:root { --input-padding-x: .75rem; --input-padding-y: .75rem; } html, body { height: 100%; } body { display: -ms-flexbox; display: -webkit-box; display: flex; -ms-flex-align: center; -ms-flex-pack: center; -webkit-box-align: center; align-items: center; -webkit-box-pack: center; justify-content: center; padding-top: 40px; padding-bottom: 40px; background-color: #f5f5f5; } .form-signin { width: 100%; max-width: 420px; padding: 15px; margin: 0 auto; } .form-label-group { position: relative; margin-bottom: 1rem; } .form-label-group > input, .form-label-group > label { padding: var(--input-padding-y) var(--input-padding-x); } .form-label-group > label { position: absolute; top: 0; left: 0; display: block; width: 100%; margin-bottom: 0; /* Override default `