/* Hosta Research — mobile-first stylesheet
   Target: iPhone Safari. Dark theme, calm, high contrast, no motion. */

:root {
  --bg: #0a0e0c;
  --bg-2: #121815;
  --bg-3: #1b2420;
  --fg: #e6efe8;
  --fg-dim: #a8b6ad;
  --accent: #7ec488;
  --accent-2: #c9e6cf;
  --rule: #2a3530;
  --warn: #e0b46a;
  --serif: Georgia, "Iowan Old Style", "Palatino Linotype", serif;
  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, sans-serif;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  padding-bottom: 88px; /* room for fixed bottom nav */
}

/* Top bar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(10, 14, 12, 0.92);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--rule);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  padding-top: max(10px, env(safe-area-inset-top));
}
.topbar a.home {
  color: var(--accent-2);
  font-family: var(--serif);
  font-size: 18px;
  text-decoration: none;
  letter-spacing: 0.02em;
}
.topbar .menu-btn {
  background: var(--bg-3);
  color: var(--fg);
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 8px 14px;
  font-size: 15px;
  min-height: 40px;
  min-width: 60px;
  cursor: pointer;
}

/* Drawer */
.drawer {
  position: fixed;
  inset: 0;
  z-index: 40;
  background: rgba(0,0,0,0.6);
  display: none;
}
.drawer.open { display: block; }
.drawer .panel {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(86vw, 360px);
  background: var(--bg-2);
  border-left: 1px solid var(--rule);
  padding: 16px 18px;
  padding-top: max(16px, env(safe-area-inset-top));
  overflow-y: auto;
}
.drawer h2 {
  font-family: var(--serif);
  color: var(--accent-2);
  font-size: 18px;
  margin: 6px 0 14px;
}
.drawer ol {
  list-style: none;
  margin: 0;
  padding: 0;
}
.drawer li { margin: 0; }
.drawer a {
  display: block;
  color: var(--fg);
  text-decoration: none;
  padding: 12px 8px;
  border-bottom: 1px solid var(--rule);
  font-size: 16px;
  min-height: 44px;
}
.drawer a.current { color: var(--accent); }
.drawer .close {
  float: right;
  background: transparent;
  color: var(--fg-dim);
  border: 0;
  font-size: 22px;
  cursor: pointer;
}

/* Main */
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 18px 18px 32px;
  padding-left: max(18px, env(safe-area-inset-left));
  padding-right: max(18px, env(safe-area-inset-right));
}

h1, h2, h3, h4 { font-family: var(--serif); color: var(--accent-2); line-height: 1.25; }
h1 { font-size: 30px; margin: 0.4em 0 0.2em; }
h2 { font-size: 23px; margin: 1.6em 0 0.4em; border-bottom: 1px solid var(--rule); padding-bottom: 6px; }
h3 { font-size: 19px; margin: 1.2em 0 0.3em; color: var(--accent); }
h4 { font-size: 17px; margin: 1em 0 0.2em; color: var(--accent); }
p { margin: 0.6em 0; }
strong { color: var(--accent-2); }
em { color: var(--fg); }
a { color: var(--accent); }
a:visited { color: var(--accent); }

.lede {
  font-family: var(--serif);
  font-size: 19px;
  color: var(--fg-dim);
  margin: 0.6em 0 1.2em;
}
.kicker {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 6px;
}

ul, ol { padding-left: 22px; }
li { margin: 0.25em 0; }

blockquote {
  border-left: 3px solid var(--accent);
  margin: 1em 0;
  padding: 4px 14px;
  color: var(--fg-dim);
  background: var(--bg-2);
  border-radius: 0 8px 8px 0;
}

.callout {
  background: var(--bg-2);
  border: 1px solid var(--rule);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  padding: 12px 14px;
  margin: 1.2em 0;
}
.callout.warn { border-left-color: var(--warn); }
.callout h4 { margin-top: 0; }

figure {
  margin: 1.3em -4px;
  padding: 8px;
  background: var(--bg-2);
  border: 1px solid var(--rule);
  border-radius: 10px;
}
figure img, figure svg {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 6px;
  background: var(--bg-3);
}
figcaption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--fg-dim);
  line-height: 1.5;
}
figcaption .credit { color: var(--accent); }

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1em 0;
  font-size: 15px;
}
th, td {
  border: 1px solid var(--rule);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}
th { background: var(--bg-3); color: var(--accent-2); }

hr { border: 0; border-top: 1px solid var(--rule); margin: 2em 0; }

/* Cards on index */
.cardgrid {
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr;
  margin: 1.2em 0;
}
.card {
  display: block;
  padding: 14px 16px;
  background: var(--bg-2);
  border: 1px solid var(--rule);
  border-radius: 12px;
  text-decoration: none;
  color: var(--fg);
}
.card .num {
  font-family: var(--serif);
  color: var(--accent);
  font-size: 14px;
  letter-spacing: 0.06em;
}
.card .ttl {
  display: block;
  font-family: var(--serif);
  color: var(--accent-2);
  font-size: 18px;
  margin-top: 2px;
}
.card .sub {
  color: var(--fg-dim);
  font-size: 14px;
  margin-top: 4px;
}

/* Fixed bottom nav */
.botnav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 25;
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: rgba(10, 14, 12, 0.95);
  border-top: 1px solid var(--rule);
  padding-bottom: env(safe-area-inset-bottom);
}
.botnav a {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  text-decoration: none;
  color: var(--fg);
  padding: 14px 10px;
  font-size: 15px;
  min-height: 56px;
}
.botnav a.disabled { color: #4d5853; pointer-events: none; }
.botnav a + a { border-left: 1px solid var(--rule); }
.botnav .label { display: block; font-size: 11px; color: var(--accent); letter-spacing: 0.1em; }
.botnav .ttl { display: block; font-family: var(--serif); }

.toc-list {
  list-style: none;
  padding: 0;
  margin: 1em 0;
}
.toc-list li {
  border-bottom: 1px solid var(--rule);
}
.toc-list a {
  display: block;
  padding: 12px 6px;
  text-decoration: none;
  color: var(--fg);
  min-height: 44px;
}
.toc-list .num { color: var(--accent); font-size: 13px; letter-spacing: 0.08em; }
.toc-list .ttl { font-family: var(--serif); color: var(--accent-2); }

/* Diagram-specific */
.diagram { background: #f3efe5; }
.diagram-dark { background: var(--bg-3); }

/* Print */
@media print {
  :root { --bg: #fff; --bg-2: #fff; --bg-3: #f4f4f4; --fg: #111; --fg-dim: #444; --accent: #2f6b39; --accent-2: #1d4423; --rule: #ccc; }
  body { color: #111; background: #fff; padding-bottom: 0; font-size: 12pt; }
  .topbar, .botnav, .drawer { display: none !important; }
  main { max-width: 100%; padding: 0; }
  figure { break-inside: avoid; }
  a { color: #1d4423; text-decoration: none; }
}

/* Tablet/desktop */
@media (min-width: 760px) {
  body { font-size: 18px; }
  main { padding: 28px 28px 48px; }
  h1 { font-size: 36px; }
  h2 { font-size: 26px; }
  .cardgrid { grid-template-columns: 1fr 1fr; }
}