refactor: remove underline animation and update styling

- Remove underline-animation UnoCSS shortcut from uno.config.ts
- Update Navbar component to remove underline-animation classes
- Remove inline script for link transition animations
- Add cover images to existing posts
- Update font and date display classes in index pages
- Modify global CSS for iOS rendering optimization

src/components/PhotoSwipe.astro

@@ -21,6 +21,7 @@
       pswpModule: () => pswp,
       closeSVG: '<svg xmlns="http://www.w3.org/2000/svg" height="2.4rem" viewBox="0 -960 960 960" width="3.8rem" fill="#A0A09F"><path d="M480-424 284-228q-11 11-28 11t-28-11q-11-11-11-28t11-28l196-196-196-196q-11-11-11-28t11-28q11-11 28-11t28 11l196 196 196-196q11-11 28-11t28 11q11 11 11 28t-11 28L536-480l196 196q11 11 11 28t-11 28q-11 11-28 11t-28-11L480-424Z"/></svg>',
       zoomSVG: '<svg xmlns="http://www.w3.org/2000/svg" height="2.4rem" viewBox="0 -960 960 960" width="3.8rem" fill="#A0A09F"><path d="M340-540h-40q-17 0-28.5-11.5T260-580q0-17 11.5-28.5T300-620h40v-40q0-17 11.5-28.5T380-700q17 0 28.5 11.5T420-660v40h40q17 0 28.5 11.5T500-580q0 17-11.5 28.5T460-540h-40v40q0 17-11.5 28.5T380-460q-17 0-28.5-11.5T340-500v-40Zm40 220q-109 0-184.5-75.5T120-580q0-109 75.5-184.5T380-840q109 0 184.5 75.5T640-580q0 44-14 83t-38 69l224 224q11 11 11 28t-11 28q-11 11-28 11t-28-11L532-372q-30 24-69 38t-83 14Zm0-80q75 0 127.5-52.5T560-580q0-75-52.5-127.5T380-760q-75 0-127.5 52.5T200-580q0 75 52.5 127.5T380-400Z"/></svg>',
+      padding: { top: window.innerHeight * 0.1, bottom: window.innerHeight * 0.1, left: window.innerWidth * 0.06, right: window.innerWidth * 0.06 },
       wheelToZoom: true,
       arrowPrev: false,
       arrowNext: false,