667: Jen Simmons on Declarative Web Push, Form Control Styling, & More

What It Covers

Jen Simmons from Apple's Safari team discusses declarative web push notifications, form control styling improvements with appearance-based CSS, color contrast algorithms, and Safari's implementation of wide gamut color pickers with display-p3 support.

Key Questions Answered

• •Declarative Web Push: Safari 18.4 ships declarative web push using standardized JSON format instead of service workers, eliminating JavaScript requirements while improving battery efficiency and preventing code expiration issues that affect traditional push implementations on Apple platforms.
• •Color Contrast Algorithm Flaws: The WCAG 2.2 contrast algorithm produces incorrect results for mid-range colors, particularly blues and greens. APCA provides better guidance by considering font size and weight, though it lacks the binary simplicity developers prefer for accessibility compliance decisions.
• •Appearance-Based Form Controls: New appearance-based CSS property standardizes form control shadow DOM structure across browsers, inherits fonts automatically, uses transparent backgrounds by default, and eliminates the need to override decades-old styling quirks that made forms difficult to customize consistently.
• •Input Color Enhancements: Safari 18.4 adds color-space attribute supporting display-p3 wide gamut colors and alpha attribute for opacity control in native color pickers. Developers can now specify initial values using oklch, oklab, lch, or lab color formats directly.
• •Progressive Enhancement Strategy: Safari implements opt-in CSS features like appearance-based-select and declarative push to maintain backward compatibility while enabling new capabilities. This approach prevents breaking existing websites while allowing developers to adopt modern features when ready through explicit property declarations.