/* ==========================================================================
   우리 반 자리바꾸기 - 스타일시트 (style.css)
   ========================================================================== */

/* 1. 디자인 시스템 토큰 (CSS 변수) */
:root {
  /* 파스텔톤 컬러 팔레트 */
  --bg-color: #F8F9FD;
  --text-main: #374151;
  --text-muted: #6B7280;
  
  --card-bg: #FFFFFF;
  --card-border: #E5E7EB;
  --card-shadow: 0 4px 12px rgba(148, 163, 184, 0.08);
  --card-shadow-hover: 0 8px 20px rgba(148, 163, 184, 0.15);
  
  /* 테마 파스텔 컬러 */
  --color-primary: #A3E2D4; /* 소프트 파스텔 민트 */
  --color-primary-hover: #86D3C3;
  --color-secondary: #FFB7B2; /* 소프트 파스텔 코랄/핑크 */
  --color-secondary-hover: #FFA29C;
  --color-success: #B5EAD7; /* 파스텔 그린 */
  --color-success-hover: #9BE0C8;
  --color-accent: #E8F0FE; /* 파스텔 블루 */
  
  --error-bg: #FFEBEA;
  --error-text: #E53935;
  --error-border: #FFCDD2;
  
  --seat-empty-bg: #F3F4F6;
  --seat-empty-border: #D1D5DB;
  --seat-empty-text: #9CA3AF;
  
  /* 보더 래디우스 및 폰트 */
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  
  --font-family: 'Apple SD Gothic Neo', 'Malgun Gothic', '맑은 고딕', sans-serif;
}

/* 2. 초기 리셋 및 기본 설정 */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  padding: 24px 16px;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.app-container {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* 3. 헤더 디자인 */
.app-header {
  text-align: center;
  margin-bottom: 8px;
}

.app-header h1 {
  font-size: 2.2rem;
  font-weight: 800;
  color: #1E293B;
  margin-bottom: 8px;
}

.app-header .subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* 4. 컨트롤 영역 (설정 카드) */
.control-card {
  background-color: var(--card-bg);
  border: 2px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* 입력 그룹 (텍스트에어리어) */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.group-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #1E293B;
  display: flex;
  align-items: center;
  gap: 6px;
}

textarea {
  font-family: var(--font-family);
  font-size: 1rem;
  padding: 12px 16px;
  border: 2px solid #E2E8F0;
  border-radius: var(--radius-md);
  resize: vertical;
  min-height: 150px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  color: var(--text-main);
  background-color: #FAFAFB;
}

textarea:focus {
  border-color: #90CDF4;
  box-shadow: 0 0 0 3px rgba(144, 205, 244, 0.4);
  background-color: #FFFFFF;
}

/* 뱃지 및 알림 정보 행 */
.info-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 4px;
}

.info-badge {
  background-color: var(--bg-color);
  border: 1px solid #E2E8F0;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.info-badge strong {
  color: #3B82F6;
  font-size: 1rem;
}

.info-badge.font-accent strong {
  color: #10B981;
}

.warning-text {
  color: #D97706;
  font-size: 0.85rem;
  font-weight: 600;
  background-color: #FEF3C7;
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid #FDE68A;
}

/* 행/열 설정 그룹 */
.settings-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  align-items: flex-end;
  background-color: #F8FAFC;
  padding: 16px;
  border-radius: var(--radius-md);
  border: 1px solid #E2E8F0;
}

.setting-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.setting-item label {
  font-size: 0.95rem;
  font-weight: 700;
  color: #475569;
}

input[type="number"] {
  font-family: var(--font-family);
  font-size: 1.05rem;
  padding: 8px 12px;
  border: 2px solid #E2E8F0;
  border-radius: var(--radius-sm);
  outline: none;
  background-color: #FFFFFF;
  transition: border-color 0.2s, box-shadow 0.2s;
  color: var(--text-main);
}

input[type="number"]:focus {
  border-color: #90CDF4;
  box-shadow: 0 0 0 3px rgba(144, 205, 244, 0.4);
}

.seat-info {
  margin-top: 0;
  height: 100%;
  display: flex;
  align-items: center;
}

/* 버튼 스타일 */
.button-group {
  display: flex;
  gap: 12px;
}

.btn {
  font-family: var(--font-family);
  font-size: 1.05rem;
  font-weight: 700;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background-color 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

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

.btn-primary {
  background-color: var(--color-primary);
  color: #1E293B;
  box-shadow: 0 4px 6px rgba(163, 226, 212, 0.4);
  flex: 2;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  box-shadow: 0 6px 12px rgba(163, 226, 212, 0.6);
}

.btn-secondary {
  background-color: var(--color-secondary);
  color: #1E293B;
  box-shadow: 0 4px 6px rgba(255, 183, 178, 0.4);
  flex: 1;
}

.btn-secondary:hover {
  background-color: var(--color-secondary-hover);
  box-shadow: 0 6px 12px rgba(255, 183, 178, 0.6);
}

.btn-success {
  background-color: var(--color-success);
  color: #1E293B;
  box-shadow: 0 4px 6px rgba(181, 234, 215, 0.4);
}

.btn-success:hover:not(:disabled) {
  background-color: var(--color-success-hover);
  box-shadow: 0 6px 12px rgba(181, 234, 215, 0.6);
}

.btn:disabled {
  background-color: #E2E8F0;
  color: #94A3B8;
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

/* 키보드 포커스 스타일 공통 */
button:focus-visible,
textarea:focus-visible,
input:focus-visible {
  outline: 3px solid #64B5F6;
  outline-offset: 2px;
}

/* 5. 에러 메시지 박스 */
.error-box {
  background-color: var(--error-bg);
  border: 1px solid var(--error-border);
  color: var(--error-text);
  padding: 14px 20px;
  border-radius: var(--radius-md);
  font-weight: 700;
  font-size: 0.95rem;
  text-align: center;
  box-shadow: 0 4px 10px rgba(239, 68, 68, 0.05);
}

/* 6. 결과 표시 영역 카드 */
.result-card {
  background-color: var(--card-bg);
  border: 2px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* 칠판 교탁 영역 */
.blackboard-area {
  display: flex;
  justify-content: center;
}

.blackboard {
  background-color: #475569;
  color: #FFFFFF;
  padding: 8px 36px;
  border-radius: 40px;
  font-size: 1.1rem;
  font-weight: 700;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  letter-spacing: 1px;
}

/* 자리 배치 래퍼 (가로 스크롤 대응) */
.seats-wrapper {
  width: 100%;
  overflow-x: auto;
  padding: 4px;
}

/* 자리 격자판 (동적 grid) */
.seats-grid {
  display: grid;
  gap: 14px;
  justify-content: center;
  margin: 0 auto;
  min-width: 500px; /* 찌그러짐 방지를 위한 최소 너비 확보 */
}

/* 자리 카드 디자인 */
.seat-card {
  background-color: var(--card-bg);
  border: 2px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 16px 12px;
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  box-shadow: var(--card-shadow);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
  min-height: 80px;
  animation: floatIn 0.35s ease-out forwards;
}

/* 카드 배치 애니메이션 */
@keyframes floatIn {
  from {
    opacity: 0;
    transform: translateY(10px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.seat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--card-shadow-hover);
  border-color: #90CDF4;
}

.seat-card .seat-number {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 6px;
  background-color: #F1F5F9;
  padding: 2px 6px;
  border-radius: 10px;
}

.seat-card .student-name {
  font-size: 1.35rem; /* 교사가 쉽게 보도록 크게 표시 */
  font-weight: 800;
  color: #1E293B;
  width: 100%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis; /* 긴 이름은 밖으로 넘치지 않게 말줄임표 처리 */
}

/* 빈자리 카드 */
.seat-card.empty-seat {
  background-color: var(--seat-empty-bg);
  border: 2px dashed var(--seat-empty-border);
  box-shadow: none;
}

.seat-card.empty-seat:hover {
  transform: none;
  box-shadow: none;
  border-color: var(--seat-empty-border);
}

.seat-card.empty-seat .seat-number {
  background-color: #E5E7EB;
  color: #9CA3AF;
}

.seat-card.empty-seat .student-name {
  color: var(--seat-empty-text);
  font-weight: 500;
  font-size: 1.1rem;
}

/* 결과 복사 액션 영역 */
.result-action {
  display: flex;
  justify-content: center;
  margin-top: 10px;
}

.result-action .btn {
  width: 100%;
  max-width: 300px;
}

/* 7. 푸터 스타일 */
.app-footer {
  text-align: center;
  padding: 16px 0;
  margin-top: 12px;
}

.app-footer p {
  font-size: 0.8rem;
  color: var(--text-muted);
  opacity: 0.8;
}

/* 8. 미디어 쿼리 (반응형 대응) */
@media (max-width: 600px) {
  body {
    padding: 16px 8px;
  }
  
  .app-header h1 {
    font-size: 1.8rem;
  }
  
  .control-card {
    padding: 16px;
    gap: 16px;
  }
  
  .settings-group {
    grid-template-columns: 1fr 1fr;
    padding: 12px;
  }
  
  .seat-info {
    grid-column: span 2;
    justify-content: center;
  }
  
  .button-group {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
  }
  
  .result-card {
    padding: 16px;
  }
  
  .blackboard {
    padding: 6px 20px;
    font-size: 0.95rem;
  }
}