@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,400..900;1,9..144,400..700&family=Newsreader:ital,opsz,wght@0,6..72,400..600;1,6..72,400..500&family=IBM+Plex+Mono:wght@400;500;600&display=swap');

/* ─────────────────────────────────────────────────────────────────────────
   Aquameta — editorial / technical
   Warm paper, near-black ink, a single cobalt accent.
   Fraunces (display) · Newsreader (body) · IBM Plex Mono (technical)
   ───────────────────────────────────────────────────────────────────────── */

:root {
  --paper:    #f4f1e9;
  --paper-2:  #ece7da;
  --ink:      #18150f;
  --muted:    #6e675a;
  --accent:   #1b34d8;
  --accent-ink:#122296;
  --rule:     rgba(24, 21, 16, 0.16);
  --rule-soft:rgba(24, 21, 16, 0.08);

  --display: 'Fraunces', Georgia, serif;
  --body:    'Newsreader', Georgia, serif;
  --mono:    'IBM Plex Mono', ui-monospace, monospace;

  --measure: 38rem;
  --page:    74rem;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background-color: var(--paper);
  /* faint grain for paper atmosphere */
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");
  color: var(--ink);
  font-family: var(--body);
  font-optical-sizing: auto;
  font-size: 1.12rem;
  line-height: 1.62;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--accent); color: var(--paper); }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-ink); }

/* ── shell ─────────────────────────────────────────────────────────────── */
.wrap { max-width: var(--page); margin: 0 auto; padding: 0 2rem; }

/* ── masthead ──────────────────────────────────────────────────────────── */
.masthead {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 1.5rem; padding: 1.6rem 0 1.4rem;
  border-bottom: 1px solid var(--ink);
  flex-wrap: wrap;
}
.wordmark {
  font-family: var(--mono); font-weight: 600;
  letter-spacing: 0.34em; text-transform: uppercase;
  font-size: 0.92rem; color: var(--ink);
}
.wordmark .dot { color: var(--accent); }
.nav { display: flex; gap: 1.6rem; align-items: baseline; flex-wrap: wrap; }
.nav a {
  font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--muted);
  padding-bottom: 2px; border-bottom: 1px solid transparent;
}
.nav a:hover { color: var(--ink); border-bottom-color: var(--accent); }
.nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--ink); }
.nav a .ext { color: var(--accent); }

/* ── hero ──────────────────────────────────────────────────────────────── */
.hero { padding: 6.5rem 0 4.5rem; max-width: 56rem; }
.kicker {
  font-family: var(--mono); font-size: 0.8rem; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--accent); margin: 0 0 1.8rem;
}
.hero h1 {
  font-family: var(--display); font-weight: 540;
  font-size: clamp(2.9rem, 7.5vw, 6rem); line-height: 0.98;
  letter-spacing: -0.018em; margin: 0; text-wrap: balance;
}
.hero h1 em { font-style: italic; font-weight: 460; color: var(--accent-ink); }
.lede {
  font-size: clamp(1.25rem, 2.4vw, 1.6rem); line-height: 1.5;
  max-width: 40rem; margin: 1.9rem 0 0; color: #2a261d;
}
.tagline {
  font-family: var(--mono); font-size: 0.85rem; letter-spacing: 0.04em;
  color: var(--muted); margin: 1.4rem 0 0;
}

/* ── buttons ───────────────────────────────────────────────────────────── */
.actions { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 2.6rem; }
.btn {
  font-family: var(--mono); font-size: 0.82rem; letter-spacing: 0.06em;
  text-transform: uppercase; padding: 0.85rem 1.4rem; border: 1px solid var(--ink);
  display: inline-flex; align-items: center; gap: 0.5rem;
  transition: background .18s ease, color .18s ease, transform .18s ease;
}
.btn-primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn-primary:hover { background: var(--accent); border-color: var(--accent); color: var(--paper); transform: translateY(-2px); }
.btn-ghost { color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: var(--paper); transform: translateY(-2px); }

/* ── section scaffolding ───────────────────────────────────────────────── */
.section { padding: 4.5rem 0; border-top: 1px solid var(--rule); }
.section-head { display: flex; gap: 1.4rem; align-items: baseline; margin-bottom: 2.6rem; }
.section-no {
  font-family: var(--mono); font-size: 0.8rem; color: var(--accent);
  letter-spacing: 0.1em; padding-top: 0.5rem;
}
.section-head h2 {
  font-family: var(--display); font-weight: 520; letter-spacing: -0.01em;
  font-size: clamp(1.7rem, 3.6vw, 2.7rem); line-height: 1.05; margin: 0; text-wrap: balance;
}
.section-head p { margin: 0.7rem 0 0; color: var(--muted); max-width: var(--measure); }

/* ── the stack-collapse figure ─────────────────────────────────────────── */
.collapse { display: grid; grid-template-columns: 1fr auto 1fr; gap: 2rem; align-items: center; margin-top: 1rem; }
.stack { display: flex; flex-direction: column; gap: 0.5rem; }
.stack .cap { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 0.4rem; }
.cell {
  font-family: var(--mono); font-size: 0.86rem; text-align: center;
  padding: 0.85rem 1rem; border: 1px solid var(--rule); background: var(--paper-2);
  color: var(--muted);
}
.cell.db { color: var(--ink); border-color: var(--ink); background: transparent; }
.cell.one {
  background: var(--ink); color: var(--paper); border-color: var(--ink);
  padding: 2.4rem 1rem; display: flex; align-items: center; justify-content: center;
  font-size: 1rem; letter-spacing: 0.04em; height: 100%;
}
.collapse .arrow { font-family: var(--mono); color: var(--accent); font-size: 1.4rem; text-align: center; }

/* ── ideas grid ────────────────────────────────────────────────────────── */
.ideas { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 0; border-top: 1px solid var(--rule); }
.idea { padding: 1.8rem 1.6rem 2rem 0; border-bottom: 1px solid var(--rule); }
.idea .n { font-family: var(--mono); font-size: 0.78rem; color: var(--accent); letter-spacing: 0.1em; }
.idea h3 { font-family: var(--display); font-weight: 540; font-size: 1.4rem; margin: 0.7rem 0 0.5rem; letter-spacing: -0.01em; }
.idea p { margin: 0; color: var(--muted); font-size: 1rem; line-height: 1.55; }

/* ── prose (concepts / architecture) ──────────────────────────────────── */
.lead { font-size: clamp(1.3rem, 2.6vw, 1.7rem); line-height: 1.45; max-width: 42rem; color: #2a261d; margin: 0 0 1rem; font-family: var(--display); font-weight: 420; }
.prose { max-width: var(--measure); }
.prose p { margin: 0 0 1.2rem; }
.prose h3 { font-family: var(--display); font-weight: 560; font-size: 1.5rem; margin: 2.4rem 0 0.6rem; letter-spacing: -0.01em; }
.prose strong { font-weight: 600; }
.prose code, .inline-code { font-family: var(--mono); font-size: 0.86em; background: var(--paper-2); padding: 0.08em 0.34em; border-radius: 2px; }
.prose ul { padding-left: 1.1rem; margin: 0 0 1.2rem; }
.prose li { margin: 0.3rem 0; }

/* code block */
.code {
  font-family: var(--mono); font-size: 0.82rem; line-height: 1.7;
  background: var(--ink); color: #e9e4d6; padding: 1.3rem 1.5rem;
  overflow-x: auto; margin: 1.6rem 0; border-radius: 2px;
}
.code .k { color: #9db4ff; }     /* keyword */
.code .c { color: #8c8474; }     /* comment */
.code .s { color: #d8b46a; }     /* string */

/* pull quote */
.pull { font-family: var(--display); font-weight: 460; font-style: italic;
  font-size: clamp(1.5rem, 3.4vw, 2.3rem); line-height: 1.25; letter-spacing: -0.01em;
  max-width: 46rem; margin: 3rem 0; color: var(--ink); }
.pull .accent { color: var(--accent-ink); }

/* two-column module list (architecture) */
.modules { border-top: 1px solid var(--ink); margin-top: 1.5rem; }
.module { display: grid; grid-template-columns: 12rem 1fr; gap: 1.5rem; padding: 1rem 0; border-bottom: 1px solid var(--rule); }
.module .name { font-family: var(--mono); font-size: 0.92rem; color: var(--ink); font-weight: 500; }
.module .desc { color: var(--muted); font-size: 1rem; }
@media (max-width: 38rem) { .module { grid-template-columns: 1fr; gap: 0.2rem; } }

/* ── footer ────────────────────────────────────────────────────────────── */
.footer { border-top: 1px solid var(--ink); margin-top: 4rem; padding: 2.5rem 0 4rem;
  display: flex; justify-content: space-between; gap: 1.5rem; flex-wrap: wrap; align-items: baseline; }
.footer .meta { font-family: var(--mono); font-size: 0.76rem; color: var(--muted); letter-spacing: 0.04em; line-height: 1.8; }
.footer .meta a { color: var(--muted); border-bottom: 1px solid var(--rule); }
.footer .meta a:hover { color: var(--ink); border-bottom-color: var(--accent); }
.footer .sig { font-family: var(--display); font-style: italic; font-size: 1.1rem; color: var(--muted); }

/* ── page-load reveal (CSS only, staggered) ────────────────────────────── */
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: no-preference) {
  .reveal > * { opacity: 0; animation: rise 0.9s cubic-bezier(0.2, 0.7, 0.2, 1) forwards; }
  .reveal > *:nth-child(1) { animation-delay: 0.05s; }
  .reveal > *:nth-child(2) { animation-delay: 0.16s; }
  .reveal > *:nth-child(3) { animation-delay: 0.27s; }
  .reveal > *:nth-child(4) { animation-delay: 0.38s; }
  .reveal > *:nth-child(5) { animation-delay: 0.49s; }
}

@media (max-width: 46rem) {
  .collapse { grid-template-columns: 1fr; gap: 1rem; }
  .collapse .arrow { transform: rotate(90deg); }
  .hero { padding: 4rem 0 3rem; }
}

/* ── install tabs (CSS-only) ───────────────────────────────────────────── */
.tabs { margin: 1.6rem 0; max-width: 46rem; }
.tabs > input { position: absolute; opacity: 0; pointer-events: none; }
.tab-labels { display: flex; gap: 0; flex-wrap: wrap; border-bottom: 1px solid var(--ink); }
.tab-labels label {
  font-family: var(--mono); font-size: 0.76rem; letter-spacing: 0.06em;
  text-transform: uppercase; padding: 0.7rem 1.1rem; cursor: pointer;
  color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px;
  transition: color .15s ease;
}
.tab-labels label:hover { color: var(--ink); }
#os-mac:checked   ~ .tab-labels label[for="os-mac"],
#os-deb:checked   ~ .tab-labels label[for="os-deb"],
#os-linux:checked ~ .tab-labels label[for="os-linux"],
#os-win:checked   ~ .tab-labels label[for="os-win"] { color: var(--ink); border-bottom-color: var(--accent); }
.tab-panels .panel { display: none; }
#os-mac:checked   ~ .tab-panels .panel-mac,
#os-deb:checked   ~ .tab-panels .panel-deb,
#os-linux:checked ~ .tab-panels .panel-linux,
#os-win:checked   ~ .tab-panels .panel-win { display: block; }
.panel .note { font-family: var(--mono); font-size: 0.74rem; color: var(--muted); margin: 0.7rem 0 0; }
.panel .note a { border-bottom: 1px solid var(--rule); }
.code .p { color: #8c8474; }   /* dim path/prompt */

/* ── steps ─────────────────────────────────────────────────────────────── */
.step { display: grid; grid-template-columns: 2.4rem 1fr; gap: 1.2rem; padding: 0.3rem 0 1.6rem; }
.step-n {
  font-family: var(--mono); font-size: 0.82rem; color: var(--accent);
  border: 1px solid var(--rule); border-radius: 50%;
  width: 2rem; height: 2rem; display: flex; align-items: center; justify-content: center;
  align-self: start;
}
.step h3 { font-family: var(--display); font-weight: 540; font-size: 1.25rem; margin: 0.15rem 0 0.4rem; letter-spacing: -0.01em; }
.step p { margin: 0 0 0.4rem; color: var(--muted); font-size: 1rem; }
.step .code { margin: 0.7rem 0 0; max-width: 44rem; }
@media (max-width: 38rem) { .step { grid-template-columns: 1fr; gap: 0.4rem; } .step-n { display: none; } }