/* Container layout */
.etl-container { 
    position: relative;
    display: flex; 
    width: 100%; 
    max-width: 100%; 
    margin: 40px auto; 
    border: 1px solid #e2e8f0; 
    border-radius: 8px; 
    overflow: hidden; 
    font-family: 'Monterra'; 
    background: #fff; 
    box-shadow: 0 4px 6px rgba(0,0,0,0.05); 
}

/* Sidebar structure */
.etl-sidebar { 
    width: 320px; 
    background: #16264a; 
    display: flex; 
    flex-direction: column; 
    flex-shrink: 0; 
    align-self: stretch;
    min-height: 100%;
}

.etl-tab-btn { 
    background: none; 
    border: none; 
    color: #a0aec0; 
    padding: 24px 20px; 
    text-align: left; 
    cursor: pointer; 
    transition: background 0.3s ease, color 0.3s ease; 
    font-size: 15px; 
    font-weight: 400;
    font-family: 'Montserrat', sans-serif !important;
    border-bottom: 1px solid rgba(255,255,255,0.05); 
    display: flex;
    align-items: center;
}

.etl-tab-btn:last-child {
    border-bottom: none; 
}

.etl-tab-btn:hover, .etl-tab-btn.active { 
    color: #fff; 
    background: #123b77; 
}

.etl-content-area { 
    flex-grow: 1; 
    padding: 50px; 
}

.etl-tab-content { 
    display: none; 
    grid-template-columns: 1.1fr 1fr; 
    gap: 40px; 
    align-items: center; 
}

.etl-tab-content.active { 
    display: grid; 
}

/* Typography strict rules: 20px non-bold headings, 15px non-bold subtext */
.etl-text-column h3 { 
    margin-top: 0; 
    margin-bottom: 16px;
    color: #1a202c; 
    font-size: 20px;
    font-weight: 400;
    font-family: 'Montserrat', sans-serif !important;
}

.etl-text-column p {
    color: #4a5568;
    font-size: 15px;
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 24px;
    font-family: 'Montserrat', sans-serif !important;
}

.etl-checklist { 
    list-style: none; 
    padding: 0; 
    margin: 0;
}

.etl-checklist li { 
    padding-left: 25px; 
    position: relative; 
    margin-bottom: 12px; 
    font-size: 15px;
    font-weight: 400;
    color: #2d3748;
    font-family: 'Montserrat', sans-serif !important;
}

.etl-checklist li::before { 
    content: '✓'; 
    position: absolute; 
    left: 0; 
    color: #3182ce; 
    font-weight: bold; 
}

.etl-image-column img {
    width: 100%;
    height: auto;
    border-radius: 6px;
}

.etl-img-placeholder { 
    background: #f7fafc; 
    border: 2px dashed #cbd5e0; 
    height: 300px; 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    color: #718096; 
    border-radius: 6px; 
    font-size: 15px;
    font-weight: 400;
}

/* Responsive Viewports */
@media (max-width: 900px) {
    .etl-container { 
        flex-direction: column; 
    }
    .etl-sidebar { 
        width: 100%; 
        flex-direction: row; 
        overflow-x: auto; 
    }
    .etl-tab-btn { 
        white-space: nowrap; 
        padding: 15px 20px; 
        border-bottom: none;
        border-right: 1px solid rgba(255,255,255,0.05);
    }
    .etl-tab-content.active { 
        grid-template-columns: 1fr; 
        gap: 20px; 
    }
    .etl-content-area {
        padding: 30px;
    }
}