JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">

  <div class="row1">
  </div>

  <div class="row2">
    <div class="panel">
      <div class="panel-title">
        <span>Lorem ipsum. Lorem ipsum. Lorem ipsum. Lorem ipsum. Lorem ipsum. Lorem ipsum. Lorem ipsum.</span>
      </div>
    </div>
  </div>
</div>
<div class="container">

  <div class="row1">
  </div>

  <div class="row2">
    <div class="panel">
      <div class="panel-title">
        <span>Lorem ipsum. </span>
      </div>
    </div>
  </div>
</div>

CSS

.container {
  background: #ddd;
  width: 400px;
  height: 200px;
  padding: 10px;
  display: flex;
}

.container + .container {
  margin-top: 10px;
}

.row1 {
  background: red;
  width: 10%;
}

.row2 {
  background: blue;
  flex-basis: 90%;
  margin-left: 10px;
  padding: 10px;
  display: flex;
  max-width: 90%;
}

.panel {
  background: green;
  width: 50%;
  overflow: hidden;
}

.panel-title {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}