:root {
  --paper: #e4ebdf;
  --ink: #1c2430;
  --muted: #556158;
  --line: #c9d3c6;
  --card: #fbfaf4;
  --navy: #1a3148;
  --accent: #0f5c4c;
  --chip: #e7efe4;
  --strip: #f4f1e4;
  --strip-edge: #d4cbb0;
  --good: #e5f4ea;
  --good-line: #1b7a45;
  --bad: #fdecea;
  --bad-line: #b42318;
  --vfr: #1b7a45;
  --mvfr: #1d5ea8;
  --ifr: #b42318;
  --lifr: #9d1d62;
  --shadow: 0 18px 40px rgba(26, 49, 72, 0.06);
  --serif: "Iowan Old Style", Palatino, "Palatino Linotype", Georgia, serif;
  --sans: "Avenir Next", "Segoe UI", sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #121816;
    --ink: #e7eee6;
    --muted: #a9b6ad;
    --line: #314038;
    --card: #1c2622;
    --navy: #d7e6db;
    --accent: #8fd0b4;
    --chip: #24302a;
    --strip: #18211c;
    --strip-edge: #3c4a40;
    --good: #163528;
    --good-line: #8fd0b4;
    --bad: #3a1e1c;
    --bad-line: #f0a8a2;
    --shadow: none;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(900px 420px at 0% -10%, rgba(255, 255, 255, 0.45), transparent 55%),
    var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.45;
}

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

button { cursor: pointer; }

button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible, a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

.app { max-width: 1080px; margin: 0 auto; padding: 28px 20px 72px; }

.top {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-end;
  margin-bottom: 18px;
}

.kicker {
  margin: 0 0 4px;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: 40px;
  font-weight: 560;
  letter-spacing: -0.03em;
  line-height: 1;
}

.lede { margin: 8px 0 0; max-width: 62ch; color: var(--muted); }

.score {
  min-width: 112px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--card);
  text-align: right;
}

.score b { display: block; font-family: var(--serif); font-size: 28px; font-weight: 560; }
.score span { color: var(--muted); font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; }

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 18px 0 22px;
  border-bottom: 1px solid var(--line);
}

nav button {
  appearance: none;
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  padding: 10px 12px 8px;
  color: var(--muted);
}

nav button[aria-current="page"] {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  padding: 18px;
  margin-bottom: 16px;
}

.row, .toolbar, .actions { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }

.toolbar { justify-content: space-between; margin-bottom: 14px; }

label.inline { display: flex; gap: 8px; align-items: center; color: var(--muted); font-size: 15px; }

select, input, textarea {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 8px 10px;
}

textarea { width: 100%; min-height: 72px; resize: vertical; font-family: var(--mono); font-size: 14px; }

.btn, .choice {
  border: 1px solid var(--navy);
  background: transparent;
  padding: 9px 12px;
}

.btn.primary, .choice.primary { background: var(--navy); color: var(--paper); }

@media (prefers-color-scheme: dark) {
  .btn.primary { background: var(--accent); color: #10211b; }
}

.metar-strip {
  margin: 0;
  padding: 16px 16px 14px;
  background: var(--strip);
  border: 1px solid var(--strip-edge);
  box-shadow: inset 0 0 0 4px var(--strip), inset 0 0 0 5px var(--strip-edge);
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1.6;
  overflow-wrap: anywhere;
}

.legend { display: flex; flex-wrap: wrap; gap: 12px; margin: 8px 0 0; padding: 0; list-style: none; color: var(--muted); font-size: 13px; }
.legend i { font-style: normal; font-family: var(--mono); }

.tok-wind { color: #163e66; }
.tok-vis, .tok-rvr { color: #0e5c45; }
.tok-wx { color: #8a3412; }
.tok-sky { color: #34386e; }
.tok-temp { color: #6d4a12; }
.tok-alt { color: #1c4d38; }
.tok-remark, .tok-rmk { color: #5e5648; }

@media (prefers-color-scheme: dark) {
  .tok-wind { color: #9ec1e6; }
  .tok-vis, .tok-rvr { color: #8fd0b4; }
  .tok-wx { color: #f0b089; }
  .tok-sky { color: #c5c8ef; }
  .tok-temp { color: #e6c98a; }
  .tok-alt { color: #9ad7bf; }
  .tok-remark, .tok-rmk { color: #c8bfa8; }
}

.topic {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 8px;
  background: var(--chip);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.stem { margin: 0 0 14px; font-family: var(--serif); font-size: 28px; font-weight: 560; letter-spacing: -0.02em; line-height: 1.2; }

.choices { display: grid; gap: 8px; }

.choice {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 10px;
  width: 100%;
  text-align: left;
  background: var(--card);
  padding: 12px;
}

.choice .letter { font-family: var(--mono); color: var(--muted); }

.choice.is-selected { border-color: var(--accent); }
.choice.is-correct { background: var(--good); border-color: var(--good-line); }
.choice.is-wrong { background: var(--bad); border-color: var(--bad-line); }
.choice:disabled { cursor: default; }

.explain {
  margin-top: 14px;
  padding-left: 12px;
  border-left: 3px solid var(--accent);
}

.explain p { margin: 0 0 8px; }
.explain p:last-child { margin-bottom: 0; }

.note { color: var(--muted); font-size: 14px; }

.error { color: var(--bad-line); }

.split { display: grid; gap: 16px; }
@media (min-width: 900px) {
  .split { grid-template-columns: 1.05fr 0.95fr; align-items: start; }
}

.fields { display: grid; gap: 10px; grid-template-columns: 1fr 1fr; }
.field { display: flex; flex-direction: column; gap: 4px; font-size: 14px; }
.field.wide { grid-column: 1 / -1; }
.field small { color: var(--muted); }
.field.is-bad input, .field.is-bad select { border-color: var(--bad-line); background: var(--bad); }
.field.is-good input, .field.is-good select { border-color: var(--good-line); }

.grade-summary { font-family: var(--serif); font-size: 28px; margin: 0 0 8px; }

.readback { font-size: 16px; }

.progress { height: 8px; background: var(--chip); margin: 8px 0 14px; }
.progress span { display: block; height: 100%; background: var(--accent); }

.review { display: grid; gap: 12px; }
.review article { border-top: 1px solid var(--line); padding-top: 10px; }

.facts { display: grid; gap: 6px; margin: 0 0 12px; }
.facts div { display: grid; grid-template-columns: 140px 1fr; gap: 8px; }
.facts dt { color: var(--muted); }

.wind-svg { width: min(100%, 240px); height: auto; background: var(--strip); border: 1px solid var(--strip-edge); }

.ref-block { margin-bottom: 28px; }
.ref-block h2 { font-family: var(--serif); font-size: 28px; font-weight: 560; margin: 0 0 8px; }
.ref-block h3 { font-size: 16px; margin: 16px 0 6px; }

table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { text-align: left; vertical-align: top; padding: 8px 8px 8px 0; border-bottom: 1px solid var(--line); }
th { font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); font-weight: 600; }

.bars { display: grid; gap: 8px; }
.bar { display: grid; grid-template-columns: 120px 1fr 52px; gap: 8px; align-items: center; font-size: 14px; }
.bar i { display: block; height: 8px; background: var(--chip); }
.bar i b { display: block; height: 100%; background: var(--accent); }

.miss { border-top: 1px solid var(--line); padding: 10px 0; }
code, .mono { font-family: var(--mono); font-size: 0.92em; }

.footer { margin-top: 28px; color: var(--muted); font-size: 13px; max-width: 78ch; }

.cat { display: inline-block; padding: 0 6px; color: white; font-size: 13px; }
.cat-VFR { background: var(--vfr); }
.cat-MVFR { background: var(--mvfr); }
.cat-IFR { background: var(--ifr); }
.cat-LIFR { background: var(--lifr); }

@media (max-width: 640px) {
  h1 { font-size: 34px; }
  .stem { font-size: 24px; }
  .top { flex-direction: column; align-items: flex-start; }
  .fields, .facts div, .bar { grid-template-columns: 1fr; }
  .score { text-align: left; }
}

@media print {
  nav, .toolbar, .actions, .footer, .score { display: none; }
  body { background: white; }
  .card { box-shadow: none; }
}