AI Gradient Input Border
A prompt field ringed by a soft rotating gradient that turns vivid and glows while you type. :focus-within transitions a registered @property that sets the color strength, so nothing jumps.
Also known as: ai search bar gradient border, animated input border css, gradient border input focus.
HTML
<label class="bdr-ai-gradient-input-border"> <svg class="bdr-ai-gradient-input-border-icon" viewBox="0 0 24 24" aria-hidden="true"><path d="M12 2.5l2.2 7.3 7.3 2.2-7.3 2.2-2.2 7.3-2.2-7.3L2.5 12l7.3-2.2z"/></svg> <input class="bdr-ai-gradient-input-border-field" type="text" placeholder="Ask anything..." aria-label="Ask anything"> </label>
CSS
@property --bdr-ai-gradient-input-border-a {
syntax: "<angle>";
inherits: false;
initial-value: 0deg;
}
@property --bdr-ai-gradient-input-border-v {
syntax: "<percentage>";
inherits: false;
initial-value: 50%;
}
.bdr-ai-gradient-input-border {
--c: var(--bdr-color, #3b82f6);
font-size: var(--bdr-size, 16px);
--ring: conic-gradient(from var(--bdr-ai-gradient-input-border-a),
color-mix(in srgb, var(--c) var(--bdr-ai-gradient-input-border-v), #cbd5e1),
color-mix(in srgb, #a855f7 var(--bdr-ai-gradient-input-border-v), #cbd5e1),
color-mix(in srgb, #ec4899 var(--bdr-ai-gradient-input-border-v), #cbd5e1),
color-mix(in srgb, #f59e0b var(--bdr-ai-gradient-input-border-v), #cbd5e1),
color-mix(in srgb, var(--c) var(--bdr-ai-gradient-input-border-v), #cbd5e1));
position: relative;
isolation: isolate;
display: flex;
align-items: center;
gap: 0.6em;
box-sizing: border-box;
width: 17em;
height: 3.2em;
padding: 0 1.2em;
border-radius: 99em;
font-family: system-ui, sans-serif;
cursor: text;
animation: bdr-ai-gradient-input-border-spin 5s linear infinite;
transition: --bdr-ai-gradient-input-border-v 0.4s ease;
}
.bdr-ai-gradient-input-border::before,
.bdr-ai-gradient-input-border::after {
content: "";
position: absolute;
z-index: -1;
border-radius: inherit;
pointer-events: none;
}
.bdr-ai-gradient-input-border::before {
inset: 0.3em 0.8em;
background: var(--ring);
filter: blur(0.8em);
opacity: 0;
transition: opacity 0.4s ease;
}
.bdr-ai-gradient-input-border::after {
inset: 0;
border: 0.14em solid transparent;
background: linear-gradient(#fff, #fff) padding-box, var(--ring) border-box;
}
.bdr-ai-gradient-input-border-icon {
flex: none;
width: 1.1em;
height: 1.1em;
fill: var(--c);
}
.bdr-ai-gradient-input-border-field {
flex: 1;
min-width: 0;
padding: 0;
border: 0;
background: none;
color: #0f172a;
font: inherit;
outline: none;
}
.bdr-ai-gradient-input-border-field::placeholder { color: #94a3b8; }
.bdr-ai-gradient-input-border:hover { --bdr-ai-gradient-input-border-v: 75%; }
.bdr-ai-gradient-input-border:focus-within { --bdr-ai-gradient-input-border-v: 100%; }
.bdr-ai-gradient-input-border:focus-within::before { opacity: 0.6; }
@keyframes bdr-ai-gradient-input-border-spin {
to { --bdr-ai-gradient-input-border-a: 360deg; }
}
@media (prefers-reduced-motion: reduce) {
.bdr-ai-gradient-input-border, .bdr-ai-gradient-input-border *, .bdr-ai-gradient-input-border::before, .bdr-ai-gradient-input-border::after, .bdr-ai-gradient-input-border *::before, .bdr-ai-gradient-input-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.