ul
  li: a メニュー01
  li: a
    | メニュー02
    br
    | メニュー02
  li: a メニュー03メニュー03メニュー03
View Compiled 
ul {
  display: flex;
  justify-content: space-between;
  width: 100%;
  max-width: 600px;
  margin: 0 auto;
  li {
    display: flex;
    width: 32%;
    a {
      background-color: gray;
      box-sizing: border-box;
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      width: 100%;
      padding: 12px 30px;
    }
  }
}
View Compiled

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.