diff --git a/website/src/_includes/navbar.html b/website/src/_includes/navbar.html
index 6ce8f71dac..20039e282b 100644
--- a/website/src/_includes/navbar.html
+++ b/website/src/_includes/navbar.html
@@ -274,11 +274,14 @@ window.addEventListener('click',(e)=>{
         }
     }
     else if(e.target.closest('.nav-toggle-btn')){
-        document.body.classList.toggle('lock-scroll');
         if(nav.classList.contains('open')){
             nav.classList.remove('open');
+            document.getElementById('mobile-header').classList.remove('nav-open');
+            document.documentElement.classList.remove('lock-scroll');
         }
         else{
+            document.documentElement.classList.add('lock-scroll');
+            document.getElementById('mobile-header').classList.add('nav-open');
             nav.classList.add('open');
         }
     }
diff --git a/website/src/css/design3-nav.css b/website/src/css/design3-nav.css
index 7694d5244d..1e27141c9b 100644
--- a/website/src/css/design3-nav.css
+++ b/website/src/css/design3-nav.css
@@ -538,4 +538,37 @@ button#cross-btn {
         left: 0;
         right: auto;
     }
+}
+
+#mobile-header.cover {
+    background: #d7fbfe09;
+}
+
+.dark #mobile-header.cover {
+    background: #283b630a;
+}
+
+#mobile-header.main {
+    background: #ffefd60e;
+}
+
+.dark #mobile-header.main {
+    background: #fff6e00a;
+}
+
+#mobile-header.nav-open {
+    background: #ffffff0c;
+}
+
+.dark #mobile-header.nav-open {
+    background: #0a0f2b0f;
+}
+
+#mobile-header.footer {
+    background: #d3e9ff11;
+}
+
+.dark #mobile-header.footer {
+    background: #080d250e;
+    --nav-color: #ffffff;
 }
\ No newline at end of file
diff --git a/website/src/css/design3.css b/website/src/css/design3.css
index fdcf98a95d..d82e8e348c 100644
--- a/website/src/css/design3.css
+++ b/website/src/css/design3.css
@@ -218,12 +218,12 @@ html {
 
 html,
 body {
-    background: #ccf9fc;
+    background: #ffffff;
 }
 
 .dark html,
 .dark body {
-    background: #2d3f64;
+    background: #0a0f2b;
 }
 
 @media screen and (min-width: 950px) {
@@ -301,13 +301,21 @@ p {
 }
 
 /* Make the viewport the scroll snap container (works in iOS Safari) */
-html,
-body {
+html {
     scroll-snap-type: y mandatory;
     scroll-behavior: smooth;
     -webkit-overflow-scrolling: touch;
 }
 
+html.lock-scroll {
+    scroll-snap-type: none !important;
+}
+
+.lock-scroll body {
+    overflow: hidden !important;
+    height: 100svh;
+}
+
 section.page {
     min-height: 100svh;
     /* fallback */
diff --git a/website/src/index.html b/website/src/index.html
index 44afe69804..7d298563ea 100644
--- a/website/src/index.html
+++ b/website/src/index.html
@@ -250,6 +250,105 @@ active_home: true
         io.observe(cover);
     })();
     </script>
+    <script>
+    (function sectionHeaderState(){
+        const mobileHeader = document.getElementById('mobile-header');
+        if (!mobileHeader) return;
+
+        const cover     = document.querySelector('.page-1.cover');
+        const messaging = document.getElementById('messaging');
+        const nextweb   = document.getElementById('nextweb');
+        const token     = document.getElementById('token');
+        const roadmap   = document.getElementById('roadmap');
+        const directory = document.getElementById('directory');
+        const footer    = document.querySelector('footer, .footer, #footer');
+
+        const observed = [
+            { key: 'cover',  el: cover },
+            { key: 'main',   el: messaging },
+            { key: 'main',   el: nextweb },
+            { key: 'main',   el: token },
+            { key: 'main',   el: roadmap },
+            { key: 'main',   el: directory },
+            { key: 'footer', el: footer }
+        ].filter(t => t.el);
+
+        if (!observed.length) return;
+
+        const MIN_COVER = 0.02;
+
+        function clear(){
+            mobileHeader.classList.remove('cover','main','footer');
+        }
+
+        function apply(key){
+            clear();
+            if (key) mobileHeader.classList.add(key);
+        }
+
+        function viewportCoverageY(el){
+            const r  = el.getBoundingClientRect();
+            const vh = window.innerHeight || document.documentElement.clientHeight;
+            const visibleY = Math.max(0, Math.min(vh, r.bottom) - Math.max(0, r.top));
+            return visibleY / Math.max(1, vh);
+        }
+
+        function computeKeyMax(){
+            const keyMax = { cover: 0, main: 0, footer: 0 };
+            for (const t of observed) {
+                const ratio = viewportCoverageY(t.el);
+                if (ratio > keyMax[t.key]) keyMax[t.key] = ratio;
+            }
+            return keyMax;
+        }
+
+        let lastKey = null;
+        let rafId = null;
+
+        function update(){
+            rafId = null; // Reset RAF flag
+
+            const keyMax = computeKeyMax();
+
+            let bestKey = null, best = MIN_COVER;
+            for (const [k, r] of Object.entries(keyMax)) {
+                if (r > best) { best = r; bestKey = k; }
+            }
+
+            // Only update DOM if state actually changed
+            if (bestKey !== lastKey) {
+                if (bestKey) {
+                    apply(bestKey);
+                } else {
+                    clear();
+                }
+                lastKey = bestKey;
+            }
+        }
+
+        function scheduleUpdate(){
+            if (rafId) return; // Already scheduled
+            rafId = requestAnimationFrame(update);
+        }
+
+        let observer = null;
+
+        if ('IntersectionObserver' in window) {
+            observer = new IntersectionObserver(scheduleUpdate, {
+                threshold: [0, 0.02, 0.1, 0.25, 0.5, 0.75, 1],
+                rootMargin: '0px 0px -35% 0px'
+            });
+            observed.forEach(t => observer.observe(t.el));
+            scheduleUpdate(); // Initial update
+        } else {
+            // Fallback for older browsers
+            ['scroll','resize','load'].forEach(ev => 
+                window.addEventListener(ev, scheduleUpdate, { passive: true })
+            );
+            scheduleUpdate();
+        }
+    })();
+    </script>
 </body>
 
 </html>