Liquid Glass Design System

Apple-inspired translucent glass UI with depth, refraction, and ambient light response.

Core Principles

1. Translucency — Surfaces reveal layered content beneath via backdrop blur
2. Depth — Elements float on distinct z-layers with realistic shadows
3. Ambient Response — Glass tints shift based on underlying content color
4. Minimal Chrome — Borders are subtle; shape and blur define boundaries
5. Motion — Transitions feel physical: spring-based, with inertia

Usage

Import the token file in your CSS:

@import 'references/tokens.css';

CSS Tokens Reference

All tokens are defined in references/tokens.css. Key categories:

Category	Prefix	Example
Glass backgrounds	--lg-bg-*	--lg-bg-primary
Blur	--lg-blur-*	--lg-blur-md
Borders	--lg-border-*	--lg-border-color
Shadows	--lg-shadow-*	--lg-shadow-elevated
Radius	--lg-radius-*	--lg-radius-lg
Animation	--lg-duration-*	--lg-duration-normal

Component Patterns

Glass Card

.glass-card {
  background: var(--lg-bg-primary);
  backdrop-filter: blur(var(--lg-blur-md));
  -webkit-backdrop-filter: blur(var(--lg-blur-md));
  border: 1px solid var(--lg-border-color);
  border-radius: var(--lg-radius-lg);
  box-shadow: var(--lg-shadow-elevated);
  transition: transform var(--lg-duration-normal) var(--lg-easing-spring);
}

.glass-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--lg-shadow-high);
}

Glass Toolbar

.glass-toolbar {
  background: var(--lg-bg-toolbar);
  backdrop-filter: blur(var(--lg-blur-lg)) saturate(var(--lg-saturate));
  -webkit-backdrop-filter: blur(var(--lg-blur-lg)) saturate(var(--lg-saturate));
  border-bottom: 1px solid var(--lg-border-subtle);
}

Glass Button

.glass-btn {
  background: var(--lg-bg-interactive);
  backdrop-filter: blur(var(--lg-blur-sm));
  border: 1px solid var(--lg-border-color);
  border-radius: var(--lg-radius-md);
  transition: all var(--lg-duration-fast) var(--lg-easing-spring);
}

.glass-btn:active {
  transform: scale(0.97);
  background: var(--lg-bg-pressed);
}

Glass Modal Overlay

.glass-overlay {
  background: var(--lg-bg-scrim);
  backdrop-filter: blur(var(--lg-blur-xl));
}

.glass-modal {
  background: var(--lg-bg-elevated);
  border: 1px solid var(--lg-border-color);
  border-radius: var(--lg-radius-xl);
  box-shadow: var(--lg-shadow-high);
}

Dark / Light Mode

Tokens auto-switch via prefers-color-scheme. Light mode uses white-tinted glass; dark mode uses dark-tinted glass with higher blur to maintain readability.

/* Force a mode on a subtree */
.light-glass { color-scheme: light; }
.dark-glass  { color-scheme: dark; }

Animations

Use spring-based easing for physical feel:

/* Entry */
@keyframes glass-enter {
  from { opacity: 0; transform: scale(0.95) translateY(8px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

.glass-animate-in {
  animation: glass-enter var(--lg-duration-normal) var(--lg-easing-spring) both;
}

Accessibility

• Ensure contrast-ratio ≥ 4.5:1 for text over glass surfaces
• Respect prefers-reduced-motion — disable blur animations, use opacity-only transitions
• Provide prefers-contrast: high overrides that replace translucent backgrounds with solid ones