/* Layout: a collector's coin folder. Navigation pages are quiet lists on the
   page ground; a series opens as a navy folder board with recessed holes,
   and a coin opens full screen in the zoom viewer. The board stays navy in
   both themes because it is a physical object; the page ground flips. */
:root {
  --ground: #f1f2f4;
  --ink: #18213a;
  --muted: #5b6378;
  --rule: #d5d8e0;
  --surface: #ffffff;
  --board: #1d2c52;
  --board-hi: #26386a;
  --board-ink: #e9e4d4;
  --board-muted: #a9b0c6;
  --hole: #0f1830;
  --hole-rim: #3a4d82;
  --foil: #b8923a;
  --foil-bright: #d8b45c;
  --accent: #2c4a9a;
  --viewer-bg: #0a0d16;
  --viewer-ink: #e8e9ee;
  --font-display: "Cinzel", "Trajan Pro", Georgia, serif;
  --font-body: "Alegreya Sans", "Segoe UI", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Consolas, monospace;
  --hole-size: 84px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ground: #0e1220;
    --ink: #e6e8ef;
    --muted: #98a0b6;
    --rule: #262d44;
    --surface: #151b2e;
    --accent: #9db3f0;
    --foil: #d0ab55;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --ground: #0e1220;
  --ink: #e6e8ef;
  --muted: #98a0b6;
  --rule: #262d44;
  --surface: #151b2e;
  --accent: #9db3f0;
  --foil: #d0ab55;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--ground);
  color: var(--ink);
  font: 400 1.0625rem/1.55 var(--font-body);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--foil); outline-offset: 3px; border-radius: 4px; }
[hidden] { display: none !important; }

.wrap {
  max-width: 72rem;
  margin: 0 auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}

/* ---------- masthead ---------- */
.masthead {
  border-bottom: 1px solid var(--rule);
  background: var(--ground);
  position: sticky;
  top: env(safe-area-inset-top, 0px);
  z-index: 5;
}
body::before {
  content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px);
  z-index: 10; background: var(--ground);
}
.masthead-row { display: flex; align-items: baseline; gap: 1.25rem; flex-wrap: wrap; padding-block: 0.9rem; }
.brand {
  font: 700 1.25rem/1 var(--font-display);
  letter-spacing: 0.08em;
  text-decoration: none;
  color: var(--ink);
}
.crumbs { display: flex; flex-wrap: wrap; gap: 0.35rem; font-size: 0.95rem; color: var(--muted); min-width: 0; }
.crumbs a { text-decoration: none; }
.crumbs a:hover { color: var(--ink); text-decoration: underline; }
.crumbs span[aria-hidden] { opacity: 0.5; }

main { padding-block: 2rem 4rem; display: grid; gap: 2.5rem; }
main:focus { outline: none; }
.loading, .error { color: var(--muted); }
.error { border-left: 3px solid #b5443a; padding-left: 0.75rem; }

h1, h2, h3 { text-wrap: balance; margin: 0; }
.page-head { display: grid; gap: 0.4rem; }
.page-head h1 { font: 700 clamp(1.8rem, 4vw, 2.6rem)/1.1 var(--font-display); letter-spacing: 0.03em; }
.page-head p { margin: 0; color: var(--muted); max-width: 62ch; }
.eyebrow {
  margin: 0; font: 500 0.75rem/1.2 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted);
}
.section-title { font: 500 0.8rem/1 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }

/* ---------- index lists (countries, denominations) ---------- */
.index-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--rule); }
.index-list li { border-bottom: 1px solid var(--rule); }
.index-list a {
  display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 0.25rem 1.5rem; align-items: center;
  padding-block: 1.1rem; text-decoration: none;
}
.index-list a:hover .index-name { color: var(--accent); }
.index-name { font: 700 1.5rem/1.15 var(--font-display); letter-spacing: 0.02em; }
.index-meta { color: var(--muted); grid-column: 1; font-size: 0.95rem; }
.index-count { grid-row: 1 / span 2; grid-column: 2; text-align: right; display: grid; gap: 0.35rem; justify-items: end; }
.count { font: 500 0.95rem/1 var(--font-mono); font-variant-numeric: tabular-nums; }
.bar { width: 7.5rem; height: 4px; background: var(--rule); border-radius: 2px; overflow: hidden; }
.bar i { display: block; height: 100%; background: var(--foil); }

/* ---------- series covers ---------- */
.covers { display: grid; grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr)); gap: 1.25rem; }
.cover {
  position: relative; display: flex; flex-direction: column; gap: 0.6rem;
  padding: 1.4rem 1.3rem 1.2rem; min-height: 13rem;
  background: linear-gradient(160deg, var(--board-hi), var(--board));
  color: var(--board-ink); text-decoration: none; border-radius: 3px 10px 10px 3px;
  box-shadow: inset 6px 0 0 rgba(0,0,0,0.25), 0 1px 2px rgba(0,0,0,0.25), 0 8px 20px -12px rgba(0,0,0,0.6);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.cover:hover { transform: translateY(-2px); box-shadow: inset 6px 0 0 rgba(0,0,0,0.25), 0 2px 4px rgba(0,0,0,0.25), 0 14px 26px -12px rgba(0,0,0,0.7); }
.cover-title { font: 700 1.35rem/1.15 var(--font-display); color: var(--foil-bright); letter-spacing: 0.04em; }
.cover-dates { font: 500 0.85rem/1 var(--font-mono); color: var(--board-muted); letter-spacing: 0.06em; }
.cover-desc { font-size: 0.95rem; color: var(--board-muted); margin: 0; }
.cover-foot { display: flex; align-items: center; justify-content: space-between; gap: 0.75rem; margin-top: auto; padding-top: 0.6rem; }
.cover-foot .count { color: var(--board-ink); }
.cover-foot .bar { background: rgba(255,255,255,0.12); }
.cover-preview { display: flex; }
.cover-preview img {
  width: 2.4rem; height: 2.4rem; border-radius: 50%; object-fit: cover; background: var(--hole);
  border: 2px solid var(--board); margin-left: -0.55rem;
}
.cover-preview img:first-child { margin-left: 0; }

/* ---------- folder board ---------- */
.board {
  background:
    radial-gradient(120% 80% at 20% 0%, rgba(255,255,255,0.06), transparent 60%),
    linear-gradient(180deg, var(--board-hi), var(--board));
  color: var(--board-ink);
  border-radius: 6px;
  padding: clamp(1.25rem, 3vw, 2.25rem);
  box-shadow: 0 1px 2px rgba(0,0,0,0.3), 0 18px 40px -24px rgba(0,0,0,0.7);
  display: grid; gap: 1.75rem;
}
.board-head { display: grid; gap: 0.5rem; text-align: center; justify-items: center; }
.board-head h1 { font: 700 clamp(1.6rem, 4.5vw, 2.5rem)/1.1 var(--font-display); color: var(--foil-bright); letter-spacing: 0.06em; }
.board-head .eyebrow { color: var(--board-muted); }
.board-head p { margin: 0; color: var(--board-muted); max-width: 60ch; font-size: 0.98rem; }
.board-stats { display: flex; gap: 1.25rem; flex-wrap: wrap; justify-content: center; font: 500 0.85rem/1 var(--font-mono); color: var(--board-muted); }
.board-stats b { color: var(--board-ink); font-weight: 500; }
.board-tools { display: flex; justify-content: center; gap: 0.5rem; flex-wrap: wrap; }
.chip {
  font: 500 0.8rem/1 var(--font-mono); letter-spacing: 0.04em;
  color: var(--board-muted); background: transparent; border: 1px solid var(--hole-rim);
  padding: 0.45rem 0.75rem; border-radius: 999px; cursor: pointer;
}
.chip[aria-pressed="true"] { background: var(--board-ink); color: var(--board); border-color: var(--board-ink); }

.slots {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(calc(var(--hole-size) + 1.5rem), 1fr));
  gap: 1.4rem 0.75rem; justify-items: center;
}
.slot { display: grid; justify-items: center; align-content: start; gap: 0.45rem; text-align: center; width: 100%; }
.hole {
  width: var(--hole-size); height: var(--hole-size); border-radius: 50%;
  background: radial-gradient(circle at 50% 38%, #1a2645, var(--hole) 70%);
  box-shadow: inset 0 3px 8px rgba(0,0,0,0.75), inset 0 -1px 0 rgba(255,255,255,0.05), 0 0 0 2px var(--hole-rim), 0 1px 0 3px rgba(255,255,255,0.04);
  display: grid; place-items: center; overflow: hidden; padding: 0; border: 0;
  font: inherit; color: inherit;
}
button.hole { cursor: pointer; transition: transform 0.15s ease, box-shadow 0.15s ease; }
button.hole:hover { transform: scale(1.06); box-shadow: inset 0 0 0 1px rgba(0,0,0,0.4), 0 0 0 2px var(--foil-bright), 0 6px 14px -4px rgba(0,0,0,0.7); }
button.hole img { width: 100%; height: 100%; object-fit: contain; display: block; }
.hole-empty-mark { font: 500 0.65rem/1 var(--font-mono); color: #4b5a85; letter-spacing: 0.08em; }
.slot-label { font: 500 0.82rem/1.15 var(--font-mono); color: var(--board-ink); font-variant-numeric: tabular-nums; }
.slot-sub { display: block; font: 400 0.78rem/1.2 var(--font-body); color: var(--board-muted); margin-top: 0.15rem; }
.slot.is-empty .slot-label { color: var(--board-muted); }
.slot-flags { display: flex; gap: 3px; height: 6px; }
.slot-flags i { width: 6px; height: 6px; border-radius: 50%; background: var(--foil-bright); }
.slot-flags i.off { background: transparent; box-shadow: inset 0 0 0 1px var(--hole-rim); }
.slots.filled-only .slot.is-empty { display: none; }
.slots.hide-varieties .slot.is-variety { display: none; }
.slot.is-variety .hole { box-shadow: inset 0 3px 8px rgba(0,0,0,0.75), 0 0 0 2px var(--board), 0 0 0 3.5px var(--foil); }
.slot.is-variety .slot-sub { color: var(--foil-bright); }
.variety-key { display: inline-block; width: 0.7rem; height: 0.7rem; border-radius: 50%; box-shadow: 0 0 0 1.5px var(--foil-bright); margin-right: 0.45rem; vertical-align: -0.05rem; }
.sample-tag { font: 500 0.62rem/1 var(--font-mono); letter-spacing: 0.08em; color: var(--board); background: var(--foil-bright); padding: 2px 5px; border-radius: 3px; }

/* ---------- recent strip ---------- */
.recent { display: grid; gap: 0.9rem; }
.recent-row { display: grid; grid-template-columns: repeat(auto-fill, minmax(8.5rem, 1fr)); gap: 1rem; }
.recent-row a { display: grid; gap: 0.45rem; text-decoration: none; justify-items: center; text-align: center; }
.recent-row img {
  width: 100%; max-width: 8.5rem; aspect-ratio: 1; object-fit: contain; border-radius: 50%;
  background: var(--board); box-shadow: 0 0 0 2px var(--hole-rim);
}
.recent-row b { font: 500 0.85rem/1.1 var(--font-mono); }
.recent-row span { font-size: 0.85rem; color: var(--muted); }
.empty-note { color: var(--muted); margin: 0; }

/* ---------- viewer ---------- */
.viewer {
  position: fixed; inset: 0; z-index: 50; background: var(--viewer-bg); color: var(--viewer-ink);
  display: grid; grid-template-rows: auto minmax(0, 1fr) auto;
  padding: env(safe-area-inset-top, 0px) env(safe-area-inset-right, 0px) env(safe-area-inset-bottom, 0px) env(safe-area-inset-left, 0px);
}
.viewer-top {
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  padding: 0.8rem max(16px, env(safe-area-inset-right, 0px)) 0.8rem max(16px, env(safe-area-inset-left, 0px));
}
.viewer-heading { flex: 1 1 12rem; min-width: 0; display: grid; gap: 0.2rem; }
.viewer-heading .eyebrow { color: #9aa2b8; }
.viewer-heading h2 { font: 700 1.4rem/1.1 var(--font-display); letter-spacing: 0.04em; }
.side-tabs { display: flex; gap: 0.25rem; background: rgba(255,255,255,0.06); border-radius: 999px; padding: 0.25rem; }
.side-tabs button {
  font: 500 0.8rem/1 var(--font-mono); letter-spacing: 0.06em; text-transform: uppercase;
  background: transparent; color: #aab1c5; border: 0; border-radius: 999px; padding: 0.5rem 0.8rem; cursor: pointer;
}
.side-tabs button[aria-selected="true"] { background: var(--viewer-ink); color: var(--viewer-bg); }
.side-tabs button:disabled { opacity: 0.35; cursor: default; }
.viewer-stage { position: relative; min-height: 0; }
.osd { position: absolute !important; inset: 0; } /* OpenSeadragon sets position inline */
.icon-btn {
  width: 2.6rem; height: 2.6rem; border-radius: 50%; border: 1px solid rgba(255,255,255,0.18);
  background: rgba(10,13,22,0.7); color: var(--viewer-ink); font-size: 1.25rem; line-height: 1; cursor: pointer;
  display: grid; place-items: center; backdrop-filter: blur(6px);
}
.icon-btn:hover { border-color: var(--foil-bright); }
.icon-btn:disabled { opacity: 0.3; cursor: default; }
.nav { position: absolute; top: 50%; transform: translateY(-50%); font-size: 1.8rem; z-index: 2; }
.nav.prev { left: max(12px, env(safe-area-inset-left, 0px)); }
.nav.next { right: max(12px, env(safe-area-inset-right, 0px)); }
.zoom-tools { position: absolute; right: max(12px, env(safe-area-inset-right, 0px)); bottom: 12px; display: grid; gap: 0.4rem; z-index: 2; }
.viewer-info {
  margin: 0; display: flex; flex-wrap: wrap; gap: 0.6rem 2rem;
  padding: 0.8rem max(16px, env(safe-area-inset-right, 0px)) 1rem max(16px, env(safe-area-inset-left, 0px));
  border-top: 1px solid rgba(255,255,255,0.08); font-size: 0.92rem;
}
.viewer-info div { display: grid; gap: 0.15rem; min-width: 0; }
.viewer-info dt { font: 500 0.7rem/1 var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; color: #8a92a8; }
.viewer-info dd { margin: 0; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.viewer-info a { color: var(--foil-bright); }
.viewer-info .notes { flex: 1 1 18rem; }

@media (max-width: 480px) {
  :root { --hole-size: 68px; }
  .index-name { font-size: 1.25rem; }
  .bar { width: 5rem; }
  .nav { top: auto; bottom: 12px; transform: none; }
  .nav.next { right: calc(max(12px, env(safe-area-inset-right, 0px)) + 3.2rem); }
}
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}