/* ============================================================================
   Layout — page shell, topbar, sections, overture, anatomy, footer
   ========================================================================= */

.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.topbar__inner {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: var(--s-3) var(--s-5);
  display: flex;
  align-items: center;
  gap: var(--s-5);
}

.topbar__brand {
  display: flex;
  align-items: baseline;
  gap: var(--s-2);
  flex: none;
}
.topbar__mark { align-self: center; flex: none; }
.topbar__title {
  font-family: var(--font-display);
  font-size: var(--t-xl);
  letter-spacing: var(--tracking-tight);
}
.topbar__sub {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 200;
  font-size: var(--t-md);
  color: var(--fg-muted);
}

.topbar__nav { margin-inline-start: auto; }
.topbar__nav ul { display: flex; gap: var(--s-5); }
.topbar__nav a {
  font-size: var(--t-sm);
  color: var(--fg-muted);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  transition: color var(--d-fast) var(--ease-out);
}
.topbar__nav a:hover { color: var(--fg); }

.topbar__prefs { display: flex; gap: var(--s-2); flex: none; }
.pref__label--short { display: none; }

@media (max-width: 62rem) {
  .topbar__nav { display: none; }
  .topbar__prefs { margin-inline-start: auto; }
}
@media (max-width: 30rem) {
  .topbar__inner { padding-inline: var(--s-4); gap: var(--s-3); }
  .topbar__sub { display: none; }
  /* Drop the status dot rather than the label. Two unlabelled circles side by
     side are indistinguishable; two short words are not. */
  .pref__icon { display: none; }
  .pref { padding-inline: var(--s-3); font-size: var(--t-2xs); }
  .pref__label { display: none; }
  .pref__label--short { display: inline; }
}

/* --- Section rhythm ------------------------------------------------------ */

main { display: block; }

.overture,
.anatomy,
.console-section,
.explainer {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: var(--s-9) var(--s-5);
  position: relative;
}

@media (max-width: 48rem) {
  .overture,
  .anatomy,
  .console-section,
  .explainer { padding: var(--s-7) var(--s-4); }
}

.anatomy,
.console-section,
.explainer { border-top: 1px solid var(--line); }

.section-head { max-width: 52rem; margin-bottom: var(--s-7); }
.section-head__lede {
  margin-top: var(--s-5);
  max-width: var(--prose-max);
  color: var(--fg-muted);
  font-size: var(--t-lg);
  line-height: 1.55;
  text-wrap: pretty;
}

/* --- Overture ------------------------------------------------------------ */

.overture {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: var(--s-8);
  align-items: center;
  padding-block: var(--s-10) var(--s-9);
  min-height: min(84vh, 46rem);
}

.overture__lede {
  margin-top: var(--s-6);
  max-width: 38rem;
  font-size: var(--t-lg);
  line-height: 1.55;
  text-wrap: pretty;
  /* the hairline accent ampcode.com uses beside its lede paragraphs */
  border-inline-start: 1px solid var(--line-strong);
  padding-inline-start: var(--s-4);
}
.overture__sub {
  margin-top: var(--s-4);
  max-width: 36rem;
  color: var(--fg-muted);
  font-size: var(--t-sm);
  padding-inline-start: calc(var(--s-4) + 1px);
}
.overture__cta {
  margin-top: var(--s-6);
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  padding-inline-start: calc(var(--s-4) + 1px);
}

.overture__specimen { display: flex; justify-content: center; }

.specimen { display: flex; flex-direction: column; align-items: center; gap: var(--s-5); }
.specimen__stage {
  --orb-px: 220;
  display: grid;
  place-items: center;
  width: 300px;
  height: 300px;
}
.specimen__caption { text-align: center; max-width: 24rem; }
.specimen__label {
  display: flex;
  flex-direction: column;
  gap: var(--s-1);
}
.specimen__state {
  font-family: var(--font-display);
  font-size: var(--t-xl);
  letter-spacing: var(--tracking-tight);
}
.specimen__meta {
  font-family: var(--font-mono);
  font-size: var(--t-2xs);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--fg-muted);
}
.specimen__note {
  margin-top: var(--s-3);
  font-size: var(--t-sm);
  color: var(--fg-muted);
  min-height: 3.2em;
  text-wrap: pretty;
}

@media (max-width: 60rem) {
  .overture {
    grid-template-columns: 1fr;
    gap: var(--s-7);
    min-height: 0;
    padding-block: var(--s-8) var(--s-7);
  }
  .overture__specimen { order: -1; justify-content: flex-start; }
  .specimen { align-items: flex-start; }
  .specimen__stage { --orb-px: 140; width: 180px; height: 180px; }
  .specimen__caption { text-align: start; }
}

/* --- Anatomy ------------------------------------------------------------- */

.anatomy__grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: var(--s-8);
  align-items: start;
}

.anatomy__viz { position: sticky; top: 6rem; display: flex; justify-content: center; }
.anatomy__stage {
  --orb-px: 260;
  display: grid;
  place-items: center;
  width: 340px;
  height: 340px;
  max-width: 100%;
}

.anatomy__detail-h {
  font-family: var(--font-mono);
  font-size: var(--t-2xs);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--fg-muted);
  margin-bottom: var(--s-3);
}

.anatomy__layers {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
  margin-bottom: var(--s-5);
}

.layer-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  min-height: 38px;
  padding: var(--s-2) var(--s-3);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: transparent;
  color: var(--fg-muted);
  font: inherit;
  font-size: var(--t-xs);
  cursor: pointer;
  transition:
    color var(--d-fast) var(--ease-out),
    border-color var(--d-fast) var(--ease-out),
    background-color var(--d-fast) var(--ease-out);
}
.layer-btn:hover { color: var(--fg); border-color: var(--line-strong); }
.layer-btn[aria-pressed="true"] {
  color: var(--fg);
  border-color: var(--brand);
  background: color-mix(in oklab, var(--brand) 14%, transparent);
}
.layer-btn__count {
  font-family: var(--font-mono);
  font-size: var(--t-2xs);
  opacity: 0.65;
}
@media (pointer: coarse) { .layer-btn { min-height: var(--tap); } }

.anatomy__readout {
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: var(--s-5);
  background: var(--card);
  min-height: 16rem;
}
.anatomy__readout-h {
  font-family: var(--font-mono);
  font-size: var(--t-2xs);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--fg-muted);
  margin-bottom: var(--s-3);
}
.anatomy__readout-title {
  font-family: var(--font-display);
  font-size: var(--t-2xl);
  letter-spacing: var(--tracking-tight);
  margin-bottom: var(--s-2);
}
.anatomy__readout-blurb {
  color: var(--fg-muted);
  font-size: var(--t-sm);
  margin-bottom: var(--s-4);
  max-width: 34rem;
  text-wrap: pretty;
}
/* `dt`/`dd` are direct children of the list, so the grid is declared on the
   list itself rather than on a wrapper per row. */
.anatomy__tools {
  display: grid;
  grid-template-columns: minmax(9rem, max-content) minmax(0, 1fr);
  gap: var(--s-2) var(--s-4);
  align-items: baseline;
  font-size: var(--t-sm);
}
.anatomy__tools dt {
  grid-column: 1;
  font-family: var(--font-mono);
  color: var(--fg);
  overflow-wrap: anywhere;
}
.anatomy__tools dt code { background: none; padding: 0; }
.anatomy__tools dd {
  grid-column: 2;
  margin: 0;
  color: var(--fg-muted);
  text-wrap: pretty;
}
.anatomy__readout-note {
  margin-top: var(--s-4);
  padding-top: var(--s-3);
  border-top: 1px solid var(--line);
  font-size: var(--t-xs);
  color: var(--fg-faint);
  text-wrap: pretty;
}

@media (max-width: 60rem) {
  .anatomy__grid { grid-template-columns: 1fr; gap: var(--s-6); }
  .anatomy__viz { position: static; }
  .anatomy__stage { --orb-px: 170; width: 220px; height: 220px; }
}
@media (max-width: 40rem) {
  .anatomy__tools { grid-template-columns: 1fr; gap: var(--s-1); }
  .anatomy__tools dt { grid-column: 1; margin-top: var(--s-2); }
  .anatomy__tools dd { grid-column: 1; }
}

/* --- Footer -------------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: var(--s-8);
}
.site-footer__inner {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: var(--s-7) var(--s-5) var(--s-8);
  display: grid;
  gap: var(--s-4);
}
.site-footer__note {
  max-width: 44rem;
  font-size: var(--t-sm);
  color: var(--fg-muted);
  text-wrap: pretty;
}
.site-footer__note--quiet { color: var(--fg-faint); font-size: var(--t-xs); }
.site-footer cite { font-style: italic; }