Scribble Fill Button: CSS Hover Effect

Scribble Fill Button

A marker zigzags across the button and colors it in like a margin doodle, then the ink settles solid. One inline SVG path drawn with stroke-dashoffset; pathLength=1 keeps the math simple.

Also known as: marker fill button, hand drawn fill hover, crayon scribble button.

Color Base size 16px Dark background Hold hover state

HTML

<button class="hfx-scribble-fill"><svg class="hfx-scribble-fill-svg" viewBox="0 0 100 28" preserveAspectRatio="xMidYMid slice" aria-hidden="true"><path pathLength="1" d="M-8 30 L8 -3 L4 31 L20 -5 L16 33 L32 -2 L28 30 L44 -4 L40 32 L56 -3 L52 31 L68 -5 L64 33 L80 -2 L76 30 L92 -4 L88 32 L104 -3 L100 31 L116 -5 L112 33"/></svg>Sign the petition</button>

CSS

.hfx-scribble-fill {
  --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 0.2s ease, background-color 0.15s ease;
}
.hfx-scribble-fill-svg {
  position: absolute;
  inset: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  fill: none;
  stroke: var(--c);
  stroke-width: 6.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 1 1.1;
  stroke-dashoffset: 1.02;
  transition: stroke-dashoffset 0.4s cubic-bezier(0.5, 0, 0.75, 0);
}
/* once the scribble is done, the button's own background fills the gaps */
.hfx-scribble-fill:is(:hover, :focus-visible) {
  background-color: var(--c);
  color: #fff;
  transition: color 0.2s ease 0.45s, background-color 0.25s ease 0.6s;
}
.hfx-scribble-fill:is(:hover, :focus-visible) .hfx-scribble-fill-svg {
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 0.7s cubic-bezier(0.45, 0, 0.3, 1);
}

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

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.

Scribble Fill Button

HTML

CSS

Customizing this snippet

Similar hover effects