CSS Tip

Corner-only borders with hover effect

Add corner-only borders to your images with a nice hover effect

Images with corner-only border

img {
  --s: 50px; /* the size on the corner */
  --t: 5px;  /* the thickness of the border */
  --g: 20px; /* the gap between the border and image */
  
  padding: calc(var(--g) + var(--t));
  outline: var(--t) solid #B38184; /* the color here */
  outline-offset: calc(-1*var(--t));
  mask:
    conic-gradient(at var(--s) var(--s),#0000 75%,#000 0)
    0 0/calc(100% - var(--s)) calc(100% - var(--s)),
    linear-gradient(#000 0 0) content-box;
  transition: .4s;
}
img:hover {
  outline-offset: calc(var(--g)/-1);
}

See the Pen Corner-only borders with hover effect by Temani Afif (@t_afif) on CodePen.

More detail: verpex.com/blog/website-tips/css-effects-on-images-ii