:root {
  --paper: #e7dfcf;
  --paper-2: #efe8d8;
  --ink: #1a1712;
  --ink-soft: #4a453c;
  --rule: #c9bea8;
  --rule-hard: #1a1712;
  --oxide: #9c3218;
  --stamp: #2f4a3c;
  --space: 8px;
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    linear-gradient(var(--rule) 1px, transparent 1px) 0 0 / 100% 28px,
    var(--paper);
  font-family: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  font-optical-sizing: auto;
  font-size: 18px;
  line-height: 1.45;
  text-wrap: pretty;
}

.skip {
  position: absolute;
  left: -999px;
  top: 8px;
}
.skip:focus {
  left: 8px;
  z-index: 20;
  background: var(--ink);
  color: var(--paper);
  padding: 8px 12px;
}

.sheet {
  max-width: 980px;
  margin: 24px auto 64px;
  padding: 0 16px;
}

.titleblock {
  display: grid;
  grid-template-columns: 1fr auto;
  border: 2px solid var(--rule-hard);
  background: var(--paper-2);
}

.titleblock > * {
  padding: 14px 16px;
  border-bottom: 1px solid var(--rule-hard);
}

.tb-id {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
  grid-column: 1 / -1;
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.tb-name {
  border-right: 1px solid var(--rule-hard);
}

.tb-name h1 {
  margin: 0;
  font-size: clamp(40px, 8vw, 72px);
  font-weight: 600;
  line-height: 0.95;
  letter-spacing: -0.02em;
}

.tb-meta {
  min-width: 220px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 12px;
  line-height: 1.6;
}

.tb-meta dt {
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0;
}
.tb-meta dd {
  margin: 0 0 10px;
  font-weight: 500;
}

.tb-lede {
  grid-column: 1 / -1;
  border-bottom: 0;
  font-size: 20px;
  max-width: 46rem;
}

.tb-lede p { margin: 0; }

nav.toc {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  margin: 18px 0 28px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 13px;
}

nav.toc a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
nav.toc a:hover,
nav.toc a:focus-visible {
  border-bottom-color: var(--oxide);
  outline: none;
}

h2 {
  margin: 0 0 16px;
  font-size: 13px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--stamp);
}

.rev {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 0 20px;
  padding: 18px 0;
  border-top: 1px solid var(--rule-hard);
}
.rev:last-of-type { border-bottom: 1px solid var(--rule-hard); }

.rev time {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 12px;
  color: var(--ink-soft);
  padding-top: 6px;
}

.rev h3 {
  margin: 0 0 4px;
  font-size: 22px;
  font-weight: 600;
}

.org {
  margin: 0 0 8px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 13px;
}

.rev p {
  margin: 0;
  color: var(--ink-soft);
  max-width: 40rem;
}

.modules {
  width: 100%;
  border-collapse: collapse;
  margin: 8px 0 32px;
  font-size: 16px;
}
.modules th,
.modules td {
  text-align: left;
  padding: 10px 12px;
  border: 1px solid var(--rule-hard);
  vertical-align: top;
}
.modules th {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--paper-2);
  width: 28%;
}

.edu {
  display: grid;
  gap: 12px;
  margin-bottom: 32px;
}
.edu article {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--rule);
}
.edu h3 { margin: 0; font-size: 18px; font-weight: 600; }
.edu p { margin: 0; color: var(--ink-soft); }
.edu span {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 12px;
  color: var(--ink-soft);
}

.contact {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  padding: 18px;
  border: 2px solid var(--rule-hard);
  background: var(--paper-2);
}

.btn {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 16px;
  background: var(--ink);
  color: var(--paper);
  text-decoration: none;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 13px;
  letter-spacing: 0.04em;
}
.btn:hover,
.btn:focus-visible {
  background: var(--oxide);
  outline: 2px solid var(--oxide);
  outline-offset: 2px;
}

.note {
  margin: 0;
  color: var(--ink-soft);
  font-size: 15px;
}

footer {
  margin-top: 28px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 11px;
  color: var(--ink-soft);
}

@media (max-width: 700px) {
  .titleblock,
  .rev,
  .edu article {
    grid-template-columns: 1fr;
  }
  .tb-name { border-right: 0; }
  .tb-meta { min-width: 0; }
  .modules th { width: auto; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}