:root {
  --bg: #0e1116; --card: #171c24; --line: #262e3a; --fg: #e8edf4; --dim: #93a1b5;
  --accent: #6ea8fe; --good: #7ee2a8; --bad: #ff8f8f; --warn: #ffd479;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 15px/1.55 -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
header {
  display: flex; align-items: center; gap: 1rem; padding: .6rem 1rem;
  border-bottom: 1px solid var(--line); background: #11151c; position: sticky; top: 0;
  flex-wrap: wrap;
}
.brand { font-weight: 700; color: var(--fg); text-decoration: none; }
nav { display: flex; gap: .8rem; flex-wrap: wrap; align-items: center; }
nav a { color: var(--dim); text-decoration: none; }
nav a:hover { color: var(--fg); }
main { max-width: 980px; margin: 0 auto; padding: 1rem; }
footer { max-width: 980px; margin: 2rem auto 3rem; padding: 0 1rem; }
.dim { color: var(--dim); }
.small { font-size: .85em; }
.mono { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; }
.big { font-size: 1.25em; }
.good { color: var(--good); }
.bad { color: var(--bad); }
.warn { color: var(--warn); }
.err { color: var(--bad); }
.info { color: var(--accent); }
.hidden { display: none; }
.center { text-align: center; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 1rem 1.1rem; margin: .8rem 0;
}
.card.narrow { max-width: 560px; margin-left: auto; margin-right: auto; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: .8rem; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: .8rem; }
.row { display: flex; justify-content: space-between; align-items: center; gap: .8rem; }
.row.wrap { flex-wrap: wrap; }
.grow { flex: 1; }
.actions { display: flex; gap: .5rem; flex-wrap: wrap; }
h1 { font-size: 1.4rem; } h2 { font-size: 1.1rem; } h3 { font-size: 1rem; }
a { color: var(--accent); }
button, .btn {
  background: var(--accent); color: #0b0f14; border: 0; border-radius: 8px;
  padding: .5rem .9rem; font-weight: 600; cursor: pointer; text-decoration: none;
  display: inline-block; font-size: .95rem;
}
button:disabled { opacity: .4; cursor: default; }
.btn.ghost, button.ghost { background: transparent; color: var(--accent); border: 1px solid var(--line); }
.btn.small, button.small { padding: .25rem .55rem; font-size: .85rem; }
.linklike { background: none; color: var(--dim); border: 0; padding: 0; font-weight: 400;
  cursor: pointer; font-size: 1rem; }
label { display: block; margin: .5rem 0; }
input[type=text], input[type=password], input[type=number], input[type=date], select {
  background: #0f141b; color: var(--fg); border: 1px solid var(--line); border-radius: 8px;
  padding: .45rem .6rem; font-size: 1rem; width: 100%; max-width: 420px;
}
input.answer { font-family: ui-monospace, Menlo, Consolas, monospace; }
table { border-collapse: collapse; width: 100%; }
th, td { text-align: left; border-bottom: 1px solid var(--line); padding: .35rem .4rem; }
th { color: var(--dim); font-weight: 600; }
.chip {
  background: #22303f; color: var(--fg); border-radius: 999px; padding: .05rem .5rem;
  font-size: .8rem; margin-left: .3rem;
}
.chip.good { background: #1d3a2c; color: var(--good); }
.chip.bad { background: #3d2424; color: var(--bad); }
.famlist { list-style: none; padding: 0; }
.famlist li { padding: .2rem 0; }
.stopwatch {
  display: flex; align-items: center; gap: .8rem; background: var(--card);
  border: 1px solid var(--line); border-radius: 10px; padding: .7rem 1rem; margin: .8rem 0;
}
.clock { font-family: ui-monospace, Menlo, monospace; font-size: 1.5rem; min-width: 6.5rem; }
.items { padding-left: 1.4rem; }
.items li { margin: .8rem 0; }
.math { display: inline-block; margin: 0 .2rem; }
.katex { font-size: 1.12em; }
.hintbox { text-align: right; min-width: 130px; }
.hinttext { color: var(--warn); max-width: 260px; }
.conf label { display: inline; margin-right: .5rem; }
.entry-item .answer { flex: 1; min-width: 220px; }
.verdict-ok { color: var(--good); font-weight: 700; }
.verdict-bad { color: var(--bad); font-weight: 700; }
.verdict-manual { color: var(--warn); font-weight: 700; }
.wilson .bar { position: relative; background: #202836; height: 14px; width: 180px;
  border-radius: 999px; display: inline-block; vertical-align: middle; overflow: hidden; }
.wilson .fill { position: absolute; top: 0; bottom: 0; background: var(--accent); opacity: .8; }
.levelbar { display: flex; gap: .3rem; }
.levelbar .lv { font-size: .75rem; padding: .1rem .35rem; border: 1px solid var(--line);
  border-radius: 6px; color: var(--dim); }
.levelbar .lv.on { background: #1d3a2c; color: var(--good); border-color: #2c5a44; }
pre { background: #0f141b; border: 1px solid var(--line); border-radius: 8px; padding: .6rem;
  overflow-x: auto; white-space: pre-wrap; }
details summary { cursor: pointer; color: var(--dim); }