:root {
  --bg: #fafaf7;
  --panel: #ffffff;
  --text: #1d2330;
  --muted: #5b6475;
  --accent: #1f4e8c;
  --accent-bg: #e8eff8;
  --ok: #1d6b3a;
  --ok-bg: #e6f3ea;
  --ng: #a3311f;
  --ng-bg: #f9e8e4;
  --soft: #f0f0eb;
}
* { box-sizing: border-box; }
html { font-size: 17px; scroll-padding-bottom: 5rem; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Hiragino Sans", "Yu Gothic UI", "Yu Gothic", "Meiryo", sans-serif;
  line-height: 1.85;
  padding-bottom: 5rem;
  -webkit-text-size-adjust: 100%;
}
.top {
  padding: 0.8rem 1rem;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--muted);
}
.top a { color: inherit; text-decoration: none; display: inline-block; min-height: 2.75rem; line-height: 2.75rem; }
main { max-width: 42rem; margin: 0 auto; padding: 0.5rem 1rem 2rem; }
h2 { font-size: 1.6rem; line-height: 1.4; margin: 0.6rem 0 0.8rem; }
h3 { font-size: 1.15rem; margin: 0 0 0.4rem; }
h4 { font-size: 1rem; margin: 1rem 0 0.2rem; }
p { margin: 0.3rem 0 0.9rem; }
a { color: var(--accent); }
.block { margin: 1.8rem 0; }
.yomi, .alt, .meta, .progress { color: var(--muted); font-size: 0.92rem; margin: 0.1rem 0; }
.note { color: var(--muted); font-size: 0.9rem; min-height: 1.4rem; margin: 0.2rem 0 0.6rem; }
.caution { background: #fff4d6; padding: 0.6rem 0.8rem; border-radius: 6px; font-size: 0.95rem; }

.btn {
  display: block; width: 100%;
  min-height: 3rem; padding: 0.7rem 1rem;
  font: inherit; font-weight: 700;
  color: var(--accent); background: var(--accent-bg);
  border: 0; border-radius: 8px; margin: 0.5rem 0;
  cursor: pointer; text-align: center;
}
.btn.primary { color: #fff; background: var(--accent); }
.btn:disabled { opacity: 0.45; cursor: default; }
.stack { margin-top: 0.4rem; }

textarea {
  width: 100%; font: inherit; line-height: 1.7;
  padding: 0.7rem; border: 1px solid #c9ccd4; border-radius: 8px; background: var(--panel); color: var(--text);
}
input[type="file"] { width: 100%; font: inherit; margin: 0.4rem 0; }

.list { list-style: none; margin: 0.4rem 0; padding: 0; }
.list li { margin: 0.5rem 0; }
.list a { display: block; padding: 0.7rem 0.9rem; background: var(--panel); border-radius: 8px; text-decoration: none; color: var(--text); }
.list .name { display: block; font-weight: 700; }
.list .sub, .sub { display: block; color: var(--muted); font-size: 0.88rem; }
.list.plain li { background: var(--panel); border-radius: 8px; padding: 0.6rem 0.9rem; }
.statrow { display: flex; justify-content: space-between; gap: 1rem; }
.statrow .name { font-weight: 700; }
.statrow .val { white-space: nowrap; }

.diff { margin: 0; }
.diff dt { font-weight: 700; margin-top: 0.7rem; }
.diff dd { margin: 0.1rem 0 0.4rem 0; padding: 0.4rem 0.7rem; background: var(--soft); border-radius: 6px; }
.compare { background: var(--soft); border-radius: 8px; padding: 0.4rem 0.9rem; margin-top: 0.6rem; }

.stem { font-size: 1.1rem; font-weight: 700; margin: 0.8rem 0 1rem; white-space: pre-line; overflow-wrap: anywhere; }
.choices { margin: 0.4rem 0 1rem; }
.choice {
  display: flex; gap: 0.7rem; align-items: flex-start; text-align: left;
  width: 100%; min-height: 3rem; padding: 0.7rem 0.9rem; margin: 0.5rem 0;
  font: inherit; color: var(--text); background: var(--panel);
  border: 2px solid transparent; border-radius: 8px; cursor: pointer;
}
.choice .lab { font-weight: 700; min-width: 1.4rem; }
.choice.picked { border-color: var(--accent); background: var(--accent-bg); }
.choice.right { border-color: var(--ok); background: var(--ok-bg); }
.choice.wrong { border-color: var(--ng); background: var(--ng-bg); }
.choice:disabled { cursor: default; color: var(--text); }
.check { display: flex; gap: 0.6rem; align-items: center; margin: 0.6rem 0; min-height: 2.6rem; }
.check input { width: 1.4rem; height: 1.4rem; }
.okmsg { color: var(--ok); font-size: 1.3rem; }
.ngmsg { color: var(--ng); font-size: 1.3rem; }
.why { padding: 0.6rem 0.9rem; margin: 0.6rem 0; background: var(--soft); border-radius: 8px; }
.why.right { background: var(--ok-bg); }
.why p { margin: 0.1rem 0; }
.case { background: var(--panel); border-radius: 8px; padding: 0.7rem 0.9rem; margin: 0.8rem 0; }
.case p { white-space: pre-line; }
.case .fig { background: var(--soft); border-radius: 6px; padding: 0.5rem 0.7rem; margin: 0.6rem 0; font-size: 0.95rem; }
.case .figcap { font-weight: 700; margin: 0.8rem 0 0.2rem; font-size: 0.95rem; }
.case .fig p { margin: 0.25rem 0; }
.tablewrap { overflow-x: auto; margin: 0.4rem 0; }
.case table { border-collapse: collapse; width: 100%; font-size: 0.92rem; }
.case th, .case td { border: 1px solid #c9ccd4; padding: 0.35rem 0.5rem; vertical-align: top; text-align: left; min-width: 3rem; }
.case th { background: var(--soft); }
.fieldhead { font-size: 1.25rem; }
.timer { position: sticky; top: 0; z-index: 2; background: var(--accent); color: #fff; font-weight: 700; padding: 0.4rem 0.8rem; border-radius: 6px; margin: 0 0 0.5rem; }
.score { font-size: 2rem; font-weight: 700; margin: 0.4rem 0; }
.mocknav { display: flex; gap: 0.6rem; }
.mocknav .btn { flex: 1; }
.jump { display: grid; grid-template-columns: repeat(auto-fill, minmax(3rem, 1fr)); gap: 0.4rem; }
.jumpbtn { min-height: 2.75rem; font: inherit; font-size: 0.85rem; background: var(--panel); color: var(--text); border: 2px solid transparent; border-radius: 6px; cursor: pointer; }
.jumpbtn.done { background: var(--accent-bg); }
.jumpbtn.now { border-color: var(--accent); font-weight: 700; }
input[type="date"] { display: block; width: 100%; font: inherit; padding: 0.6rem; margin: 0.4rem 0; border: 1px solid #c9ccd4; border-radius: 8px; background: var(--panel); color: var(--text); }
.week { padding: 0.6rem 0.9rem; margin: 0.6rem 0; background: var(--panel); border-radius: 8px; border: 2px solid transparent; }
.week.now { border-color: var(--accent); }
.week p { margin: 0.15rem 0; }
.weekhead { color: var(--muted); font-size: 0.9rem; }
.weektitle { font-weight: 700; }
.whyhead { font-weight: 700; }

#nav {
  position: fixed; left: 0; right: 0; bottom: 0;
  display: flex; background: var(--panel); box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.06);
  padding-bottom: env(safe-area-inset-bottom);
}
#nav a {
  flex: 1; text-align: center; padding: 0.9rem 0; min-height: 3rem;
  text-decoration: none; color: var(--muted); font-weight: 700; font-size: 0.95rem;
}
#nav a.on { color: var(--accent); background: var(--accent-bg); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
[tabindex="-1"]:focus { outline: none; }