/* bst-library — editorial design system
 *
 * Light theme. Cream paper, deep ink, oxblood accent.
 * Body in serif. Headers in display sans. Code in mono.
 * No shadows, no rounded corners, no gradients.
 */

:root {
  --paper:    #faf8f3;
  --ink:      #0c0a09;
  --ink-2:    #1c1917;
  --ink-3:    #44403c;
  --muted:    #78716c;
  --line:     #d6d3c8;
  --line-2:   #e7e5d8;
  --accent:   #7c2d12;     /* oxblood */
  --accent-2: #9a3412;     /* persimmon highlight */

  --serif:  'Iowan Old Style', 'Source Serif Pro', Charter, Cambria, Georgia, serif;
  --sans:   -apple-system, BlinkMacSystemFont, 'Helvetica Neue', 'Segoe UI', Roboto, sans-serif;
  --mono:   ui-monospace, 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;

  --measure: 68ch;
}

* { box-sizing: border-box; }

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

body {
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.75;
  color: var(--ink-2);
  background: var(--paper);
  margin: 0;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
a:hover { text-decoration-thickness: 2px; }

/* ---------- LAYOUT ---------- */

.page {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 64px 24px 128px;
}

.wide {
  max-width: 92ch;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- TYPE ---------- */

h1, h2, h3, h4 {
  font-family: var(--sans);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 0;
}
h1 { font-size: 56px; line-height: 1.05; margin-top: 80px; letter-spacing: -0.03em; }
h2 { font-size: 28px; line-height: 1.2;  margin: 64px 0 16px; }
h3 { font-size: 19px; line-height: 1.3;  margin: 40px 0 8px; font-weight: 700; }

p { margin: 0 0 24px; }
p + p { margin-top: -8px; }

.byline {
  font-family: var(--sans);
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
  margin: 12px 0 64px;
  text-transform: uppercase;
  font-weight: 600;
}

.lede {
  font-size: 22px;
  line-height: 1.5;
  color: var(--ink-3);
  margin: 24px 0 56px;
  font-style: italic;
}

hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 64px 0;
}

/* ---------- CODE ---------- */

code, pre {
  font-family: var(--mono);
  font-size: 15px;
  color: var(--ink);
}

p code, li code, td code {
  background: var(--line-2);
  padding: 1px 6px;
  border-radius: 0;
  font-size: 0.88em;
}

pre {
  background: transparent;
  border: 1px solid var(--line);
  padding: 20px 24px;
  overflow-x: auto;
  margin: 24px 0 40px;
  line-height: 1.6;
}

pre code { background: none; padding: 0; }

/* ---------- PLAYGROUND ---------- */

.playground {
  border: 1px solid var(--line);
  padding: 32px;
  margin: 40px 0 56px;
  background: #fffefa;
}

.playground h3 {
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  font-weight: 700;
  margin: 0 0 24px;
}

.pg-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-bottom: 24px;
}

.pg-numpad {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  max-width: 240px;
}

.pg-btn {
  font-family: var(--mono);
  font-size: 14px;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--line);
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 600;
  transition: background 0.1s, border-color 0.1s;
}
.pg-btn:hover { background: var(--line-2); border-color: var(--accent); }
.pg-btn.primary {
  background: var(--accent);
  color: var(--paper);
  border-color: var(--accent);
}
.pg-btn.primary:hover { background: var(--ink); border-color: var(--ink); }

.pg-tree {
  width: 100%;
  height: 360px;
  background: var(--paper);
  border: 1px solid var(--line-2);
  display: block;
}

.pg-output {
  font-family: var(--mono);
  font-size: 13px;
  background: var(--ink);
  color: var(--paper);
  padding: 16px 20px;
  min-height: 56px;
  max-height: 160px;
  overflow-y: auto;
  white-space: pre-wrap;
  margin-top: 16px;
}
.pg-output .err { color: #f87171; }
.pg-output .ok  { color: #86efac; }

/* ---------- TABLES / LISTS ---------- */

ul, ol { padding-left: 1.5em; }
li { margin-bottom: 8px; }

table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0 40px;
  font-size: 16px;
}
th, td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  font-family: var(--sans);
}
th {
  font-weight: 700;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}
td { color: var(--ink-2); }
td:last-child { font-family: var(--mono); font-size: 14px; }

blockquote {
  border-left: 2px solid var(--accent);
  margin: 32px 0;
  padding: 0 24px;
  font-style: italic;
  color: var(--ink-3);
}

/* ---------- FOOTER ---------- */

footer {
  border-top: 1px solid var(--line);
  margin-top: 96px;
  padding: 32px 24px 64px;
  max-width: var(--measure);
  margin-left: auto;
  margin-right: auto;
  font-family: var(--sans);
  font-size: 13px;
  color: var(--muted);
}
footer a { color: var(--ink-3); }
footer p { margin: 0 0 6px; }