/* 概念解释模态框 - 移动端 */
.concept-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    animation: modalFadeIn 0.3s ease;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: white;
    border-radius: 12px;
    max-width: 90%;
    width: 400px;
    max-height: 80%;
    overflow-y: auto;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    animation: modalSlideUp 0.3s ease;
}

@keyframes modalSlideUp {
    from { 
        transform: translateY(30px);
        opacity: 0;
    }
    to { 
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 25px 10px;
    border-bottom: 1px solid #eee;
}

.modal-header h4 {
    color: #2c1810;
    font-size: 1.3rem;
    font-weight: bold;
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    font-size: 2rem;
    color: #999;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    color: #666;
}

.modal-body {
    padding: 20px 25px 25px;
}

.modal-body p {
    color: #3e2723;
    line-height: 1.6;
    font-size: 1rem;
    margin: 0;
}

/* 概念词样式系统 */
.concept-word {
    color: #2c1810;
    font-weight: bold;
    cursor: pointer;
    text-decoration: none;
    border-bottom: 2px dotted #2c1810;
    background: rgba(255, 255, 255, 0.6);
    padding: 1px 3px;
    border-radius: 3px;
    transition: all 0.2s ease;
}

.concept-word:hover {
    background: rgba(255, 255, 255, 0.8);
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(44, 24, 16, 0.2);
}

/* 桌面端tooltip样式增强 */
@media (min-width: 769px) {
    .concept-word .tooltip {
        position: absolute;
        bottom: 100%;
        left: 50%;
        transform: translateX(-50%);
        background: linear-gradient(145deg, #2c1810, #3e2723);
        color: white;
        padding: 12px 16px;
        border-radius: 8px;
        font-size: 0.9rem;
        max-width: 320px;
        width: max-content;
        text-align: left;
        box-shadow: 0 6px 20px rgba(44, 24, 16, 0.4);
        z-index: 1000;
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        line-height: 1.5;
        margin-bottom: 10px;
        border: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .concept-word .tooltip::after {
        content: '';
        position: absolute;
        top: 100%;
        left: 50%;
        transform: translateX(-50%);
        width: 0;
        height: 0;
        border-left: 8px solid transparent;
        border-right: 8px solid transparent;
        border-top: 8px solid #2c1810;
    }
    
    .concept-word:hover .tooltip {
        opacity: 1;
        visibility: visible;
        transform: translateX(-50%) translateY(-5px);
    }
}