.dashboard {
    display: flex;
    flex-direction: column;
    gap: 40px; /* spacing between cards */
    margin: auto;
    font-family: Arial, sans-serif;
}

.chart-card {
    background: #f9f9f9;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 40px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    height: 450px; /* fix card height */
}

.chart-card h2 {
    margin: 0 0 15px 0;
    font-size: 1.2rem;
    color: #333;
    text-align: center;
}

.chart-card canvas {
    width: 100%;
    height: 100%; /* canvas fills card */
}