.container { background: dodgerblue; border: 4px solid midnightblue; width: 400px; height: 300px; /* look at this! */ display: flex; align-items: center; justify-content: center; } .box { background: palevioletred; font-weight: bold; text-align: center; border: 6px solid maroon; width: 80px; height: 80px; }