:root { --bg: #f3f7f6; --fg: #17302c; --card: #fff; --line: #d3dfdc; --accent: #0f766e; --danger: #c33a32; --muted: #5f7471; --warn: #a35f00; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #0e1716; --fg: #e4efed; --card: #172422; --line: #2c3f3c; --accent: #3cc1b1; --danger: #ff6b61; --muted: #93a8a4; --warn: #f0a640; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.5 system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP", sans-serif; }
main { max-width: 520px; margin: 0 auto; padding: 0 16px 16px; }
h1 { font-size: 1.2rem; margin: 0; color: var(--accent); }
h2 { font-size: 1.05rem; margin: 0 0 8px; }
h3 { font-size: .95rem; margin: 16px 0 6px; }
.bar { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between;
       max-width: 520px; margin: 0 auto; padding: 12px 16px; background: var(--bg); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px; margin-bottom: 16px; }
details.card > summary { font-weight: 600; cursor: pointer; }
details.card[open] > summary { margin-bottom: 12px; }
.state { font-size: 1.4rem; font-weight: 600; margin: 4px 0 8px; }
.row { display: flex; gap: 12px; }
button { flex: 1; font: inherit; padding: 14px 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--fg); }
button.primary { width: 100%; background: var(--accent); color: #fff; border-color: var(--accent); }
button.danger { border-color: var(--danger); color: var(--danger); }
button.link { flex: none; padding: 0 4px; border: 0; background: none; color: var(--accent); text-decoration: underline; }
button:disabled { opacity: .5; }
label { display: block; margin: 12px 0; }
input, select, textarea { display: block; width: 100%; margin-top: 4px; font: inherit; padding: 10px; border-radius: 8px; border: 1px solid var(--line); background: var(--card); color: var(--fg); }
textarea { font-size: .8rem; resize: vertical; margin-bottom: 12px; }
#msg { min-height: 1.5em; }
#msg.error { color: var(--danger); }
.sub { color: var(--muted); font-size: .9rem; margin: 0 0 12px; }
[hidden] { display: none !important; }
dialog { border: 1px solid var(--line); border-radius: 12px; padding: 20px; max-width: min(92vw, 420px); background: var(--card); color: var(--fg); }
dialog::backdrop { background: rgba(0, 0, 0, .45); }
.warn { color: var(--danger); font-weight: 600; }
.cal-list, .history { list-style: none; padding: 0; margin: 0 0 12px; font-size: .9rem; }
.cal-list li, .history li { display: flex; flex-wrap: wrap; align-items: baseline; gap: 2px 8px; padding: 8px 0; border-top: 1px solid var(--line); }
.cal-op { flex: none; font-size: .75rem; font-weight: 600; padding: 0 6px; border-radius: 6px; border: 1px solid currentColor; }
.op-add .cal-op { color: var(--accent); }
.op-update .cal-op { color: var(--warn); }
.op-delete .cal-op { color: var(--danger); }
.op-same { color: var(--muted); }
.cal-sum { font-weight: 600; }
.cal-when, .h-time { color: var(--muted); font-variant-numeric: tabular-nums; }
.h-result { margin-left: auto; }
.cal-lines, .h-note { flex-basis: 100%; color: var(--muted); font-size: .85rem; white-space: pre-line; font-variant-numeric: tabular-nums; }
.steps { padding-left: 1.4em; font-size: .9rem; margin: 0 0 12px; }
.steps li { margin: 4px 0; }