body { margin: 0; padding: 0; overflow: scroll; /* Font from https://www.cssfontstack.com/Lucida-Console */ font-family: Lucida Console,Lucida Sans Typewriter,monaco,Bitstream Vera Sans Mono,monospace; background: radial-gradient(circle, transparent 20%, black 80vw), white; } .canvas-holder canvas { padding: 0; margin: auto; display: block; height: 70vh; width: auto; max-width: 100%; } .button { border: 1px solid black; border-radius: 5px; padding: 5px; cursor: pointer; }