.size-option {
    display: inline-block;
    cursor: pointer;
    border: 2px solid transparent;
    position: relative;
    text-align: center;
}

.size-option input[type="radio"] {
    display: none;
}

.size-option label {
    width: 100%;
    height: 100%;
    display: inline-block;
    font-size: 14px;
    border: 1px solid #ccc;
    border-radius: 4px;
    padding:5px 10px 5px 10px;
    background-color: #f9f9f9;
    cursor: pointer;
}

/* Rectangular selection border for selected size */
.size-option input[type="radio"]:checked + label {
    outline: 2px solid #007bff;
    outline-offset: 2px;
    background-color: #007bff;
    color: white;
}