Donc on PEUT styler les boutons radio sans casser l'accessibilité ni recourir à des libs ou frameworks hippopotamesques.

Hop, dans mon snippetvamp.

La lecture de l'article est intéressante.

input[type="radio"] {
  /* Disable the browser's default radio button styles */
  appearance: none;
  margin: 0;
/ Recreate the circle container /
border: 1px solid black;
background: white;
border-radius: 50%;
/ Center our dot in the container /
display: inline-grid;
place-content: center;
/ Use a pseudo-element to display our "dot" /
&::before {
content: "";
width: 0.75rem;
height: 0.75rem;
border-radius: 50%;
}
/ And display it when the radio button is checked /
&:checked::before {
background: black;
}
}

via https://www.devenet.eu/links/?_X-l9g