JSFiddle - React, Tailwind, and code Playground

HTML

<div class="maincontainer">
  <div id="block1" class="blocks">
  </div>
  <div id="block2" class="blocks">
  </div>
</div>

CSS

.maincontainer {
  display: block;
  background-color: black;
  margin: 0 auto;
  width: 100%;
  min-width: 600px;
  height: 250px;
}

body {
  background-color: white;
}

.blocks {
  position: absolute;
  display: inline-block;
  width: 100px;
  height: 50px;
}

#block1 {
  background-color: green;
  top: 100px;
  left: calc(50% - 50px);
}

#block2 {
  background-color: red;
  top: 100px;
  left: 25%;
}

@media (max-width: 600px) {
  #block2 {
    left: auto;
    right: calc(50% + 50px);
  }
}