/* Cloudflare Pages 배포용 Sleek Interface 스타일 */
:root {
  --primary-color: #FF5732;
  --primary-hover: #e04a29;
  --primary-light: rgba(255, 87, 50, 0.1);
  --bg-color: #f8f9fa;
  --card-bg: #ffffff;
  --text-main: #1f2937;
  --text-muted: #9ca3af;
  --text-completed: #9ca3af;
  --border-color: #f3f4f6;
  --input-bg: #f9fafb;
  --danger-color: #ef4444;
  --danger-hover: #dc2626;
  --danger-light: #fef2f2;
  --shadow-card: 0 25px 50px -12px rgba(0, 0, 0, 0.08);
  --radius-xl: 32px;
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Pretendard", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

/* 전체 컨테이너 */
.app-container {
  width: 100%;
  max-width: 440px;
  margin: 0 auto;
}

/* 메인 흰색 둥근 카드 (Sleek Interface) */
.todo-card {
  background-color: var(--card-bg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-color);
  padding: 32px 28px;
  width: 100%;
}

/* 헤더 영역 */
.card-header {
  margin-bottom: 24px;
}

.date-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--primary-color);
  background-color: var(--primary-light);
  padding: 4px 12px;
  border-radius: 9999px;
  margin-bottom: 12px;
}

.app-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.5px;
  margin-bottom: 4px;
}

.app-subtitle {
  font-size: 14px;
  color: var(--text-muted);
}

/* 입력 폼 */
.todo-input-form {
  margin-bottom: 24px;
}

.input-wrapper {
  display: flex;
  gap: 8px;
}

.todo-input {
  flex: 1;
  height: 52px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: var(--radius-lg);
  font-size: 15px;
  color: var(--text-main);
  background-color: var(--input-bg);
  transition: all 0.2s ease;
  outline: none;
}

.todo-input:focus {
  background-color: #ffffff;
  border-color: rgba(255, 87, 50, 0.3);
  box-shadow: 0 0 0 3px rgba(255, 87, 50, 0.15);
}

.todo-input::placeholder {
  color: #9ca3af;
}

/* 버튼 스타일 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
  user-select: none;
}

.btn-add {
  height: 52px;
  padding: 0 24px;
  font-size: 15px;
  background-color: var(--primary-color);
  color: #ffffff;
  box-shadow: 0 10px 15px -3px rgba(255, 87, 50, 0.25);
}

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

.btn-add:active {
  transform: scale(0.97);
}

/* 에러 메시지 */
.error-message {
  color: var(--primary-color);
  font-size: 13px;
  font-weight: 600;
  margin-top: 8px;
  padding-left: 4px;
  animation: shake 0.3s ease-in-out;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

/* 필터 탭 */
.filter-tabs {
  display: flex;
  gap: 6px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 14px;
  margin-bottom: 16px;
}

.tab-btn {
  background: none;
  border: none;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  padding: 6px 12px;
  border-radius: 9999px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.tab-btn:hover {
  color: var(--text-main);
  background-color: #f1f5f9;
}

.tab-btn.active {
  color: var(--primary-color);
  background-color: var(--primary-light);
}

/* 목록 영역 */
.todo-list-section {
  min-height: 180px;
}

.todo-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 360px;
  overflow-y: auto;
  padding-right: 2px;
}

/* 커스텀 스크롤바 */
.todo-list::-webkit-scrollbar {
  width: 4px;
}
.todo-list::-webkit-scrollbar-track {
  background: transparent;
}
.todo-list::-webkit-scrollbar-thumb {
  background: #e5e7eb;
  border-radius: 10px;
}
.todo-list::-webkit-scrollbar-thumb:hover {
  background: #d1d5db;
}

/* 개별 할 일 아이템 */
.todo-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  background-color: var(--input-bg);
  border: 1px solid transparent;
  border-radius: var(--radius-lg);
  transition: all 0.15s ease;
}

.todo-item:hover {
  border-color: #e5e7eb;
}

.todo-item.completed {
  background-color: var(--input-bg);
}

.item-left {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  min-width: 0;
  cursor: pointer;
}

/* 체크박스 스타일 (원형) */
.item-checkbox {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid #d1d5db;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  flex-shrink: 0;
  background-color: #ffffff;
}

.todo-item:hover .item-checkbox {
  border-color: var(--primary-color);
}

.todo-item.completed .item-checkbox {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
}

.item-checkbox::after {
  content: '';
  width: 5px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg) translate(-1px, -1px);
  display: none;
}

.todo-item.completed .item-checkbox::after {
  display: block;
}

/* 텍스트 내용 */
.item-text {
  font-size: 15px;
  font-weight: 500;
  color: #374151;
  word-break: break-all;
  line-height: 1.4;
  transition: all 0.2s ease;
}

.todo-item.completed .item-text {
  text-decoration: line-through;
  color: var(--text-completed);
}

/* 항목 내 버튼들 */
.item-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 10px;
  flex-shrink: 0;
}

.btn-item {
  padding: 6px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-complete {
  background-color: #ffffff;
  color: #6b7280;
  border: 1px solid #e5e7eb;
}

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

.todo-item.completed .btn-complete {
  background-color: var(--primary-light);
  color: var(--primary-color);
}

.btn-delete {
  background-color: transparent;
  color: #d1d5db;
}

.btn-delete:hover {
  background-color: var(--danger-light);
  color: var(--danger-color);
}

/* 빈 상태 */
.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-muted);
}

.empty-icon {
  font-size: 40px;
  margin-bottom: 12px;
}

.empty-text {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 4px;
}

.empty-subtext {
  font-size: 13px;
  color: var(--text-muted);
}

/* 푸터 요약 바 */
.card-footer {
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
}

.btn-clear-completed {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 12px;
  cursor: pointer;
  text-decoration: underline;
  padding: 2px 4px;
  transition: color 0.15s;
}

.btn-clear-completed:hover {
  color: var(--danger-color);
}

/* 반응형 모바일 최적화 */
@media (max-width: 480px) {
  body {
    padding: 16px 12px;
  }

  .todo-card {
    padding: 24px 18px;
    border-radius: 24px;
  }

  .app-title {
    font-size: 26px;
  }

  .input-wrapper {
    gap: 8px;
  }

  .btn-add {
    padding: 0 16px;
  }

  .item-actions {
    gap: 4px;
  }

  .btn-item {
    padding: 5px 8px;
    font-size: 12px;
  }
}