.history-intro {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: #f8f9fa;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    text-align: center;
    font-size: 1.1rem;
    line-height: 1.6;
}

.history-hierarchy {
    display: flex;
    flex-direction: column;
    gap: 3rem;
    margin: 2rem 0;
    position: relative;
}

.history-hierarchy::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(to bottom, #3498db, #2c3e50);
    transform: translateX(-50%);
}

.history-era {
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    position: relative;
    margin-left: 2rem;
    margin-right: 2rem;
}

.era-header {
    background-color: #2c3e50;
    padding: 1.5rem;
    color: white;
}

.era-header h3 {
    margin: 0;
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.era-image, .era-images {
    margin-top: 1rem;
    display: grid;
    gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.era-image img, .era-images img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
}

.era-image img:hover, .era-images img:hover {
    transform: scale(1.05);
}

.era-details {
    padding: 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.milestone {
    background-color: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid #3498db;
}

.milestone h4 {
    color: #2c3e50;
    margin: 0 0 1rem 0;
    font-size: 1.3rem;
}

.milestone ul {
    list-style-type: none;
    padding-left: 0;
    margin-top: 1rem;
}

.milestone li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.8rem;
    line-height: 1.4;
}

.milestone li::before {
    content: '→';
    color: #3498db;
    position: absolute;
    left: 0;
    top: 0;
}

.history-conclusion {
    margin-top: 3rem;
    padding: 2.5rem;
    background: linear-gradient(135deg, #2c3e50, #3498db);
    color: white;
    border-radius: 12px;
    text-align: center;
    font-size: 1.2rem;
    line-height: 1.6;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.read-more-container {
    margin-top: 2rem;
    text-align: center;
}

.read-more-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: linear-gradient(135deg, #3498db, #2c3e50);
    color: white;
    padding: 1rem 2rem;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.read-more-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
    background: linear-gradient(135deg, #2c3e50, #3498db);
}

.read-more-btn i {
    transition: transform 0.3s ease;
}

.read-more-btn:hover i {
    transform: translateX(5px);
}

@media (max-width: 768px) {
    .history-hierarchy::before {
        left: 20px;
    }

    .history-era {
        margin-left: 40px;
        margin-right: 0;
    }

    .era-details {
        grid-template-columns: 1fr;
        padding: 1.5rem;
    }

    .era-image, .era-images {
        grid-template-columns: 1fr;
    }

    .era-header h3 {
        font-size: 1.5rem;
    }
}