vitalso78,
<!DOCTYPE html>
<html>
<head>
<title>css localStorage</title>
<meta charset="UTF-8" />
<base href="https://delivery.foodsonic.ru/" />
<link rel="stylesheet" href="https://delivery.foodsonic.ru/dark.css" id="theme-css-file" />
<script>
document.addEventListener("DOMContentLoaded", function() {
const styleElement = document.querySelector("#theme-css-file");
const button = document.querySelector("#SuperButton");
let CssFilePath = localStorage.getItem("CssFilePath");
if (CssFilePath) styleElement.href = CssFilePath;
button.addEventListener("click", function() {
let href = "https://delivery.foodsonic.ru/light.css";
button.classList.toggle("switch-on");
if(button.classList.contains("switch-on")) href = "https://delivery.foodsonic.ru/dark.css";
styleElement.href = href;
localStorage.setItem("CssFilePath", href);
})
});
</script>
</head>
<body>
<div>Switch theme:</div>
<div class="switch-btn switch-on" id="SuperButton" name="SuperButton">click me SuperButton</div>
</body>
</html>