:root {
  --bg: #ffffff;
  --fg: #161616;
  --muted: #6b6b6b;
  --line: #e6e6e6;
  --soft: #f5f5f5;
  --accent: #1f6feb;
  --ok: #1a7f37;
  --warn: #b35900;
  --code: #f3f3f3;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111111;
    --fg: #e8e8e8;
    --muted: #9a9a9a;
    --line: #2a2a2a;
    --soft: #1b1b1b;
    --accent: #58a6ff;
    --ok: #3fb950;
    --warn: #e3a34a;
    --code: #1e1e1e;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--fg); }
body {
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
  padding-bottom: calc(64px + env(safe-area-inset-bottom));
}
main { max-width: 680px; margin: 0 auto; padding: calc(16px + env(safe-area-inset-top)) 18px 24px; }
a { color: var(--accent); text-decoration: none; }
h1 { font-size: 22px; margin: 4px 0 4px; }
h2 { font-size: 17px; margin: 24px 0 8px; }
.sub { color: var(--muted); font-size: 14px; margin: 0 0 16px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }

nav#tabs {
  position: fixed; left: 0; right: 0; bottom: 0;
  display: flex; background: var(--bg); border-top: 1px solid var(--line);
  padding-bottom: env(safe-area-inset-bottom); z-index: 10;
}
nav#tabs a { flex: 1; text-align: center; padding: 14px 0; color: var(--muted); font-size: 14px; }
nav#tabs a.on { color: var(--fg); font-weight: 600; }

/* task rows */
.list { border-top: 1px solid var(--line); }
.row { display: flex; gap: 12px; align-items: flex-start; padding: 12px 0; border-bottom: 1px solid var(--line); }
.row .body { flex: 1; min-width: 0; }
.row .title { display: block; color: var(--fg); }
.row .meta { color: var(--muted); font-size: 13px; }
.row.done .title { color: var(--muted); text-decoration: line-through; }
.check {
  flex: none; width: 24px; height: 24px; margin-top: 1px; border-radius: 6px;
  border: 2px solid var(--muted); background: none; padding: 0; cursor: pointer; color: transparent;
  font-size: 15px; line-height: 20px;
}
.check.on { background: var(--ok); border-color: var(--ok); color: #fff; }
.tag { font-size: 11px; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin-right: 6px; }
.go { flex: none; color: var(--accent); font-size: 14px; padding-top: 2px; }

/* bars */
.bar { height: 6px; background: var(--soft); border-radius: 3px; overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--ok); }
.stat { display: flex; justify-content: space-between; font-size: 14px; margin: 14px 0 6px; }

/* plan */
details.week { border-bottom: 1px solid var(--line); }
details.week > summary { list-style: none; cursor: pointer; padding: 14px 0; display: flex; justify-content: space-between; gap: 8px; }
details.week > summary::-webkit-details-marker { display: none; }
.day { margin: 4px 0 14px; }
.day h3 { font-size: 14px; margin: 10px 0 2px; color: var(--muted); font-weight: 600; }
.day h3.today { color: var(--accent); }

/* buttons */
.btn {
  display: inline-block; font: inherit; font-size: 15px; padding: 9px 14px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--soft); color: var(--fg); cursor: pointer;
}
.btn.primary { background: var(--fg); color: var(--bg); border-color: var(--fg); }
.btn.on { border-color: var(--ok); color: var(--ok); }
.btns { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.back { display: inline-block; padding: 4px 0 10px; font-size: 15px; }
input[type=date], select { font: inherit; padding: 8px; border-radius: 8px; border: 1px solid var(--line); background: var(--soft); color: var(--fg); }

/* reader */
.reader { font-size: var(--rs, 17px); line-height: 1.65; }
.reader h1 { font-size: 1.4em; line-height: 1.3; }
.reader h2 { font-size: 1.12em; margin-top: 1.8em; }
.reader h3 { font-size: 1em; margin-top: 1.4em; }
.reader p, .reader ul, .reader ol { margin: .6em 0; }
.reader ul, .reader ol { padding-left: 1.3em; }
.reader li { margin: .25em 0; }
.reader code { font: .88em ui-monospace, SFMono-Regular, Menlo, monospace; background: var(--code); padding: 1px 4px; border-radius: 4px; }
.reader pre { background: var(--code); padding: 12px; border-radius: 8px; overflow-x: auto; line-height: 1.4; }
.reader pre code { background: none; padding: 0; font-size: .8em; }
.reader blockquote { margin: .8em 0; padding: .2em 0 .2em 12px; border-left: 3px solid var(--accent); color: var(--muted); }
.reader table { border-collapse: collapse; width: 100%; font-size: .85em; display: block; overflow-x: auto; }
.reader th, .reader td { border: 1px solid var(--line); padding: 6px 8px; text-align: left; vertical-align: top; }
.reader th { background: var(--soft); }
.reader hr { border: 0; border-top: 1px solid var(--line); margin: 2em 0; }
.endbox { border-top: 1px solid var(--line); margin-top: 28px; padding-top: 12px; }
.timer { font: 600 28px ui-monospace, Menlo, monospace; margin: 8px 0; }
.empty { padding: 24px 0; color: var(--muted); }