use 0.5px media border on high DPI screens on web (#9311)

src/lib/browser.native.ts

@@ -2,3 +2,4 @@ export const isSafari = false
 export const isFirefox = false
 export const isTouchDevice = true
 export const isAndroidWeb = false
+export const isHighDPI = true

src/lib/browser.ts

@@ -6,3 +6,4 @@ export const isFirefox = /firefox|fxios/i.test(navigator.userAgent)
 export const isTouchDevice = window.matchMedia('(pointer: coarse)').matches
 export const isAndroidWeb =
   /android/i.test(navigator.userAgent) && isTouchDevice
+export const isHighDPI = window.matchMedia('(min-resolution: 2dppx)').matches