CSS Tip

Inner curve/notch shape using CSS mask

Create an inner curve/notch shape using CSS mask and a few lines of code

CSS only inner curve/notch shape

.shape {
  --r: 20px; /* control the rounded part*/
  --s: 40px; /* control the size of the cut */
  --a: 40deg; /* control the depth of the curvature*/
  
  --_m:0/calc(2*var(--r)) var(--r) no-repeat
    radial-gradient(50% 100% at bottom,#000 calc(100% - 1px),#0000);
  --_d:(var(--s) + var(--r))*cos(var(--a));
  mask:
    calc(50% + var(--_d)) var(--_m),calc(50% - var(--_d)) var(--_m),
    radial-gradient(var(--s) at 50% calc(-1*sin(var(--a))*var(--s)),
      #0000 100%,#000 calc(100% + 1px)) 0 calc(var(--r)*(1 - sin(var(--a)))) no-repeat,
    linear-gradient(90deg,#000 calc(50% - var(--_d)),#0000 0 calc(50% + var(--_d)),#000 0);
}

See the Pen Untitled by Temani Afif (@t_afif) on CodePen.

More CSS Shapes: css-shape.com

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