JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
		<div id="b1">первый блок</div>
		<div id="b2">второй блок</div>
	</div>

CSS

#b1 {
				background:red;   
}
#b2 {
  background:green;  
}

JavaScript

(function(){
		
			var wrapper = document.getElementById('wrapper');
			var b1 = document.getElementById('b1');
			var b2 = document.getElementById('b2');
	
			var state = JSON.parse( localStorage.getItem('data') ) || {last: false};

			if(state.last) {
				wrapper.insertBefore(b2, b1);
				state.last = false;
				localStorage.setItem('data', JSON.stringify(state));
			} else {
				state.last = true;
				localStorage.setItem('data', JSON.stringify(state));
			};
			
		})();