styles.css

html,
body {
    font-family: Courier New, Courier, monospace;
    width: 100%;
    height: 100%;
    margin: 0;
}
h3 {
    align-items: center;
    display: flex;
    font-size: 25px;
    height: 50px;
    justify-content: center;
    margin: 0;
    padding: 10px;
    text-align: center;
}
#map {
    height: calc(100% - 70px);
    width: 100%;
}
.main-info {
    font-family: Courier New, Courier, monospace;
    font-size: 20px;
    font-weight: bold;
}
.secondary-info {
    font-family: Courier New, Courier, monospace;
    font-size: 12px;
    margin-top: 12px;
}
.secondary-info .title {
    border-bottom: 1px solid #000;
    display: block;
    margin-bottom: 3px;
    text-align: center;
}
.secondary-info p {
    margin: 0;
}

.open-alert {
    width: 25px;
    height: 25px;
    border-radius: 50%;
    border: 2px solid #000;
    display: inline-block;
    background-color: #ddd;
    cursor: pointer;
    line-height: 27px;
}
#alert {
    align-items: center;
    justify-content: center;
    display: flex;
    position: fixed;
    top: 0;
    left: 0;
    opacity: 0;    
    width: 100%;
    height: 100%;
    transition: opacity 0.5s ease-out;
    visibility: hidden;
    z-index: 10;
}

#alert .content {
    background-color: #fff;
    max-width: 80%;
    padding: 20px;
    position: relative;
}

#alert .close-alert {
    position: absolute;
    top: 10px;
    right: 10px;
}

#alert-background {
    background-color: #000;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    opacity: 0;
    height: 100%;
    visibility: hidden;
    transition: opacity 0.5s ease-out;
    z-index: 1;
}