Fill Up Button
The fill rises from the bottom edge instead of sliding sideways. Same one pseudo-element, different axis, and it pairs well with the slide version on the same page.
Also known as: bottom fill hover, rising fill button.
HTML
<button class="hfx-fill-up">Book a demo</button>
CSS
.hfx-fill-up {
--c: var(--hfx-color, #3b82f6);
font-size: var(--hfx-size, 16px);
display: inline-flex;
align-items: center;
gap: 0.5em;
padding: 0.7em 1.6em;
border-radius: 0.5em;
font: 600 1em system-ui, sans-serif;
cursor: pointer;
position: relative;
isolation: isolate;
overflow: hidden;
border: 2px solid var(--c);
background: transparent;
color: var(--c);
transition: color 0.3s ease;}
.hfx-fill-up::before {
content: "";
position: absolute;
inset: 0;
z-index: -1;
background: var(--c);
transform: translateY(101%);
transition: transform 0.3s ease;
}
.hfx-fill-up:hover { color: #fff; }
.hfx-fill-up:hover::before { transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
.hfx-fill-up, .hfx-fill-up *, .hfx-fill-up::before, .hfx-fill-up::after {
animation-duration: 0.01ms !important;
animation-iteration-count: 1 !important;
transition-duration: 0.01ms !important;
}
}Customizing this snippet
- Color: set
--hfx-coloron the element or a parent. Currently previewing#3b82f6. - Base size: set
--hfx-size. Every other dimension is inem, so the whole thing scales together. Currently previewing16px. - 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.