* { margin: 0; padding: 0; box-sizing: border-box; } html { font-size: 10px; } body { font-family: "Open Sans", sans-serif; background-color: #eee; } p { font-size: 1.6rem; line-height: 1.5; } .container { max-width: 900px; margin: 0 auto; padding: 0 20px; } /* Start Here */ .box { width: 100%; height: 100vh; display: flex; justify-content: center; align-items: center; }