:root {
  --paper: #f6f3ec;
  --card: #fffdf8;
  --ink: #1d1b18;
  --muted: #6b655b;
  --rule: #ddd6c8;
  --navy: #1f3a5f;
  --right: #2f6b3a;
  --right-bg: #e7f0e3;
  --wrong: #a3322a;
  --wrong-bg: #f6e4e0;
  --mark: #fff2b3;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #17171a;
    --card: #1f1f23;
    --ink: #e8e4dc;
    --muted: #9a958b;
    --rule: #34343a;
    --navy: #8fb0d9;
    --right: #8cc596;
    --right-bg: #1f2e22;
    --wrong: #ec8d84;
    --wrong-bg: #36211f;
    --mark: #4a4220;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.55 Charter, "Bitstream Charter", "Sitka Text", Cambria, Georgia, serif;
}

.wrap { max-width: 700px; margin: 0 auto; padding: 0 16px; }

button, input, select { font: inherit; color: inherit; }

/* header ---------------------------------------------------------------- */

.top { border-bottom: 1px solid var(--rule); margin-bottom: 28px; }
.top .wrap { display: flex; align-items: baseline; gap: 12px; padding-top: 18px; padding-bottom: 14px; flex-wrap: wrap; }
.brand { font-weight: 700; font-size: 20px; color: var(--navy); text-decoration: none; }
.brand span { font-weight: 400; color: var(--muted); }
.sub { color: var(--muted); font-size: 15px; }

.foot { color: var(--muted); font-size: 14px; padding-top: 40px; padding-bottom: 40px; }

h1, h2 { font-weight: 700; line-height: 1.25; }
h1 { font-size: 26px; margin: 0 0 6px; }
h2 { font-size: 15px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin: 28px 0 10px; font-family: system-ui, sans-serif; font-weight: 600; }
.lede { color: var(--muted); margin: 0 0 8px; }

/* setup ----------------------------------------------------------------- */

.picks { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 2px 18px; }
.pick { display: flex; align-items: baseline; gap: 10px; padding: 6px 0; cursor: pointer; }
.pick input { accent-color: var(--navy); transform: translateY(1px); }
.pick .n { color: var(--muted); font-size: 14px; margin-left: auto; font-variant-numeric: tabular-nums; }
.pick .num { color: var(--muted); font-variant-numeric: tabular-nums; min-width: 1.4em; }

.links { font-size: 15px; margin-top: 4px; }
.links button { background: none; border: 0; padding: 0; color: var(--navy); text-decoration: underline; cursor: pointer; }

.seg { display: inline-flex; border: 1px solid var(--rule); border-radius: 6px; overflow: hidden; flex-wrap: wrap; }
.seg label { cursor: pointer; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg span { display: block; padding: 6px 14px; border-right: 1px solid var(--rule); background: var(--card); }
.seg label:last-child span { border-right: 0; }
.seg input:checked + span { background: var(--navy); color: var(--paper); }
.seg input:focus-visible + span { outline: 2px solid var(--navy); outline-offset: -4px; }

.hint { color: var(--muted); font-size: 14px; margin: 6px 0 0; }

.btn {
  display: inline-block; border: 1px solid var(--navy); background: var(--navy); color: var(--paper);
  padding: 9px 20px; border-radius: 6px; cursor: pointer; font-family: system-ui, sans-serif; font-size: 15px; font-weight: 600;
}
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.ghost { background: transparent; color: var(--navy); }
.actions { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-top: 26px; }
.actions .note { color: var(--muted); font-size: 14px; }

/* question -------------------------------------------------------------- */

.meta { display: flex; justify-content: space-between; gap: 12px; font-family: system-ui, sans-serif; font-size: 13px; color: var(--muted); margin-bottom: 6px; flex-wrap: wrap; }
.bar { height: 3px; background: var(--rule); margin-bottom: 22px; }
.bar i { display: block; height: 100%; background: var(--navy); transition: width .2s; }

.q { font-size: 20px; line-height: 1.45; margin: 0 0 6px; }
.kind { font-family: system-ui, sans-serif; font-size: 13px; color: var(--muted); margin-bottom: 16px; }

.opts { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.opts li { border-bottom: 1px solid var(--rule); }
.opt { display: flex; gap: 12px; align-items: baseline; padding: 11px 6px; cursor: pointer; }
.opt:hover { background: var(--card); }
.opt input { accent-color: var(--navy); flex: none; transform: translateY(2px); }
.opt .k { font-family: system-ui, sans-serif; font-size: 13px; color: var(--muted); min-width: 1em; }
.opt.right { background: var(--right-bg); }
.opt.wrong { background: var(--wrong-bg); }
.opt.right .k, .opt.wrong .k { font-weight: 700; }
.opt.right .k { color: var(--right); }
.opt.wrong .k { color: var(--wrong); }
.locked .opt { cursor: default; }
.locked .opt:hover { background: inherit; }
.locked .opt.right:hover { background: var(--right-bg); }
.locked .opt.wrong:hover { background: var(--wrong-bg); }

.blank {
  width: 100%; max-width: 360px; padding: 8px 2px; border: 0; border-bottom: 2px solid var(--ink);
  background: transparent; font-size: 19px; outline: none; border-radius: 0;
}
.blank:focus { border-bottom-color: var(--navy); }
.blank.right { border-bottom-color: var(--right); color: var(--right); }
.blank.wrong { border-bottom-color: var(--wrong); color: var(--wrong); text-decoration: line-through; }

.fb { margin-top: 18px; padding: 12px 14px; border-left: 3px solid var(--rule); background: var(--card); }
.fb.ok { border-left-color: var(--right); }
.fb.no { border-left-color: var(--wrong); }
.fb b { font-family: system-ui, sans-serif; font-size: 14px; }
.fb.ok b { color: var(--right); }
.fb.no b { color: var(--wrong); }
.fb p { margin: 4px 0 0; }
mark { background: var(--mark); color: inherit; padding: 0 2px; }

.keys { font-family: system-ui, sans-serif; font-size: 12px; color: var(--muted); margin-top: 14px; }
.keys kbd { border: 1px solid var(--rule); border-bottom-width: 2px; border-radius: 3px; padding: 0 4px; font-size: 11px; background: var(--card); }
@media (hover: none) { .keys { display: none; } }

/* results --------------------------------------------------------------- */

.score { font-size: 54px; font-weight: 700; line-height: 1; margin: 6px 0 4px; font-variant-numeric: tabular-nums; }
.score small { font-size: 22px; color: var(--muted); font-weight: 400; }
.bylec { width: 100%; border-collapse: collapse; font-size: 15px; }
.bylec td { padding: 6px 4px; border-bottom: 1px solid var(--rule); }
.bylec td:last-child { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }

.missed { list-style: none; padding: 0; margin: 0; }
.missed li { padding: 12px 0; border-bottom: 1px solid var(--rule); }
.missed .mq { margin: 0 0 4px; }
.missed .ma { font-size: 15px; margin: 0; }
.missed .ma s { color: var(--wrong); }
.missed .ma strong { color: var(--right); }
.missed .tag { font-family: system-ui, sans-serif; font-size: 12px; color: var(--muted); }

@media (max-width: 520px) {
  body { font-size: 16px; }
  .q { font-size: 18px; }
  h1 { font-size: 22px; }
  .score { font-size: 44px; }
}