/* Components every course page shares, sitting on top of theme.css. The
   palette, the header, the footer and the buttons are theme.css's; this file
   is the vocabulary the learner-facing pages add to it — page shells, cards,
   chips, progress bars, prose, the toast dock.

   Trap: this file assumes theme.css is already linked. It reads --border,
   --card, --primary and the rest and defines none of them, so a page that
   links only this one renders unstyled black on white.

   Trap: a card is hairline on all four sides. The module accent belongs
   inside it — in the chip, the numeral, the fill of a bar — never painted
   onto one edge. */

/* ---------- page shell ---------- */

.page {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 30px 24px 0;
}

.crumbs {
  font-family: var(--label);
  font-size: var(--fs-xs);
  color: var(--muted-foreground);
}
/* Breadcrumbs are a nav landmark, not a sentence — same 24px floor as the
   footer row, reached the same way so the line's height does not move. */
.crumbs a { color: var(--muted-foreground); text-decoration: none;
  display: inline-block;
  padding-block: 5px;
  margin-block: -5px;
}
.crumbs a:hover { color: var(--foreground); text-decoration: underline; }

/* A section label that carries something the heading does not — a count, a
   state. It is not a decorative kicker; if it only repeats the heading below
   it, delete it rather than styling it. */
.eyebrow,
.sec-eyebrow {
  font-family: var(--label);
  font-size: var(--fs-2xs);
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--muted-foreground);
}
.sec-eyebrow { margin: 40px 0 14px; }

/* "Optional:" — the course's one mark for material that never gates, and it
   is a prefix in the title rather than a chip beside it. NOT called `.opt`:
   exercise.css already owns that for an answer button, and the memo desk
   loads both. The app side says the same thing the same way — see
   src/components/content/optional-tag.tsx. */
.optional-prefix {
  color: var(--muted-foreground);
  font-weight: 400;
}

/* ---------- cards ---------- */

.card {
  padding: 20px;
  border: var(--hairline) solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
}
.card-flat { background: var(--background); }

/* ---------- chips ---------- */

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 2px 8px;
  border: var(--hairline) solid var(--border);
  border-radius: 999px;
  background: var(--background);
  font-family: var(--label);
  font-size: var(--fs-2xs);
  line-height: 1.5;
  color: var(--muted-foreground);
  white-space: nowrap;
}
/* Done is a word plus a tick, never the tint on its own. */
.chip.done { color: var(--brand-ink); border-color: color-mix(in srgb, var(--brand-ink) 40%, var(--border)); }
.chip.done::before { content: '✓'; }
.chip.accent { color: var(--brand-ink); }

.lock { font-family: var(--label); font-size: var(--fs-2xs); color: var(--muted-foreground); }

/* ---------- progress ---------- */

/* The bar is decoration for the fraction beside it; the fraction is the
   reading. Never ship the bar without its counter.

   The empty track has to be visible against the card it sits on, or a
   just-started learner sees no bar at all and the row reads as a stray rule —
   which is why the track is mixed toward --border rather than left at
   --muted. */
.progress-row { display: flex; align-items: center; gap: 10px; }
.meter {
  position: relative;
  flex: 1;
  height: 9px;
  min-width: 72px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--border) 65%, var(--muted));
  overflow: hidden;
}
.meter > i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--primary);
  transition: width .28s ease;
}

/* Segmented: one cell per unit, so a short bar can be counted and not only
   read as a hue. The gaps are masked out of the whole bar — track and fill
   together — so the fill stays one element and a half-finished cell still
   reads as half. Set --cells inline; it is only worth it while the cells stay
   countable at a glance (six-ish), so track-level bars stay continuous.
   The mask lays out cells of (100% + gap)/n and cuts the last gap back off,
   which is what keeps the final cell flush with the end of the bar. */
.meter.seg {
  --cells: 1;
  --cell-gap: 2px;
  border-radius: var(--radius-xs);
  -webkit-mask-image: repeating-linear-gradient(to right,
    #000 0 calc((100% + var(--cell-gap)) / var(--cells) - var(--cell-gap)),
    transparent 0 calc((100% + var(--cell-gap)) / var(--cells)));
  mask-image: repeating-linear-gradient(to right,
    #000 0 calc((100% + var(--cell-gap)) / var(--cells) - var(--cell-gap)),
    transparent 0 calc((100% + var(--cell-gap)) / var(--cells)));
}
.meter.seg > i { border-radius: 0; }

@media (prefers-reduced-motion: reduce) {
  .meter > i { transition: none; }
}

.counter {
  font-family: var(--label);
  font-size: var(--fs-xs);
  color: var(--muted-foreground);
  white-space: nowrap;
}
.frac { font-family: var(--label); font-size: var(--fs-xs); color: var(--muted-foreground); }

/* ---------- authored prose ---------- */

.prose { font-size: var(--fs-lg); line-height: 1.68; }
.prose > * + * { margin-top: 16px; }
.prose h3 { font-size: var(--fs-xl); margin-top: 30px; }
.prose ul { padding-left: 20px; display: grid; gap: 8px; }
.prose li { line-height: 1.6; }
.prose code {
  font-family: var(--label);
  font-size: .89em;
  padding: 2px 4px;
  border-radius: var(--radius-xs);
  background: var(--muted);
}
.prose a { color: var(--brand-ink); text-underline-offset: 3px; }
.prose b { font-weight: 600; }

/* An editorial aside. Uniform hairline, tinted ground — the emphasis is the
   surface, not a painted rib. */
.note {
  padding: 14px 16px;
  border: var(--hairline) solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--muted);
  font-size: var(--fs-md);
  line-height: 1.6;
  color: var(--muted-foreground);
}
.note b { color: var(--foreground); font-weight: 600; }

/* An honest placeholder: says what is missing and who owns it. It must never
   look finished — the dashed edge is the signal that content is absent, and
   it is the one place a non-uniform border is correct because it is not a
   card claiming to hold something. */
.stub {
  padding: 14px 16px;
  border: var(--hairline) dashed color-mix(in srgb, var(--foreground) 30%, transparent);
  border-radius: var(--radius-sm);
  background: transparent;
  font-size: var(--fs-md);
  line-height: 1.6;
  color: var(--muted-foreground);
}
.stub b { color: var(--foreground); font-weight: 600; }

/* ---------- preview banner ---------- */

/* Wired to real state: it shows only while auth-config.js is in preview mode.
   It is not decorative status chrome. */
.preview-banner {
  padding: 8px 24px;
  border-bottom: var(--hairline) solid var(--border);
  background: var(--muted);
  font-size: var(--fs-sm);
  line-height: 1.5;
  color: var(--muted-foreground);
  text-align: center;
}
.preview-banner code { font-family: var(--label); font-size: .92em; }

/* ---------- toast ---------- */

.toast-dock {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 50;
  display: grid;
  gap: 10px;
  width: min(340px, calc(100vw - 36px));
}
.toast {
  padding: 14px 16px;
  border: var(--hairline) solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow-soft-lg);
  animation: toast-in .22s ease;
}
.toast .label {
  font-family: var(--label);
  font-size: var(--fs-2xs);
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--brand-ink);
}
.toast p { margin-top: 4px; font-size: var(--fs-md); line-height: 1.5; }
.toast .row { display: flex; align-items: center; gap: 12px; margin-top: 10px; }
.toast .row a { font-size: var(--fs-sm); color: var(--brand-ink); text-underline-offset: 3px; }
.toast .x {
  margin-left: auto;
  width: 26px;
  height: 26px;
  border: 0;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--muted-foreground);
  font-size: var(--fs-lg);
  line-height: 1;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
}
.toast .x:hover { background: var(--muted); color: var(--foreground); }

@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } }

/* ---------- chrome is not text ---------- */

/* theme.css carries the base rule; these are this layer's own pressables.
   Anything added here that can be pressed goes in this list too. */
.chip, .counter, .frac, .lock, .eyebrow, .sec-eyebrow, .toast .label, .meter {
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}

@media (max-width: 640px) {
  .page { padding: 20px 16px 0; }
  .toast-dock { right: 12px; left: 12px; bottom: 12px; width: auto; }
}

/* Breadcrumbs are navigation, not prose — a selection smear across "Home /
   Track" is always a mis-drag. */
.crumbs, .crumbs a {
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}