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Added 2 Aug 2026
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blue-marching-ants-border-3345
Blue Marching Ants Border
Borders & Outlines

Blue Marching Ants Border

Dashed blue outline whose dashes crawl around the box — the classic dropzone cue.

Borders & Outlinesborderdashedmarching-antsdropzoneblue
lines of CSS
35lines of CSS
dependencies
0dependencies
browser, for years
Everybrowser, for years
stops under reduced motion
Guardedstops under reduced motion
Backdrop
Drop files here
Open a live copy in

Vue, Svelte, styled-components and Tailwind exports are part of Pro. HTML, CSS and React are free forever.

blue-marching-ants-border-3345.css
.fx-bd-ants-blue-3344 {
  padding: 1.1rem 1.6rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: #e2e8f0;
  border-radius: 0.5rem;
  background-color: #0f172a;
  background-image:
    linear-gradient(90deg, #3b82f6 50%, transparent 0),
    linear-gradient(90deg, #3b82f6 50%, transparent 0),
    linear-gradient(0deg, #3b82f6 50%, transparent 0),
    linear-gradient(0deg, #3b82f6 50%, transparent 0);
  background-repeat: repeat-x, repeat-x, repeat-y, repeat-y;
  background-size: 16px 2px, 16px 2px, 2px 16px, 2px 16px;
  background-position: 0 0, 0 100%, 0 0, 100% 0;
  animation: fx-bd-ants-blue-3344-ants 0.5s linear infinite;
}
@keyframes fx-bd-ants-blue-3344-ants {
  to { background-position: 16px 0, -16px 100%, 0 -16px, 100% 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .fx-bd-ants-blue-3344,
  .fx-bd-ants-blue-3344::before,
  .fx-bd-ants-blue-3344::after,
  .fx-bd-ants-blue-3344 *,
  .fx-bd-ants-blue-3344 *::before,
  .fx-bd-ants-blue-3344 *::after {
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    animation-delay: 0ms !important;
    transition-duration: 1ms !important;
    transition-delay: 0ms !important;
  }
}
blue-marching-ants-border-3345.html
<div class="fx-bd-ants-blue-3344">Drop files here</div>

What do I do with this?

  1. Put blue-marching-ants-border-3345.css anywhere your page already loads CSS from — in Next.js that is app/globals.css, or any stylesheet with a <link> in your HTML.
  2. Then put the class on the element you want it on: <button class="fx-bd-ants-blue-3344">. The CSS does nothing until a class name in it matches something on the page.
  • Link the stylesheet, then paste the markup wherever you need it.
npx hoverlab add blue-marching-ants-border-3345

What's included

  • The markup and the stylesheet, in whichever framework you pick
  • No runtime dependencies

Works with

  • React
  • Vue
  • Svelte
  • Tailwind
  • styled-components
  • Plain CSS

npx hoverlab add blue-marching-ants-border-3345

Or over MCP, from your editor's agent — no account needed.

License

Free to read, copy and install, for personal and non-commercial projects. Shipping it in client work or a paid product needs Pro ($79 once). The source lands in your repo and stops being ours — no attribution, nothing to upgrade.

Was this useful?

Motion safety

Static estimate, read from the CSS

Reduced motion
Guarded

Ships a prefers-reduced-motion block, so the loop settles into its end state for visitors who ask for less motion.

What it animates
Repaints

Animates background-position. No reflow, but the browser repaints every frame, which is fine for one element and costly across many.

Flashing (WCAG 2.3.1)
No flashing found

No repeating change in opacity, colour or brightness large enough to count as a flash.

Layout shift (CLS)
No shift expected

Nothing it animates moves or resizes the box in flow. A category from the CSS, not a measurement for this effect.

Every row is read from the shipped CSS. Only a figure marked measured came from a browser. Customizing the speed changes the timing, so recheck a customized copy. How it is computed

29 more effects in Borders & Outlines

All of them free to read, copy and install — no account, no locked tiles, no watermarked preview. The whole catalog is open, and so are the API and the CLI.

Browse Borders & Outlines

Shipping one commercially

Copying the code is free. Putting it in client work or a paid product is what Pro is for — the licence, not the access.

  • A commercial licence for everything in the catalog
  • Unlimited bundle exports, in Vue, Svelte and Tailwind
  • One payment — no subscription, nothing to renew
Pro — $79 once

7 variations of Blue Marching Ants Border

Finished looks, each one a position in the customizer above. Copy any of them, or open it and keep moving the sliders.