Release Notes for Safari Technology Preview 245

Safari Technology Preview 245 is available for macOS Tahoe and Sequoia. Key highlights include new CSS features (case-sensitive modifier `s` in attribute selectors, `:host:has()` compound selector support), JavaScript static `import defer` semantics, and MathML operator dictionary improvements. The release fixes numerous CSS layout bugs involving `aspect-ratio`, flex containers, and `:has()` selector performance. Other fixes address HTML performance regressions for dynamic `<img>` insertion, WebRTC screen sharing quality issues, rendering bugs with `filter: blur()` and `drop-shadow`, SVG rendering issues, and Web Extensions compatibility problems including Cloudflare bot challenge pages.