:root {
  color-scheme: light;
  --bg: #ffffff;
  --panel: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --faint: #64748b;
  --border: #d8dee5;
  --soft: #edf1f5;
  --accent: #111827;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, monospace;
  --serif: "Source Serif 4", Georgia, serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--serif);
}

a {
  color: inherit;
}

.page {
  width: min(860px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 28px 0 56px;
}

.doc {
  display: grid;
  gap: 18px;
}

.kicker {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--faint);
}

h1,
h2,
p,
ul,
pre,
blockquote {
  margin: 0;
}

h1 {
  font-size: clamp(3rem, 8vw, 5rem);
  line-height: 0.95;
  letter-spacing: -0.04em;
}

.lede {
  max-width: 58ch;
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--muted);
}

p,
li,
blockquote {
  font-size: 1.03rem;
  line-height: 1.75;
}

code,
pre,
textarea,
.panel-label,
.meta-row,
.kicker {
  font-family: var(--mono);
}

code {
  padding: 0.1em 0.35em;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #fafafa;
}

blockquote {
  padding: 14px 16px;
  border-left: 3px solid var(--accent);
  background: #fafafa;
  color: var(--muted);
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding-top: 6px;
  color: var(--muted);
  font-size: 0.88rem;
}

.meta-row a {
  color: var(--text);
}

.section {
  display: grid;
  gap: 10px;
  padding-top: 8px;
}

.section-head {
  display: grid;
  gap: 6px;
}

.section h2 {
  font-size: 1.45rem;
  line-height: 1.2;
}

ul {
  padding-left: 1.25rem;
  display: grid;
  gap: 8px;
}

pre {
  overflow: auto;
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fafafa;
}

.demo {
  padding-top: 14px;
}

.demo-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 14px;
  align-items: stretch;
}

.panel {
  display: grid;
  gap: 10px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--panel);
  min-height: 420px;
}

.panel-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--faint);
}

#editor {
  width: 100%;
  min-height: 360px;
  resize: vertical;
  border: 0;
  outline: none;
  background: transparent;
  color: var(--text);
  font: inherit;
  font-family: var(--mono);
  line-height: 1.7;
}

.preview {
  min-height: 360px;
  display: grid;
  gap: 12px;
  color: var(--text);
}

.preview h1,
.preview h2,
.preview h3 {
  line-height: 1.15;
}

.preview p,
.preview li,
.preview blockquote {
  font-size: 0.98rem;
}

.preview blockquote {
  margin: 0;
}

.preview pre {
  margin: 0;
}

.preview table {
  width: 100%;
  border-collapse: collapse;
}

.preview th,
.preview td {
  padding: 8px 10px;
  border: 1px solid var(--border);
  text-align: left;
}

@media (max-width: 760px) {
  .page {
    width: min(100vw - 20px, 860px);
    padding-top: 18px;
  }

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

  .panel {
    min-height: 320px;
  }

  #editor,
  .preview {
    min-height: 260px;
  }
}