Adjust AdminPanel spacing and enhance modal UI effects

Reduced grid gap in AdminPanel for better spacing consistency. Improved modal overlay and card design with stronger darkening, added blur, and responsive adjustments to prevent layout issues in smaller viewports.

frontend/src/styles/styles.js

@@ -189,25 +189,32 @@ export const styles = {
   modalOverlay: {
     position: "fixed",
     inset: 0,
-    background: "rgba(0,0,0,0.65)",
+    background: "rgba(0,0,0,0.78)",      // stärker abdunkeln
+    backdropFilter: "blur(6px)",         // Hintergrund weich (macht viel aus)
     display: "flex",
     alignItems: "center",
     justifyContent: "center",
     padding: 16,
     zIndex: 9999,
     animation: "fadeIn 160ms ease-out",
+    overflowY: "auto",                   // falls Viewport zu klein
   },
+
   modalCard: {
     width: "100%",
     maxWidth: 560,
     borderRadius: 18,
     border: `1px solid rgba(233,216,166,0.18)`,
-    background: "linear-gradient(180deg, rgba(20,20,24,0.92), rgba(12,12,14,0.86))",
+    background: "linear-gradient(180deg, rgba(20,20,24,0.95), rgba(12,12,14,0.92))",
     boxShadow: "0 18px 55px rgba(0,0,0,0.70)",
     padding: 14,
-    backdropFilter: "blur(6px)",
+    backdropFilter: "blur(8px)",
     animation: "popIn 160ms ease-out",
     color: stylesTokens.textMain,
+
+    // neu: damit es nie “kaputt” aussieht
+    maxHeight: "calc(100dvh - 32px)",
+    overflow: "auto",
   },
   modalHeader: {
     display: "flex",