Flexbox

<div class="container">
  <div class="col1">
    <h2>Solar System</h2>
    <p>
      The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly.
    </p>
  </div>
  <div class="col2">
    <h2>The Sun</h2>
    <p>
      The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core.
    </p>
  </div>
</div>

.container {
  display: flex;
}
.col1, .col2 {
  margin: 10px;
  padding: 10px 30px;
  border: 1px solid lightgray;
}


.container {
  display: flex;
}
.col1, .col2 {
  margin: 10px;
  padding: 10px 30px;
  border: 1px solid lightgray;
}
.col1 {
  flex-basis: 40%;
}
.col2 {
  flex-basis: 60%;
}
