html,body{margin:0;padding:0;overflow:hidden}#start-screen{position:fixed;top:0;right:0;bottom:0;left:0;background:#1a1a2e;display:flex;flex-direction:column;align-items:center;justify-content:center;z-index:10;font-family:monospace}#play-btn{padding:1rem 3rem;font-size:1.5rem;font-family:monospace;background:#ca4158;color:#fff;border:none;cursor:pointer;border-radius:4px}.diff-btn{padding:.75rem 2.5rem;font-size:1.2rem;background:#ffffff1a;color:#fff;border:2px solid white;cursor:pointer;letter-spacing:.1em;transition:background .2s}.diff-btn:hover{background:#ffffff40}