* { box-sizing: border-box; }
body { background-color: #737491; color: white; }
h1 { font-size: 3em; text-align: center; }

.placeholders { clear: all; }
.placeholder {
    float: left;
    border-radius: 50%;
    min-width: 8em;
    min-height: 8em;
    margin: 2em;
    background-color: #4A4B65;
    color: white;
}

.placeholder1 {
    width: 10em;
    height: 10em;
}

.placeholder2 {
    width: 12em;
    height: 12em;
    background-color: #F74F78;
}

.placeholder3 {
    width: 15em;
    height: 15em;
    background-color: #766DF4;
}

.placeholder4 {
    background-color: #FFBD5C;
}

.placeholder5 {
    width: 16em;
    height: 16em;
    background-color: #15C995;
}

.placeholder6 {
    width: 12em;
    height: 12em;
    background-color: white;
    color: gray;
}

.placeholder7 {
    width: 16em;
    height: 16em;
    background-color: rebeccapurple;
}