const delay = 60 // seconds
* 60 // minutes
* 24 // hours
* 30 // days
* 1000 // in ms;<body>
<script>
const color = localStorage.getItem('skin-color');
if (color != null)
document.documentElement.style.setProperty('--skin-color', color);
</script>function setColor(color) {
document.documentElement.style.setProperty('--skin-color', color);
localStorage.setItem('skin-color', color);
}<button onclick="setColor('red')">red</button>
<button onclick="setColor('#1fc586')">#1fc586</button>
sqrt(vmax**2 + vmin**2) - vmax