style.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background-color: #333;
    color: #fff;
    padding: 1.25rem;
}

.container {
    max-width: 75rem;
    margin: 0 auto;
    padding: 1.25rem;
}

.row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.25rem;
}

.card {
    background-color: #444;
    border-radius: 0.5rem;
    padding: 1.25rem;
    width: 32%;
    min-height: 17.625rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

input, button {
    margin-bottom: 1.25rem;
    padding: 0.625rem;
    border: none;
    border-radius: 0.25rem;
    outline: none;
    font-size: 1rem;
}

input {
    width: 17.5rem;
}

button {
    background-color: #28a745;
    color: white;
    cursor: pointer;
}

button:hover {
    background-color: #218838;
}

.chart-card {
    display: none;
    height: 19.625rem; /* Set the height to match the card's minimum height */
}

canvas {
    width: 100%;
    height: 100%; /* Make the canvas fill the entire chart card */
}

@media (max-width: 48rem) {
    .row {
        flex-direction: column;
    }

    .card {
        width: 100%;
        margin-bottom: 1.25rem;
    }
}