Transparent Gradient Border
A rotating gradient border with a see-through middle, so it sits on any background or image. A mask with mask-composite exclude cuts the inside out of a conic-gradient layer.
Also known as: gradient border transparent background css, gradient border without background, see-through gradient border.
See-through middle
HTML
<div class="bdr-transparent-gradient-border">See-through middle</div>
CSS
@property --bdr-transparent-gradient-border-a {
syntax: "<angle>";
inherits: false;
initial-value: 0deg;
}
.bdr-transparent-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;
}
.bdr-transparent-gradient-border::before {
content: "";
position: absolute;
inset: 0;
padding: 0.2em;
border-radius: inherit;
background: conic-gradient(from var(--bdr-transparent-gradient-border-a), var(--c), color-mix(in oklch, var(--c), #ec4899 80%), var(--c));
-webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
-webkit-mask-composite: xor;
mask: linear-gradient(#000 0 0) content-box exclude, linear-gradient(#000 0 0);
pointer-events: none;
animation: bdr-transparent-gradient-border-spin 4s linear infinite;
}
@keyframes bdr-transparent-gradient-border-spin {
to { --bdr-transparent-gradient-border-a: 360deg; }
}
@media (prefers-reduced-motion: reduce) {
.bdr-transparent-gradient-border, .bdr-transparent-gradient-border *, .bdr-transparent-gradient-border::before, .bdr-transparent-gradient-border::after, .bdr-transparent-gradient-border *::before, .bdr-transparent-gradient-border *::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.
<div class="relative grid h-[8.5em] w-[15em] place-items-center rounded-2xl font-semibold">
<div class="pointer-events-none absolute inset-0 overflow-hidden rounded-[inherit] p-[3px] [-webkit-mask-composite:xor] [mask-composite:exclude] [mask:linear-gradient(#000_0_0)_content-box,linear-gradient(#000_0_0)]">
<div class="absolute inset-[-100%] animate-spin bg-[conic-gradient(#3b82f6,#ec4899,#3b82f6)] [animation-duration:4s]"></div>
</div>
See-through middle
</div>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.