/* --- 전역 변수 및 테마 설정 --- */
:root {
  --font-title: 'Gowun Dodum', sans-serif;
  --font-body: 'Noto Sans KR', sans-serif;

  /* 파스텔톤 컬러 팔레트 */
  --bg-main: #fcfaf2;           /* 부드러운 우유빛 크림색 */
  --bg-card: #ffffff;           /* 순백색 카드 */
  --text-main: #2d3748;         /* 진한 흑갈색 (가독성 최우선) */
  --text-muted: #718096;        /* 보조 텍스트 회색 */
  
  --color-boy-bg: #ccfbf1;      /* 남학생 파스텔 민트 */
  --color-boy-border: #99f6e4;
  --color-boy-text: #0f766e;

  --color-girl-bg: #ffedd5;     /* 여학생 파스텔 오렌지 */
  --color-girl-border: #fed7aa;
  --color-girl-text: #c2410c;

  --color-empty-bg: #f7fafc;    /* 빈자리 파스텔 회색 */
  --color-empty-border: #cbd5e1;
  --color-empty-text: #94a3b8;

  --color-x-bg: #fee2e2;        /* 제외된 자리 파스텔 빨강 */
  --color-x-border: #fca5a5;
  --color-x-text: #ef4444;

  /* 기능성 테마 컬러 */
  --primary: #fbcfe8;           /* 러블리 파스텔 핑크 */
  --primary-hover: #f9a8d4;
  --primary-text: #be185d;

  --success: #a7f3d0;           /* 활기찬 파스텔 민트 */
  --success-hover: #6ee7b7;
  --success-text: #065f46;

  --secondary: #e0e7ff;         /* 차분한 파스텔 인디고 */
  --secondary-hover: #c7d2fe;
  --secondary-text: #3730a3;

  --border-light: #edf2f7;      /* 연한 보더 */
  --border-card: #e2e8f0;       /* 카드 보더 */
  
  /* 그림자 효과 */
  --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.07), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-button: 0 4px 0px #cbd5e1;
  --shadow-button-success: 0 4px 0px #059669;
}

/* --- 기본 스타일 및 초기화 --- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px;
}

/* 전체 컨테이너 및 래퍼 */
.main-wrapper {
  width: 100%;
  max-width: 1280px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* --- 헤더 디자인 (아기자기하고 직관적) --- */
.app-header {
  text-align: center;
  padding: 10px 0;
}

.app-header h1 {
  font-family: var(--font-title);
  font-size: 2.2rem;
  color: #1a202c;
  margin-bottom: 8px;
  text-shadow: 1px 1px 0px #fff, 2px 2px 0px #e2e8f0;
}

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

/* --- 메인 그리드 및 패널 레이아웃 --- */
.app-container {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 900px) {
  .app-container {
    grid-template-columns: 1fr;
  }
}

/* 카드 공통 스타일 */
.card {
  background: var(--bg-card);
  border-radius: 24px;
  padding: 24px;
  box-shadow: var(--shadow-md);
  border: 4px solid #ffffff;
}

.card-title {
  font-family: var(--font-title);
  font-size: 1.4rem;
  margin-bottom: 20px;
  color: #1a202c;
  border-bottom: 3px dashed #edf2f7;
  padding-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* --- 좌측 설정 패널 스타일 --- */
.controls-panel {
  display: flex;
  flex-direction: column;
  gap: 24px;
  border: 4px solid #fbcfe8; /* 따뜻한 핑크색 테두리로 귀여움 강조 */
}

.section-title {
  font-family: var(--font-title);
  font-size: 1.1rem;
  color: var(--text-main);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
}

.input-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

/* 행/열 설정 인풋 */
.grid-inputs {
  display: flex;
  gap: 16px;
  margin-bottom: 16px;
}

.input-group {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.input-group label {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-main);
}

.input-group input {
  padding: 10px 14px;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  font-family: var(--font-body);
  font-size: 1.05rem;
  outline: none;
  transition: border-color 0.2s;
  text-align: center;
}

.input-group input:focus {
  border-color: var(--primary-hover);
}

/* 텍스트 영역 */
textarea {
  width: 100%;
  height: 120px;
  padding: 12px;
  border: 2px solid #e2e8f0;
  border-radius: 16px;
  font-family: var(--font-body);
  font-size: 1rem;
  resize: none;
  outline: none;
  transition: border-color 0.2s;
  margin-bottom: 16px;
}

textarea:focus {
  border-color: var(--primary-hover);
}

/* 학생 실시간 성별 리스트 */
.student-list-container {
  border: 2px solid #edf2f7;
  border-radius: 16px;
  padding: 14px;
  background-color: #f7fafc;
}

.student-list-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 10px;
  color: var(--text-main);
}

.counter-badge {
  background-color: #edf2f7;
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.student-list {
  max-height: 250px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-right: 4px;
}

/* 스크롤바 디자인 */
.student-list::-webkit-scrollbar {
  width: 6px;
}
.student-list::-webkit-scrollbar-thumb {
  background-color: #cbd5e1;
  border-radius: 10px;
}

.empty-list-msg {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 20px 10px;
}

/* 학생 로우 */
.student-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 12px;
  background-color: #ffffff;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.student-name {
  font-weight: 500;
  font-size: 0.95rem;
  max-width: 140px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 성별 선택 세그먼트 버튼 */
.gender-toggle {
  display: flex;
  border: 2px solid #cbd5e1;
  border-radius: 20px;
  overflow: hidden;
  background-color: #f1f5f9;
}

.gender-btn {
  border: none;
  padding: 4px 14px;
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  background: none;
  transition: all 0.2s;
  color: var(--text-muted);
}

.gender-btn.boy.active {
  background-color: var(--color-boy-bg);
  color: var(--color-boy-text);
}

.gender-btn.girl.active {
  background-color: var(--color-girl-bg);
  color: var(--color-girl-text);
}

/* 학생 컨트롤 영역 (성별) */
.student-controls {
  display: flex;
  align-items: center;
}

/* 금지 짝꿍 목록 아이템 */
.forbidden-pair-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 12px;
  background-color: #ffffff;
  border: 2px solid #fed7aa; /* 따뜻한 파스텔 오렌지 테두리 */
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.forbidden-pair-names {
  font-weight: 550;
  font-size: 0.9rem;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
  text-align: left;
}

.btn-delete-pair {
  border: none;
  background: none;
  cursor: pointer;
  font-size: 0.95rem;
  padding: 2px 6px;
  border-radius: 6px;
  transition: background-color 0.2s, transform 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-delete-pair:hover {
  background-color: #fee2e2;
  transform: scale(1.1);
}

/* --- 버튼 디자인 (공통) --- */
.btn {
  font-family: var(--font-title);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  font-weight: 700;
  user-select: none;
}

/* 둥근 버튼 */
.btn-action {
  width: 100%;
  padding: 12px;
  border-radius: 30px;
  background-color: var(--secondary);
  color: var(--secondary-text);
  font-size: 1.05rem;
  box-shadow: 0 4px 0px #b4c6ef;
  transform: translateY(0);
}

.btn-action:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 0px #b4c6ef;
}

.btn-action:active {
  transform: translateY(2px);
  box-shadow: 0 2px 0px #b4c6ef;
}

.btn-primary {
  background-color: #6ee7b7; /* 둥글고 친근한 연녹색 */
  color: var(--success-text);
  box-shadow: 0 6px 0px #34d399;
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--success-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 0px #34d399;
}

.btn-primary:active:not(:disabled) {
  transform: translateY(2px);
  box-shadow: 0 2px 0px #34d399;
}

.btn-secondary {
  background-color: var(--secondary);
  color: var(--secondary-text);
  box-shadow: 0 6px 0px #a5b4fc;
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--secondary-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 0px #a5b4fc;
}

.btn-secondary:active:not(:disabled) {
  transform: translateY(2px);
  box-shadow: 0 2px 0px #a5b4fc;
}

.btn-large {
  padding: 14px 32px;
  font-size: 1.15rem;
  border-radius: 9999px; /* 완전한 알약형 버튼 */
  min-width: 180px;
}

.btn:disabled {
  background-color: #e2e8f0;
  color: #94a3b8;
  cursor: not-allowed;
  box-shadow: none !important;
  transform: none !important;
}

/* --- 우측 배치판 영역 --- */
.grid-panel {
  border: 4px solid #a7f3d0; /* 따뜻한 초록색 테두리로 귀여움 강조 */
  display: flex;
  flex-direction: column;
  min-height: 500px;
}

.grid-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

/* 범례 */
.seat-legend {
  display: flex;
  gap: 12px;
  font-size: 0.85rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 500;
}

.legend-color {
  display: inline-block;
  width: 14px;
  height: 14px;
  border-radius: 4px;
  border: 1px solid #cbd5e1;
}

.legend-color.boy { background-color: var(--color-boy-bg); border-color: var(--color-boy-border); }
.legend-color.girl { background-color: var(--color-girl-bg); border-color: var(--color-girl-border); }
.legend-color.empty { background-color: var(--color-empty-bg); border-color: var(--color-empty-border); }
.legend-color.x-seat { background-color: var(--color-x-bg); border-color: var(--color-x-border); }

/* 귀여운 칠판 일러스트 */
.board-indicator {
  width: 100%;
  max-width: 500px;
  margin: 0 auto 30px auto;
  background-color: #1b4332; /* 진한 녹색 칠판 */
  border: 6px solid #b45309; /* 우드 프레임 */
  border-radius: 12px;
  padding: 10px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  position: relative;
}

/* 분필 받침대 디자인 */
.board-indicator::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 10%;
  width: 80%;
  height: 6px;
  background-color: #854d0e;
  border-radius: 2px;
}

.board-text {
  font-family: var(--font-title);
  color: #ffffff;
  font-size: 1.15rem;
  letter-spacing: 4px;
  font-weight: 700;
}

/* 격자 스크롤 감싸기 */
.grid-scroll-container {
  width: 100%;
  overflow-x: auto;
  display: flex;
  justify-content: center;
  padding: 10px 0;
  margin-bottom: 24px;
}

/* 자리 격자판 (동적 세팅) */
.seating-grid {
  display: grid;
  gap: 16px;
  width: 100%;
  max-width: 900px;
  justify-content: center;
}

.grid-placeholder {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-muted);
  font-size: 1.1rem;
  border: 3px dashed #cbd5e1;
  border-radius: 20px;
  width: 100%;
}

/* --- 자리 카드 스타일 --- */
.seat-card {
  aspect-ratio: 4 / 3;
  min-width: 100px;
  max-width: 160px;
  border-radius: 16px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  user-select: none;
  font-weight: 700;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  box-shadow: 0 4px 6px rgba(0,0,0,0.03);
  position: relative;
  text-align: center;
}

.seat-card:hover {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 10px 15px rgba(0,0,0,0.06);
}

.seat-card:active {
  transform: translateY(1px);
}

/* 드래그 앤 드롭 마우스 커서 및 상태 */
.seat-card[draggable="true"] {
  cursor: grab;
}

.seat-card[draggable="true"]:active {
  cursor: grabbing;
}

.seat-card.dragging {
  opacity: 0.4;
  transform: scale(0.95);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05) !important;
}

.seat-card.drag-over {
  border: 3px dashed var(--success-text) !important;
  background-color: var(--success) !important;
  box-shadow: 0 0 12px rgba(110, 231, 183, 0.5) !important;
  transform: translateY(-4px) scale(1.05) !important;
}

/* 빈자리 상태 */
.seat-card.state-empty {
  background-color: var(--color-empty-bg);
  border: 3px dashed var(--color-empty-border);
  color: var(--color-empty-text);
}

.seat-card.state-empty::after {
  content: "빈자리";
  font-size: 0.85rem;
  font-weight: 500;
}

/* 제외된 자리 (X) 상태 */
.seat-card.state-x {
  background-color: var(--color-x-bg);
  border: 3px solid var(--color-x-border);
  color: var(--color-x-text);
  overflow: hidden;
}

.seat-card.state-x::after {
  content: "X";
  font-size: 2rem;
  font-family: var(--font-title);
  color: var(--color-x-text);
}

/* 남학생 배치 상태 */
.seat-card.state-boy {
  background-color: var(--color-boy-bg);
  border: 3px solid var(--color-boy-border);
  color: var(--color-boy-text);
  animation: cardAssign 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.seat-card.state-boy .student-name-text {
  font-size: 1.15rem;
  margin-bottom: 2px;
}

.seat-card.state-boy .gender-tag {
  font-size: 0.75rem;
  background-color: #99f6e4;
  padding: 1px 8px;
  border-radius: 10px;
}

/* 여학생 배치 상태 */
.seat-card.state-girl {
  background-color: var(--color-girl-bg);
  border: 3px solid var(--color-girl-border);
  color: var(--color-girl-text);
  animation: cardAssign 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.seat-card.state-girl .student-name-text {
  font-size: 1.15rem;
  margin-bottom: 2px;
}

.seat-card.state-girl .gender-tag {
  font-size: 0.75rem;
  background-color: #fed7aa;
  padding: 1px 8px;
  border-radius: 10px;
}

/* 카드 정보 내부 구조 */
.card-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* 하단 버튼 컨테이너 */
.actions-container {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: auto;
  padding-top: 20px;
  border-top: 3px dashed #edf2f7;
  flex-wrap: wrap;
}

/* --- 토스트 알림창 디자인 --- */
.toast-container {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 90%;
  max-width: 400px;
}

.toast {
  background-color: #319795; /* 부드러운 청록색 */
  color: #ffffff;
  padding: 12px 24px;
  border-radius: 30px;
  box-shadow: var(--shadow-md);
  font-weight: 700;
  text-align: center;
  font-size: 0.95rem;
  animation: toastSlideUp 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards,
             toastFadeOut 0.3s 2.7s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
  border: 3px solid #e6fffa;
}

.toast.toast-warning {
  background-color: #dd6b20; /* 주의 오렌지 */
  border-color: #fffaf0;
}

/* --- 푸터 스타일 --- */
.app-footer {
  text-align: center;
  padding: 20px 0;
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-top: 2px dashed #edf2f7;
  margin-top: 20px;
}

.copyright {
  font-weight: 500;
  color: #a0aec0;
}

/* --- 키프레임 애니메이션 정의 --- */
@keyframes popIn {
  0% {
    transform: scale(0.8);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes cardAssign {
  0% {
    transform: scale(0.7) rotate(-5deg);
    opacity: 0;
  }
  50% {
    transform: scale(1.1) rotate(3deg);
  }
  100% {
    transform: scale(1) rotate(0deg);
    opacity: 1;
  }
}

@keyframes toastSlideUp {
  0% {
    transform: translateY(20px);
    opacity: 0;
  }
  100% {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes toastFadeOut {
  0% {
    transform: translateY(0);
    opacity: 1;
  }
  100% {
    transform: translateY(-20px);
    opacity: 0;
  }
}