diff --git a/app/achievements/AchievementsClient.tsx b/app/achievements/AchievementsClient.tsx
index 38c35dc8b..53efb8474 100644
--- a/app/achievements/AchievementsClient.tsx
+++ b/app/achievements/AchievementsClient.tsx
@@ -236,7 +236,7 @@ export function UnlockCelebration({
       );
       if (!focusable || focusable.length === 0) return;
       const first = focusable[0];
-      const last = focusable[focusable.length - 1];
+      const last = focusable.at(-1);
       if (event.shiftKey && document.activeElement === first) {
         event.preventDefault();
         last.focus();
diff --git a/app/api/streak/live/route.ts b/app/api/streak/live/route.ts
index b7745f720..1f979fb8d 100644
--- a/app/api/streak/live/route.ts
+++ b/app/api/streak/live/route.ts
@@ -16,7 +16,7 @@ export async function GET(request: Request) {
   let interval = 30; // default 30s
   if (intervalParam) {
     const parsed = parseInt(intervalParam, 10);
-    if (!isNaN(parsed)) {
+    if (!Number.isNaN(parsed)) {
       interval = Math.max(30, Math.min(parsed, 300));
     }
   }
diff --git a/components/AdvancedColorPicker.tsx b/components/AdvancedColorPicker.tsx
index 1ec62dddc..9e692bc52 100644
--- a/components/AdvancedColorPicker.tsx
+++ b/components/AdvancedColorPicker.tsx
@@ -397,7 +397,7 @@ export default function AdvancedColorPicker({
           {hexError && (
             <p className="-mt-1.5 text-[10px] text-red-400 dark:text-red-500">{hexError}</p>
           )}
-          {eyedropperSupported === false && (
+          {eyedropperSupported ! && (
             <p className="-mt-1.5 text-[10px] text-amber-500 dark:text-amber-400">
               Eyedropper not supported in this browser
             </p>