JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Заголовок</title> 
  <style>
.header {
  position: relative;
  border: 1px solid black;
}
.block1 {
  width: 100px;
  background: red;
}
.block2 {
  width: 100px;
  background: gray;
  height: 200px;
}
.block3 {
  margin: 10px;
  background: green;
  position: absolute;
  top: 0;
  right: 0;
}
 </style>
</head>
<body>
<div class="header">
  <div class="block1">Я верхний левый блок</div>
  <div class="block2">Я нижний левый блок</div>
  
  <div class="block3">Forever alone</div>
</div>

</body>
</html>