/* miniproof.openfp.net: the page layout on top of the shared design kit.
 *
 * The design kit (design-kit/design-kit.css) owns the faces, gradient text
 * and the scroll-progress bar. This file owns the theme and the layout.
 *
 * The theme is white and grey. The kit's accent is a set of custom
 * properties (--dk-*), which a page may set in its own stylesheet; here
 * they are a zinc ramp, darkest at 600, so the accent reads on white. The
 * page's surface is its own tokens (--bg, --panel, --hair, --text, --muted,
 * --ink, --title). The kit's hero grid and aurora are dark by design, so
 * the page does not use them.
 */
:root {
  --dk-300: #71717a;
  --dk-400: #52525b;
  --dk-500: #3f3f46;
  --dk-600: #18181b;
  --dk-500-rgb: 63, 63, 70;
  --dk-pop: #71717a;

  --bg: #ffffff;
  --panel: #f4f4f5;
  --hair: #e4e4e7;
  --text: #27272a;
  --muted: #52525b;
  --ink: #3f3f46;
  --title: #09090b;

  --font-prose: 'Open Sans', system-ui, sans-serif;
  --font-display: 'Montserrat', sans-serif;
  --font-mono: ui-monospace, 'DejaVu Sans Mono', 'Cascadia Mono', Menlo, monospace;
  color-scheme: light;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-prose);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--dk-600); text-decoration: underline; text-decoration-color: var(--dk-pop);
  text-underline-offset: .18em; }
a:hover { text-decoration-color: var(--dk-600); }
a:focus-visible { outline: 2px solid var(--dk-600); outline-offset: 3px; border-radius: 2px; }
.container { max-width: 64rem; margin: 0 auto; padding: 0 1.5rem; }

/* Chrome: sticky header and footer. */
header.chrome {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--hair);
}
.chrome .container { display: flex; align-items: center; justify-content: space-between; height: 4.25rem; gap: 1rem; }
.wordmark { font-family: var(--font-display); font-weight: 900; font-size: 1.3rem;
  letter-spacing: .06em; text-transform: uppercase; color: var(--title); text-decoration: none; }
nav.links { display: flex; gap: 1.5rem; align-items: center; }
nav.links a { font-family: var(--font-display); font-weight: 700; font-size: .78rem;
  letter-spacing: .12em; text-transform: uppercase; color: var(--muted); text-decoration: none; }
nav.links a:hover { color: var(--title); }

/* Buttons. */
.btn, .ghost {
  display: inline-flex; align-items: center; gap: .5rem; text-decoration: none;
  font-family: var(--font-display); font-weight: 700; font-size: .82rem;
  letter-spacing: .08em; text-transform: uppercase;
  border-radius: .5rem; padding: .75rem 1.4rem;
}
.btn { background: var(--dk-600); color: var(--bg); border: 1px solid var(--dk-600); }
.btn:hover { background: var(--dk-500); color: var(--bg); }
.ghost { background: transparent; color: var(--text); border: 1px solid var(--hair); }
.ghost:hover { border-color: var(--dk-500); color: var(--title); }

/* Hero. */
.hero { padding: 6rem 0 5rem; border-bottom: 1px solid var(--hair);
  background: linear-gradient(180deg, var(--panel), var(--bg)); }
.eyebrow { margin: 0; font-family: var(--font-display); font-weight: 800; font-size: .85rem;
  letter-spacing: .2em; text-transform: uppercase; color: var(--muted); }
h1.display {
  font-size: clamp(2.2rem, 5.4vw, 4rem); line-height: 1.05; text-transform: uppercase;
  color: var(--title); margin: 1rem 0 0; max-width: 18ch;
}
.lead { font-size: clamp(1.05rem, 2.1vw, 1.3rem); color: var(--ink); max-width: 44rem; margin: 1.6rem 0 0; }
.actions { display: flex; flex-wrap: wrap; gap: .8rem; margin: 2.2rem 0 0; }

/* Sections. */
.band { padding: 4.5rem 0; border-bottom: 1px solid var(--hair); }
.band:nth-of-type(odd) { background: var(--panel); }
.section-title { font-size: clamp(1.4rem, 2.6vw, 1.9rem); text-transform: uppercase;
  color: var(--title); margin: 0 0 1.2rem; line-height: 1.15; }
.band p { max-width: 44rem; }

pre.theory {
  margin: 1.6rem 0; padding: 1.3rem 1.5rem; overflow-x: auto;
  background: var(--bg); color: var(--title); border: 1px solid var(--hair); border-radius: .6rem;
  font-family: var(--font-mono); font-size: .88rem; line-height: 1.6;
}
.band:nth-of-type(odd) pre.theory { background: var(--bg); }
pre.theory code { font: inherit; }

ol.stages { list-style: none; margin: 1.6rem 0 0; padding: 0;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); gap: 1rem; }
ol.stages li { background: var(--bg); border: 1px solid var(--hair); border-radius: .6rem; padding: 1.3rem 1.3rem 1rem; }
ol.stages .step { display: inline-flex; width: 1.9rem; height: 1.9rem; align-items: center; justify-content: center;
  border-radius: 999px; background: var(--dk-600); color: var(--bg);
  font-family: var(--font-display); font-weight: 800; font-size: .85rem; }
ol.stages h3 { font-family: var(--font-display); font-weight: 800; font-size: 1rem; color: var(--title);
  margin: .8rem 0 .4rem; }
ol.stages p { margin: 0; color: var(--ink); font-size: .95rem; }

.status { display: grid; grid-template-columns: 1.3fr 1fr; gap: 3rem; }
@media (max-width: 800px) { .status { grid-template-columns: 1fr; gap: 2rem; } }
.ticks, .planned { margin: 0; padding: 0; list-style: none; display: grid; gap: .65rem; }
.ticks li, .planned li { padding-left: 1.4rem; position: relative; }
.ticks li::before { content: ""; position: absolute; left: 0; top: .62em; width: .55rem; height: .55rem;
  border-radius: 2px; background: var(--dk-600); }
.planned li::before { content: ""; position: absolute; left: 0; top: .62em; width: .55rem; height: .55rem;
  border-radius: 2px; border: 1.5px solid var(--dk-300); }
.planned .issue { color: var(--muted); font-size: .85rem; }

/* Footer. */
footer.chrome { position: static; padding: 2.5rem 0; }
footer .container { flex-wrap: wrap; height: auto; }
footer .copy { color: var(--muted); font-size: .88rem; }
@media (max-width: 480px) {
  .container { padding: 0 1rem; }
  nav.links { gap: .9rem; }
  nav.links a { font-size: .7rem; letter-spacing: .08em; }
  .wordmark { font-size: 1.05rem; }
}