Choosing adjacent sibling in css

Question

I need to select the "trangle-border" in my css only if the following div is present:

<div class="option en selected" data-dojo-attach-point="LanguageEnNode">Anglais</div>

This is what I did - What am I missing?

.triangle-border [class="option en selected"] {
  bottom: 7.5vh;
}

<div class="help welcomeScreen" widgetid="Bubble" id="Bubble">
  <div class="triangle-border">
    <div class="language panel">
      <div class="option en selected" data-dojo-attach-point="LanguageEnNode">Anglais</div>
      <div class="option es hidden" data-dojo-attach-point="LanguageEsNode">Espagnol</div>
      <div class="option fr" data-dojo-attach-point="LanguageFrNode">Francais</div>
    </div>
  </div>
</div>