html, body { height: 100%; } app { display: block; height: 100%; } .header-logo { flex-shrink: 0; background-color: currentColor; -webkit-mask: url('../images/Logo.svg'); mask: url('../images/Logo.svg'); -webkit-mask-position: center; mask-position: center; -webkit-mask-repeat: no-repeat; mask-repeat: no-repeat; width: 180px; height: 24px; } #blazor-error-ui { background: inherit; bottom: 0; display: none; position: fixed; width: 100%; height: 100%; z-index: 100001; }