:root {
  --bg: #0f1420;
  --card: #1a2233;
  --card-border: #2a3550;
  --text: #e8ecf4;
  --text-dim: #9aa5bd;
  --accent: #4c8dff;
  --accent-dark: #2f6ae0;
  --correct: #2ecc71;
  --correct-bg: #123a24;
  --wrong: #ff5d5d;
  --wrong-bg: #3d1a1f;
  --review: #f0a832;
  --radius: 14px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  padding-bottom: env(safe-area-inset-bottom);
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px 16px 48px;
}

/* ---------- header ---------- */
.app-header {
  text-align: center;
  padding: 18px 16px 6px;
}
.app-header h1 { font-size: 1.25rem; letter-spacing: .02em; }
.header-sub { font-size: .78rem; color: var(--text-dim); }

/* ---------- cards & buttons ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 14px;
}

.btn {
  display: block;
  width: 100%;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  cursor: pointer;
  padding: 14px 16px;
  margin-bottom: 12px;
  transition: transform .06s, filter .15s;
}
.btn:active { transform: scale(.98); }
.btn-big { font-weight: 700; font-size: 1.05rem; }
.btn-primary { background: linear-gradient(135deg, var(--accent), var(--accent-dark)); }
.btn-review { background: linear-gradient(135deg, #c98a1e, #a06a10); }
.btn-ghost {
  background: transparent;
  border: 1px solid var(--card-border);
  color: var(--text-dim);
}
.badge {
  background: rgba(255,255,255,.25);
  border-radius: 999px;
  padding: 1px 10px;
  font-size: .85rem;
  margin-left: 6px;
}

/* ---------- home ---------- */
.overall-stats { display: flex; justify-content: space-around; text-align: center; }
.stat-value { display: block; font-size: 1.5rem; font-weight: 700; color: var(--accent); }
.stat-label { font-size: .72rem; color: var(--text-dim); }

.section-title { font-size: .95rem; color: var(--text-dim); margin: 20px 0 10px; }

.domain-card {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin-bottom: 10px;
  color: var(--text);
  font-family: inherit;
  font-size: .95rem;
  cursor: pointer;
}
.domain-card:active { transform: scale(.99); }
.domain-card .domain-name { font-weight: 700; display: flex; justify-content: space-between; gap: 8px; }
.domain-card .domain-weight { color: var(--text-dim); font-size: .78rem; white-space: nowrap; }
.domain-card .domain-stats { font-size: .8rem; color: var(--text-dim); margin-top: 4px; }
.domain-card .mini-bar {
  height: 6px; border-radius: 3px; background: #0d1320; margin-top: 8px; overflow: hidden;
}
.domain-card .mini-fill { height: 100%; background: var(--accent); border-radius: 3px; }

.home-footer { margin-top: 26px; }

/* ---------- quiz ---------- */
.quiz-meta {
  display: flex; justify-content: space-between; align-items: center;
  font-size: .85rem; color: var(--text-dim); margin-bottom: 8px;
}
.domain-tag {
  background: rgba(76,141,255,.15);
  color: var(--accent);
  border-radius: 999px;
  padding: 2px 12px;
  font-size: .75rem;
}
.progress-bar {
  height: 6px; background: var(--card); border-radius: 3px; overflow: hidden; margin-bottom: 16px;
}
.progress-fill { height: 100%; background: var(--accent); width: 0; transition: width .3s; }

.topic-label { font-size: .75rem; color: var(--accent); margin-bottom: 8px; }
.question-text { font-size: 1.02rem; font-weight: 600; white-space: pre-wrap; }

.choices { margin-bottom: 4px; }
.choice-btn {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--card);
  border: 1.5px solid var(--card-border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: inherit;
  font-size: .95rem;
  line-height: 1.5;
  padding: 13px 15px;
  margin-bottom: 10px;
  cursor: pointer;
}
.choice-btn:active { transform: scale(.99); }
.choice-btn.correct { border-color: var(--correct); background: var(--correct-bg); }
.choice-btn.wrong { border-color: var(--wrong); background: var(--wrong-bg); }
.choice-btn:disabled { cursor: default; opacity: .92; }
.choice-btn.dimmed { opacity: .45; }

/* ---------- feedback ---------- */
.feedback-card { border-width: 1.5px; }
.feedback-card.is-correct { border-color: var(--correct); }
.feedback-card.is-wrong { border-color: var(--wrong); }
.feedback-badge { font-size: 1.1rem; font-weight: 800; margin-bottom: 10px; }
.feedback-badge.ok { color: var(--correct); }
.feedback-badge.ng { color: var(--wrong); }
.feedback-section { margin-bottom: 14px; }
.feedback-section h3 { font-size: .85rem; color: var(--text-dim); margin-bottom: 6px; }
#feedback-explanation { font-size: .92rem; white-space: pre-wrap; }

.term-card {
  background: #131b2c;
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 10px 12px;
  margin-bottom: 8px;
  font-size: .88rem;
}
.term-official { font-weight: 700; }
.term-en { color: var(--accent); font-size: .8rem; }
.term-plain { color: var(--text-dim); font-size: .85rem; margin-top: 3px; }

.learn-link {
  display: inline-block;
  color: var(--accent);
  font-size: .88rem;
  text-decoration: none;
}
.learn-link:active { text-decoration: underline; }

.quiz-actions { margin-top: 4px; }

/* ---------- result ---------- */
.result-card { text-align: center; }
.result-score { font-size: 2.4rem; font-weight: 800; color: var(--accent); margin: 8px 0 2px; }
.result-accuracy { color: var(--text-dim); }
.result-domain-row {
  display: flex; justify-content: space-between;
  font-size: .9rem; padding: 6px 0;
  border-bottom: 1px solid var(--card-border);
}
.result-domain-row:last-child { border-bottom: none; }
.wrong-list { list-style: none; }
.wrong-list li {
  font-size: .88rem;
  padding: 7px 0;
  border-bottom: 1px solid var(--card-border);
  color: var(--text-dim);
}
.wrong-list li:last-child { border-bottom: none; }
.wrong-list .wrong-topic { color: var(--text); font-weight: 600; }

@media (min-width: 480px) {
  .app-header h1 { font-size: 1.4rem; }
}