Corner sweep

Corner sweep: a CSS button. Copy the rules, or the prompt that rebuilds it.

hover-fillcornercircle-growrounded

CSS
.btn-063 {
  position: relative;
  overflow: hidden;
  font: 600 14px/1 system-ui,sans-serif;
  color: #be185d;
  background: #fff;
  border: 2px solid #be185d;
  border-radius: 10px;
  padding: 12px 26px;
  cursor: pointer;
  z-index: 0;
  transition: color .35s
}
.btn-063::before {
  content: "";
  position: absolute;
  top: -10px;
  left: -10px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #be185d;
  transform: scale(0);
  transition: transform .35s ease;
  z-index: -1
}
.btn-063:hover {
  color: #fff
}
.btn-063:hover::before {
  transform: scale(20)
}
.btn-063:focus-visible {
  outline: 2px solid #be185d;
  outline-offset: 3px
}
.btn-063:active::before {
  background: #9d174d
}
HTML
<button class="btn-063">Sweep</button>
Prompt

A pink outline button (2px #be185d border, pink text, 10px radius, 12px by 26px padding, white fill). On hover a small circle anchored at the top-left corner scales up 20x (350ms) to flood the button pink while the text turns white. Active #9d174d. Focus outline 2px pink.