/* ===== Base / Reset ===== */
*, *::before, *::after { box-sizing: border-box; }

:root {
  --color-bg: #f4f6fb;
  --color-surface: #ffffff;
  --color-text: #1c2330;
  --color-text-soft: #56607a;
  --color-text-muted: #8a93a8;
  --color-primary: #1a3a6e;
  --color-primary-soft: #e8eef9;
  --color-accent: #c8a85c;
  --color-correct: #2e8b57;
  --color-correct-soft: #e3f4eb;
  --color-incorrect: #c84b4b;
  --color-incorrect-soft: #fbe8e8;
  --color-border: #dfe3ed;
  --radius: 12px;
  --radius-lg: 16px;
  --shadow-card: 0 2px 8px rgba(28, 35, 48, 0.06);
  --tap-min: 48px;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN",
               "Hiragino Sans", "Yu Gothic", "Meiryo", "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

a { color: var(--color-primary); }

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}

/* ===== Header ===== */
.app-header {
  background: var(--color-primary);
  color: #fff;
  padding: 14px 16px calc(14px + env(safe-area-inset-top, 0)) 16px;
  padding-top: calc(14px + env(safe-area-inset-top, 0));
  text-align: center;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: 0 1px 0 rgba(0,0,0,0.06);
}

.app-title {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.app-subtitle {
  margin: 2px 0 0;
  font-size: 12px;
  opacity: 0.75;
}

/* Quiz header layout */
.quiz-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 8px;
  text-align: left;
}
.quiz-title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.back-link {
  color: #fff;
  text-decoration: none;
  font-size: 14px;
  padding: 8px 4px;
  min-height: var(--tap-min);
  display: inline-flex;
  align-items: center;
}
.progress {
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  opacity: 0.9;
  min-width: 3.5em;
  text-align: right;
}

/* ===== Container ===== */
.container {
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: 16px 16px calc(32px + env(safe-area-inset-bottom, 0));
  flex: 1;
}

.lead {
  margin: 8px 0 16px;
  color: var(--color-text-soft);
  font-size: 14px;
}

.notice {
  margin: 8px 0 12px;
  padding: 12px 14px;
  background: var(--color-primary-soft);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius);
  color: var(--color-text);
  font-size: 13px;
  line-height: 1.7;
}

/* ===== Links (学習サイト紹介) ===== */
.links {
  margin: 16px 0 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.links-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-soft);
  letter-spacing: 0.04em;
}

/* ===== Accordion ===== */
.accordion {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}
.accordion-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
  min-height: var(--tap-min);
  cursor: pointer;
  list-style: none;
  user-select: none;
}
.accordion-summary::-webkit-details-marker { display: none; }
.accordion-summary:active { background: var(--color-primary-soft); }
.accordion-icon {
  flex: 0 0 auto;
  color: var(--color-text-muted);
  font-size: 14px;
  line-height: 1;
  transition: transform 0.18s ease;
}
.accordion[open] .accordion-icon { transform: rotate(180deg); }
.accordion-body {
  border-top: 1px solid var(--color-border);
  padding: 12px 16px 14px;
}
.accordion-body .lead { margin: 0; }
.accordion-body .links-list {
  background: transparent;
  border-radius: 0;
  box-shadow: none;
}
.accordion-body .links-link { padding: 10px 0; }
.accordion-body .links-item:first-child .links-link { padding-top: 0; }
.accordion-body .links-item:last-child .links-link { padding-bottom: 0; }
.links-list {
  list-style: none;
  margin: 0;
  padding: 0;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}
.links-item + .links-item {
  border-top: 1px solid var(--color-border);
}
.links-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
  min-height: var(--tap-min);
  text-decoration: none;
  color: var(--color-text);
  transition: background 0.12s ease;
}
.links-link:active { background: var(--color-primary-soft); }
.links-body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1 1 auto;
  min-width: 0;
}
.links-name {
  font-weight: 500;
  font-size: 14px;
}
.links-desc {
  font-size: 12px;
  color: var(--color-text-soft);
  line-height: 1.5;
}
.links-arrow {
  flex: 0 0 auto;
  color: var(--color-text-muted);
  font-size: 16px;
  line-height: 1;
}

/* ===== HOME ===== */
.section-title {
  margin: 24px 0 4px;
  font-size: 17px;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.04em;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--color-primary-soft);
}

.category-list { display: flex; flex-direction: column; gap: 20px; }

.category-title {
  margin: 4px 0 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-soft);
  letter-spacing: 0.04em;
}

.item-list {
  list-style: none;
  margin: 0;
  padding: 0;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.item + .item { border-top: 1px solid var(--color-border); }

.item-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  min-height: var(--tap-min);
  text-decoration: none;
  color: var(--color-text);
  transition: background 0.12s ease;
}
.item-link:active { background: var(--color-primary-soft); }
.item-link.is-disabled {
  color: var(--color-text-muted);
  cursor: not-allowed;
}

.item-title { font-weight: 500; }

.item-arrow {
  color: var(--color-text-muted);
  font-size: 22px;
  line-height: 1;
}
.item-badge {
  font-size: 11px;
  background: var(--color-bg);
  color: var(--color-text-muted);
  border-radius: 999px;
  padding: 2px 10px;
  border: 1px solid var(--color-border);
}

/* ===== Card ===== */
.card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 18px 16px;
  margin: 0 0 16px;
}

/* ===== Question ===== */
.question-number {
  margin: 0 0 8px;
  font-size: 12px;
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
}
.question-text {
  margin: 0 0 16px;
  font-size: 16px;
  font-weight: 500;
  line-height: 1.7;
}

.choices {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.choice {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  width: 100%;
  text-align: left;
  padding: 12px 14px;
  min-height: var(--tap-min);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius);
  background: #fff;
  color: var(--color-text);
  font-size: 15px;
  line-height: 1.6;
  transition: background 0.12s ease, border-color 0.12s ease, transform 0.05s ease;
}
.choice:active { transform: scale(0.99); }
.choice:not(:disabled):hover { background: var(--color-primary-soft); }

.choice-mark {
  flex: 0 0 auto;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-primary-soft);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}
.choice-text { flex: 1 1 auto; }

.choice:disabled { cursor: default; opacity: 1; }
.choice.is-correct {
  background: var(--color-correct-soft);
  border-color: var(--color-correct);
  color: #1a5836;
}
.choice.is-correct .choice-mark {
  background: var(--color-correct);
  color: #fff;
}
.choice.is-incorrect.is-selected {
  background: var(--color-incorrect-soft);
  border-color: var(--color-incorrect);
  color: #7a2222;
}
.choice.is-incorrect.is-selected .choice-mark {
  background: var(--color-incorrect);
  color: #fff;
}

/* ===== Feedback ===== */
.feedback {
  margin-top: 16px;
  padding: 14px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background: #fafbfd;
}
.feedback.hidden { display: none; }
.feedback.is-correct {
  background: var(--color-correct-soft);
  border-color: #b7dec5;
}
.feedback.is-incorrect {
  background: var(--color-incorrect-soft);
  border-color: #ecc1c1;
}
.feedback-heading {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
}
.feedback.is-correct .feedback-heading { color: var(--color-correct); }
.feedback.is-incorrect .feedback-heading { color: var(--color-incorrect); }

.feedback-answer {
  margin: 0 0 8px;
  font-size: 14px;
  font-weight: 500;
}
.feedback-answer .label { color: var(--color-text-soft); margin-right: 4px; }

.feedback-supplement {
  margin: 0 0 14px;
  font-size: 14px;
  color: var(--color-text-soft);
  line-height: 1.7;
}

/* ===== Buttons ===== */
.primary-btn, .secondary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: var(--tap-min);
  padding: 12px 16px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  border: 1.5px solid transparent;
  transition: opacity 0.12s ease, background 0.12s ease;
}
.primary-btn {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.primary-btn:active { opacity: 0.85; }

.secondary-btn {
  background: #fff;
  color: var(--color-primary);
  border-color: var(--color-border);
  margin-top: 10px;
}
.secondary-btn:active { background: var(--color-primary-soft); }

/* ===== Result ===== */
.result-card { text-align: center; padding: 28px 16px; }
.result-heading {
  margin: 0 0 12px;
  font-size: 20px;
  color: var(--color-primary);
}
.result-score {
  margin: 0;
  font-size: 16px;
  color: var(--color-text-soft);
}
.result-percent {
  display: block;
  font-size: 56px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.1;
  margin-bottom: 4px;
}
.result-detail {
  margin: 8px 0 16px;
  font-size: 14px;
  color: var(--color-text-soft);
}
.result-bar {
  height: 10px;
  background: var(--color-border);
  border-radius: 999px;
  overflow: hidden;
  margin: 12px 0 24px;
}
.result-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transition: width 0.6s ease;
}

.actions { display: flex; flex-direction: column; }

/* ===== Misc ===== */
.loading, .error {
  text-align: center;
  color: var(--color-text-soft);
  padding: 24px 8px;
}
.error { color: var(--color-incorrect); }
.error-card { text-align: center; }

.app-footer {
  text-align: center;
  color: var(--color-text-muted);
  padding: 12px 16px calc(12px + env(safe-area-inset-bottom, 0));
  font-size: 12px;
}
.footer-legal {
  margin: 0 0 6px;
  font-size: 12px;
}
.footer-legal a {
  color: var(--color-text-soft);
  text-decoration: underline;
}

/* ===== Settings Bar ===== */
.settings-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 10px 0 8px;
  padding: 10px 14px;
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}
.setting-item {
  display: flex;
  align-items: center;
  gap: 8px;
}
.setting-label {
  font-size: 13px;
  color: var(--color-text-soft);
  white-space: nowrap;
}
.toggle-label {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  user-select: none;
}
.toggle-input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}
.toggle-track {
  position: relative;
  width: 40px;
  height: 22px;
  background: var(--color-border);
  border-radius: 999px;
  transition: background 0.2s ease;
  flex-shrink: 0;
}
.toggle-input:checked + .toggle-track { background: var(--color-primary); }
.toggle-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 18px;
  height: 18px;
  background: #fff;
  border-radius: 50%;
  box-shadow: 0 1px 3px rgba(0,0,0,0.25);
  transition: transform 0.2s ease;
}
.toggle-input:checked + .toggle-track .toggle-thumb { transform: translateX(18px); }
.toggle-status {
  font-size: 12px;
  color: var(--color-text-muted);
  min-width: 2em;
}

/* ===== Quiz: font-large ===== */
.font-large .question-text { font-size: 24px; }
.font-large .choice { font-size: 22px; }
.font-large .feedback-heading { font-size: 19px; }
.font-large .feedback-answer,
.font-large .feedback-supplement { font-size: 17px; }

/* ===== Quiz: ruby-off ===== */
.ruby-off rt,
.ruby-off rp { display: none; }

/* ===== Tablet/Desktop tweaks ===== */
@media (min-width: 600px) {
  .question-text { font-size: 17px; }
  .choice { font-size: 16px; }
  .primary-btn, .secondary-btn { width: auto; min-width: 240px; align-self: center; }
  .actions { align-items: center; }
}