Shutter In Button: CSS Hover Effect

Shutter In Button

Two panels slide in from the left and right edges and meet in the middle, like doors closing. Each panel is a pseudo-element a hair over half wide, so no seam shows where they meet.

Also known as: split doors button, fill from both sides hover, shutter in horizontal.

Color Base size 16px Dark background Hold hover state

HTML

<button class="hfx-shutter-in">Book a call</button>

CSS

.hfx-shutter-in {
  --c: var(--hfx-color, #3b82f6);
  position: relative;
  isolation: isolate;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.75em 1.75em;
  border-radius: 0.5em;
  font: 600 var(--hfx-size, 16px)/1.2 system-ui, sans-serif;
  white-space: nowrap;
  cursor: pointer;
  border: 2px solid var(--c);
  background: transparent;
  color: var(--c);
  transition: color 0.25s ease 0.12s;
}
.hfx-shutter-in::before,
.hfx-shutter-in::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  z-index: -1;
  width: 51%;
  background: var(--c);
  transition: transform 0.4s cubic-bezier(0.7, 0, 0.2, 1);
}
.hfx-shutter-in::before {
  left: 0;
  transform: translateX(-100%);
}
.hfx-shutter-in::after {
  right: 0;
  transform: translateX(100%);
}
.hfx-shutter-in:is(:hover, :focus-visible) {
  background-color: var(--c); /* hides the hairline where the fill meets the border */
  color: #fff;
  transition: color 0.25s ease 0.12s, background-color 0s 0.4s;
}
.hfx-shutter-in:is(:hover, :focus-visible)::before,
.hfx-shutter-in:is(:hover, :focus-visible)::after {
  transform: translateX(0);
}

@media (prefers-reduced-motion: reduce) {
  .hfx-shutter-in, .hfx-shutter-in *, .hfx-shutter-in::before, .hfx-shutter-in::after, .hfx-shutter-in *::before, .hfx-shutter-in *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

Tailwind CSS version

The same effect using Tailwind utility classes. No custom CSS or config needed.

<button class="group relative isolate overflow-hidden rounded-lg border-2 border-blue-500 px-7 py-3 font-semibold text-blue-500 transition-colors delay-100 duration-300 hover:text-white">
  <span class="absolute inset-y-0 left-0 -z-10 w-[51%] -translate-x-full bg-blue-500 transition-transform duration-500 ease-in-out group-hover:translate-x-0"></span>
  <span class="absolute inset-y-0 right-0 -z-10 w-[51%] translate-x-full bg-blue-500 transition-transform duration-500 ease-in-out group-hover:translate-x-0"></span>
  Book a call
</button>

Customizing this snippet

Color: set --hfx-color on the element or a parent. Currently previewing #3b82f6.
Base size: set --hfx-size. Every other dimension is in em, so the whole thing scales together. Currently previewing 16px.
Speed: change the duration on the transition or animation shorthand. 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.

Shutter In Button

HTML

CSS

Tailwind CSS version

Customizing this snippet

Similar hover effects