Theming with CSS Custom Properties (CSS Variables)

Stephanie Liu has replicated the native Slack theming capabilities in the browser using CSS Variables CSS Custom Properties. The essence of the demo is actually quite simple: define the variables on the :root level, and use ‘m where needed.

:root {
  --column-bg: #ae0001;
  --menu-bg-hover: #680001;
  --active-item: #D3A625;
  --active-item-text: #680001;
  --hover-item: #BE0002;
  --text-color: #FFFFFF;
  --active-presence: #00FFBA;
  --mention-badge: #DE4C0D;
}

.sidebar {
  background: var(--column-bg, #ae0001);
}

Here’s a full working demo:

See the Pen Slack Theming with CSS Custom Properties by Stephanie (@ramenhog) on CodePen.

Theming with CSS Custom Properties →
Slack Theming with CSS Custom Properties →