/* ===== 變數與基礎 ===== */
:root {
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-success: #16a34a;
  --color-error: #dc2626;
  --color-bg: #f8fafc;
  --color-card: #ffffff;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --radius: 12px;
  --font-sans: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
}

/* ===== 頁首 ===== */
.header {
  background: linear-gradient(135deg, var(--color-primary) 0%, #1e40af 100%);
  color: white;
  padding: 2rem 1.5rem;
  text-align: center;
  box-shadow: var(--shadow);
}

.header h1 {
  margin: 0 0 0.25rem 0;
  font-size: 1.75rem;
  font-weight: 700;
}

.subtitle {
  margin: 0;
  opacity: 0.9;
  font-size: 0.95rem;
}

/* ===== 參數配置頁 ===== */
.config-page {
  max-width: 560px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.config-card,
.info-card {
  background: var(--color-card);
  border-radius: var(--radius);
  padding: 1.75rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

.config-card h2,
.info-card h3 {
  margin: 0 0 1.25rem 0;
  font-size: 1.25rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

.checkbox-group,
.radio-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
}

.checkbox-item,
.radio-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 0.95rem;
}

.checkbox-item input,
.radio-item input {
  width: 1.1rem;
  height: 1.1rem;
  accent-color: var(--color-primary);
  cursor: pointer;
}

.actions {
  margin-top: 1.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  width: 100%;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
}

.info-card ul {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--color-text-muted);
}

.info-card li {
  margin-bottom: 0.5rem;
}

kbd {
  background: #e2e8f0;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.85em;
}

/* ===== 模擬試卷頁 ===== */
.exam-page {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

.exam-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid #e2e8f0;
}

.exam-title {
  margin: 0;
  font-size: 1.25rem;
}

.print-info {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 1.5rem;
  margin-bottom: 2rem;
  padding: 1rem;
  background: #f1f5f9;
  border-radius: 8px;
}

.print-info label {
  font-weight: 500;
  font-size: 0.9rem;
}

.print-info input {
  width: 100%;
  padding: 0.4rem 0.6rem;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
  font-size: 0.95rem;
}

.question-list {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.question-item {
  padding: 1.25rem;
  background: var(--color-card);
  border-radius: var(--radius);
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.08);
  position: relative;
  break-inside: avoid;
}

.question-item.correct {
  border-left: 4px solid var(--color-success);
  background: #f0fdf4;
}

.question-item.wrong {
  border-left: 4px solid var(--color-error);
  background: #fef2f2;
}

.question-number {
  position: absolute;
  top: 1rem;
  left: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  font-size: 1rem;
}

.question-text {
  margin: 0 0 1rem 2rem;
  font-size: 1.05rem;
  line-height: 1.7;
}

.question-input-wrap {
  margin-left: 2rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.question-input-wrap input {
  width: 120px;
  padding: 0.5rem 0.75rem;
  border: 2px solid #e2e8f0;
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.2s;
}

.question-input-wrap input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.question-input-wrap input.correct {
  border-color: var(--color-success);
  background: #f0fdf4;
}

.question-input-wrap input.wrong {
  border-color: var(--color-error);
  background: #fef2f2;
}

.answer-feedback {
  font-size: 0.9rem;
  font-weight: 500;
}

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

.answer-feedback.wrong {
  color: var(--color-error);
}

.correct-answer {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.exam-footer {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 2px solid #e2e8f0;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn-secondary {
  background: #e2e8f0;
  color: var(--color-text);
}

.btn-secondary:hover {
  background: #cbd5e1;
}

.btn-save-wrong {
  background: #f59e0b;
  color: white;
}

.btn-save-wrong:hover {
  background: #d97706;
}

/* 計算紙空間 - 每題之間預留視覺空白 */
.question-item {
  margin-bottom: 0.5rem;
}

.question-item::after {
  content: '';
  display: block;
  height: 1.5rem;
}

/* ===== 列印模式 ===== */
@media print {
  .no-print {
    display: none !important;
  }

  body {
    background: white;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }

  .header {
    display: none !important;
  }

  .exam-footer {
    display: none !important;
  }

  .exam-header {
    flex-direction: column;
    align-items: flex-start;
    border-bottom: 2px solid #333;
    padding-bottom: 0.75rem;
    margin-bottom: 1rem;
  }

  .exam-header .no-print {
    display: none !important;
  }

  .print-info {
    display: grid !important;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem 2rem;
    margin-bottom: 1.5rem;
    padding: 0.75rem;
    border: 1px solid #ccc;
    background: #fafafa;
  }

  .question-list {
    gap: 1.5rem;
  }

  .question-item {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
    padding: 1rem;
    background: white;
  }

  .question-item.correct,
  .question-item.wrong {
    border: 1px solid #ddd;
    background: white;
  }

  .question-input-wrap input {
    border: 1px solid #999;
    background: white;
    min-height: 28px;
  }

  /* 列印時隱藏批改結果，只保留題目與作答空格 */
  .answer-feedback,
  .correct-answer {
    display: none !important;
  }

  .exam-page {
    max-width: 100%;
    padding: 0.5rem;
  }
}