/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --primary: #1a2a4a;
  --primary-light: #2a3f6e;
  --accent: #f5a623;
  --accent-light: #ffd080;
  --correct: #27ae60;
  --correct-bg: #e8f8f0;
  --incorrect: #e74c3c;
  --incorrect-bg: #fde8e8;
  --bg: #f5f6fa;
  --card: #ffffff;
  --text: #2c3e50;
  --text-light: #7f8c8d;
  --border: #e0e4ec;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --radius: 14px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100dvh;
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
  -webkit-tap-highlight-color: transparent;
}

/* ===== Screen Management ===== */
.screen {
  display: none;
  min-height: 100dvh;
  padding: 20px 16px;
  max-width: 480px;
  margin: 0 auto;
}

.screen.active {
  display: flex;
  flex-direction: column;
}

/* ===== Header ===== */
.app-header {
  padding: 20px 0 16px;
}

.header-row {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 12px;
}

.header-left {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.app-brand {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  margin-bottom: 2px;
}

.brand-luna {
  color: #27ae60;
}

.brand-riku {
  color: var(--accent);
}

.app-title {
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--primary);
  letter-spacing: 0.06em;
  line-height: 1.1;
}

.header-right {
  display: flex;
  align-items: stretch;
}

.marubatsu-box {
  background: linear-gradient(135deg, #2a3f6e 0%, #3a5a9e 100%);
  border-radius: 12px;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: 0 3px 10px rgba(26,42,74,0.25);
}

.marubatsu-text {
  font-size: 1.5rem;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
}

.marubatsu-text .maru {
  color: #5dade2;
  font-size: 1.2rem;
  -webkit-text-stroke: 2px #5dade2;
}

.marubatsu-text .batsu {
  color: #e74c3c;
}

.challenge-text {
  color: #fff;
  font-size: 0.65rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  margin-top: 1px;
}

/* ===== Stats Bar (Top) ===== */
.stats-bar {
  display: flex;
  gap: 8px;
  margin: 12px 0;
}

.stat-card {
  flex: 1;
  background: var(--card);
  border-radius: 10px;
  padding: 12px 8px;
  text-align: center;
  box-shadow: var(--shadow);
}

.stat-number {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--primary);
}

.stat-label {
  font-size: 0.7rem;
  color: var(--text-light);
  margin-top: 2px;
}

/* ===== Mode Selection ===== */
.section-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 20px 0 10px;
}

.mode-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.mode-btn {
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 12px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  -webkit-user-select: none;
  user-select: none;
}

.mode-btn:active {
  transform: scale(0.97);
  border-color: var(--accent);
}

.mode-btn .mode-icon {
  font-size: 1.6rem;
  margin-bottom: 6px;
}

.mode-btn .mode-name {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--primary);
}

.mode-btn .mode-count {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-top: 2px;
}

.mode-btn.highlight {
  border-color: var(--accent);
  background: linear-gradient(135deg, #fff8ed, #fff);
}

/* ===== Year/Subject Select ===== */
.select-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.select-subject-header {
  font-weight: 900;
  font-size: 0.85rem;
  color: var(--primary);
  padding: 8px 4px 4px;
  margin-top: 12px;
  border-bottom: 2px solid var(--accent);
}

.select-subject-header:first-child {
  margin-top: 0;
}

.select-item {
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: all 0.2s;
}

.select-item:active {
  transform: scale(0.98);
  border-color: var(--accent);
}

.select-item .item-name {
  font-weight: 700;
  font-size: 1rem;
}

.select-item .item-count {
  font-size: 0.8rem;
  color: var(--text-light);
  background: var(--bg);
  padding: 4px 10px;
  border-radius: 20px;
}

/* ===== Back Button ===== */
.back-btn {
  background: none;
  border: none;
  color: var(--primary);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

.back-btn::before {
  content: '\2190';
  font-size: 1.2rem;
}

/* ===== Quiz Screen ===== */
.quiz-top-bar {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 4px;
}

.quit-btn {
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 700;
  padding: 10px 20px;
  cursor: pointer;
  transition: all 0.2s;
  -webkit-tap-highlight-color: rgba(0,0,0,0.1);
  touch-action: manipulation;
}

.quit-btn:active {
  background: var(--incorrect-bg);
  color: var(--incorrect);
  border-color: var(--incorrect);
  transform: scale(0.96);
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.quiz-counter {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--primary);
}

.quiz-label {
  font-size: 0.75rem;
  color: var(--text-light);
  background: var(--bg);
  padding: 4px 10px;
  border-radius: 20px;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  margin-bottom: 16px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-light));
  border-radius: 3px;
  transition: width 0.3s ease;
}

.question-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.question-meta {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}

.question-tag {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 6px;
  background: #eef1f8;
  color: var(--primary-light);
}

.question-text {
  font-size: 1rem;
  line-height: 1.75;
  flex: 1;
  white-space: pre-wrap;
  overflow-y: auto;
}

/* ===== Answer Buttons ===== */
.answer-area {
  margin-top: 16px;
  padding: 0 0 20px;
}

.answer-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.answer-btn {
  border: none;
  border-radius: 16px;
  padding: 20px;
  font-size: 2.2rem;
  font-weight: 900;
  cursor: pointer;
  transition: all 0.15s;
  position: relative;
  overflow: hidden;
}

.answer-btn:active {
  transform: scale(0.95);
}

.answer-btn.btn-maru {
  background: linear-gradient(135deg, #3498db, #2980b9);
  color: #fff;
}

.answer-btn.btn-batsu {
  background: linear-gradient(135deg, #e74c3c, #c0392b);
  color: #fff;
}

.answer-btn:disabled {
  opacity: 0.5;
  cursor: default;
  transform: none;
}

/* ===== Feedback ===== */
.feedback {
  display: none;
  border-radius: var(--radius);
  padding: 16px;
  margin-top: 12px;
  animation: fadeSlideIn 0.3s ease;
}

.feedback.show {
  display: block;
}

.feedback.correct {
  background: var(--correct-bg);
  border: 2px solid var(--correct);
}

.feedback.incorrect {
  background: var(--incorrect-bg);
  border: 2px solid var(--incorrect);
}

.feedback-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.feedback-icon {
  font-size: 1.4rem;
}

.feedback-title {
  font-size: 1rem;
  font-weight: 800;
}

.feedback.correct .feedback-title {
  color: var(--correct);
}

.feedback.incorrect .feedback-title {
  color: var(--incorrect);
}

.feedback-explanation {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text);
}

.next-btn {
  width: 100%;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 12px;
  padding: 16px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  margin-top: 12px;
  transition: all 0.2s;
}

.next-btn:active {
  transform: scale(0.98);
  background: var(--primary-light);
}

/* ===== Result Screen ===== */
.result-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  text-align: center;
  margin-bottom: 16px;
}

.result-circle {
  width: 160px;
  height: 160px;
  margin: 0 auto 16px;
  position: relative;
}

.result-circle svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.result-circle .circle-bg {
  fill: none;
  stroke: var(--border);
  stroke-width: 10;
}

.result-circle .circle-fill {
  fill: none;
  stroke-width: 10;
  stroke-linecap: round;
  transition: stroke-dashoffset 1s ease;
}

.result-percentage {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--primary);
}

.result-percentage span {
  font-size: 1rem;
  color: var(--text-light);
}

.result-score {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 4px;
}

.result-message {
  font-size: 0.9rem;
  color: var(--text-light);
}

/* Subject breakdown */
.result-breakdown {
  background: var(--card);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  margin-bottom: 16px;
}

.breakdown-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 12px;
}

.breakdown-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.breakdown-label {
  font-size: 0.8rem;
  font-weight: 600;
  width: 90px;
  flex-shrink: 0;
}

.breakdown-bar-bg {
  flex: 1;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.breakdown-bar-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.8s ease;
}

.breakdown-value {
  font-size: 0.8rem;
  font-weight: 700;
  width: 45px;
  text-align: right;
  flex-shrink: 0;
}

/* Wrong questions list */
.wrong-list {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin-bottom: 16px;
  overflow: hidden;
}

.wrong-list-header {
  padding: 14px 16px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-light);
  border-bottom: 1px solid var(--border);
}

.wrong-item {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background 0.2s;
}

.wrong-item:last-child {
  border-bottom: none;
}

.wrong-item:active {
  background: var(--bg);
}

.wrong-item-id {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-bottom: 4px;
}

.wrong-item-text {
  font-size: 0.85rem;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.wrong-item-detail {
  display: none;
  margin-top: 8px;
  padding: 10px;
  background: var(--incorrect-bg);
  border-radius: 8px;
  font-size: 0.8rem;
  line-height: 1.5;
}

.wrong-item.expanded .wrong-item-detail {
  display: block;
}

/* Result action buttons */
.result-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 20px;
}

.result-btn {
  border: none;
  border-radius: 12px;
  padding: 14px;
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
}

.result-btn:active {
  transform: scale(0.97);
}

.result-btn.primary {
  background: var(--primary);
  color: #fff;
}

.result-btn.secondary {
  background: var(--border);
  color: var(--text);
}

/* ===== Weak mode banner ===== */
.weak-banner {
  background: linear-gradient(135deg, #fff3e0, #ffe0b2);
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 10px 0;
  display: none;
  cursor: pointer;
  transition: all 0.2s;
}

.weak-banner:active {
  transform: scale(0.98);
}

.weak-banner.show {
  display: flex;
  align-items: center;
  gap: 10px;
}

.weak-icon {
  font-size: 1.4rem;
}

.weak-info .weak-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--primary);
}

.weak-info .weak-count {
  font-size: 0.75rem;
  color: var(--text-light);
}

/* ===== Diagnosis Banner (Top Screen) ===== */
.diagnosis-banner {
  background: linear-gradient(135deg, #e8f5e9, #c8e6c9);
  border: 2px solid #81c784;
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 10px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  transition: all 0.2s;
}

.diagnosis-banner:active {
  transform: scale(0.98);
}

.diagnosis-icon {
  font-size: 1.4rem;
}

.diagnosis-info .diagnosis-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--primary);
}

.diagnosis-info .diagnosis-desc {
  font-size: 0.75rem;
  color: var(--text-light);
}

.diagnosis-arrow {
  margin-left: auto;
  font-size: 1.4rem;
  color: #81c784;
  font-weight: 700;
}

/* ===== Diagnosis Screen ===== */
.diagnosis-header {
  text-align: center;
  padding: 12px 0 16px;
}

.diagnosis-header-icon {
  font-size: 2rem;
  margin-bottom: 4px;
}

.diagnosis-header-title {
  font-size: 1.3rem;
  font-weight: 900;
  color: var(--primary);
}

/* Luna Message */
.luna-message {
  display: flex;
  gap: 10px;
  margin-bottom: 16px;
  align-items: flex-start;
}

.luna-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: #e8f5e9;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
  border: 2px solid #81c784;
}

.luna-bubble {
  background: var(--card);
  border: 1px solid #c8e6c9;
  border-radius: 0 12px 12px 12px;
  padding: 12px 14px;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--text);
  box-shadow: var(--shadow);
  flex: 1;
}

/* Subject Tabs */
.subject-tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 16px;
  overflow-x: auto;
}

.subject-tab {
  padding: 8px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  border: 2px solid var(--border);
  background: var(--card);
  color: var(--text);
  transition: all 0.2s;
}

.subject-tab.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.subject-tab:active {
  transform: scale(0.95);
}

/* Radar Chart */
.radar-container {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
  margin-bottom: 16px;
  display: flex;
  justify-content: center;
}

#radar-canvas {
  max-width: 100%;
  height: auto;
}

/* Topic List */
.topic-list-header {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 10px;
}

.topic-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
}

.topic-row {
  background: var(--card);
  border-radius: 10px;
  padding: 10px 14px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.04);
  display: flex;
  align-items: center;
  gap: 10px;
}

.topic-rank {
  font-size: 0.75rem;
  font-weight: 900;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
}

.topic-rank.danger { background: var(--incorrect); }
.topic-rank.warn { background: var(--accent); }
.topic-rank.good { background: var(--correct); }

.topic-info {
  flex: 1;
  min-width: 0;
}

.topic-name {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topic-detail {
  font-size: 0.7rem;
  color: var(--text-light);
}

.topic-bar-bg {
  width: 60px;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
  flex-shrink: 0;
}

.topic-bar-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.6s ease;
}

.topic-pct {
  font-size: 0.8rem;
  font-weight: 700;
  width: 38px;
  text-align: right;
  flex-shrink: 0;
}

/* Diagnosis Summary */
.diagnosis-summary {
  background: var(--card);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.summary-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 10px;
}

.summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.summary-item {
  text-align: center;
  padding: 10px;
  background: var(--bg);
  border-radius: 8px;
}

.summary-value {
  font-size: 1.3rem;
  font-weight: 900;
  color: var(--primary);
}

.summary-label {
  font-size: 0.7rem;
  color: var(--text-light);
  margin-top: 2px;
}

/* ===== Rank Selection ===== */
.rank-intro {
  background: linear-gradient(135deg, #eef1f8 0%, #f8f9fd 100%);
  border: 2px solid var(--primary-light);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 12px;
  text-align: center;
}

.rank-intro-icon {
  font-size: 1.6rem;
  margin-bottom: 6px;
}

.rank-intro-text {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text);
  margin-bottom: 10px;
}

.rank-progress {
  margin-top: 6px;
}

.rank-progress-label {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}

.rank-progress-bar {
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}

.rank-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--correct));
  border-radius: 3px;
  transition: width 0.6s ease;
}

.rank-item {
  flex-wrap: wrap;
}

.rank-item-left {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
}

.rank-stars {
  font-size: 0.9rem;
  flex-shrink: 0;
}

.rank-desc {
  font-size: 0.7rem;
  color: var(--text-light);
  margin-top: 1px;
}

.rank-item.disabled {
  opacity: 0.45;
  pointer-events: none;
}

.rank-hint {
  font-size: 0.78rem;
  color: var(--text-light);
  line-height: 1.6;
  padding: 12px;
  text-align: center;
  background: #fffbe6;
  border-radius: 10px;
  border: 1px solid #f5e6a3;
  margin-top: 8px;
}

/* ===== Animations ===== */
@keyframes fadeSlideIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pop {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

.pop {
  animation: pop 0.3s ease;
}

/* ===== Scrollbar ===== */
.question-text::-webkit-scrollbar {
  width: 4px;
}

.question-text::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

/* ===== Desktop ===== */
@media (min-width: 481px) {
  .screen {
    padding: 24px;
  }

  .answer-btn {
    padding: 24px;
    font-size: 2.6rem;
  }
}