/* The EDLC site. Tutelage's marketing skin (tutelage.design DESIGN.md §Three skins), copied by
   role name: warm paper, one deep teal, flat by construction (no shadows), colour that means
   something. Light values on :root, dark values in the media query. */

:root {
  --bg: #fbfaf8;
  --surface: #ffffff;
  --sunken: #efeeea;
  --line: #e2e0db;
  --line-strong: #cbc8c1;
  --ink: #21201c;
  --label: #6b6863;
  --faint: #736f67;
  --accent: #0f6f63;
  --accent-emphasis: #0c5a50;
  --accent-soft: #d7ece8;
  --accent-text: #0c5f54;
  --accent-fg: #ffffff;
  --warning-soft: #f6e7cd;
  --warning-text: #8a560b;

  --font: "Hanken Grotesk", system-ui, sans-serif;
  --mono: "Spline Sans Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --r-chip: 8px;
  --r-control: 10px;
  --r-card: 18px;
  --measure: 68ch;
  --gutter: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1a1916;
    --surface: #22211d;
    --sunken: #2a2924;
    --line: #34322b;
    --line-strong: #4a473f;
    --ink: #ece9e2;
    --label: #a9a59b;
    --faint: #8f8b81;
    --accent: #4fb3a3;
    --accent-emphasis: #6cc4b5;
    --accent-soft: #173a35;
    --accent-text: #8fd6c9;
    --accent-fg: #0f1a18;
    --warning-soft: #3b2e17;
    --warning-text: #e6b660;
  }
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.65;
}

a { color: var(--accent-text); text-underline-offset: 0.18em; }
a:hover { color: var(--accent-emphasis); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.skip { position: absolute; left: -999px; top: 8px; background: var(--surface); padding: 8px 12px; z-index: 10; }
.skip:focus { left: 8px; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 var(--gutter); }
@media (min-width: 720px) { :root { --gutter: 32px; } }

/* Masthead */
.masthead { border-bottom: 1px solid var(--line); background: var(--bg); }
.masthead__row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 24px; padding-top: 14px; padding-bottom: 14px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-size: 0.95rem; }
.brand__long { color: var(--label); }
@media (max-width: 520px) { .brand__long { display: none; } }
.nav { display: flex; flex-wrap: wrap; gap: 2px 4px; list-style: none; margin: 0; padding: 0; }
.nav a { display: block; padding: 6px 10px; border-radius: var(--r-chip); color: var(--label); text-decoration: none; font-size: 0.875rem; font-weight: 560; }
.nav a:hover { background: var(--sunken); color: var(--ink); }
.nav a[aria-current="page"] { background: var(--accent-soft); color: var(--accent-text); }

/* Type */
h1, h2, h3 { line-height: 1.15; letter-spacing: -0.02em; font-weight: 640; }
h1 { font-size: clamp(1.75rem, 3.6vw, 2.75rem); letter-spacing: -0.028em; margin: 0 0 12px; }
h2 { font-size: 1.45rem; margin: 2.2em 0 0.5em; }
h3 { font-size: 1.1rem; margin: 1.8em 0 0.4em; }
.display { font-size: clamp(2.5rem, 6.5vw, 4.5rem); font-weight: 680; line-height: 1.02; letter-spacing: -0.035em; margin: 0 0 20px; max-width: 16ch; }
.lede { font-size: clamp(1.0625rem, 1.9vw, 1.3rem); line-height: 1.5; color: var(--label); max-width: 60ch; margin: 0; }
.eyebrow { font-size: 0.75rem; font-weight: 620; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-text); margin: 0 0 12px; }
code { font-family: var(--mono); font-size: 0.9em; background: var(--sunken); padding: 0.1em 0.35em; border-radius: 4px; }

/* Pages */
.page { padding-top: 48px; padding-bottom: 72px; }
.page__head { margin-bottom: 32px; max-width: var(--measure); }
.prose { max-width: var(--measure); }
.prose > :first-child { margin-top: 0; }
.prose li + li { margin-top: 0.35em; }
.prose blockquote { margin: 1.5em 0; padding: 4px 0 4px 18px; border-left: 3px solid var(--accent); color: var(--label); }
.prose .source { font-size: 0.85rem; color: var(--label); border-top: 1px solid var(--line); padding-top: 12px; margin-top: 2.5em; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2.5em 0; }

/* Tables scroll inside their own box, never the page */
.table { overflow-x: auto; margin: 1.5em 0; border: 1px solid var(--line); border-radius: var(--r-control); background: var(--surface); }
.prose .table { max-width: none; }
table { border-collapse: collapse; width: 100%; font-size: 0.92rem; line-height: 1.45; }
th, td { text-align: left; vertical-align: top; padding: 10px 14px; border-bottom: 1px solid var(--line); }
th { font-size: 0.78rem; font-weight: 620; letter-spacing: 0.04em; text-transform: uppercase; color: var(--label); background: var(--sunken); }
tr:last-child td { border-bottom: 0; }
td { min-width: 9rem; }
td:first-child:not(:only-child) { min-width: 0; }
.wide { max-width: none; }

/* Stage facts */
.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1px; margin: 0 0 40px; background: var(--line); border: 1px solid var(--line); border-radius: var(--r-card); overflow: hidden; }
.facts div { background: var(--surface); padding: 16px 18px; }
.facts dt { font-size: 0.75rem; font-weight: 620; letter-spacing: 0.08em; text-transform: uppercase; color: var(--label); margin-bottom: 4px; }
.facts dd { margin: 0; }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 56px; max-width: var(--measure); }
.pager a { display: block; padding: 14px 16px; border: 1px solid var(--line); border-radius: var(--r-control); background: var(--surface); text-decoration: none; color: var(--ink); font-weight: 600; }
.pager a:hover { border-color: var(--accent); }
.pager span { display: block; font-size: 0.8rem; font-weight: 400; color: var(--label); }
.pager__next { text-align: right; }

/* Home */
.hero { padding: 64px 0 40px; }
.hero__actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.button { display: inline-block; padding: 10px 18px; border-radius: var(--r-control); font-weight: 560; text-decoration: none; border: 1px solid transparent; }
.button--primary { background: var(--accent); color: var(--accent-fg); }
.button--primary:hover { background: var(--accent-emphasis); color: var(--accent-fg); }
.button--secondary { background: var(--surface); color: var(--ink); border-color: var(--line-strong); }
.button--secondary:hover { background: var(--sunken); color: var(--ink); }

.band { padding: 48px 0; border-top: 1px solid var(--line); }
.band__head { max-width: var(--measure); margin-bottom: 24px; }
.band__head h2 { margin-top: 0; }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr)); gap: 16px; list-style: none; margin: 0; padding: 0; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-card); padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 1.05rem; }
.card p { margin: 0; color: var(--label); font-size: 0.95rem; line-height: 1.55; }

.note { background: var(--warning-soft); color: var(--warning-text); border-radius: var(--r-control); padding: 12px 16px; font-size: 0.92rem; max-width: var(--measure); }
.note a { color: inherit; }

/* The loop figure */
.loop { margin: 0; display: grid; gap: 24px; align-items: center; }
@media (min-width: 960px) { .loop { grid-template-columns: 1.3fr 1fr; } }
.loop svg { width: 100%; height: auto; max-width: 680px; font-family: var(--font); }
.loop__track { fill: none; stroke: var(--line-strong); stroke-width: 2; }
.loop__feedback { fill: none; stroke: var(--accent); stroke-width: 2; stroke-dasharray: 6 5; }
.loop__arrowhead { fill: var(--accent); }
.loop__note { fill: var(--label); font-size: 13px; }
.loop__node circle { fill: var(--surface); stroke: var(--accent); stroke-width: 2; }
.loop__node--operate circle { fill: var(--accent-soft); stroke-dasharray: 5 4; }
.loop__node:hover circle, .loop__node:focus circle { fill: var(--accent); }
.loop__node:hover .loop__num, .loop__node:focus .loop__num { fill: var(--accent-fg); }
.loop__num { fill: var(--ink); font-size: 17px; font-weight: 650; }
.loop__label { fill: var(--ink); font-size: 15px; font-weight: 560; }
.loop__list { margin: 0; padding-left: 1.4em; font-size: 0.95rem; }
.loop__list li + li { margin-top: 6px; }
.loop__list a { font-weight: 600; }
.loop__list span { color: var(--label); }

/* Footer */
.footer { border-top: 1px solid var(--line); color: var(--label); font-size: 0.85rem; }
.footer__row { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 4px 24px; padding-top: 20px; padding-bottom: 28px; }
.footer p { margin: 0; }
.footer a { color: var(--label); }