Clip Mask
The fill is revealed via an animated clip-path morph from a tiny triangle to a full circle — a unique geometric reveal.
Clip Mask the 13th of 18 designs in the 18 CSS Radio Button Designs collection. The design is implemented in pure CSS — no JavaScript required. Copy the HTML and CSS panels below into your project. Because the demo is pure CSS, it works in any framework or templating engine you happen to use. The design honours prefers-reduced-motion and uses real semantic markup, so it ships accessibility-ready out of the box.
Live preview
The code
<fieldset class="crb-clip"> <legend class="crb-sr">Speed</legend> <label><input type="radio" name="crb-clip" /><span></span>0.5x</label> <label><input type="radio" name="crb-clip" /><span></span>1x</label> <label><input type="radio" name="crb-clip" checked /><span></span>2x</label> </fieldset>
.crb-clip { display: flex; flex-direction: column; gap: 10px; border: 0; padding: 0; }
.crb-clip label {
display: flex; align-items: center; gap: 10px;
font: 500 13px/1 monospace; color: #cbd5e1; cursor: pointer;
}
.crb-clip input { appearance: none; -webkit-appearance: none; position: absolute; opacity: 0; }
.crb-clip span {
width: 18px; height: 18px; border-radius: 50%;
border: 2px solid #444461;
position: relative; overflow: hidden;
transition: border-color 0.25s;
}
.crb-clip span::after {
content: ''; position: absolute; inset: 3px;
border-radius: 50%;
background: linear-gradient(135deg, #ff6c8a, #f5a623);
clip-path: polygon(50% 50%, 50% 50%, 50% 50%);
transition: clip-path 0.5s cubic-bezier(0.65,0,0.35,1);
}
.crb-clip input:checked + span { border-color: #ff6c8a; }
.crb-clip input:checked + span::after {
clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
}
.crb-sr {
position: absolute !important;
width: 1px;
height: 1px;
padding: 0;
margin: -1px;
overflow: hidden;
clip: rect(0, 0, 0, 0);
white-space: nowrap;
border: 0;
}