*{box-sizing:border-box;margin:0;padding:0}.container{align-items:center;background-color:#fff;display:flex;height:100vh;justify-content:center;transition:background-color .3s ease,color .3s ease;width:100%}.container.dark{background-color:#0f0f0f}.message{color:#1a1a2e;font-family:sans-serif;font-size:2.5rem;font-weight:600;letter-spacing:.05em;text-align:center;transition:color .3s ease}.container.dark .message{color:#fff}.toggle{align-items:center;background:none;border:2px solid;border-radius:50%;color:#1a1a2e;cursor:pointer;display:flex;font-size:1.1rem;height:2.5rem;justify-content:center;position:fixed;right:1.25rem;top:1.25rem;transition:opacity .2s ease;width:2.5rem}.container.dark .toggle{color:#fff}.toggle:hover{opacity:.7}