body {
    margin: 0; padding: 0; background-color: azure; font-family:verdana 
}
html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    height: 100vh;
    display: flex;
    flex-direction: column;

}
header {
    background-color: rgb(69, 177, 132);
    padding: 25px;
    text-align: center;
    font-size: 25px;
    color: white;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
footer {
    background-color: rgb(69, 177, 132);
    color: white;
    text-align: center;
    padding: 10px;
    font-size: 1em;
}

.marker {
    display: block;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    padding: 0;
    width: 40px;
    height: 40px;
    background-color: transparent;
    background-size: cover;   /* oder contain */
    background-position: center;
    background-repeat: no-repeat;
}
