Cut Corner Gradient Border
A sci-fi panel with two chamfered corners and a gradient edge that turns around it. clip-path erases normal borders, so the gradient fills the clipped box and a smaller clipped face sits on top.
Also known as: clip-path border css, chamfered border css, notched corner border.
Chamfered
HTML
<div class="bdr-cut-corner-gradient-border">Chamfered</div>
CSS
@property --bdr-cut-corner-gradient-border-a {
syntax: "<angle>";
inherits: false;
initial-value: 0deg;
}
.bdr-cut-corner-gradient-border {
--c: var(--bdr-color, #3b82f6);
font-size: var(--bdr-size, 16px);
position: relative;
display: grid;
place-items: center;
width: 15em;
height: 8.5em;
border-radius: 1em;
font-family: system-ui, sans-serif;
font-weight: 600;
isolation: isolate;
border-radius: 0;
clip-path: polygon(1.4em 0, 100% 0, 100% calc(100% - 1.4em), calc(100% - 1.4em) 100%, 0 100%, 0 1.4em);
background: conic-gradient(from var(--bdr-cut-corner-gradient-border-a), var(--c), color-mix(in oklch, var(--c), #22d3ee 75%), color-mix(in srgb, var(--c) 30%, transparent) 30% 45%, color-mix(in oklch, var(--c), #22d3ee 75%), var(--c) 70%, color-mix(in srgb, var(--c) 30%, transparent) 85%, var(--c));
color: color-mix(in srgb, var(--c) 30%, #fff);
font-family: ui-monospace, "SFMono-Regular", Menlo, monospace;
letter-spacing: 0.18em;
text-transform: uppercase;
animation: bdr-cut-corner-gradient-border-spin 4s linear infinite;
}
.bdr-cut-corner-gradient-border::before {
content: "";
position: absolute;
inset: 0.18em;
z-index: -1;
clip-path: polygon(1.295em 0, 100% 0, 100% calc(100% - 1.295em), calc(100% - 1.295em) 100%, 0 100%, 0 1.295em);
background: color-mix(in srgb, var(--c) 10%, #0b0f19);
}
@keyframes bdr-cut-corner-gradient-border-spin {
to { --bdr-cut-corner-gradient-border-a: 360deg; }
}
@media (prefers-reduced-motion: reduce) {
.bdr-cut-corner-gradient-border, .bdr-cut-corner-gradient-border *, .bdr-cut-corner-gradient-border::before, .bdr-cut-corner-gradient-border::after, .bdr-cut-corner-gradient-border *::before, .bdr-cut-corner-gradient-border *::after {
animation-duration: 0.01ms !important;
animation-iteration-count: 1 !important;
transition-duration: 0.01ms !important;
}
}Customizing this snippet
- Color: set
--bdr-coloron the element or a parent. Currently previewing#3b82f6. - Base size: set
--bdr-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.