Liquid Fill Checkbox
Checking fills the box with liquid: a slowly turning rounded square rises from below, so its surface sloshes as it climbs, then the tick draws in white. Unchecking drains it back out.
Also known as: water fill checkbox, wave fill checkbox css.
HTML
<label class="chk-liquid-fill-checkbox">
<input type="checkbox">
<span class="chk-liquid-fill-checkbox-box">
<span class="chk-liquid-fill-checkbox-liquid"></span>
<svg viewBox="0 0 24 24" aria-hidden="true"><path d="M5.5 12.5l4 4L18.5 7.5"/></svg>
</span>
Back up to cloud
</label>CSS
.chk-liquid-fill-checkbox {
--c: var(--chk-color, #3b82f6);
font-size: var(--chk-size, 24px);
position: relative;
display: inline-flex;
align-items: center;
gap: 0.6em;
font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
line-height: 1.3;
cursor: pointer;
-webkit-tap-highlight-color: transparent;
}
.chk-liquid-fill-checkbox input {
position: absolute;
inset: 0;
width: 100%;
height: 100%;
margin: 0;
opacity: 0;
cursor: pointer;
z-index: 1;
}
.chk-liquid-fill-checkbox-box {
position: relative;
box-sizing: border-box;
display: grid;
place-items: center;
flex: none;
width: 1.4em;
height: 1.4em;
overflow: hidden;
border: 0.125em solid color-mix(in srgb, currentColor 38%, transparent);
border-radius: 0.35em;
transition: border-color 0.3s ease 0.2s;
}
.chk-liquid-fill-checkbox-liquid {
position: absolute;
left: 50%;
top: 0;
width: 3.2em;
height: 3.2em;
margin-left: -1.6em;
transform: translateY(1.4em);
transition: transform 0.5s cubic-bezier(0.55, 0, 0.8, 0.5) 0.1s;
}
.chk-liquid-fill-checkbox-liquid::before {
content: "";
position: absolute;
inset: 0;
border-radius: 39%;
background: var(--c);
animation: chk-liquid-fill-checkbox-turn 2.4s linear infinite;
}
.chk-liquid-fill-checkbox-box svg {
display: block;
fill: none;
stroke-linecap: round;
stroke-linejoin: round;
position: relative;
width: 0.9em;
height: 0.9em;
stroke: #fff;
stroke-width: 3.2;
stroke-dasharray: 22;
stroke-dashoffset: 22;
transition: stroke-dashoffset 0.12s ease-in;
}
.chk-liquid-fill-checkbox input:checked + .chk-liquid-fill-checkbox-box {
border-color: var(--c);
transition-delay: 0s;
}
.chk-liquid-fill-checkbox input:checked + .chk-liquid-fill-checkbox-box .chk-liquid-fill-checkbox-liquid {
transform: translateY(-0.3em);
transition: transform 0.8s cubic-bezier(0.25, 0.6, 0.3, 1);
}
.chk-liquid-fill-checkbox input:checked + .chk-liquid-fill-checkbox-box svg {
stroke-dashoffset: 0;
transition: stroke-dashoffset 0.3s ease-out 0.5s;
}
.chk-liquid-fill-checkbox input:focus-visible + .chk-liquid-fill-checkbox-box {
outline: 0.125em solid var(--c);
outline-offset: 0.18em;
}
@keyframes chk-liquid-fill-checkbox-turn {
to { transform: rotate(360deg); }
}
@media (prefers-reduced-motion: reduce) {
.chk-liquid-fill-checkbox, .chk-liquid-fill-checkbox *, .chk-liquid-fill-checkbox::before, .chk-liquid-fill-checkbox::after, .chk-liquid-fill-checkbox *::before, .chk-liquid-fill-checkbox *::after {
animation-duration: 0.01ms !important;
animation-iteration-count: 1 !important;
transition-duration: 0.01ms !important;
}
}Customizing this snippet
- Color: set
--chk-coloron the element or a parent. Currently previewing#3b82f6. - Size: set
--chk-size. Every other dimension is inem, so the whole thing scales together. Currently previewing24px. - Speed: change the duration on the
transitionoranimationshorthand. Staggered delays are relative, so they keep their rhythm. - Reduced motion: the rule at the end of the CSS turns the motion off for people who asked their OS for less of it. Keep it.