/* ==========================================================================
   PROPRA project page.

   Typographic, not decorative: one serif, near-monochrome, hairlines instead
   of shadows, a single column. Deliberately no gradients, no cards, no
   accent colour — the figures are the only colour on the page.
   ========================================================================== */

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

:root {
  color-scheme: light;

  /* warm greys — the only palette */
  --ink:       #1b1917;
  --ink-2:     #423d38;
  --ink-3:     #6f685f;
  --ink-4:     #98918a;
  --bg:        #fdfcfa;
  --bg-soft:   #f3f1ec;
  --line:      #ddd8d1;
  --line-soft: #eae6e0;

  --col: 44rem;   /* the one column everything sits in */

  /* kept only so tools/snippets/results-chart.html still resolves */
  --radius: 2px;
  --shadow: none;
  --accent: var(--ink);
  --accent-dark: var(--ink);
  --accent-soft: var(--bg-soft);
  --baseline: #8a8379;
  --neutral: #b6afa6;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink-2);
  font-family: 'Source Serif 4', Charter, Georgia, 'Times New Roman', serif;
  font-size: 18px;
  line-height: 1.62;
  font-synthesis-weight: none;
  -webkit-font-smoothing: antialiased;
}

p { margin: 0 0 1.1em; }
img, video, svg { max-width: 100%; }
b, strong { font-weight: 600; color: var(--ink); }
em { font-style: italic; }

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  text-decoration-color: var(--line);
}
a:hover { text-decoration-color: currentColor; }

h1, h2, h3, h4 {
  font-weight: 600;
  color: var(--ink);
  line-height: 1.28;
  margin: 0;
}

.wrap { max-width: var(--col); margin: 0 auto; padding: 0 1.5rem; }

/* ---------- top line: language only ---------------------------------------- */
.topline {
  max-width: var(--col); margin: 0 auto;
  padding: 1.6rem 1.5rem 0;
  display: flex; justify-content: flex-end; gap: .55rem;
  font-size: .82rem; color: var(--ink-4);
}
.topline a { text-decoration: none; color: var(--ink-4); }
.topline a:hover { color: var(--ink); }
.topline a.is-current { color: var(--ink); }
.topline span { color: var(--line); }

/* ---------- title block ---------------------------------------------------- */
.head { padding: 2.6rem 0 0; }
.status {
  font-size: .82rem; color: var(--ink-4);
  letter-spacing: .02em; margin-bottom: 1.5rem;
}
h1.title {
  font-size: clamp(1.45rem, 1.05rem + 1.7vw, 2.05rem);
  line-height: 1.26;
  letter-spacing: -.008em;
  margin-bottom: .7rem;
  text-wrap: pretty;
}
.expand { font-size: .95rem; color: var(--ink-3); margin-bottom: 1.6rem; }
.byline { font-size: .95rem; color: var(--ink-2); margin-bottom: .3rem; }
.byline + .note { font-size: .86rem; color: var(--ink-4); margin-bottom: 1.5rem; }
.where { font-size: .95rem; color: var(--ink-3); margin: 0; }
.where .off { color: var(--ink-4); }
.where .sep { color: var(--line); padding: 0 .35rem; }

/* ---------- media ---------------------------------------------------------- */
.media { margin: 2.4rem 0; }
.media img { display: block; width: 100%; height: auto; border: 1px solid var(--line-soft); }
.media figcaption,
.caption { font-size: .88rem; line-height: 1.55; color: var(--ink-3); margin-top: .8rem; }
figure { margin: 0; }

.slot {
  position: relative; width: 100%; padding-bottom: 56.25%;
  background: var(--bg-soft); border: 1px solid var(--line-soft);
}
.slot iframe, .slot video { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.slot .waiting {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: .3rem;
  font-size: .88rem; color: var(--ink-4);
}
.slot .waiting code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: .78rem; color: var(--ink-4);
}

/* ---------- sections ------------------------------------------------------- */
section { margin-top: 3.4rem; }
h2 {
  font-size: 1.02rem;
  margin-bottom: .9rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--line);
}

/* ---------- lede ----------------------------------------------------------- */
.lede { font-size: 1.06rem; color: var(--ink); margin: 2.2rem 0 1.4rem; }

/* ---------- disclosure ----------------------------------------------------- */
details { margin-bottom: 1rem; }
summary {
  cursor: pointer; font-size: .88rem; color: var(--ink-4);
  list-style: none; display: inline-block;
}
summary::-webkit-details-marker { display: none; }
summary::before { content: '+ '; }
details[open] summary::before { content: '– '; }
summary:hover { color: var(--ink); }
details > div { padding-top: 1rem; }
details p { font-size: .94rem; color: var(--ink-3); }

/* ---------- rollouts ------------------------------------------------------- */
.rollouts {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem;
  margin-top: 1.6rem; padding: 0; list-style: none;
}
.rollouts li { margin: 0; }
.rollouts video, .rollouts img {
  display: block; width: 100%; aspect-ratio: 1 / 1; object-fit: cover;
  background: var(--bg-soft); border: 1px solid var(--line-soft);
}
.rollouts figcaption { font-size: .82rem; color: var(--ink-3); margin-top: .45rem; }
@media (max-width: 620px) { .rollouts { grid-template-columns: repeat(2, 1fr); } }

/* ---------- bibtex (only used if that section is uncommented) -------------- */
pre {
  background: var(--bg-soft); border: 1px solid var(--line-soft);
  padding: 1rem 1.1rem; overflow-x: auto; margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: .78rem; line-height: 1.6; color: var(--ink-2);
}
.copy-btn {
  font: inherit; font-size: .82rem; color: var(--ink-4);
  background: none; border: 0; padding: 0; cursor: pointer; margin-bottom: .5rem;
}
.copy-btn:hover { color: var(--ink); }

/* ---------- footer --------------------------------------------------------- */
footer {
  margin: 4rem 0 0;
  padding: 1.2rem 0 3.5rem;
  border-top: 1px solid var(--line);
  font-size: .82rem; color: var(--ink-4);
}
footer p { margin: 0; }

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }