:root {
  --bg: #10131a;
  --card: #1b2030;
  --card2: #232a3d;
  --accent: #5b8cff;
  --accent2: #37d67a;
  --danger: #ff5d6c;
  --text: #eef1f8;
  --text-dim: #9aa4bd;
  --border: #2e3550;
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  font-family: "Hiragino Sans", "Yu Gothic", "Segoe UI", system-ui, sans-serif;
  background: radial-gradient(circle at 20% -10%, #202946 0%, var(--bg) 55%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  padding: 24px 16px 60px;
}

#app {
  width: 100%;
  max-width: 720px;
}

header.top {
  text-align: center;
  margin-bottom: 20px;
}

header.top h1 {
  font-size: 1.6rem;
  margin: 0 0 4px;
  letter-spacing: 0.02em;
}

header.top p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.screen {
  display: none;
}

.screen.active {
  display: block;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.25);
}

.field {
  margin-bottom: 20px;
}

.field-label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.option-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.option-btn {
  flex: 1 1 auto;
  min-width: 120px;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--card2);
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.92rem;
  text-align: center;
  transition: all 0.15s ease;
}

.option-btn:hover {
  border-color: var(--accent);
}

.option-btn.selected {
  background: linear-gradient(135deg, var(--accent), #3d63d1);
  color: #fff;
  border-color: var(--accent);
  font-weight: 600;
}

.option-btn.disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

.range-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.range-row input[type="number"] {
  width: 80px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card2);
  color: var(--text);
  font-size: 0.95rem;
}

.mistake-info {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-top: 6px;
}

.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 10px;
  border: none;
  background: linear-gradient(135deg, var(--accent), #3d63d1);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s ease, opacity 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn.secondary {
  background: var(--card2);
  border: 1px solid var(--border);
  color: var(--text);
}

.btn.danger {
  background: linear-gradient(135deg, var(--danger), #c23f4c);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

.btn-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.progress-bar {
  height: 6px;
  border-radius: 3px;
  background: var(--card2);
  overflow: hidden;
  margin-bottom: 18px;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width 0.2s ease;
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.prompt-box {
  text-align: center;
  padding: 30px 10px;
}

.prompt-label {
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-bottom: 8px;
}

.prompt-ja {
  font-size: 1.7rem;
  font-weight: 700;
  line-height: 1.4;
}

.answer-input {
  width: 100%;
  padding: 14px 16px;
  font-size: 1.15rem;
  border-radius: 10px;
  border: 2px solid var(--border);
  background: var(--card2);
  color: var(--text);
  text-align: center;
}

.answer-input:focus {
  outline: none;
  border-color: var(--accent);
}

.answer-input.correct {
  border-color: var(--accent2);
}

.answer-input.wrong {
  border-color: var(--danger);
}

.canvas-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

#ocr-canvas {
  background: #fff;
  border-radius: 10px;
  border: 2px solid var(--border);
  touch-action: none;
  cursor: crosshair;
  max-width: 100%;
}

.ocr-recognized {
  font-size: 0.9rem;
  color: var(--text-dim);
  min-height: 20px;
}

.ocr-recognized b {
  color: var(--text);
}

.feedback {
  margin-top: 18px;
  padding: 14px 16px;
  border-radius: 10px;
  font-size: 1.05rem;
  text-align: center;
  display: none;
}

.feedback.show {
  display: block;
}

.feedback.correct {
  background: rgba(55, 214, 122, 0.15);
  border: 1px solid var(--accent2);
  color: var(--accent2);
}

.feedback.wrong {
  background: rgba(255, 93, 108, 0.15);
  border: 1px solid var(--danger);
  color: var(--danger);
}

.feedback .answer-line {
  color: var(--text);
  font-weight: 700;
  margin-top: 4px;
}

.hint {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: center;
  margin-top: 10px;
}

.result-score {
  text-align: center;
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 6px;
}

.result-sub {
  text-align: center;
  color: var(--text-dim);
  margin-bottom: 20px;
}

.mistake-list {
  list-style: none;
  margin: 0;
  padding: 0;
  max-height: 320px;
  overflow-y: auto;
}

.mistake-list li {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
}

.mistake-list li:last-child {
  border-bottom: none;
}

.mistake-list .m-ja {
  color: var(--text-dim);
  flex: 1;
}

.mistake-list .m-en {
  color: var(--accent2);
  font-weight: 600;
}

.mistake-list .m-user {
  color: var(--danger);
  font-size: 0.82rem;
}

.empty-note {
  color: var(--text-dim);
  text-align: center;
  padding: 20px 0;
}

.spinner {
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  margin-right: 6px;
  vertical-align: -2px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.section-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 12px;
}