@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:ital,wght@0,400;0,500;0,600;1,400&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #f7f7f5;
  --text: #111;
  --muted: #666;
  --border: #ccc;
  --code-bg: #efefed;

  /* font sizes */
  --fs-2xs: 0.72rem;  /* labels, tags, micro UI */
  --fs-xs:  0.78rem;  /* captions, eyebrow, secondary meta */
  --fs-sm:  0.85rem;  /* nav, note, h3, copy-btn */
  --fs-base: 0.9rem;  /* body text, lists, lead */
  --fs-code: 0.82rem; /* pre, inline ref */
  --fs-h2:  1rem;
  --fs-h1:  1.6rem;
}

html { font-size: var(--fs-base); }

body {
  font-family: 'IBM Plex Mono', monospace;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  padding: 0 1.5rem;
}

/* ── Header & nav ── */

.site-header {
  border-bottom: 1px solid var(--border);
  padding: 1.25rem 0;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  max-width: 820px;
  margin: 0 auto;
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 100;
}

.site-title {
  font-size: var(--fs-sm);
  font-weight: 500;
  text-decoration: none;
  color: var(--text);
  transition: color 0.15s ease;
}

.site-title:hover { color: var(--muted); }

nav {
  display: flex;
  gap: 1.5rem;
  font-size: var(--fs-sm);
}

nav a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

nav a:hover { color: var(--text); }
nav a.active { color: var(--text); }

/* ── Layout ── */

main {
  max-width: 820px;
  margin: 0 auto;
  padding: 4rem 0 6rem;
}

/* ── Typography ── */

.eyebrow {
  font-size: var(--fs-xs);
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: var(--fs-h1);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: 0.5rem;
}

h2 {
  font-size: var(--fs-h2);
  font-weight: 600;
  margin: 1.5rem 0 1rem;
}

h2::before { content: '## '; color: var(--muted); }

h3 {
  font-size: var(--fs-sm);
  font-weight: 600;
  margin: 0.75rem 0;
  color: var(--muted);
}

p { margin-bottom: 0.5rem; }

.lead {
  font-size: var(--fs-base);
  color: var(--muted);
  max-width: 740px;
}

.note {
  font-size: var(--fs-sm);
  color: var(--muted);
  font-style: italic;
}

blockquote p {
  color: var(--muted);
  font-style: italic;
  margin: 1rem 3.5rem 0;
}

ul, ol {
  padding-left: 1.25rem;
  margin-bottom: 1rem;
  font-size: var(--fs-base);
}

li { margin-bottom: 0.3rem; }

a {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.15s ease;
}

a:hover { color: var(--muted); }

/* ── Anchor links on headings ── */

.anchor-link {
  color: inherit;
  text-decoration: none;
}

.anchor-link:hover { color: inherit; }

.anchor-link::after {
  content: ' #';
  color: var(--border);
  font-weight: 400;
  transition: color 0.15s ease;
}

.anchor-link:hover::after { color: var(--muted); }

/* ── Sections ── */

section {
  padding-top: 1rem;
  margin-top: 1rem;
}

/* ── Code blocks ── */

.code-block {
  position: relative;
  margin: 1.25rem 0;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  overflow-x: auto;
  font-family: 'IBM Plex Mono', monospace;
  font-size: var(--fs-code);
  line-height: 1.65;
}

code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.85em;
  background: var(--code-bg);
  padding: 0.1em 0.3em;
  border: 1px solid var(--border);
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
  white-space: pre-wrap;
}

.copy-btn {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: var(--fs-2xs);
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.2rem 0.5rem;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.copy-btn:hover { color: var(--text); border-color: var(--text); }
.copy-btn.copied { color: var(--text); }

/* ── Sketch embed ── */

.sketch {
  margin: 1.5rem 0;
  border: 1px solid var(--border);
  background: #fff;
}

.sketch-header {
  border-bottom: 1px solid var(--border);
  padding: 0.5rem 1rem;
  font-size: var(--fs-xs);
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sketch-header a {
  color: var(--muted);
  text-decoration: none;
  font-size: var(--fs-2xs);
  transition: color 0.15s ease;
}

.sketch-header a:hover { color: var(--text); }

/* iframe embed ; replace canvas */
.sketch-frame {
  display: block;
  width: 100%;
  height: 500px;
  border: none;
}

/* ── Exercise ── */

.exercise {
  border: 1px solid var(--text);
  padding: 1.5rem;
  margin: 2rem 0;
}

.exercise-label {
  font-size: var(--fs-2xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.exercise ul {
  padding-left: 1.2rem;
  font-size: var(--fs-base);
}

.exercise li { margin-bottom: 0.35rem; }

.exercise .duration {
  margin-top: 1rem;
  font-size: var(--fs-sm);
  color: var(--muted);
}

/* ── Reference table ── */

.ref-table {
  border-top: 1px solid var(--border);
  margin: 1rem 0;
}

.ref-row {
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
  padding: 0.45rem 0;
  border-bottom: 1px solid var(--border);
  font-size: var(--fs-xs);
}

.ref-row code {
  font-size: var(--fs-sm);
  white-space: nowrap;
  flex-shrink: 0;
}

.ref-desc { color: var(--muted); }

/* ── Link list ── */

.link-list {
  list-style: none;
  border-top: 1px solid var(--border);
  font-size: var(--fs-base);
}

.link-list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--border);
}

.link-list .link-desc {
  color: var(--muted);
  font-size: var(--fs-xs);
  text-align: right;
  flex-shrink: 0;
}

/* ── Schedule (index) ── */

.intro { margin-bottom: 4rem; }

.schedule { border-top: 1px solid var(--border); }

.day {
  display: grid;
  grid-template-columns: 80px 1fr;
  border-bottom: 1px solid var(--border);
}

.day-label {
  padding: 1.25rem 1.5rem 1.25rem 0;
  font-size: var(--fs-xs);
  color: var(--muted);
}

.day-content {
  padding: 1.25rem 0;
  font-size: var(--fs-base);
}

.day-content a {
  display: block;
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.15s ease;
}

.day-content a:hover { color: var(--muted); }

.day-sub {
  display: block;
  font-size: var(--fs-xs);
  color: var(--muted);
  margin-top: 0.25rem;
}

.day-sub code,
.day-content code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
  color: inherit;
}

.tag {
  font-size: var(--fs-2xs);
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 0.1rem 0.4rem;
  margin-left: 0.5rem;
  vertical-align: middle;
}

/* ── Tour de table ── */

.numbered-list {
  border-top: 1px solid var(--border);
  margin: 1.25rem 0;
}

.numbered-list-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 1rem;
  align-items: baseline;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
}

.numbered-list-item p { margin-bottom: 0; font-size: var(--fs-base); }

.numbered-list-label {
  font-size: var(--fs-2xs);
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* ── Figure ── */

.figure {
  margin: 1.5rem 0 2em;
}

.figure img, .figure video {
  max-width: 100%;
  width: auto;
  display: inline-block;
  border: 1px solid var(--border);
  transition: opacity 0.2s ease;
}

.figure.figure-sm img, .figure.figure-sm video {
  margin: auto;
  width: auto;
  max-width: 50%;
}

.figure img:hover, .figure video:hover { opacity: 0.9; }

.figure-caption {
  font-size: var(--fs-xs);
  color: var(--muted);
  margin-top: 0.4rem;
}

.figure-sm .figure-caption {
  text-align: center;
}

/* ── Day separator ── */

.day-separator {
  font-size: var(--fs-xs);
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 35vh 0;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.day-separator::before,
.day-separator::after {
  content: '';
  flex: 1;
  border-top: 1px solid var(--border);
}

/* ── RNG widget ── */

.rng {
  border: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  margin: 1.25rem 0;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.rng-label {
  font-size: var(--fs-2xs);
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  flex-shrink: 0;
}

.rng-result {
  font-size: 2rem;
  font-weight: 600;
  min-width: 4rem;
  text-align: center;
  transition: opacity 0.1s ease;
}

.rng-result.rolling { opacity: 0.3; }

.rng-buttons {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.rng-btn {
  font-family: 'IBM Plex Mono', monospace;
  font-size: var(--fs-2xs);
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  padding: 0.3rem 0.75rem;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.rng-btn:hover {
  border-color: var(--text);
  background: var(--code-bg);
}

.rng-btn:active { background: var(--border); }

/* ── Checklist ── */

.checklist {
  border-top: 1px solid var(--border);
  margin: 1rem 0;
}

.checklist-item {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  align-items: start;
}

.checklist-marker {
  font-size: var(--fs-sm);
  color: var(--muted);
  padding-top: 0.1rem;
}

.checklist-label {
  font-size: var(--fs-base);
  font-weight: 500;
  margin-bottom: 0.2rem;
}

.checklist-desc {
  font-size: var(--fs-xs);
  color: var(--muted);
  margin-bottom: 0;
}

/* ── Eval grid ── */

.eval-grid {
  border-top: 1px solid var(--border);
  margin: 1rem 0;
}

.eval-item {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.5rem;
  align-items: center;
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--border);
}

.eval-label {
  margin-bottom: 0;
  font-size: var(--fs-xs);
}

.eval-scale {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--muted);
  font-size: var(--fs-sm);
}

.dot {
  width: 14px;
  height: 14px;
  border: 1px solid var(--border);
  display: inline-block;
  flex-shrink: 0;
}

/* ── Page navigation ── */

.page-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  font-size: var(--fs-sm);
}

.page-nav a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.page-nav a:hover { color: var(--text); }
.page-nav .next { text-align: right; }