You need to enable JavaScript to run this app. body { overflow: hidden; } .center { align-items: center; display: flex; flex-direction: column; height: 100vh; justify-content: center; width: 100vw; } @keyframes fade-in { from { opacity: 0; } to { opacity: 1; } } .fade-in { animation-delay: 750ms; animation-direction: normal; animation-duration: 500ms; animation-fill-mode: forwards; animation-iteration-count: 1; animation-name: fade-in; animation-timing-function: ease-in-out; opacity: 0; } @keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } } .spinner { animation-duration: var(--transitionDurationSlow, 600ms); animation-iteration-count: infinite; animation-name: spin; animation-timing-function: linear; border-color: var(--colorNeutral600Transparent, rgba(125, 134, 153, 0.25)); border-radius: 100%; border-style: solid; border-top-color: rgba(125, 134, 153, 0.9); border-width: var(--borderWidthHeavy, 3px); display: block; height: var(--spacingXxlarge, 48px); width: var(--spacingXxlarge, 48px); }