* {
    box-sizing: border-box;
}

.columns {
    float: left;
    width: 25%;
    padding: 8px;
}

.price {
    list-style-type: none;
    border: 1px solid #eee;
    margin: 0;
    padding: 0;
    -webkit-transition: 0.3s;
    transition: 0.3s;
}

    .price:hover {
        box-shadow: 0 8px 12px 0 rgba(0,0,0,0.2);
    }

    .price .header {
        background-color: #111;
        color: white;
        font-size: 25px;
    }

    .price li {
        border-bottom: 1px solid #eee;
        padding: 20px;
        text-align: center;
    }

    .price .grey {
        background-color: #eee;
        font-size: 20px;
    }

.button {
    background-color: #4CAF50;
    border: none;
    color: white;
    padding: 10px 25px;
    text-align: center;
    text-decoration: none;
    font-size: 18px;
}

@media only screen and (max-width: 600px) {
    .columns {
        width: 100%;
    }
}

/******/

.card-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

.card {
    flex: 1 1 250px;
    max-width: 300px;
    background-color: var(--color-white);
    border: 1px solid var(--color-light-gray);
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

    .card:hover {
        transform: translateY(-5px);
        box-shadow: 0 8px 16px rgba(0,0,0,0.15);
    }

.card-header {
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: 1.25rem;
    padding: 1rem;
    text-align: center;
    font-weight: bold;
}

.card-content {
    list-style: none;
    padding: 0;
    margin: 0;
}

    .card-content li {
        border-bottom: 1px solid var(--color-light-gray);
        padding: 1rem;
        text-align: center;
        font-size: 1rem;
    }

        .card-content li.highlight {
            background-color: var(--color-secondary-light-yellow);
            font-weight: bold;
        }

.card-footer {
    padding: 1rem;
    text-align: center;
}