────────── */
.demo-rule-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.8rem;
  margin-top: 1rem;
}

.demo-rule-card {
  display: grid;
  gap: 0.5rem;
  padding: 1rem 1.1rem;
  border-radius: var(--demo-radius-sm);
  border: 1px solid var(--demo-border);
  background: var(--demo-surface);
}

/* ── Frame / poster ────────────────────────────────────── */
.demo-frame {
  overflow: hidden;
  border-radius: var(--demo-radius-lg);
  border: 1px solid var(--demo-border);
  background: var(--demo-panel);
  box-shadow: var(--demo-shadow-md);
}

.demo-frame-inner {
  padding: 2rem 2.25rem;
}

.demo-poster {
  display: grid;
  place-items: center;
  text-align: center;
  min-block-size: 24rem;
  background:
    radial-gradient(ellipse 60% 50% at 50% 20%, rgba(236, 230, 212, 0.08), transparent 60%),
    linear-gradient(160deg, #172623 0%, #2c3a34 40%, #6f4826 100%);
  color: #fdf3de;
  box-shadow: inset 0 0 120px rgba(0, 0, 0, 0.25);
}

.demo-poster small {
  display: block;
  margin-top: 1.25rem;
  font-size: 0.7rem;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  opacity: 0.65;
}

.demo-poster-amber {
  background:
    radial-gradient(ellipse 50% 45% at 70% 15%, rgba(255, 210, 140, 0.1), transparent 60%),
    linear-gradient(160deg, #1d1410 0%, #3a221a 50%, #7a4b22 100%);
}

.demo-poster-teal {
  background:
    radial-gradient(ellipse 50% 40% at 20% 85%, rgba(120, 196, 135, 0.1), transparent 60%),
    linear-gradient(160deg, #0d1c1f 0%, #163033 50%, #44517e 100%);
}

/* ── Specimen (shape-comparison) ──────────────────────── */
.demo-specimen-section {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}

.demo-specimen-section > h2 {
  margin: 0;
  font-family: var(--demo-display);
  font-weight: 750;
  font-size: 1.4rem;
  letter-spacing: -0.03em;
  color: var(--demo-ink);
}

.demo-specimen-note {
  margin: 0;
  color: var(--demo-muted);
  font-size: 0.9rem;
  line-height: 1.7;
}

.demo-specimen-topology {
  display: grid;
  gap: 0.9rem;
  padding: 1.5rem 1.5rem 1.75rem;
  border: 1px solid var(--demo-border);
  border-radius: var(--demo-radius);
  background: var(--demo-panel);
  box-shadow: var(--demo-shadow-sm);
}

.demo-specimen-topology > h3 {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--demo-display);
  font-weight: 750;
  font-size: 1.02rem;
  color: var(--demo-ink);
  letter-spacing: -0.02em;
}

.demo-specimen-tag {
  display: inline-flex;
  align-items: center;
  padding: 0.18rem 0.55rem;
  border-radius: 999px;
  background: rgba(28, 26, 22, 0.08);
  color: var(--demo-ink);
  font-family: var(--demo-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0;
}

.demo-specimen-tag--split {
  background: rgba(36, 71, 168, 0.14);
  color: var(--demo-accent);
}

.demo-specimen-tag--double {
  background: rgba(68, 81, 126, 0.14);
  color: var(--demo-accent-2);
}

.demo-specimen-tag--both {
  background: linear-gradient(90deg, rgba(36, 71, 168, 0.16), rgba(68, 81, 126, 0.16));
  color: var(--demo-ink);
}

.demo-specimen-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
}

.demo-specimen-pair {
  --specimen-frame-size: 140px;
  display: inline-flex;
  gap: 0.5rem;
  padding: 0.6rem 0.7rem 0.75rem;
  border: 1px solid var(--demo-border);
  border-radius: var(--demo-radius-sm);
  background: var(--demo-surface);
}

.demo-specimen-pair > div {
  display: grid;
  grid-template-rows: auto var(--specimen-frame-size);
  justify-items: center;
  inline-size: var(--specimen-frame-size);
}

.demo-specimen-pair .demo-specimen-label {
  min-block-size: 1.4rem;
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--demo-muted);
  text-align: center;
  line-height: 1.2;
}

/* 기준 표본과 font-kku는 상자 높이가 다르다 — 기준 span은 line-height:1(1em)이고
 * font-kku host는 --fy-glyph-height(1.17~1.2em)다. 상자를 세로 중앙 정렬하면 두 상자의
 * 윗변이 어긋나서 font-kku 쪽 글자가 안내선 위로 삐져나온다. 두 렌더 모두 em 상자
 * 윗변에서 잉크가 시작하므로(실측 0.04em 이내) **윗변 정렬**이 곧 광학 정렬이다. */
.demo-specimen-frame {
  position: relative;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  inline-size: var(--specimen-frame-size);
  block-size: var(--specimen-frame-size);
  padding-block-start: 6px;
  box-sizing: border-box;
  overflow: visible;
}

.demo-specimen-frame::after {
  content: "";
  position: absolute;
  inset: 4px;
  border: 1px dashed rgba(28, 26, 22, 0.18);
  pointer-events: none;
}

.demo-specimen-frame > font-kku,
.demo-specimen-frame > span {
  flex: 0 0 auto;
}

.demo-specimen-sentence {
  display: grid;
  gap: 0.35rem;
  padding: 0.85rem 1rem 1rem;
  border-radius: var(--demo-radius-sm);
  background: var(--demo-surface);
  border: 1px solid var(--demo-border);
}

.demo-specimen-sentence .demo-specimen-label {
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--demo-muted);
}

.demo-specimen-sentence-group {
  display: grid;
  gap: 0.75rem;
  margin-top: 1rem;
}

.demo-specimen-readout {
  display: block;
  margin-top: 0.4rem;
  color: var(--demo-muted);
  font-family: var(--demo-mono);
  font-size: 0.76rem;
}

.demo-specimen-problem {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 0.9rem;
  margin-top: 1rem;
}

.demo-specimen-problem-card {
  display: grid;
  gap: 0.5rem;
  padding: 0.85rem 0.95rem 1rem;
  border: 1px solid var(--demo-border);
  border-radius: var(--demo-radius-sm);
  background: var(--demo-surface);
}

.demo-specimen-catalog-wrap {
  overflow-x: auto;
  margin-top: 1rem;
  border: 1px solid var(--demo-border);
  border-radius: var(--demo-radius-sm);
}

.demo-specimen-catalog {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.84rem;
  background: var(--demo-surface);
}

.demo-specimen-catalog th,
.demo-specimen-catalog td {
  padding: 0.5rem 0.85rem;
  text-align: left;
  border-bottom: 1px solid var(--demo-border);
  vertical-align: top;
}

.demo-specimen-catalog th {
  background: var(--demo-surface-muted);
  font-family: var(--demo-sans);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--demo-muted);
}

.demo-specimen-catalog td:nth-child(1) {
  font-family: var(--demo-serif);
  font-weight: 500;
  font-size: 1rem;
  color: var(--demo-ink);
}

.demo-specimen-catalog td code {
  background: transparent;
  padding: 0;
  color: var(--demo-accent-2);
}

/* 기준(reference) 표본은 변형 없이 원본 그대로 보여준다.
 * 예전에는 layout-key별 translate/scale로 font-kku 쪽에 억지로 맞췄지만,
 * 그러면 "기준과 얼마나 닮았는가"를 판정할 수 없다. round8에서 두 프로필의
 * advance·space·slot을 기준 실측에 정합시켰으므로 보정이 필요 없다. */
.demo-specimen-ref-glyph--square {
  display: inline-block;
  font-family: var(--demo-square-reference-font);
  font-weight: 400;
  line-height: 1;
}

.demo-specimen-ref-glyph--desquare {
  display: inline-block;
  font-family: var(--demo-desquare-reference-font);
  font-weight: 500;
  line-height: 1;
}

/* ── Section rhythm ────────────────────────────────────── */
/* index.html은 섹션들을 main(display:contents) 랜드마크로 감싸므로
   main > 변형을 병기해야 같은 리듬이 유지된다. */
.demo-shell > .demo-columns,
.demo-shell > .demo-stack,
.demo-shell > .demo-panel,
.demo-shell > .demo-frame,
.demo-shell > .demo-section,
.demo-shell > .demo-specimen-section,
.demo-shell > main > .demo-section {
  margin-top: 1.5rem;
}

.demo-shell > .demo-hero + .demo-columns,
.demo-shell > .demo-hero + .demo-stack,
.demo-shell > .demo-hero + .demo-panel,
.demo-shell > .demo-hero + .demo-grid,
.demo-shell > .demo-hero + .demo-frame{
  margin-top: 0;
}

/* ── Debug boundaries ──────────────────────────────────── */
:root[data-demo-boundaries="on"] [part="word"] {
  background: rgba(67, 47, 16, 0.04);
  outline: 1px solid rgba(109, 91, 67, 0.14);
  outline-offset: 1px;
}

:root[data-demo-boundaries="on"] [part="glyph"] {
  background: rgba(173, 94, 28, 0.08);
  outline: 1px solid rgba(173, 94, 28, 0.48);
  outline-offset: -1px;
}

:root[data-demo-boundaries="on"] [part="glyph-body"] {
  background: rgba(33, 88, 160, 0.05);
  outline: 1px dashed rgba(33, 88, 160, 0.42);
  outline-offset: -1px;
}

:root[data-demo-boundaries="on"] [part="space"] {
  position: relative;
}

:root[data-demo-boundaries="on"] [part="space"]::before {
  content: "";
  position: absolute;
  inset-inline: 0;
  inset-block-start: calc(var(--fy-glyph-height, 1.2em) * -0.92);
  block-size: var(--fy-glyph-height, 1.2em);
  border-inline: 1px dashed rgba(39, 132, 92, 0.4);
  background:
    repeating-linear-gradient(
      90deg,
      rgba(39, 132, 92, 0.08) 0 0.2em,
      rgba(39, 132, 92, 0) 0.2em 0.4em
    );
  pointer-events: none;
}

/* ── Footer ────────────────────────────────────────────── */
.demo-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--demo-rule-strong);
  color: var(--demo-muted);
  font-size: 0.84rem;
}

.demo-footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 650;
  color: var(--demo-ink-soft);
}

.demo-footer-brand .demo-badge {
  inline-size: 1.6rem;
  block-size: 1.6rem;
  font-size: 0.8rem;
  border-radius: 5px;
}

.demo-footer-meta {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 1.1rem;
}

.demo-footer a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--demo-rule-strong);
  transition: color 160ms var(--demo-ease), border-color 160ms var(--demo-ease);
}

.demo-footer a:hover {
  color: var(--demo-accent);
  border-color: currentColor;
}

/* ── Scroll reveal ─────────────────────────────────────── */
.demo-reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 680ms var(--demo-ease), transform 680ms var(--demo-ease);
  will-change: opacity, transform;
}

.demo-reveal.is-visible {
  opacity: 1;
  transform: none;
}

.demo-reveal[data-reveal-delay="1"] { transition-delay: 60ms; }
.demo-reveal[data-reveal-delay="2"] { transition-delay: 120ms; }
.demo-reveal[data-reveal-delay="3"] { transition-delay: 180ms; }
.demo-reveal[data-reveal-delay="4"] { transition-delay: 240ms; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
  .demo-reveal { opacity: 1; transform: none; }
}

@media (max-width: 920px) {
  .demo-hero {
    padding: 1.75rem 0 1.9rem;
  }
}

@media (max-width: 1100px) {
  .demo-nav {
    flex: 1 1 100%;
    flex-wrap: nowrap;
    max-inline-size: 100%;
    overflow-x: auto;
    scrollbar-width: none;
  }

  .demo-nav::-webkit-scrollbar {
    display: none;
  }

  .demo-nav a,
  .demo-debug-toggle {
    flex: 0 0 auto;
  }
}

@media (max-width: 720px) {
  .demo-shell {
    padding: 0.5rem 1rem 4rem;
  }

  .demo-topbar {
    top: 0;
    margin-inline: -1rem;
    margin-bottom: 1.25rem;
    padding: 0.55rem 0.75rem;
    border-inline: 0;
    border-radius: 0 0 var(--demo-radius) var(--demo-radius);
  }

  .demo-nav {
    flex: 1 1 100%;
    flex-wrap: nowrap;
    max-inline-size: 100%;
    overflow-x: auto;
    padding-block-end: 0.1rem;
    scrollbar-width: none;
  }

  .demo-nav::-webkit-scrollbar {
    display: none;
  }

  .demo-nav a,
  .demo-debug-toggle {
    flex: 0 0 auto;
  }

  .demo-context {
    grid-template-columns: 1fr;
    padding: 0.9rem 1rem;
  }

  .demo-context-links {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .demo-context-link {
    min-inline-size: 0;
  }

  .demo-hero {
    padding: 1.5rem 0 1.75rem;
  }

  .demo-title {
    max-width: 100%;
  }

  .demo-panel {
    padding: 1.25rem;
  }

  .demo-poster {
    min-block-size: 18rem;
  }

  .demo-frame-inner {
    padding: 1.5rem 1.25rem;
  }

  .demo-specimen-pair {
    --specimen-frame-size: 110px;
  }
}