Newton's Cradle
Five hanging balls where the outer ones swing out and knock back in, one side then the other. A desk-toy loader for pages that want a little wit.
Also known as: pendulum balls loader, swinging balls.
HTML
<div class="ldr-newton-cradle" role="status" aria-label="Loading"> <span></span><span></span><span></span><span></span><span></span> </div>
CSS
.ldr-newton-cradle {
--s: var(--ldr-size, 48px);
--c: var(--ldr-color, #3b82f6);
position: relative;
width: var(--s);
height: var(--s);
}
.ldr-newton-cradle span {
position: absolute;
top: 0;
width: 20%;
height: 100%;
transform-origin: 50% 0;
}
.ldr-newton-cradle span:nth-child(1) { left: 0; }
.ldr-newton-cradle span:nth-child(2) { left: 20%; }
.ldr-newton-cradle span:nth-child(3) { left: 40%; }
.ldr-newton-cradle span:nth-child(4) { left: 60%; }
.ldr-newton-cradle span:nth-child(5) { left: 80%; }
.ldr-newton-cradle span::before {
content: "";
position: absolute;
top: 0;
left: 50%;
width: 1px;
height: 80%;
background: color-mix(in srgb, var(--ldr-color, #3b82f6) 45%, transparent);
}
.ldr-newton-cradle span::after {
content: "";
position: absolute;
bottom: 0;
left: 0;
width: 100%;
aspect-ratio: 1;
border-radius: 50%;
background: var(--c);
}
.ldr-newton-cradle span:first-child { animation: ldr-newton-cradle-left 1.2s ease-in-out infinite; }
.ldr-newton-cradle span:last-child { animation: ldr-newton-cradle-right 1.2s ease-in-out infinite; }
@keyframes ldr-newton-cradle-left {
0%, 50%, 100% { transform: rotate(0deg); }
25% { transform: rotate(50deg); }
}
@keyframes ldr-newton-cradle-right {
0%, 50%, 100% { transform: rotate(0deg); }
75% { transform: rotate(-50deg); }
}
@media (prefers-reduced-motion: reduce) {
.ldr-newton-cradle, .ldr-newton-cradle *, .ldr-newton-cradle::before, .ldr-newton-cradle::after {
animation-duration: 3s;
}
}Customizing this loader
- Color: set
--ldr-coloron the element or a parent. Currently previewing#3b82f6. - Size: set
--ldr-size. Every dimension in the snippet is derived from it. Currently previewing64px. - Speed: change the duration on the
animationshorthand. Delays on the children are relative, so they keep their rhythm. - Accessibility: the root carries
role="status"and anaria-labelso screen readers announce the wait. The reduced-motion rule at the end slows the animation for users who asked for less motion.