diff --git a/components/layout/AnnouncementBanner.tsx b/components/layout/AnnouncementBanner.tsx
index 29b7a02..2e3c880 100644
--- a/components/layout/AnnouncementBanner.tsx
+++ b/components/layout/AnnouncementBanner.tsx
@@ -4,7 +4,30 @@ import { useEffect, useState } from 'react'
 import Link from 'next/link'
 import { activeAnnouncement } from '@/data/announcements'
 
-type WrapperProps = { children: React.ReactNode; className?: string }
+type BannerLinkProps = {
+  href: string
+  external?: boolean
+  children: React.ReactNode
+  className?: string
+}
+
+/** Declared at module scope — defining this inside the render remounted the
+ *  banner contents on every render and reset their state. */
+function BannerLink({ href, external, children, className }: BannerLinkProps) {
+  if (external) {
+    return (
+      <a href={href} target="_blank" rel="noopener noreferrer" className={className}>
+        {children}
+      </a>
+    )
+  }
+
+  return (
+    <Link href={href} className={className}>
+      {children}
+    </Link>
+  )
+}
 
 export default function AnnouncementBanner() {
   const [visible, setVisible] = useState(false)
@@ -20,6 +43,9 @@ export default function AnnouncementBanner() {
     // Check dismiss state
     if (localStorage.getItem(`banner_dismissed_${id}`)) return
 
+    // localStorage does not exist during SSR, so dismissal can only be resolved
+    // after mount. The banner starts hidden and reveals itself here.
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     setVisible(true)
   }, [])
 
@@ -32,25 +58,17 @@ export default function AnnouncementBanner() {
     setVisible(false)
   }
 
-  const LinkOrA = external
-    ? ({ children, className }: WrapperProps) => (
-        <a href={href} target="_blank" rel="noopener noreferrer" className={className}>
-          {children}
-        </a>
-      )
-    : ({ children, className }: WrapperProps) => (
-        <Link href={href} className={className}>
-          {children}
-        </Link>
-      )
-
   return (
     <div className="w-full bg-[#3b1445] border-b border-[#5c2070]">
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
         <div className="flex items-center justify-between gap-3 h-10">
 
           {/* Left: badge + message (clickable) */}
-          <LinkOrA className="flex items-center gap-3 flex-1 min-w-0 overflow-hidden group">
+          <BannerLink
+            href={href}
+            external={external}
+            className="flex items-center gap-3 flex-1 min-w-0 overflow-hidden group"
+          >
             {/* Badge */}
             <span className="font-mono text-[10px] uppercase tracking-widest text-[#00FF41] border border-[#00FF41] px-1.5 py-0.5 shrink-0 leading-none">
               {label}
@@ -64,13 +82,17 @@ export default function AnnouncementBanner() {
                 <span className="ml-16 sm:hidden" aria-hidden="true">{message}</span>
               </span>
             </span>
-          </LinkOrA>
+          </BannerLink>
 
           {/* Right: "View Event →" + dismiss */}
           <div className="flex items-center gap-3 shrink-0">
-            <LinkOrA className="font-mono text-xs text-[#c084d8] hover:text-white transition-colors hidden sm:block whitespace-nowrap">
+            <BannerLink
+              href={href}
+              external={external}
+              className="font-mono text-xs text-[#c084d8] hover:text-white transition-colors hidden sm:block whitespace-nowrap"
+            >
               View Fundraising Event →
-            </LinkOrA>
+            </BannerLink>
 
             <button
               onClick={dismiss}
diff --git a/components/telehash/CountdownTimer.tsx b/components/telehash/CountdownTimer.tsx
index f4e650f..1659b29 100644
--- a/components/telehash/CountdownTimer.tsx
+++ b/components/telehash/CountdownTimer.tsx
@@ -35,6 +35,9 @@ export default function CountdownTimer({ targetDate, endDate }: CountdownTimerPr
   const [concluded, setConcluded] = useState(false)
 
   useEffect(() => {
+    // The countdown reads the client clock, so it stays hidden until after
+    // hydration to avoid a server/client mismatch.
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     setMounted(true)
     if (!targetDate) return
 
diff --git a/components/ui/Logo.tsx b/components/ui/Logo.tsx
index c04c8a0..a1634fd 100644
--- a/components/ui/Logo.tsx
+++ b/components/ui/Logo.tsx
@@ -68,7 +68,6 @@ export default function Logo({
       {/* Dark mode: browser picks this source when prefers-color-scheme: dark */}
       <source media="(prefers-color-scheme: dark)" srcSet={asset.black} />
       {/* Light mode fallback */}
-      {/* eslint-disable-next-line @next/next/no-img-element */}
       <img
         src={asset.white}
         alt={alt}
diff --git a/eslint.config.mjs b/eslint.config.mjs
new file mode 100644
index 0000000..70cbfb5
--- /dev/null
+++ b/eslint.config.mjs
@@ -0,0 +1,7 @@
+import next from "eslint-config-next";
+
+// eslint-config-next ships its own ignores for .next/, out/, build/ and
+// next-env.d.ts, so they are not repeated here.
+const config = [...next];
+
+export default config;
diff --git a/package.json b/package.json
index 0760a34..1f574f9 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "lint": "next lint",
+    "lint": "eslint .",
     "test": "node --test tests/"
   },
   "keywords": [],