4. 레이아웃
   ========================================================================== */

/* 헤더 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.85); /* 다크모드 대응 필요 */
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}



.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding: 0 var(--space-4);
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
}

.logo-icon {
  font-size: 28px;
}

.logo-text {
  font-size: var(--font-size-xl);
  font-weight: 900;
  color: var(--color-primary);
  letter-spacing: -0.5px;
}

/* 검색바 */
.search-bar {
  position: relative;
  flex: 1;
  max-width: 400px;
  margin: 0 var(--space-4);
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 12px;
  color: var(--color-text-muted);
}

#searchInput {
  width: 100%;
  height: 40px;
  padding: 0 16px 0 40px;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background-color: var(--color-bg);
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
}

#searchInput:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.2);
  background-color: var(--color-bg-card);
}

.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  margin-top: var(--space-2);
  border: 1px solid var(--color-border);
  display: none;
  z-index: 101;
  max-height: 300px;
  overflow-y: auto;
}

.search-result-item {
  padding: var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  cursor: pointer;
  border-bottom: 1px solid var(--color-border);
}
.search-result-item:last-child {
  border-bottom: none;
}
.search-result-item:hover {
  background-color: var(--color-bg);
}

/* 헤더 액션 */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* 메인 콘텐츠 영역 */
.main-content {
  padding-top: var(--header-height);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 푸터 */
.footer {
  text-align: center;
  padding: var(--space-5) var(--space-4);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin-top: auto;
}


/* ==========================================================================
   5. 내비게이션
   ========================================================================== */

/* 사이드바 (PC) */
.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: var(--sidebar-width);
  height: calc(100vh - var(--header-height));
  background-color: var(--color-bg-card);
  border-right: 1px solid var(--color-border);
  padding: var(--space-4) 0;
  overflow-y: auto;
  z-index: 90;
  display: none; /* 기본 숨김, 미디어 쿼리에서 노출 */
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: 0 var(--space-3);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-weight: 500;
  transition: all var(--transition-fast);
}

.nav-item:hover {
  background-color: var(--color-bg);
  color: var(--color-text);
}

.nav-item.active {
  background-color: rgba(108, 99, 255, 0.1);
  color: var(--color-primary);
  font-weight: 700;
}


.nav-icon {
  font-size: 20px;
}

/* 하단 내비게이션 (모바일) */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: var(--bottom-nav-height);
  background-color: var(--color-bg-card);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-around;
  align-items: center;
  z-index: 100;
  padding-bottom: env(safe-area-inset-bottom);
}

.bottom-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex: 1;
  height: 100%;
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 11px;
}

.bottom-nav-item.active {
  color: var(--color-primary);
}

.bottom-nav-icon {
  font-size: 24px;
  transition: transform var(--transition-fast);
}

.bottom-nav-item:active .bottom-nav-icon {
  transform: scale(0.9);
}

/* 모바일 광고 바닥 */
.ad-mobile-bottom {
  position: fixed;
  bottom: calc(var(--bottom-nav-height) + env(safe-area-inset-bottom));
  left: 0;
  width: 100%;
  height: var(--ad-bottom-height);
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 99;
}


/* ==========================================================================
   6. 카드 & 도구 아이템
   ========================================================================== */
.card {
  background-color: var(--color-bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}

.card-body {
  /* 본문 영역 */
}

.card-footer {
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: flex-end;
}

/* 도구 카드 */
.tool-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.tool-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: var(--space-5) var(--space-4);
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
}

.tool-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-light);
}

.tool-icon {
  font-size: 48px;
  margin-bottom: var(--space-3);
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.tool-card:hover .tool-icon {
  transform: scale(1.1) rotate(5deg);
}

.tool-name {
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.tool-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-3);
  line-height: 1.4;
}

.tool-tags {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  justify-content: center;
  margin-top: auto;
}

/* 통계 카드 */
.stat-card {
  text-align: center;
  padding: var(--space-4);
}
.stat-value {
  font-size: var(--font-size-3xl);
  font-weight: 900;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}
.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}


/* ==========================================================================
   7. 버튼 (Buttons)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  user-select: none;
}

.btn:active {
  transform: scale(0.96);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 10px rgba(108, 99, 255, 0.3);
}
.btn-primary:hover {
  background-color: var(--color-primary-dark);
  box-shadow: 0 6px 15px rgba(108, 99, 255, 0.4);
}

.btn-secondary {
  background-color: transparent;
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-secondary:hover {
  background-color: var(--color-bg);
  border-color: var(--color-text-muted);
}

.btn-success { background-color: var(--color-success); color: #fff; }
.btn-danger { background-color: var(--color-danger); color: #fff; }
.btn-warning { background-color: var(--color-warning); color: #fff; }

.btn-sm {
  padding: 8px 16px;
  font-size: var(--font-size-sm);
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 16px 32px;
  font-size: var(--font-size-lg);
  border-radius: var(--radius-lg);
}

.btn-block {
  width: 100%;
}

.btn-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  background-color: transparent;
  color: var(--color-text);
  border: none;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}
.btn-icon:hover {
  background-color: var(--color-bg);
}

.btn-back {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: 20px;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.btn-back:hover {
  background-color: var(--color-border);
  transform: translateX(-2px);
}

.btn-favorite {
  font-size: 24px;
  color: var(--color-text-muted);
  background: none;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, color 0.2s;
}
.btn-favorite.active {
  color: #FFD700;
}
.btn-favorite:hover {
  transform: scale(1.1);
}

.btn-group {
  display: flex;
}
.btn-group .btn {
  border-radius: 0;
  border-right: 1px solid var(--color-border);
}
.btn-group .btn:first-child {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}
.btn-group .btn:last-child {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  border-right: none;
}
.btn-group .btn.active {
  background-color: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}


/* ==========================================================================
   8. 폼 (Forms)
   ========================================================================== */
.form-group {
  margin-bottom: var(--space-4);
}

.form-label {
  display: block;
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-text);
  font-size: var(--font-size-sm);
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-bg-card);
  color: var(--color-text);
  font-size: var(--font-size-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.2);
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.form-row {
  display: flex;
  gap: var(--space-3);
}
.form-row .form-group {
  flex: 1;
}

.input-group {
  display: flex;
}
.input-group .form-input {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}
.input-group .btn {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

/* 커스텀 체크박스/라디오 (간단 구현) */
.form-checkbox, .form-radio {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  cursor: pointer;
}
.form-checkbox input, .form-radio input {
  width: 20px;
  height: 20px;
  accent-color: var(--color-primary);
  cursor: pointer;
}


/* ==========================================================================
   9. 퀴즈 엔진 스타일
   ========================================================================== */
.quiz-setup {
  max-width: 600px;
  margin: 0 auto;
}

.quiz-area {
  max-width: 800px;
  margin: 0 auto;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-4);
}

.quiz-number {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
  background-color: var(--color-primary-light);
  color: white;
  padding: 4px 12px;
  border-radius: var(--radius-full);
}

.quiz-timer {
  font-size: var(--font-size-xl);
  font-weight: 900;
  font-variant-numeric: tabular-nums;
}
.quiz-timer.warning {
  color: var(--color-danger);
  animation: pulse 1s infinite;
}

.quiz-progress-bar {
  width: 100%;
  height: 8px;
  background-color: var(--color-border);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-5);
  overflow: hidden;
}

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

.quiz-question {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--space-6);
  padding: var(--space-4);
  background-color: var(--color-bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3);
}

.quiz-option {
  position: relative;
  padding: var(--space-4);
  background-color: var(--color-bg-card);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-lg);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
}

.quiz-option:hover {
  border-color: var(--color-primary-light);
  background-color: var(--color-bg);
}

.quiz-option.selected {
  border-color: var(--color-primary);
  background-color: rgba(108, 99, 255, 0.05);
}

.quiz-option.correct {
  border-color: var(--color-success);
  background-color: rgba(39, 174, 96, 0.1);
}
.quiz-option.correct::after {
  content: '⭕';
  position: absolute;
  right: 16px;
  font-size: 24px;
}

.quiz-option.wrong {
  border-color: var(--color-danger);
  background-color: rgba(231, 76, 60, 0.1);
}
.quiz-option.wrong::after {
  content: '❌';
  position: absolute;
  right: 16px;
  font-size: 24px;
}

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

.quiz-input {
  text-align: center;
}
.quiz-input .form-input {
  font-size: var(--font-size-xl);
  text-align: center;
  padding: 20px;
  max-width: 400px;
  margin: 0 auto;
}

.quiz-result {
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

.quiz-score {
  font-size: 80px;
  font-weight: 900;
  color: var(--color-primary);
  margin: var(--space-4) 0;
  text-shadow: 2px 2px 0px var(--color-primary-light);
}

.quiz-stats {
  display: flex;
  justify-content: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.quiz-explanation {
  background-color: var(--color-bg);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  margin-top: var(--space-4);
  text-align: left;
  border-left: 4px solid var(--color-primary);
}


/* ==========================================================================
   10. 홈페이지 섹션
   ========================================================================== */
.section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: var(--space-4);
  margin-top: var(--space-6);
}
.section-header:first-child {
  margin-top: 0;
}

.section-title {
  font-size: var(--font-size-xl);
  font-weight: 900;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.section-more {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  font-weight: 500;
  text-decoration: none;
}
.section-more:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

.hero-section {
  margin-bottom: var(--space-6);
}

.daily-problem {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: white;
  padding: var(--space-6);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.daily-problem h2 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-3);
}
.daily-problem p {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-5);
  opacity: 0.9;
}

/* 가로 스크롤 영역 */
.horizontal-scroll {
  display: flex;
  gap: var(--space-4);
  overflow-x: auto;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-4);
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none; /* Firefox */
}
.horizontal-scroll::-webkit-scrollbar {
  display: none; /* Chrome, Safari */
}
.horizontal-scroll > * {
  flex: 0 0 calc(80% - var(--space-4));
  scroll-snap-align: start;
}



.category-tag {
  display: inline-block;
  padding: 8px 16px;
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-weight: 500;
  white-space: nowrap;
  transition: all var(--transition-fast);
}
.category-tag.active {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}


/* ==========================================================================
   11. 모달 및 설정 (Modals & Settings)
   ========================================================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  backdrop-filter: blur(5px);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background-color: var(--color-bg-card);
  width: 90%;
  max-width: 500px;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  transform: translateY(20px);
  transition: transform var(--transition-normal);
  max-height: 90vh;
  display: flex;
  flex-direction: column;
}

.modal-overlay.active .modal-content {
  transform: translateY(0);
}

.modal-header {
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h2 {
  font-size: var(--font-size-xl);
  font-weight: 700;
}

.modal-body {
  padding: var(--space-5);
  overflow-y: auto;
}

.modal-footer {
  padding: var(--space-4) var(--space-5);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: flex-end;
  gap: var(--space-3);
}

/* 설정 아이템 */
.setting-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-border);
}
.setting-item:last-child {
  border-bottom: none;
}

.setting-label {
  font-size: var(--font-size-base);
  font-weight: 500;
}

/* 토글 스위치 */
.toggle-switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 28px;
}
.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: var(--color-border);
  transition: .4s;
  border-radius: 34px;
}
.toggle-slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: .4s;
  border-radius: 50%;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}
.toggle-switch input:checked + .toggle-slider {
  background-color: var(--color-primary);
}
.toggle-switch input:focus + .toggle-slider {
  box-shadow: 0 0 1px var(--color-primary);
}
.toggle-switch input:checked + .toggle-slider:before {
  transform: translateX(22px);
}


/* ==========================================================================
   12. 토스트 및 알림 (Toast & Alerts)
   ========================================================================== */
.toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1100;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  background-color: var(--color-bg-card);
  color: var(--color-text);
  padding: 16px 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 250px;
  border-left: 4px solid var(--color-primary);
  animation: slideInRight 0.3s ease forwards;
  pointer-events: auto;
}

.toast.success { border-left-color: var(--color-success); }
.toast.error { border-left-color: var(--color-danger); }
.toast.info { border-left-color: var(--color-info); }
.toast.warning { border-left-color: var(--color-warning); }

/* 로딩 오버레이 */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  transition: opacity 0.3s ease;
}
.loading-overlay.fade-out {
  opacity: 0;
  pointer-events: none;
}
.loading-spinner {
  text-align: center;
}
.spinner {
  width: 50px;
  height: 50px;
  border: 5px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--space-3);
}

/* PWA 설치 프롬프트 */
.pwa-install-prompt {
  position: fixed;
  bottom: calc(var(--bottom-nav-height) + var(--space-4));
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-bg-card);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  z-index: 105;
  border: 1px solid var(--color-primary-light);
  width: 90%;
  max-width: 400px;
  animation: slideUp 0.5s ease;
}

.pwa-install-prompt p {
  font-size: var(--font-size-sm);
  font-weight: 500;
  margin: 0;
  flex: 1;
}


/* ==========================================================================
   13. 특수 컴포넌트 (도구 페이지 전용)
   ========================================================================== */

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-5);
}
.page-title {
  font-size: var(--font-size-2xl);
  font-weight: 900;
  margin: 0;
  flex: 1;
  text-align: center;
}

/* 시간표 */
.timetable {
  width: 100%;
  border-collapse: collapse;
  background-color: var(--color-bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.timetable th, .timetable td {
  border: 1px solid var(--color-border);
  padding: var(--space-3);
  text-align: center;
}
.timetable th {
  background-color: var(--color-bg);
  font-weight: 700;
}
.timetable td {
  height: 80px;
  vertical-align: middle;
}
.timetable td.selected {
  background-color: rgba(108, 99, 255, 0.1);
  border: 2px solid var(--color-primary);
}

/* 용돈기입장 */
.allowance-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.allowance-item {
  display: flex;
  justify-content: space-between;
  padding: var(--space-3);
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}
.allowance-income { color: var(--color-success); font-weight: 700; }
.allowance-expense { color: var(--color-danger); font-weight: 700; }
.allowance-total {
  font-size: var(--font-size-xl);
  font-weight: 900;
  text-align: right;
  padding: var(--space-4);
  border-top: 2px solid var(--color-border);
  margin-top: var(--space-4);
}

/* 숙제관리 */
.homework-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.homework-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}
.homework-done {
  opacity: 0.6;
  text-decoration: line-through;
}

/* 독서기록 */
.book-item {
  display: flex;
  gap: var(--space-4);
  padding: var(--space-4);
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}
.book-rating {
  color: #FFD700;
  font-size: 20px;
}

/* 암기카드 */
.flashcard-container {
  width: 100%;
  max-width: 400px;
  height: 250px;
  margin: 0 auto;
  perspective: 1000px;
}
.flashcard {
  width: 100%;
  height: 100%;
  cursor: pointer;
}
.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}
.flashcard.flipped .flashcard-inner {
  transform: rotateY(180deg);
}
.flashcard-front, .flashcard-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  padding: var(--space-5);
  font-size: var(--font-size-2xl);
  font-weight: 700;
}
.flashcard-front {
  background-color: var(--color-bg-card);
  color: var(--color-text);
  border: 2px solid var(--color-primary-light);
}
.flashcard-back {
  background-color: var(--color-primary);
  color: white;
  transform: rotateY(180deg);
}

/* ==========================================================================
   14. 애니메이션 (Animations)
   ========================================================================== */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp { from { transform: translateY(20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
@keyframes slideDown { from { transform: translateY(-20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
@keyframes slideInRight { from { transform: translateX(20px); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
@keyframes bounce { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.1); } }
@keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }
@keyframes pulse { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.05); } }
@keyframes spin { to { transform: rotate(360deg); } }

.fade-in { animation: fadeIn var(--transition-normal); }
.slide-up { animation: slideUp var(--transition-normal); }
.slide-down { animation: slideDown var(--transition-normal); }
.bounce { animation: bounce 0.3s; }
.shake { animation: shake 0.3s; }


/* ==========================================================================
   15. 미디어 쿼리 (반응형)
   ========================================================================== */

/* 태블릿 (768px 이상) */


/* PC (1024px 이상) */


/* 대형 모니터 (1280px 이상) */