/* 2026 archival botany: blotting cream, olive strap, specimen pin */
:root {
  --cream: #f3ead6;
  --sheet: #fbf6ea;
  --olive: #5c6b3a;
  --pin: #8a3b2a;
  --ink: #2c271c;
  --mute: #746b58;
  --line: rgba(92, 107, 58, 0.22);
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
section[id] { scroll-margin-top: 68px; }

body {
  margin: 0;
  background: var(--cream);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  background-image: url("images/texture.webp");
  background-size: 420px;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
code { font-family: var(--mono); color: var(--olive); }

.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; z-index: 80; background: var(--olive); color: #fff; padding: 8px 12px; }

.sheet-bar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px 22px; background: rgba(251, 246, 234, 0.94);
  border-bottom: 1px solid var(--line);
}
.brand { font-family: var(--serif); font-weight: 700; }
.brand small { display: block; font-family: var(--mono); font-size: 11px; font-weight: 400; color: var(--mute); }
.sheet-links { display: flex; flex-wrap: wrap; gap: 6px 14px; align-items: center; }
.sheet-links a { font-size: 13px; color: var(--mute); }
.sheet-links a.is-active, .sheet-links a:hover { color: var(--olive); }
.sheet-links .live { background: var(--olive); color: #fff; padding: 6px 12px; font-weight: 700; }
.nav-toggle { display: none; background: var(--sheet); border: 1px solid var(--line); padding: 6px 10px; }

.hero { position: relative; }
.hero > img { width: 100%; height: min(54vh, 500px); object-fit: cover; }
.hero-copy {
  width: min(920px, calc(100% - 40px));
  margin: -48px auto 0;
  background: var(--sheet);
  padding: 32px 36px;
  border: 1px solid var(--line);
  position: relative;
}

.kicker { font-family: var(--mono); font-size: 12px; letter-spacing: 0.14em; color: var(--olive); margin: 0 0 8px; }
h1, h2, h3 { font-family: var(--serif); margin: 0 0 12px; line-height: 1.22; }
h1 { font-size: clamp(1.9rem, 4.6vw, 3.2rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); }

.gate { margin: 18px 0; padding: 12px 14px; border-left: 4px solid var(--pin); background: #f4ead4; }
.gate.ok { border-left-color: var(--olive); }
.gate span { font-size: 13px; color: var(--mute); }
.gate strong { display: block; margin: 4px 0; }
.gate p { margin: 0; color: var(--mute); font-size: 14px; }

.cta { display: flex; flex-wrap: wrap; gap: 10px; }
.btn { display: inline-flex; align-items: center; padding: 10px 16px; border: 1px solid var(--olive); background: transparent; color: var(--ink); font-size: 14px; }
.btn.fill { background: var(--olive); color: #fff; font-weight: 700; }

.wrap { width: min(1100px, calc(100% - 40px)); margin: 0 auto; padding: 72px 0; }
.quiet { color: var(--mute); max-width: 68ch; }
.blot { background: rgba(251, 246, 234, 0.72); }

.tri { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 24px; }
.tri article { background: var(--sheet); padding: 20px; border: 1px solid var(--line); }
.tri .warn { border-color: var(--pin); }
.tri ul { margin: 0; padding-left: 1.1em; }

.row { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; align-items: center; margin: 48px 0; }
.row.flip { direction: rtl; }
.row.flip > * { direction: ltr; }
.num { font-family: var(--mono); color: var(--pin); font-size: 12px; letter-spacing: 0.12em; }
figure { margin: 0; }
figcaption { font-size: 13px; color: var(--mute); margin-top: 8px; }

.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 20px; }
.grid2 article { background: var(--sheet); padding: 18px 20px; border-top: 3px solid var(--olive); }

.rules { padding-left: 1.2em; }
.rules li { margin: 8px 0; }
.keys { display: grid; gap: 1px; background: var(--line); margin-top: 16px; }
.keys div { display: grid; grid-template-columns: 140px 1fr; gap: 12px; padding: 12px 16px; background: var(--sheet); }
.keys span { color: var(--mute); }

footer { border-top: 1px solid var(--line); background: #e6dcc4; }
.foot { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 24px 0; }

@media (max-width: 900px) {
  .nav-toggle { display: block; }
  .sheet-links { display: none; position: absolute; top: 52px; left: 12px; right: 12px; flex-direction: column; background: var(--sheet); border: 1px solid var(--line); padding: 12px; }
  .sheet-links.open { display: flex; }
  .tri, .row, .grid2 { grid-template-columns: 1fr; }
  .row.flip { direction: ltr; }
  .keys div { grid-template-columns: 1fr; }
  .foot { flex-direction: column; align-items: flex-start; }
  .hero-copy { padding: 22px 18px; }
}