Slack

index.html

<section class="loading">
  For new sidebar colors, click your <br>workspace name, then Preferences > <br> Sidebar > Theme
  <span class="loading__author"> 
    - Your friends at Slack
  </span>
  <span class="loading__anim">
  </span>
</section>

slack.markdown

Slack

A Pen by Devesh Kaushik on CodePen.

License.

style.css

body{
  display : flex;
  justify-content : center;
  align-items : center;
  min-height : 100vh;
}
.loading {  
  max-width: 50%; 
  line-height: 1.4;
  font-size: 1.2rem;
  font-weight: bold;
  text-align: center;
}
.loading__author{
  font-weight : normal;
  font-size : 0.9rem;
  color : rgba(189,189,189,1);
  margin : 0.6rem 0 2rem 0;
  display : block;
}
.loading__anim{
  width : 35px;
  height : 35px;
  display : inline-block;
  border : 5px solid rgba(189,189,189,0.25);
  border-left-color : rgba(3,155,229 ,1);
  border-top-color : rgba(3,155,229 ,1);
  border-radius : 50%;
  animation: rotate 600ms infinite linear;
}
@keyframes rotate { to {  transform: rotate(1turn) }}