:root {
  --paper: #fbfaf7;
  --ink: #1c1c1c;
  --muted: #5c5a55;
  --accent: #1b3a6b;
  --accent-hover: #8c2f39;
  --rule: #d9d4cb;
  --field: #ffffff;
  --tint: #f2efe8;

  --sans: "IBM Plex Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  --serif: "IBM Plex Serif", Georgia, "Times New Roman", serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, monospace;

  --step-0: 1.0625rem; /* 17px body */
  --step-1: 1.3125rem;
  --step-2: 1.64rem;
  --step-3: 2.05rem;

  --measure: 68ch;
  --gap: 0.75rem;
  --radius: 2px;
}

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

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

body {
  margin: 0;
  padding: 0 1rem 3rem;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: var(--step-0);
  line-height: 1.6;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; }

a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

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

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

.site-header,
main,
.site-footer {
  max-width: 60rem;
  margin-left: auto;
  margin-right: auto;
}

main {
  padding-top: 1.75rem;
}

.site-header {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding-top: 1.75rem;
}

.wordmark {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  text-decoration: none;
  color: var(--ink);
  line-height: 1;
}

.site-logo {
  height: 70px;
  width: auto;
  flex-shrink: 0;
}

.wordmark-abbr {
  font-family: var(--sans);
  font-weight: 600;
  font-size: var(--step-3);
  letter-spacing: 0.04em;
}

.site-title {
  margin: 0;
  font-family: var(--sans);
  font-weight: 400;
  font-size: 0.95rem;
  color: var(--muted);
  line-height: 1.3;
}

main h1.site-title {
  font-family: var(--sans);
  font-weight: 600;
  font-size: var(--step-2);
  line-height: 1.25;
  color: var(--ink);
  margin: 0 0 0.75rem;
}

.site-nav {
  border-bottom: 1px solid var(--rule);
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0 1.5rem;
  margin: 0;
  padding: 0.4rem 0;
  list-style: none;
}

.site-nav a,
.site-nav .nav-current,
.site-nav .nav-unavailable {
  display: inline-block;
  padding: 0.65rem 0;
  font-family: var(--sans);
  font-size: 0.9rem;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover {
  color: var(--accent-hover);
  border-bottom-color: var(--rule);
}

.site-nav .nav-current {
  color: var(--accent);
  font-weight: 600;
  border-bottom-color: var(--accent);
}

.site-nav .nav-unavailable {
  color: var(--muted);
}

main h1,
main h2,
main h3 {
  font-family: var(--sans);
  color: var(--ink);
  line-height: 1.25;
}

main h1 {
  font-size: var(--step-2);
  font-weight: 600;
  margin: 0 0 1rem;
}

main h2 {
  font-size: var(--step-1);
  font-weight: 600;
  margin: 1.75rem 0 0.75rem;
}

main h3 {
  font-size: var(--step-0);
  font-weight: 600;
  margin: 1.5rem 0 0.5rem;
}

main p { margin: 0.75em 0; max-width: var(--measure); }

main ul,
main ol {
  margin: 0.75em 0;
  padding-left: 1.6em;
  max-width: var(--measure);
}

main li { margin: 0.35em 0; }

main em { font-style: italic; }

code,
tt { font-family: var(--mono); font-size: 0.9em; }

hr {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 1.75rem 0;
}

address { font-style: normal; }

main h2.banner,
main .banner {
  background: var(--tint);
  border-left: 3px solid var(--accent);
  padding: 0.4rem 0.75rem;
}

.search {
  margin: 1.75rem 0 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}

.search-title {
  font-family: var(--sans);
  font-weight: 600;
  margin: 0 0 0.75rem;
}

.search-form { max-width: 34rem; }

.search-grid {
  display: grid;
  gap: var(--gap);
  margin: 0 0 1rem;
  padding: 0;
  border: 0;
}

.search-grid .field {
  display: grid;
  gap: 0.25rem 1rem;
  margin: 0;
  padding: 0;
}

.search-grid label {
  font-family: var(--sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ink);
}

.search-grid input[type="text"],
.search-grid select {
  width: 100%;
  padding: 0.45rem 0.5rem;
  font-family: var(--sans);
  font-size: 0.9rem;
  color: var(--ink);
  background: var(--field);
  border: 1px solid var(--ink);
  border-radius: var(--radius);
}

.search-submit {
  display: inline-block;
  padding: 0.55rem 1.5rem;
  font-family: var(--sans);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--paper);
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 120ms ease, border-color 120ms ease;
}

.search-submit:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.search-results { margin: 1.5rem 0 2.5rem; }
.search-results[hidden] { display: none; }

.results-summary {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 1rem;
  margin: 0.75rem 0;
}

.results-loading,
.results-error {
  font-family: var(--sans);
  font-size: 0.9rem;
  margin: 0.75rem 0;
}
.results-error { color: var(--accent-hover); }

.results-group {
  margin: 1.5rem 0 0.5rem;
  border-top: 1px solid var(--rule);
  padding-top: 0.75rem;
}

.results-group h2 {
  font-family: var(--sans);
  font-size: var(--step-0);
  margin: 0 0 0.5rem;
}

.results-count {
  font-weight: 400;
  font-size: 0.85rem;
  color: var(--muted);
}

.results-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.results-list li {
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--rule);
  font-size: 0.95rem;
}

.result-file a { font-weight: 600; }
.result-missing { font-weight: 600; color: var(--muted); }

.result-meta {
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--muted);
}

.result-snippet {
  margin-top: 0.2rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.site-footer {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}

.site-footer p,
.site-footer address {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0.5rem 0;
  max-width: var(--measure);
}

.site-footer a { color: var(--accent); }
.site-footer a:hover { color: var(--accent-hover); }

.site-footer .ie-note {
  font-size: 0.75rem;
  font-style: italic;
  margin-top: 1.25rem;
}

.powered-by {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.75rem;
}

.powered-by img {
  display: block;
  height: 30px;
  width: auto;
}

.toc-bar {
  font-family: var(--sans);
  font-size: 0.85rem;
  margin: 0.5rem 0 1rem;
}

.toc-bar a { color: var(--accent); }

.submission-list { list-style: disc; }

.cluster-block {
  margin-left: 0;
  padding: 0.4rem 0;
}

.cluster-block .cluster-title {
  font-family: var(--sans);
  font-weight: 600;
  font-size: var(--step-0);
  margin: 1rem 0 0.5rem;
}

.structure-img {
  display: block;
  width: 602px;
  max-width: 100%;
  height: auto;
  margin: 1rem 0;
}

figure { margin: 1rem 0; }

@media (min-width: 40em) {
  .search-grid .field {
    grid-template-columns: minmax(9rem, 12rem) 1fr;
    align-items: center;
  }

  .cluster-block {
    margin-left: 3em;
  }
}

@media (min-width: 56em) {
  .site-nav ul { gap: 0 2rem; }

  .wordmark-abbr { font-size: var(--step-3); }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}