/* 단어 학습 스타일 */
.vocabulary-container {
    padding: 20px 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 400px;
}

/* 헤더 스타일 */
.header {
    background-color: #3498db;
    color: white;
    padding: 15px;
    border-radius: 0 0 15px 15px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.back-btn {
    color: white;
    font-size: 18px;
    margin-right: 10px;
    text-decoration: none;
    display: inline-block;
}

h1 {
    margin: 10px 0;
    font-size: 22px;
}

.progress-container {
    margin-top: 10px;
}

.progress-bar {
    height: 8px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 5px;
}

.progress-fill {
    height: 100%;
    background-color: #2ecc71;
    width: 0%;
    transition: width 0.5s ease;
}

.progress-text {
    text-align: right;
    font-size: 14px;
    opacity: 0.9;
}

/* 카드 스타일 */
.card-container {
    width: 100%;
    max-width: 350px;
    height: 350px;
    perspective: 1000px;
    margin-bottom: 20px;
}

.card {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    border-radius: 15px;
}

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

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 15px;
    padding: 20px;
    box-sizing: border-box;
}

.card-front {
    background-color: white;
}

.card-back {
    background-color: #f8f9fa;
    transform: rotateY(180deg);
}

.word-content {
    width: 100%;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.word-image {
    width: 120px;
    height: 120px;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 15px;
    background-color: #f2f2f2;
    display: flex;
    align-items: center;
    justify-content: center;
}

.word-image img {
    max-width: 100%;
    max-height: 100%;
    object-fit: cover;
}

.word-text {
    font-size: 28px;
    margin: 0 0 5px;
    color: #333;
}

.word-pronunciation {
    font-size: 16px;
    margin: 0 0 20px;
    color: #666;
    font-style: italic;
}

.word-meaning {
    font-size: 30px;
    margin: 0 0 15px;
    color: #3498db;
}

.word-example {
    font-size: 16px;
    margin: 0 0 25px;
    color: #555;
    line-height: 1.4;
    font-style: italic;
}

.flip-btn {
    background-color: #f2f2f2;
    border: none;
    border-radius: 20px;
    padding: 8px 15px;
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: background-color 0.2s;
}

.flip-btn i {
    margin-right: 5px;
}

.flip-btn:hover {
    background-color: #e0e0e0;
}

/* 탐색 버튼 */
.navigation-buttons {
    display: flex;
    justify-content: space-between;
    width: 100%;
    max-width: 350px;
}

.nav-btn {
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 20px;
    padding: 10px 20px;
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: background-color 0.2s;
}

.nav-btn:hover {
    background-color: #2980b9;
}

.nav-btn:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.nav-btn i {
    margin-right: 5px;
}

.nav-btn i.fa-chevron-right {
    margin-right: 0;
    margin-left: 5px;
}

/* 완료 화면 */
.completion-screen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.completion-content {
    text-align: center;
    background-color: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    max-width: 350px;
    width: 90%;
}

.completion-icon {
    font-size: 60px;
    color: #2ecc71;
    margin-bottom: 15px;
}

.completion-content h2 {
    margin: 0 0 10px;
    color: #333;
}

.completion-content p {
    margin: 0 0 20px;
    color: #666;
}

.points-earned {
    font-size: 20px;
    color: #f39c12;
    font-weight: bold;
    margin: 15px 0 25px;
}

.points-earned i {
    margin-right: 5px;
}

.completion-buttons {
    display: flex;
    justify-content: space-between;
}

.completion-btn {
    background-color: #f2f2f2;
    border: none;
    border-radius: 20px;
    padding: 10px 15px;
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: background-color 0.2s;
    flex: 1;
    justify-content: center;
    margin: 0 5px;
}

.completion-btn i {
    margin-right: 5px;
}

.completion-btn:hover {
    background-color: #e0e0e0;
}

.completion-btn.primary {
    background-color: #3498db;
    color: white;
}

.completion-btn.primary:hover {
    background-color: #2980b9;
}

/* 로더 */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.8);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-radius: 50%;
    border-top-color: #3498db;
    animation: spin 1s ease-in-out infinite;
    margin-bottom: 15px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 오류 메시지 */
.error-message {
    text-align: center;
    padding: 40px 20px;
    color: #666;
}

.error-message i {
    font-size: 50px;
    color: #e74c3c;
    margin-bottom: 20px;
}

.error-message p {
    margin: 5px 0;
}

.retry-btn {
    margin-top: 20px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 20px;
    padding: 10px 20px;
    font-size: 14px;
    cursor: pointer;
}

/* 반응형 스타일 */
@media (max-width: 600px) {
    .card-container {
        height: 300px;
    }
    
    .word-image {
        width: 100px;
        height: 100px;
    }
    
    .word-text {
        font-size: 24px;
    }
    
    .word-meaning {
        font-size: 26px;
    }
    
    .navigation-buttons {
        padding: 0 10px;
    }
}