/* 기본 스타일 (화이트 모드) */
:root {
  --bg-color: #f5f7fa;
  --card-bg: #ffffff;
  --text-color: #333333;
  --text-secondary: #666666;
  --primary-color: #4a90d9;
  --primary-hover: #357abd;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --warning-color: #ffc107;
  --border-color: #e0e0e0;
  --shadow: 0 2px 10px rgba(0,0,0,0.1);
  --toggle-bg: #e0e0e0;
}

/* 다크 모드 */
[data-theme="dark"] {
  --bg-color: #1a1a2e;
  --card-bg: #16213e;
  --text-color: #eaeaea;
  --text-secondary: #b0b0b0;
  --primary-color: #4a90d9;
  --primary-hover: #5a9fe8;
  --border-color: #3a3a5a;
  --shadow: 0 2px 10px rgba(0,0,0,0.3);
  --toggle-bg: #3a3a5a;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', 'Malgun Gothic', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  min-height: 100vh;
  transition: background-color 0.3s ease, color 0.3s ease;
  line-height: 1.6;
}

.hidden {
  display: none !important;
}

/* 테마 토글 */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 1000;
}

.theme-toggle-btn {
  width: 50px;
  height: 26px;
  border-radius: 13px;
  background-color: var(--toggle-bg);
  position: relative;
  border: none;
  cursor: pointer;
}

.theme-toggle-btn::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: #fff;
  top: 3px;
  left: 3px;
  transition: transform 0.3s ease;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

[data-theme="dark"] .theme-toggle-btn::after {
  transform: translateX(24px);
  background-color: #1a1a2e;
}

.theme-icon {
  font-size: 1.2rem;
}

/* 컨테이너 */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 헤더 */
.header {
  text-align: center;
  padding: 30px 20px;
}

.header h1 {
  font-size: 2rem;
  margin-bottom: 8px;
  color: var(--text-color);
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* 섹션 박스 */
.section-box {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 25px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}

.section-title {
  font-size: 1.1rem;
  font-weight: bold;
  margin-bottom: 20px;
  color: var(--text-color);
  padding-bottom: 10px;
  border-bottom: 2px solid var(--border-color);
}

/* 라디오 버튼 스타일 */
.grade-radio-group,
.method-radio-group,
.exam-type-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  padding: 8px 0;
}

.radio-label input[type="radio"] {
  display: none;
}

.radio-custom {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-color);
  border-radius: 50%;
  position: relative;
  flex-shrink: 0;
  transition: border-color 0.2s ease;
}

.radio-label input[type="radio"]:checked + .radio-custom {
  border-color: var(--primary-color);
}

.radio-label input[type="radio"]:checked + .radio-custom::after {
  content: '';
  position: absolute;
  width: 10px;
  height: 10px;
  background: var(--primary-color);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.radio-text {
  font-size: 1rem;
  color: var(--text-color);
}

.radio-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* 하이라이트 텍스트 */
.highlight-blue {
  color: #0066cc;
}

.highlight-orange {
  color: #ff6600;
  font-weight: bold;
}

.highlight-red {
  color: #cc0000;
}

[data-theme="dark"] .highlight-blue {
  color: #66b3ff;
}

[data-theme="dark"] .highlight-orange {
  color: #ffaa66;
}

[data-theme="dark"] .highlight-red {
  color: #ff6666;
}

/* 체크박스 스타일 */
.subject-checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  padding: 8px 0;
}

.checkbox-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary-color);
  cursor: pointer;
}

.checkbox-text {
  font-size: 1rem;
  color: var(--text-color);
}

.checkbox-count {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* 전체 선택 버튼 */
.select-all-wrapper {
  margin-top: 15px;
  padding-top: 15px;
  border-top: 1px solid var(--border-color);
}

.select-all-btn {
  padding: 8px 16px;
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: var(--text-color);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.2s ease;
}

.select-all-btn:hover {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

/* 년도 선택 */
.year-section {
  text-align: center;
}

.year-select-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 15px;
}

.year-select {
  padding: 10px 15px;
  font-size: 1rem;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: var(--card-bg);
  color: var(--text-color);
  cursor: pointer;
  min-width: 150px;
}

.year-select:focus {
  outline: none;
  border-color: var(--primary-color);
}

.year-end-wrapper {
  display: flex;
  align-items: center;
  gap: 10px;
}

.start-btn {
  padding: 12px 30px;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.2s ease;
}

.start-btn:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
}

.mock-notice {
  font-size: 0.9rem;
  margin-top: 10px;
}

/* 시험 화면 */
.exam-screen {
  padding: 20px;
}

.exam-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
}

.exam-info {
  display: flex;
  gap: 20px;
  align-items: center;
}

.current-subject {
  font-weight: bold;
  color: var(--primary-color);
}

.question-counter {
  color: var(--text-secondary);
}

.timer {
  font-size: 1.1rem;
  font-weight: bold;
  color: var(--danger-color);
}

/* 진행 바 */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--border-color);
  border-radius: 4px;
  margin-bottom: 25px;
  overflow: hidden;
}

.progress {
  height: 100%;
  background: var(--primary-color);
  border-radius: 4px;
  transition: width 0.3s ease;
}

/* 문제 카드 */
.question-card {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 30px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.question-number {
  display: inline-block;
  background: var(--primary-color);
  color: white;
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.question-text {
  font-size: 1.15rem;
  line-height: 1.8;
  margin-bottom: 25px;
  white-space: pre-line;
}

/* 선택지 */
.options {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.option-btn {
  display: flex;
  align-items: flex-start;
  gap: 15px;
  padding: 18px 20px;
  background: var(--bg-color);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
  text-align: left;
  font-size: 1rem;
  color: var(--text-color);
}

.option-btn:hover:not(.disabled) {
  border-color: var(--primary-color);
  background: rgba(74, 144, 217, 0.1);
}

.option-btn.selected {
  border-color: var(--primary-color);
  background: rgba(74, 144, 217, 0.15);
}

.option-btn.correct {
  border-color: var(--success-color);
  background: rgba(40, 167, 69, 0.15);
}

.option-btn.wrong {
  border-color: var(--danger-color);
  background: rgba(220, 53, 69, 0.15);
}

.option-btn.disabled {
  cursor: default;
}

.option-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  background: var(--border-color);
  border-radius: 50%;
  font-weight: bold;
  flex-shrink: 0;
}

.option-btn.selected .option-number {
  background: var(--primary-color);
  color: white;
}

.option-btn.correct .option-number {
  background: var(--success-color);
  color: white;
}

.option-btn.wrong .option-number {
  background: var(--danger-color);
  color: white;
}

.option-text {
  flex: 1;
  line-height: 1.5;
}

/* 해설 */
.explanation {
  margin-top: 25px;
  padding: 20px;
  background: rgba(74, 144, 217, 0.1);
  border-radius: 12px;
  border-left: 4px solid var(--primary-color);
}

.explanation-header {
  font-weight: bold;
  margin-bottom: 10px;
  color: var(--primary-color);
}

.explanation-text {
  line-height: 1.7;
  color: var(--text-secondary);
}

/* 네비게이션 */
.exam-nav {
  display: flex;
  justify-content: center;
  gap: 15px;
  margin-bottom: 30px;
}

.nav-btn {
  padding: 12px 30px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: var(--card-bg);
  color: var(--text-color);
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

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

.nav-btn.primary {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
}

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

.nav-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* 문제 맵 */
.question-map {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}

.map-title {
  font-weight: bold;
  margin-bottom: 15px;
  color: var(--text-secondary);
}

.map-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.map-btn {
  width: 36px;
  height: 36px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: var(--card-bg);
  color: var(--text-color);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

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

.map-btn.current {
  border-color: var(--primary-color);
  background: var(--primary-color);
  color: white;
}

.map-btn.answered {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
  opacity: 0.7;
}

.map-btn.correct {
  background: var(--success-color);
  border-color: var(--success-color);
  color: white;
}

.map-btn.wrong {
  background: var(--danger-color);
  border-color: var(--danger-color);
  color: white;
}

/* 종료 버튼 */
.exit-btn {
  display: block;
  width: 100%;
  padding: 15px;
  background: var(--danger-color);
  border: none;
  border-radius: 8px;
  color: white;
  font-size: 1rem;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.exit-btn:hover {
  opacity: 0.9;
}

/* 결과 화면 */
.result-screen {
  padding: 40px 20px;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 80vh;
}

.result-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 40px;
  box-shadow: var(--shadow);
  text-align: center;
  max-width: 450px;
  width: 100%;
}

.result-card h2 {
  margin-bottom: 30px;
  font-size: 1.8rem;
}

.result-score {
  margin-bottom: 30px;
}

.score-circle {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto;
  color: white;
  font-size: 2.5rem;
  font-weight: bold;
  box-shadow: 0 5px 20px rgba(74, 144, 217, 0.3);
}

.result-details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
  margin-bottom: 30px;
}

.result-item {
  padding: 15px;
  background: var(--bg-color);
  border-radius: 10px;
}

.result-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 5px;
}

.result-value {
  font-size: 1.5rem;
  font-weight: bold;
}

.result-value.correct {
  color: var(--success-color);
}

.result-value.wrong {
  color: var(--danger-color);
}

.result-actions {
  display: flex;
  gap: 15px;
  justify-content: center;
}

.result-btn {
  padding: 12px 25px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: var(--card-bg);
  color: var(--text-color);
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

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

.result-btn.primary {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
}

/* 오답 노트 */
.review-screen {
  padding: 20px;
}

.review-screen h2 {
  text-align: center;
  margin-bottom: 30px;
}

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

.review-item {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 25px;
  box-shadow: var(--shadow);
}

.review-question {
  font-size: 1.1rem;
  margin-bottom: 15px;
  line-height: 1.6;
}

.review-answer {
  display: flex;
  gap: 20px;
  margin-bottom: 15px;
  flex-wrap: wrap;
}

.your-answer, .correct-answer {
  padding: 10px 15px;
  border-radius: 8px;
  font-size: 0.95rem;
}

.your-answer {
  background: rgba(220, 53, 69, 0.15);
  color: var(--danger-color);
}

.correct-answer {
  background: rgba(40, 167, 69, 0.15);
  color: var(--success-color);
}

.review-explanation {
  padding: 15px;
  background: var(--bg-color);
  border-radius: 8px;
  border-left: 4px solid var(--primary-color);
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 뒤로가기 버튼 */
.back-btn {
  display: block;
  margin: 30px auto 0;
  background: transparent;
  border: none;
  color: var(--primary-color);
  cursor: pointer;
  font-size: 1rem;
  padding: 10px 20px;
}

.back-btn:hover {
  text-decoration: underline;
}

/* 푸터 */
.footer {
  text-align: center;
  padding: 30px 20px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: auto;
}

/* 반응형 */
@media (max-width: 768px) {
  .header h1 {
    font-size: 1.6rem;
  }

  .section-box {
    padding: 20px;
  }

  .section-title {
    font-size: 1rem;
  }

  .year-select-wrapper {
    flex-direction: column;
    gap: 15px;
  }

  .year-select {
    width: 100%;
  }

  .start-btn {
    width: 100%;
  }

  .question-card {
    padding: 20px;
  }

  .question-text {
    font-size: 1.05rem;
  }

  .exam-nav {
    flex-wrap: wrap;
  }

  .nav-btn {
    flex: 1;
    min-width: 100px;
  }

  .result-card {
    padding: 25px;
  }

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

  .result-btn {
    width: 100%;
  }
}