<div class="menu"></div>
<div class="close"></div>
<div class="menu-round"></div>
<div class="close-round"></div>

.menu {
  width: 150px; /* control the size */
  aspect-ratio: 1;
  background: linear-gradient(#000 50%, #0000 0) 0 0/100% 40%;
}

.close {
  width: 150px; /* size of the icon */
  aspect-ratio: 1;
  background: 
    conic-gradient(from 90deg at 33% 33%, #0000 90deg, #000 0) 
    100% 100%/60% 60%;
  transform: translateZ(0px) rotate(45deg);
}

.menu-round {
  width: 150px; /* update this to control the size */
  aspect-ratio: 1;
  background:
    radial-gradient(closest-side at 12.5% 25%,#000 96%,#0000) 0 0/80% 40%,
    linear-gradient(#000 50%,#0000 0) top/80% 40% repeat-y;
}

.close-round {
  --s: 150px; /* size */
  width: var(--s);
  aspect-ratio: 1;
  padding: calc(var(--s)*.1);
  box-sizing: border-box;
  background: 
    radial-gradient(closest-side at 50% 12.5%,#000 96%,#0000) top /20% 80% repeat-y,
    radial-gradient(closest-side at 12.5% 50%,#000 96%,#0000) left/80% 20% repeat-x,
    conic-gradient(from 90deg at 33% 33%, #0000 90deg, #000 0)
     100% 100%/60% 60% padding-box content-box;
  transform: translateZ(0) rotate(45deg);
}

body {
  min-height: 100vh;
  margin: 0;
  display: grid;
  grid-auto-flow: column;
  place-content: center;
  gap: 20px;
}