Glassmorphism & Frosted Backdrops (`backdrop-filter`)

Modern operating systems (macOS Tahoe/Sonoma, iOS, Windows Fluent) use frosted glass materials to create subtle depth without completely obscuring background context.

In web design systems, this is achieved using backdrop-filter: blur():

.sticky-header {
  background-color: rgba(11, 15, 25, 0.8);
  backdrop-filter: blur(12px) saturate(160%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

• Translucent Fill: 70–85% opacity allows content scrolling behind to peek through.
• Blur & Saturation: blur(12px) softens underlying text so it doesn't distract; saturate(160%) prevents muddy grayish tones.
• Fallback: Always supply a solid background fallback for older browsers or low-power modes.