/* 메모리 게임 스타일 */
.memory-board-container {
    width: 100%;
    display: flex;
    justify-content: center;
    margin: 30px 0;
    padding: 0 10px;
    min-height: 450px;
}

.memory-board {
    display: grid;
    grid-template-columns: repeat(4, minmax(80px, 1fr));
    gap: 15px;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
    min-height: 400px;
}

.memory-card {
    width: 100%;
    aspect-ratio: 3/4;
    perspective: 1000px;
    cursor: pointer;
    background-color: transparent;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    margin-bottom: 15px;
    min-height: 140px;
    min-width: 100px;
    touch-action: manipulation; /* 터치 액션 최적화 */
    -webkit-tap-highlight-color: transparent; /* 탭 하이라이트 제거 */
    user-select: none; /* 텍스트 선택 방지 */
}

.memory-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.memory-card.flipped .memory-card-inner {
    transform: rotateY(180deg);
}

.memory-card.matched .memory-card-inner {
    transform: rotateY(180deg);
    box-shadow: 0 0 10px rgba(0, 128, 0, 0.7);
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden; /* Safari */
    backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: var(--border-radius);
    user-select: none;
}

.card-front {
    background-color: #3a86ff;
    color: white;
    border: 2px solid #2a76ef;
    font-weight: bold;
    font-size: 3rem;
}

.card-back {
    background-color: white;
    color: var(--primary-color);
    transform: rotateY(180deg);
    border: 2px solid #ddd;
}

.card-back i {
    font-size: 3.5rem;
    color: var(--primary-color);
}

/* 게임 정보 및 컨트롤 스타일 */
.exercise-info {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    background-color: var(--light-bg-color);
    padding: 15px;
    border-radius: var(--border-radius);
}

.timer, .score-display {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--primary-color);
}

/* 난이도 선택기 스타일 개선 */
.level-selector {
    margin-bottom: 15px;
}

.level-selector label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: var(--primary-color);
    font-size: 1.1rem;
}

.level-selector select {
    width: 100%;
    padding: 10px 15px;
    border-radius: 8px;
    border: 2px solid var(--primary-color);
    background-color: white;
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--primary-color);
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234285f4' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 20px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.level-selector select:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(66, 133, 244, 0.3);
    border-color: #3367d6;
}

.level-selector select:hover {
    border-color: #3367d6;
}

.level-selector select option {
    padding: 10px;
    font-size: 1rem;
}

/* 결과 모달 스타일 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: white;
    padding: 30px;
    border-radius: var(--border-radius);
    width: 80%;
    max-width: 500px;
    text-align: center;
    position: relative;
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 1.5rem;
    cursor: pointer;
}

#modalScore {
    font-size: 1.5rem;
    font-weight: bold;
    margin: 20px 0;
    color: var(--primary-color);
}

/* 난이도별 그리드 설정 */
.memory-board.easy {
    grid-template-columns: repeat(4, minmax(100px, 1fr));
    grid-template-rows: repeat(3, minmax(140px, auto));
    gap: 20px;
    padding: 20px;
}

.memory-board.medium {
    grid-template-columns: repeat(4, minmax(90px, 1fr));
    grid-template-rows: repeat(4, minmax(120px, auto));
    gap: 15px;
    padding: 15px;
}

.memory-board.hard {
    grid-template-columns: repeat(6, minmax(70px, 1fr));
    grid-template-rows: repeat(4, minmax(100px, auto));
    gap: 12px;
    padding: 10px;
}

/* 반응형 설정 */
@media (max-width: 768px) {
    .memory-board {
        grid-template-columns: repeat(4, 1fr);
        gap: 12px;
        width: 95%;
    }
    
    .memory-card {
        min-height: 110px;
    }
    
    .memory-board.hard {
        grid-template-columns: repeat(4, 1fr);
        grid-template-rows: repeat(6, 1fr);
        gap: 10px;
    }
    
    .card-front {
        font-size: 2.5rem;
    }
    
    .card-back i {
        font-size: 2.8rem;
    }
    
    .exercise-info {
        flex-direction: column;
        gap: 10px;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .memory-board {
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }
    
    .memory-card {
        min-height: 100px;
    }
    
    .memory-board.medium {
        grid-template-columns: repeat(3, 1fr);
        grid-template-rows: repeat(5, 1fr);
        gap: 8px;
    }
    
    .memory-board.hard {
        grid-template-columns: repeat(3, 1fr);
        grid-template-rows: repeat(8, 1fr);
        gap: 8px;
    }
    
    .card-front {
        font-size: 2rem;
    }
    
    .card-back i {
        font-size: 2.3rem;
    }
}

/* 버튼 터치 최적화 */
button {
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

/* 결과 모달의 버튼 터치 최적화 */
.modal-content button {
    padding: 12px 25px; /* 터치 영역 확대 */
    margin-top: 15px;
}