body {
    margin: 0;
    font-family: sans-serif;
}

.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    border-bottom: 1px solid #ccc;
}

.main-container {
    display: grid;
    grid-template-columns: 250px 1fr 250px; /* Esquerda | Centro | Direita */
    min-height: calc(100vh - 140px);
}

.sidebar-left, .sidebar-right {
    padding: 1.5rem;
    background: #f9f9f9;
    border-right: 1px solid #eee;
    border-left: 1px solid #eee;
}

.content-area {
    padding: 2rem;
}

.site-footer {
    text-align: center;
    padding: 1rem;
    border-top: 1px solid #ccc;
    background: #f1f1f1;
}