body {
    font-family: Arial, sans-serif;
}

button {
    padding: 10px 20px;
    font-size: 16px;
}

.popup {
    display: none; /* Hidden by default */
    position: fixed;
    z-index: 1;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}

.popup-content {
    background-color: #fefefe;
    margin: 15% auto; /* 15% from the top and centered */
    padding: 20px;
    border: 1px solid #888;
    width: 80%; /* Could be more or less, depending on screen size */
    max-width: 400px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
    border-radius: 10px;
    text-align: center;
    color: #000000;
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}