/* 영어 학습 앱 공통 스타일 */

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

body {
  font-family: 'Noto Sans KR', sans-serif;
  background-color: #f8f9fa;
  color: #333;
  line-height: 1.6;
}

/* 컨테이너 */
.container {
  max-width: 100%;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 헤더 */
.main-header {
  background-color: #3f51b5;
  color: white;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.app-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0;
  text-align: center;
  flex-grow: 1;
}

.back-button {
  color: white;
  font-size: 1.2rem;
  text-decoration: none;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
}

.header-right {
  width: 40px;
}

/* 메인 컨텐츠 */
main {
  flex: 1;
  padding: 1rem;
  display: flex;
  flex-direction: column;
}

/* 푸터 */
.main-footer {
  background-color: #f1f3f5;
  padding: 1rem;
  text-align: center;
  font-size: 0.8rem;
  color: #868e96;
}

/* 버튼 스타일 */
.btn, button {
  background-color: #3f51b5;
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 4px;
  cursor: pointer;
  font-weight: 500;
  font-size: 1rem;
  transition: background-color 0.3s;
}

.btn:hover, button:hover {
  background-color: #303f9f;
}

.btn-secondary {
  background-color: #f1f3f5;
  color: #495057;
}

.btn-secondary:hover {
  background-color: #e9ecef;
}

/* 카테고리 선택 */
.category-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 1rem 0;
}

.category-card {
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  padding: 1rem;
  text-align: center;
  cursor: pointer;
  transition: transform 0.3s, box-shadow 0.3s;
}

.category-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.category-card.selected {
  border: 2px solid #3f51b5;
  background-color: #e8eaf6;
}

.category-image {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  color: #3f51b5;
}

.category-name {
  font-weight: 500;
}

/* 난이도 선택 */
.difficulty-selector {
  margin: 1rem 0;
}

.difficulty-buttons {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.difficulty-button {
  flex: 1;
  padding: 0.5rem;
  border: 1px solid #dee2e6;
  background-color: white;
  color: #495057;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.3s;
  font-size: 0.9rem;
}

.difficulty-button.active {
  background-color: #3f51b5;
  color: white;
  border-color: #3f51b5;
}

/* 시작 버튼 */
.start-button {
  display: block;
  width: 100%;
  padding: 1rem;
  margin-top: 1.5rem;
  font-size: 1.1rem;
}

/* 결과 모달 */
.result-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s;
}

.result-modal.show {
  opacity: 1;
  visibility: visible;
}

.result-content {
  background-color: white;
  border-radius: 8px;
  padding: 2rem;
  width: 90%;
  max-width: 500px;
  text-align: center;
}

.result-title {
  color: #3f51b5;
  margin-bottom: 1rem;
}

.result-list {
  margin-bottom: 1.5rem;
}

.result-item {
  margin: 0.5rem 0;
  font-size: 1.1rem;
}

.result-button {
  margin: 0.5rem;
  padding: 0.75rem 1.5rem;
}

/* 반응형 스타일 */
@media (min-width: 768px) {
  .container {
    width: 100%;
    margin: 0 auto;
  }
  
  .category-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1024px) {
  .container {
    max-width: 960px;
  }
  
  .category-grid {
    grid-template-columns: repeat(5, 1fr);
  }
}