/* Light and dark follow the operating system; there is deliberately no manual toggle. */
:root {
  color-scheme: light dark;
  --bg: #F4F1EC; --column: #E9E4DC; --card: #FFFFFF; --ink: #1C1A17; --muted: #615D56; --line: #D3CDC2;
  --accent: #8C3B5E; --accent-ink: #FFFFFF; --ok: #DCEBD8; --info: #D9E4F2; --warn: #F6D9C9; --shadow: rgba(28, 26, 23, 0.08);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #161514; --column: #211F1D; --card: #2A2825; --ink: #EDE9E3; --muted: #A59F96; --line: #3C3934;
    --accent: #D98AAE; --accent-ink: #1C1A17; --ok: #2D4430; --info: #283A52; --warn: #573626; --shadow: rgba(0, 0, 0, 0.35);
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.4 system-ui, -apple-system, "Segoe UI", sans-serif; }
a { color: inherit; }
button, input, select, textarea { font: inherit; color: inherit; }
[hidden] { display: none !important; }

header { position: sticky; top: 0; z-index: 2; display: flex; flex-wrap: wrap; gap: 0.5rem 0.75rem; align-items: center;
  padding: 0.6rem 0.9rem; background: var(--bg); border-bottom: 1px solid var(--line); }
header h1 { margin: 0; font-size: 1.05rem; }
#status { color: var(--muted); font-size: 0.85rem; }
.header-tools { margin-left: auto; display: flex; gap: 0.4rem; align-items: center; }
#search { width: min(16rem, 48vw); padding: 0.35rem 0.55rem; border: 1px solid var(--line); border-radius: 6px; background: var(--card); }

.btn { display: inline-flex; align-items: center; gap: 0.3rem; padding: 0.4rem 0.75rem; border: 1px solid var(--line);
  border-radius: 6px; background: var(--card); cursor: pointer; text-decoration: none; font-size: 0.88rem; }
.btn:hover:not(:disabled) { border-color: var(--ink); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.row { display: flex; flex-wrap: wrap; gap: 0.4rem; }

#board { display: flex; gap: 0.65rem; padding: 0.75rem; overflow-x: auto; align-items: flex-start;
  min-height: calc(100dvh - 3.5rem); scroll-snap-type: x proximity; }
.column { flex: 0 0 17rem; background: var(--column); border-radius: 8px; padding: 0.5rem;
  max-height: calc(100dvh - 5rem); overflow-y: auto; scroll-snap-align: start; }
.column h2 { margin: 0.1rem 0.2rem 0.5rem; font-size: 0.85rem; display: flex; justify-content: space-between; }
.column h2 span { color: var(--muted); font-weight: 400; }
.column.dragover { outline: 2px dashed var(--ink); }
.column .empty { color: var(--muted); font-size: 0.8rem; margin: 0.3rem 0.2rem; }
.group-heading { margin: 0.7rem 0.2rem 0.35rem; padding-top: 0.5rem; border-top: 1px solid var(--line); font-size: 0.8rem; color: var(--muted); }
.group-heading:first-of-type { border-top: 0; margin-top: 0.2rem; padding-top: 0; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 6px; padding: 0.55rem 0.6rem;
  margin-bottom: 0.45rem; cursor: pointer; box-shadow: 0 1px 2px var(--shadow); }
.card.dragging { opacity: 0.5; }
.card-head { display: flex; gap: 0.3rem; align-items: flex-start; }
.card h3 { flex: 1; margin: 0 0 0.2rem; font-size: 0.93rem; }
.drag-handle { cursor: grab; color: var(--muted); font-size: 0.8rem; user-select: none; }
.meta { color: var(--muted); font-size: 0.8rem; margin: 0.15rem 0 0; }
.chip { display: inline-block; font-size: 0.72rem; font-weight: 600; padding: 0.1rem 0.5rem; border-radius: 999px;
  background: var(--column); white-space: nowrap; margin: 0.15rem 0; }
.chip.ok { background: var(--ok); } .chip.info { background: var(--info); } .chip.warn { background: var(--warn); }

dialog#detail { margin: 0 0 0 auto; padding: 0; width: min(34rem, 100%); max-width: none; height: 100dvh; max-height: 100dvh;
  border: 0; border-left: 1px solid var(--line); background: var(--bg); color: var(--ink); }
dialog#detail[open] { display: flex; flex-direction: column; }
dialog#detail::backdrop { background: rgba(0, 0, 0, 0.3); }
.detail-top { padding: 1rem 1.1rem 0.75rem; background: var(--card); border-bottom: 1px solid var(--line); }
.title-row { display: flex; gap: 0.5rem; align-items: flex-start; }
.title-row h2 { flex: 1; margin: 0; font-size: 1.15rem; }
.icon { border: 0; background: none; font-size: 1.1rem; cursor: pointer; color: var(--muted); padding: 0.1rem 0.35rem; }
#d-links { margin-top: 0.6rem; }
.next { margin: 0.75rem 1.1rem 0; padding: 0.7rem 0.8rem; background: var(--card); border: 1px solid var(--line); border-radius: 8px; }
.next p { margin: 0 0 0.5rem; font-size: 0.9rem; }
.next .meta { margin: 0.45rem 0 0; }
.tabs { display: flex; gap: 0.25rem; padding: 0.75rem 1.1rem 0; border-bottom: 1px solid var(--line); }
.tabs button { border: 0; border-bottom: 2px solid transparent; background: none; padding: 0.4rem 0.6rem; color: var(--muted); cursor: pointer; }
.tabs button[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--accent); font-weight: 600; }
.detail-body { flex: 1; overflow: auto; padding: 0.9rem 1.1rem 1.5rem; }
.fields { display: grid; grid-template-columns: 1fr 1fr; gap: 0 0.75rem; }
label { display: block; margin: 0 0 0.6rem; font-size: 0.8rem; color: var(--muted); }
label input, label select, label textarea { display: block; width: 100%; margin-top: 0.2rem; padding: 0.4rem 0.5rem;
  border: 1px solid var(--line); border-radius: 6px; background: var(--card); font-size: 0.92rem; }
.notes { list-style: none; padding: 0; margin: 0.4rem 0 0.8rem; }
.notes li, .history li { border-left: 2px solid var(--line); padding: 0.3rem 0.55rem; margin-bottom: 0.4rem; white-space: pre-wrap; overflow-wrap: anywhere; }
.notes li { background: var(--card); }
time { display: block; color: var(--muted); font-size: 0.78rem; }
.history { list-style: none; padding: 0; margin: 0; }
.history p { margin: 0.2rem 0 0; }
.form-actions { display: flex; gap: 0.5rem; justify-content: flex-end; align-items: center; }
#d-save-status { color: var(--muted); font-size: 0.85rem; margin-right: auto; }
h4 { margin: 0.4rem 0; font-size: 0.9rem; }

.login { max-width: 22rem; margin: 12vh auto; padding: 1.5rem; background: var(--card); border: 1px solid var(--line); border-radius: 10px; }
.login h1 { margin: 0 0 1rem; font-size: 1.2rem; }
.login .error { color: #C0392B; min-height: 1.2em; font-size: 0.88rem; }
@media (prefers-color-scheme: dark) { .login .error { color: #FF8A7A; } }

@media (max-width: 640px) {
  .column { flex-basis: 85vw; }
  .fields { grid-template-columns: 1fr; }
  #search { width: 100%; }
  .header-tools { width: 100%; }
}