fix: popup background color in dark mode (#176)

Fixes #175


![image](https://github.com/user-attachments/assets/dde3ab66-f5e2-4363-a975-90fe7c86de7e)


![image](https://github.com/user-attachments/assets/4dc6a6e5-d65d-4091-84c1-88364f710e12)


![image](https://github.com/user-attachments/assets/fb1983ae-7332-4161-a225-dd964a8103fa)

proxy/css/ui.css

@@ -59,6 +59,21 @@ body {
   background: rgba(var(--bs-body-bg-rgb), 0.8);
   color: var(--bs-body-color);
 }
+.maplibregl-popup-content {
+  background: var(--bs-body-bg);
+}
+.maplibregl-popup-anchor-top .maplibregl-popup-tip {
+  border-bottom-color: var(--bs-body-bg);
+}
+.maplibregl-popup-anchor-bottom .maplibregl-popup-tip {
+  border-top-color: var(--bs-body-bg);
+}
+.maplibregl-popup-anchor-right .maplibregl-popup-tip {
+  border-left-color: var(--bs-body-bg);
+}
+.maplibregl-popup-anchor-left .maplibregl-popup-tip {
+  border-right-color: var(--bs-body-bg);
+}
 [data-bs-theme="dark"] .maplibregl-ctrl-scale {
   border-top-color: var(--bs-border-color);
   border-right-color: var(--bs-light);