:root {
  --bg: #f5f6fa;
  --surface: #ffffff;
  --border: #e2e5ec;
  --text: #1f2430;
  --text-muted: #6b7280;
  --primary: #2f6fed;
  --primary-dark: #1f52c0;
  --primary-tint: #eaf1ff;
  --green: #1a9c6b;
  --green-tint: #e7f8f0;
  --red: #d8404a;
  --red-tint: #fdecee;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(20, 24, 40, 0.06), 0 1px 2px rgba(20, 24, 40, 0.04);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161d;
    --surface: #1c1f29;
    --border: #2c3040;
    --text: #e9ebf2;
    --text-muted: #9aa0b0;
    --primary: #5b8dfb;
    --primary-dark: #7ba0ff;
    --primary-tint: #1c2740;
    --green: #3ecf8e;
    --green-tint: #103828;
    --red: #f2727c;
    --red-tint: #3a1a1e;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  }
}
:root[data-theme="dark"] {
  --bg: #14161d; --surface: #1c1f29; --border: #2c3040; --text: #e9ebf2; --text-muted: #9aa0b0;
  --primary: #5b8dfb; --primary-dark: #7ba0ff; --primary-tint: #1c2740;
  --green: #3ecf8e; --green-tint: #103828; --red: #f2727c; --red-tint: #3a1a1e;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
}
:root[data-theme="light"] {
  --bg: #f5f6fa; --surface: #ffffff; --border: #e2e5ec; --text: #1f2430; --text-muted: #6b7280;
  --primary: #2f6fed; --primary-dark: #1f52c0; --primary-tint: #eaf1ff;
  --green: #1a9c6b; --green-tint: #e7f8f0; --red: #d8404a; --red-tint: #fdecee;
  --shadow: 0 1px 3px rgba(20, 24, 40, 0.06), 0 1px 2px rgba(20, 24, 40, 0.04);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", "Noto Sans JP", -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

.app { max-width: 900px; margin: 0 auto; min-height: 100vh; }

.topbar {
  position: sticky; top: 0; z-index: 10;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 14px 20px;
}
.brand { font-weight: 700; font-size: 1.1rem; margin-bottom: 10px; }
.tabs { display: flex; gap: 6px; overflow-x: auto; }
.tab-btn {
  border: none; background: transparent; color: var(--text-muted);
  padding: 8px 14px; border-radius: 999px; font-size: 0.88rem; font-weight: 600;
  cursor: pointer; white-space: nowrap; transition: background 0.15s, color 0.15s;
}
.tab-btn:hover { background: var(--primary-tint); }
.tab-btn.active { background: var(--primary); color: #fff; }

.content { padding: 20px; }
.view { display: none; animation: fadeIn 0.2s ease; }
.view.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

.hero h1 { font-size: 1.5rem; margin: 0 0 8px; }
.hero p { color: var(--text-muted); margin: 0 0 20px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 16px;
}
.card h2 { margin-top: 0; font-size: 1.15rem; }
.card h3 { margin-top: 0; font-size: 1rem; }

.stat-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 10px; margin-bottom: 18px; }
.stat-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 14px; text-align: center;
}
.stat-card .num { font-size: 1.6rem; font-weight: 700; color: var(--primary); }
.stat-card .label { font-size: 0.78rem; color: var(--text-muted); margin-top: 2px; }

.home-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 18px; }

.btn {
  border: none; border-radius: 999px; padding: 11px 22px; font-size: 0.92rem; font-weight: 700;
  cursor: pointer; transition: transform 0.08s, background 0.15s, opacity 0.15s;
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-ghost { background: var(--primary-tint); color: var(--primary); }
.btn-ghost:hover { opacity: 0.85; }

.topic-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 8px 16px; padding-left: 0; margin: 0; list-style: none;
}
.topic-grid li {
  background: var(--primary-tint); color: var(--primary-dark);
  border-radius: 8px; padding: 8px 12px; font-size: 0.85rem; font-weight: 600;
}

.hidden { display: none !important; }

.field { margin-bottom: 14px; }
.field label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 6px; font-weight: 600; }
select, input[type="text"] {
  width: 100%; padding: 10px 12px; border-radius: 8px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text); font-size: 0.95rem; font-family: inherit;
}
select:focus, input[type="text"]:focus { outline: 2px solid var(--primary); outline-offset: -1px; }

.quiz-progress { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.quiz-progress-bar { flex: 1; height: 8px; background: var(--border); border-radius: 999px; overflow: hidden; }
.quiz-progress-fill { height: 100%; background: var(--primary); width: 0%; transition: width 0.25s; }
#quiz-progress-text { font-size: 0.8rem; color: var(--text-muted); white-space: nowrap; }

.quiz-question-cat {
  display: inline-block; font-size: 0.75rem; font-weight: 700; color: var(--primary);
  background: var(--primary-tint); padding: 4px 10px; border-radius: 999px; margin-bottom: 12px;
  margin-right: 8px;
}

.streak-badge {
  display: inline-block; font-size: 0.75rem; font-weight: 800; color: #b45309;
  background: #fff3d6; padding: 4px 10px; border-radius: 999px; margin-bottom: 12px;
  animation: streakPop 0.3s ease;
}
@media (prefers-color-scheme: dark) { .streak-badge { color: #ffd27a; background: #4a3510; } }
:root[data-theme="dark"] .streak-badge { color: #ffd27a; background: #4a3510; }
:root[data-theme="light"] .streak-badge { color: #b45309; background: #fff3d6; }
@keyframes streakPop { from { transform: scale(0.7); opacity: 0; } to { transform: scale(1); opacity: 1; } }

.result-streak {
  text-align: center; font-size: 0.95rem; font-weight: 700; color: #b45309; margin-bottom: 16px;
}
:root[data-theme="dark"] .result-streak { color: #ffd27a; }
@media (prefers-color-scheme: dark) { .result-streak { color: #ffd27a; } }
.quiz-prompt { font-size: 1.05rem; font-weight: 600; margin: 0 0 18px; }

.quiz-choices { display: flex; flex-direction: column; gap: 10px; }
.choice-btn {
  text-align: left; border: 1.5px solid var(--border); background: var(--surface); color: var(--text);
  border-radius: 10px; padding: 12px 14px; font-size: 0.92rem; font-family: "SFMono-Regular", Menlo, Consolas, monospace;
  cursor: pointer; transition: border-color 0.15s, background 0.15s;
  white-space: pre-wrap;
}
.choice-btn:hover:not(:disabled) { border-color: var(--primary); background: var(--primary-tint); }
.choice-btn:disabled { cursor: default; }
.choice-btn.correct { border-color: var(--green); background: var(--green-tint); color: var(--green); font-weight: 700; }
.choice-btn.incorrect { border-color: var(--red); background: var(--red-tint); color: var(--red); font-weight: 700; }

.quiz-feedback { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--border); }
.feedback-result { font-weight: 800; font-size: 1.05rem; margin-bottom: 8px; }
.feedback-result.ok { color: var(--green); }
.feedback-result.ng { color: var(--red); }
.feedback-explanation { color: var(--text-muted); font-size: 0.9rem; margin: 0 0 16px; }

.result-score { text-align: center; font-size: 2.2rem; font-weight: 800; color: var(--primary); margin-bottom: 8px; }
.result-score span { font-size: 1.1rem; color: var(--text-muted); font-weight: 600; }
#result-mistakes { margin: 16px 0; }
.mistake-item {
  border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; margin-bottom: 8px; font-size: 0.88rem;
}
.mistake-item .mi-cat { font-size: 0.72rem; color: var(--primary); font-weight: 700; margin-bottom: 4px; }
.mistake-item .mi-ans { font-family: monospace; color: var(--green); margin-top: 6px; }

.filter-row { margin-bottom: 14px; }
.chip-row { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
.chip {
  border: 1px solid var(--border); background: var(--surface); color: var(--text-muted);
  border-radius: 999px; padding: 6px 12px; font-size: 0.8rem; font-weight: 600; cursor: pointer;
}
.chip.active { background: var(--primary); color: #fff; border-color: var(--primary); }

.account-table, .history-table { width: 100%; border-collapse: collapse; margin-top: 12px; font-size: 0.88rem; }
.account-table th, .account-table td, .history-table th, .history-table td {
  text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--border);
}
.account-table th, .history-table th { color: var(--text-muted); font-weight: 700; font-size: 0.78rem; }

.glossary-list { margin: 14px 0 0; }
.glossary-list dt { font-weight: 700; margin-top: 14px; color: var(--primary-dark); }
.glossary-list dd { margin: 4px 0 0; color: var(--text-muted); font-size: 0.9rem; }

.empty-msg { color: var(--text-muted); font-size: 0.88rem; padding: 12px 0; }

@media (max-width: 560px) {
  .content { padding: 14px; }
  .card { padding: 16px; }
}