Dụng cụ đa năng

html, body { height: 100%; font-family: Arial, Helvetica, sans-serif; font-size: 12px; background-color: #EEEEEE; } div.vertical-center { position: relative; top: 50%; transform: translateY(-50%); border: 1px solid #c0c0c0; padding: 20px; max-width: 460px; margin: 0 auto; text-align: center; } div.vertical-center p { padding-top: 20px; }