:root {
  --bg: #fbfaf8;
  --surface: #fff;
  --ink: #1b1a17;
  --muted: #6b675f;
  --line: #e3dfd7;
  --good: #1f7a4d;
  --good-bg: #eff8f2;
  --bad: #a8321f;
  --bad-bg: #fdf1ee;
  --warn: #8a6410;
  --warn-bg: #fdf8ec;
  --focus: #2f6df6;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
}

/* Sidebar + content. Content keeps its own measure; the grid column is what
   moves, so line length stays readable at any window width. */
.shell {
  display: grid;
  grid-template-columns: 16.5rem minmax(0, 1fr);
  align-items: start;
  max-width: 74rem;
  margin: 0 auto;
}

main {
  max-width: 46rem;
  padding: 2.5rem 1.25rem 4rem;
  min-width: 0;
}

.side-nav {
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
  padding: 2.5rem 0.75rem 2rem 1.25rem;
}
.side-nav-heading {
  font-size: 0.72rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 650;
  margin: 0 0 0.6rem 0.7rem;
}
.side-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.15rem;
}
.side-nav a {
  display: block;
  padding: 0.5rem 0.7rem;
  border-radius: 7px;
  font-size: 0.9rem;
  line-height: 1.35;
  text-decoration: none;
  color: var(--muted);
  border-left: 2px solid transparent;
}
.side-nav a:hover {
  background: rgba(0, 0, 0, 0.04);
  color: var(--ink);
}
.side-nav a[aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
  background: rgba(0, 0, 0, 0.05);
  border-left-color: var(--focus);
}

.nav-toggle {
  display: none;
  font: inherit;
  font-size: 0.85rem;
  padding: 0.3rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 100px;
  background: var(--surface);
  cursor: pointer;
}

@media (max-width: 56rem) {
  .shell {
    grid-template-columns: minmax(0, 1fr);
  }
  .nav-toggle {
    display: block;
  }
  .side-nav {
    position: static;
    max-height: none;
    display: none;
    padding: 1rem 1.25rem 0;
    border-bottom: 1px solid var(--line);
  }
  .side-nav.is-open {
    display: block;
  }
}

a {
  color: var(--focus);
}

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

.skip-link {
  position: absolute;
  left: -9999px;
}
.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
  background: var(--surface);
  padding: 0.5rem 0.75rem;
  z-index: 10;
}

.site-header {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: baseline;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.site-title {
  font-weight: 650;
  text-decoration: none;
  color: var(--ink);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.5rem 1.25rem;
  color: var(--muted);
  font-size: 0.9rem;
}

h1 {
  font-size: 1.9rem;
  line-height: 1.2;
  margin: 0.25rem 0 0.5rem;
}
h2 {
  font-size: 1.25rem;
  margin: 2.5rem 0 0.75rem;
}
h3 {
  font-size: 1rem;
  margin: 1.5rem 0 0.5rem;
}

.pattern-summary {
  font-size: 1.1rem;
  color: var(--muted);
  margin: 0;
}

.pattern-topics {
  margin: 0;
}
.topic {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 100px;
  padding: 0.15rem 0.6rem;
  margin-right: 0.35rem;
}

/* --- Pattern index --- */
.pattern-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}
.pattern-list a {
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.15rem;
  text-decoration: none;
  color: inherit;
}
.pattern-list a:hover {
  border-color: var(--muted);
}
.pattern-list h2 {
  margin: 0 0 0.25rem;
  font-size: 1.05rem;
  color: var(--focus);
}
.pattern-list p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

/* --- Demos --- */
.demo {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.15rem 1.25rem;
  margin: 1rem 0;
}
.demo-label {
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-weight: 650;
  margin: 0 0 0.75rem;
}
.demo.is-bad {
  border-color: #e9c4bb;
  background: var(--bad-bg);
}
.demo.is-bad .demo-label {
  color: var(--bad);
}
.demo.is-good {
  border-color: #bfe0cd;
  background: var(--good-bg);
}
.demo.is-good .demo-label {
  color: var(--good);
}

.demo.is-warn {
  border-color: #e4d4a8;
  background: var(--warn-bg);
}
.demo.is-warn .demo-label {
  color: var(--warn);
}

.demo fieldset {
  border: 1px solid #bfe0cd;
  border-radius: 8px;
  padding: 0.5rem 1rem 0.85rem;
  margin: 0;
}
.demo legend {
  padding: 0 0.4rem;
  font-weight: 600;
}

.help-text {
  padding-left: 1.65rem;
  font-size: 0.92rem;
}

.announce {
  margin: 0.85rem 0 0;
  font-size: 0.9rem;
  color: var(--muted);
}
.announce q {
  font-style: italic;
}

.demo-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.35rem 0;
}
.demo-row input[type="checkbox"] {
  width: 1.05rem;
  height: 1.05rem;
  margin: 0;
  flex: none;
}

.hit-log {
  margin: 0.85rem 0 0;
  padding: 0.6rem 0.75rem;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.05);
  font: 0.85rem/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
  min-height: 2.6rem;
}

table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.9rem;
  margin: 1rem 0;
  display: block;
  overflow-x: auto;
}
th,
td {
  border-bottom: 1px solid var(--line);
  padding: 0.5rem 0.7rem;
  text-align: left;
  white-space: nowrap;
}
th {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.callout {
  border-left: 3px solid var(--line);
  padding: 0.1rem 0 0.1rem 1rem;
  margin: 1.25rem 0;
  color: var(--muted);
}

code {
  font: 0.9em ui-monospace, SFMono-Regular, Menlo, monospace;
  background: rgba(0, 0, 0, 0.055);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}
pre {
  background: #1b1a17;
  color: #f4f1ea;
  padding: 1rem 1.15rem;
  border-radius: 10px;
  overflow-x: auto;
}
pre code {
  background: none;
  padding: 0;
  color: inherit;
}

.back {
  max-width: 46rem;
  margin: 2rem auto 0;
}