:root {
  --bg: #fbfbfa; --fg: #1a1a1a; --muted: #5c5c5c; --line: #dcdcd8;
  --card: #ffffff; --accent: #1f5f8b; --hit: #1f5f8b; --hit-fg: #ffffff;
  --warn-bg: #fff8e8; --warn-line: #d9a441;
  --err-bg: #fdf0ee; --err-line: #c0503c;
  --ok-bg: #f0f5f0; --ok-line: #6d8c6d;
  --say-bg: #f2f6fa;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181a; --fg: #e6e6e3; --muted: #9a9a95; --line: #2f3336;
    --card: #1d2023; --accent: #7fb3d5; --hit: #2d6d9e; --hit-fg: #ffffff;
    --warn-bg: #2a2418; --warn-line: #a8802f;
    --err-bg: #2b1d1a; --err-line: #a8503c;
    --ok-bg: #1b241d; --ok-line: #5d7d5d;
    --say-bg: #1b2229;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0; padding: 0 1.25rem 4rem; background: var(--bg); color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
header, main, footer { max-width: 60rem; margin: 0 auto; }
header { padding: 2.5rem 0 1.5rem; }
h1 { font-size: 1.6rem; margin: 0 0 .25rem; letter-spacing: -.01em; }
.tagline { margin: 0; color: var(--muted); }
a { color: var(--accent); }

form { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 1.25rem; }
.field { display: flex; flex-direction: column; gap: .35rem; margin-bottom: .9rem; flex: 1; }
.field.narrow { flex: 0 0 9rem; }
.row { display: flex; gap: .9rem; flex-wrap: wrap; }
label { font-size: .8rem; font-weight: 600; letter-spacing: .03em; text-transform: uppercase; color: var(--muted); }
.hint { font-weight: 400; text-transform: none; letter-spacing: 0; }
input, textarea {
  font: 15px/1.4 var(--mono); padding: .6rem .7rem; border-radius: 6px;
  border: 1px solid var(--line); background: var(--bg); color: var(--fg); width: 100%;
}
textarea { resize: vertical; min-height: 2.6rem; }
input:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.examples { display: flex; flex-wrap: wrap; gap: .4rem; align-items: center; font-size: .85rem; color: var(--muted); }
.ex {
  font: inherit; font-size: .85rem; padding: .25rem .6rem; border-radius: 999px;
  border: 1px solid var(--line); background: var(--bg); color: var(--fg); cursor: pointer;
}
.ex:hover { border-color: var(--accent); color: var(--accent); }

.error {
  margin: 1.25rem 0; padding: .9rem 1rem; border-radius: 8px;
  background: var(--err-bg); border: 1px solid var(--err-line); font-family: var(--mono); font-size: .9rem;
}

.notes { margin: 1.5rem 0; display: flex; flex-direction: column; gap: .9rem; }
.note { border-radius: 8px; padding: .9rem 1.1rem; border: 1px solid var(--line); background: var(--card); }
.note h3 { margin: 0 0 .4rem; font-size: 1rem; line-height: 1.4; }
.note p { margin: .4rem 0; font-size: .93rem; }
.note-diverges { background: var(--warn-bg); border-color: var(--warn-line); }
.note-error { background: var(--err-bg); border-color: var(--err-line); }
.note-clear { background: var(--ok-bg); border-color: var(--ok-line); }
.badge {
  display: inline-block; font-size: .68rem; font-weight: 700; letter-spacing: .06em;
  text-transform: uppercase; padding: .12rem .45rem; border-radius: 4px; margin-right: .5rem;
  background: var(--fg); color: var(--bg); vertical-align: .12em;
}
.evidence { font-size: .82rem; color: var(--muted); }
.compare { margin: .7rem 0 .3rem; padding: .6rem .75rem; border-radius: 6px; background: var(--card); border: 1px solid var(--line); }
.compare h4 { margin: 0 0 .45rem; font-size: .8rem; font-weight: 600; color: var(--muted); }
.compare-dates { display: flex; flex-wrap: wrap; gap: .3rem; }
.compare-dates code { font-family: var(--mono); font-size: .78rem; padding: .12rem .35rem; border-radius: 4px; border: 1px solid var(--line); }

h2 { font-size: 1.15rem; margin: 2rem 0 .8rem; font-weight: 600; }
h2 .hint { color: var(--muted); font-weight: 400; font-size: .9rem; }
.occ-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr)); gap: .1rem .9rem; }
.occ { display: flex; gap: .55rem; align-items: baseline; font-family: var(--mono); font-size: .87rem; padding: .12rem 0; }
.occ-day { color: var(--muted); width: 2.4rem; }
.occ-time { color: var(--muted); }
.occ-gap { color: var(--muted); font-size: .78rem; margin-left: auto; }
.occ-tag { font-size: .68rem; letter-spacing: .05em; background: var(--accent); color: var(--bg); padding: 0 .3rem; border-radius: 3px; }

.grids { display: grid; grid-template-columns: repeat(auto-fill, minmax(13rem, 1fr)); gap: 1rem; margin-top: 1.5rem; }
.month { background: var(--card); border: 1px solid var(--line); border-radius: 8px; padding: .7rem; }
.month h3 { margin: 0 0 .5rem; font-size: .85rem; font-weight: 600; }
.grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 1px; }
.grid > div { text-align: center; font-size: .75rem; font-family: var(--mono); padding: .2rem 0; border-radius: 3px; }
.dow { color: var(--muted); font-size: .62rem !important; text-transform: uppercase; }
.cell.hit { background: var(--hit); color: var(--hit-fg); font-weight: 700; }
.cell.start { outline: 2px solid var(--accent); outline-offset: -2px; }
.more { grid-column: 1 / -1; color: var(--muted); font-size: .85rem; margin: 0; }

.caveat { margin-top: 2rem; font-size: .88rem; color: var(--muted); }
.caveat summary { cursor: pointer; font-weight: 600; }
.caveat ul { margin: .6rem 0 0; padding-left: 1.2rem; }
.caveat li { margin: .25rem 0; }

footer { margin-top: 3.5rem; padding-top: 1.5rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }
footer p { margin: .5rem 0; }

/* the date explainer */
.why { border-radius: 8px; padding: .9rem 1.1rem; border: 1px solid var(--line); background: var(--card); }
.why h3 { margin: 0 0 .4rem; font-size: 1rem; line-height: 1.4; }
.why p { margin: .4rem 0; font-size: .93rem; }
.why.yes { background: var(--ok-bg); border-color: var(--ok-line); }
.why.no { background: var(--warn-bg); border-color: var(--warn-line); }
.why.broken { background: var(--err-bg); border-color: var(--err-line); }
.checks { list-style: none; margin: .7rem 0 0; padding: 0; display: flex; flex-direction: column; gap: .35rem; }
.checks li { display: flex; gap: .6rem; align-items: baseline; font-size: .89rem; }
.mark { flex: 0 0 1.1rem; font-family: var(--mono); font-weight: 700; text-align: center; }
.check-yes .mark { color: var(--hit); }
.check-no .mark { color: var(--err-line); }
.check-no { font-weight: 600; }
.check-part { font-family: var(--mono); font-size: .84rem; }
.check-name { }
.check-detail { font-weight: 400; color: var(--muted); }

/* "Is this what you meant?" -- the rule in English, above the dates. */
.say {
  margin: 1rem 0 0.5rem;
  padding: 0.9rem 1.1rem;
  border-left: 4px solid var(--accent);
  background: var(--say-bg);
  border-radius: 0 4px 4px 0;
}
.say-head {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.45;
}
.say-notes {
  margin: 0.55rem 0 0;
  padding-left: 1.1rem;
  font-size: 0.92rem;
  opacity: 0.82;
  line-height: 1.5;
}
.say-notes li { margin: 0.15rem 0; }

/* Comparing two rules. The headline is the answer; the columns are the
   evidence for it. Dropped dates are the ones a user is looking for, so they
   are the ones that carry the warning colour. */
.cmp {
  margin: 1.2rem 0; border-radius: 8px; padding: 1rem 1.15rem;
  border: 1px solid var(--line); background: var(--card);
}
.cmp h2 { margin: 0 0 .4rem; font-size: 1.1rem; line-height: 1.35; }
.cmp h3 { margin: 0 0 .4rem; font-size: 1rem; }
.cmp p { margin: .35rem 0; font-size: .93rem; color: var(--muted); }
.cmp-same { background: var(--ok-bg); border-color: var(--ok-line); }
.cmp-diff { background: var(--warn-bg); border-color: var(--warn-line); }
.cmp.bad { background: var(--err-bg); border-color: var(--err-line); }
.cmp-cols { display: flex; flex-wrap: wrap; gap: 1rem; margin: .8rem 0 .2rem; }
.cmp-col { flex: 1 1 16rem; min-width: 0; }
.cmp-col h4 { margin: 0 0 .4rem; font-size: .8rem; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: .03em; }
.cmp-dates { display: flex; flex-wrap: wrap; gap: .3rem; align-items: baseline; }
.cmp-dates code {
  font-family: var(--mono); font-size: .78rem; padding: .12rem .35rem;
  border-radius: 4px; border: 1px solid var(--line); background: var(--card);
}
.cmp-col.dropped code { border-color: var(--err-line); }
.cmp-col.added code { border-color: var(--ok-line); }
.cmp-dates .more { font-size: .8rem; color: var(--muted); }
.cmp-foot { font-size: .85rem !important; margin-top: .7rem !important; }