* {
    box-sizing: border-box;
}

body {
    margin:40px auto;
    max-width:900px;
    line-height:1.6;
    font-size:18px;
    padding:0 10px;
    font-family: -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;
}
h1 {
    text-align: center;
}

h1,h2,h3 {
    line-height:1.2;
}

h4 {
    margin-bottom: 0;
}

#gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-evenly;
}

.card {
    width: 250px;
    height: 250px;
    text-align: center;
}

.card > img {
    width: 50%;
    margin-left: auto;
    margin-right: auto;
    display: block;
    border-radius: 50% !important;
}