diff --git a/app/(core)/components/Funfact.jsx b/app/(core)/components/Funfact.jsx
new file mode 100644
index 0000000..cd3a739
--- /dev/null
+++ b/app/(core)/components/Funfact.jsx
@@ -0,0 +1,52 @@
+import React from "react";
+import funFacts from "../data/facts";
+
+function SparkleIcon() {
+  return (
+    <svg
+      width="16"
+      height="16"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="1.8"
+      strokeLinecap="round"
+      strokeLinejoin="round"
+      aria-hidden="true"
+    >
+      <path d="M12 3v4M12 17v4M5 12H1M23 12h-4M18.4 5.6l-2.8 2.8M8.4 15.6l-2.8 2.8M18.4 18.4l-2.8-2.8M8.4 8.4 5.6 5.6" />
+    </svg>
+  );
+}
+
+function Funfact({ chapterId, setshow }) {
+  const facts = funFacts.find((item) => item.id === chapterId);
+
+  if (!facts) return null;
+
+  return (
+    <div className="fun-fact">
+      <div className="fun-fact-close">
+        <button
+          className="btn-close"
+          onClick={() => {
+            setshow(false);
+          }}
+        >
+          ✕
+        </button>
+      </div>
+
+      <div className="fun-fact-header">
+        <span className="fun-fact-icon">
+          <SparkleIcon />
+        </span>
+        <span className="fun-fact-label">Did you know</span>
+      </div>
+
+      <p className="fun-fact-text">{facts.fact}</p>
+    </div>
+  );
+}
+
+export default Funfact;
diff --git a/app/(core)/components/TopSim.tsx b/app/(core)/components/TopSim.tsx
index d481879..22b4044 100644
--- a/app/(core)/components/TopSim.tsx
+++ b/app/(core)/components/TopSim.tsx
@@ -3,6 +3,8 @@ import simulations from "../data/chapters";
 import { usePathname } from "next/navigation";
 import useMobile from "../hooks/useMobile";
 import useTranslation from "../hooks/useTranslation.ts";
+import Funfact from "./Funfact.jsx";
+import { useEffect, useState } from "react";
 
 export default function TopSim() {
   const { t, meta } = useTranslation();
@@ -10,6 +12,12 @@ export default function TopSim() {
   const location = usePathname();
   const idx = simulations.findIndex((sim) => sim.link === location);
   const isMobile = useMobile();
+  const [show, setshow] = useState(true);
+  useEffect(() => {
+    setTimeout(() => {
+      setshow(false);
+    }, 5000);
+  }, [simulations[idx].id]);
 
   function getPrevious() {
     if (idx === -1) return "/";
@@ -53,7 +61,11 @@ export default function TopSim() {
           content={t("Next")}
         />
       </div>
-      {!isMobile && <div className="top-nav-sim-filler" />}
+      {!isMobile && idx !== -1 && (
+        <div className={`top-nav-sim-filler ${show ? "show" : "hide"}`}>
+          <Funfact chapterId={simulations[idx].id} setshow={setshow} />
+        </div>
+      )}
     </div>
   );
 }
diff --git a/app/(core)/data/facts.js b/app/(core)/data/facts.js
new file mode 100644
index 0000000..2279e50
--- /dev/null
+++ b/app/(core)/data/facts.js
@@ -0,0 +1,63 @@
+const funFacts = [
+  {
+    id: 1,
+    fact: "A perfectly elastic ball can bounce forever in a frictionless environment because no kinetic energy is lost.",
+  },
+  {
+    id: 2,
+    fact: "Vector addition depends on both magnitude and direction, which is why two forces can cancel each other completely.",
+  },
+  {
+    id: 3,
+    fact: "Acceleration is the rate of change of velocity, not speed. An object moving in a circle accelerates even at constant speed.",
+  },
+  {
+    id: 4,
+    fact: "On Earth, all objects fall with the same acceleration (9.8 m/s²) if air resistance is ignored.",
+  },
+  {
+    id: 5,
+    fact: "According to Hooke's Law, the restoring force of a spring is proportional to its displacement from equilibrium.",
+  },
+  {
+    id: 6,
+    fact: "For small angles, the period of a simple pendulum depends only on its length and gravity—not on its mass.",
+  },
+  {
+    id: 7,
+    fact: "Projectile motion combines constant horizontal velocity with vertically accelerated motion due to gravity.",
+  },
+  {
+    id: 8,
+    fact: "Increasing the incline angle increases the component of gravity pulling the object down the slope.",
+  },
+  {
+    id: 9,
+    fact: "An object in uniform circular motion constantly changes direction, requiring centripetal acceleration.",
+  },
+  {
+    id: 10,
+    fact: "The three-body problem has no general analytical solution and often exhibits chaotic behavior.",
+  },
+  {
+    id: 11,
+    fact: "The frequency of a horizontal spring-mass system increases when the spring constant increases.",
+  },
+  {
+    id: 12,
+    fact: "The double pendulum is one of the simplest systems that demonstrates deterministic chaos.",
+  },
+  {
+    id: 13,
+    fact: "In an elastic collision, both momentum and kinetic energy are conserved.",
+  },
+  {
+    id: 14,
+    fact: "Physics simulations often stress CPUs more than GPUs because they involve complex mathematical calculations.",
+  },
+  {
+    id: 15,
+    fact: "The number of collisions between two blocks can reveal the digits of π when their masses follow powers of 100.",
+  },
+];
+export default funFacts;
diff --git a/app/(core)/styles/index.css b/app/(core)/styles/index.css
index b102e9a..a9ff5e6 100644
--- a/app/(core)/styles/index.css
+++ b/app/(core)/styles/index.css
@@ -71,14 +71,17 @@
   background: rgba(0, 184, 184, 0.1);
   box-shadow: 0 4px 12px rgba(0, 184, 184, 0.2);
 }
+
 * {
   margin: 0;
   padding: 0;
   box-sizing: border-box;
 }
+
 html {
   scroll-behavior: smooth;
 }
+
 body {
   color: var(--text-color);
   font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
@@ -257,14 +260,16 @@ nav a:hover::after {
 
 .nav-underline {
   position: absolute;
-  bottom: -3px; /* adjust distance below text */
+  bottom: -3px;
+  /* adjust distance below text */
   left: 0;
   height: 2px;
   background: var(--accent-color);
   border-radius: 2px;
   transition:
     left 0.3s ease,
-    width 0.3s ease; /* smooth slide */
+    width 0.3s ease;
+  /* smooth slide */
   z-index: 100;
 }
 
@@ -432,7 +437,8 @@ nav a:hover::after {
 
 .horizontal-menu-container.open {
   grid-template-rows: 1fr;
-  max-height: 500px; /* Set a max height when open */
+  max-height: 500px;
+  /* Set a max height when open */
   border-radius: var(--border-radius);
   transition:
     grid-template-rows 0.3s ease-out,
@@ -449,7 +455,8 @@ nav a:hover::after {
   padding-bottom: 8px;
 
   -webkit-overflow-scrolling: touch;
-  scrollbar-width: thin; /* Firefox */
+  scrollbar-width: thin;
+  /* Firefox */
   padding: 1rem 0.5rem;
 }
 
@@ -457,6 +464,7 @@ nav a:hover::after {
 .horizontal-menu::-webkit-scrollbar {
   height: 4px;
 }
+
 .horizontal-menu::-webkit-scrollbar-thumb {
   background: rgba(0, 0, 0, 0.1);
   border-radius: 10px;
@@ -661,12 +669,14 @@ nav a:hover::after {
   /* Horizontal filters container */
   .horizontal-menu-container {
     width: 100%;
-    display: none; /* hidden by default */
+    display: none;
+    /* hidden by default */
     overflow: visible;
   }
 
   .horizontal-menu-container.open {
-    display: block; /* show when filter button clicked */
+    display: block;
+    /* show when filter button clicked */
   }
 
   .horizontal-menu {
@@ -760,9 +770,11 @@ main.simulations-page {
   display: flex;
   flex-direction: column;
   align-items: center;
-  justify-content: center; /* ⬅️ key */
+  justify-content: center;
+  /* ⬅️ key */
   padding: 4rem 0;
 }
+
 .simulations-content > * {
   width: 1000%;
 }
@@ -773,46 +785,55 @@ main.simulations-page {
   animation-duration: 1.3s;
   animation-delay: 0s;
 }
+
 .wind-streak.streak1 {
   left: 15%;
   animation-duration: 1.5s;
   animation-delay: 0.1s;
 }
+
 .wind-streak.streak2 {
   left: 25%;
   animation-duration: 1.4s;
   animation-delay: 0.2s;
 }
+
 .wind-streak.streak3 {
   left: 35%;
   animation-duration: 1.6s;
   animation-delay: 0.05s;
 }
+
 .wind-streak.streak4 {
   left: 45%;
   animation-duration: 1.3s;
   animation-delay: 0.15s;
 }
+
 .wind-streak.streak5 {
   left: 55%;
   animation-duration: 1.45s;
   animation-delay: 0.1s;
 }
+
 .wind-streak.streak6 {
   left: 65%;
   animation-duration: 1.5s;
   animation-delay: 0.2s;
 }
+
 .wind-streak.streak7 {
   left: 75%;
   animation-duration: 1.6s;
   animation-delay: 0s;
 }
+
 .wind-streak.streak8 {
   left: 85%;
   animation-duration: 1.4s;
   animation-delay: 0.12s;
 }
+
 .wind-streak.streak9 {
   left: 95%;
   animation-duration: 1.5s;
@@ -824,9 +845,11 @@ main.simulations-page {
     transform: translateX(0) translateY(100%) rotate(10deg);
     opacity: 0;
   }
+
   20% {
     opacity: 0.4;
   }
+
   100% {
     transform: translateX(-30px) translateY(0%) rotate(15deg);
     opacity: 0;
@@ -1147,13 +1170,16 @@ main.simulations-page {
   0% {
     left: -100%;
   }
+
   65% {
     left: 120%;
   }
+
   80% {
     left: 120%;
     opacity: 0;
   }
+
   100% {
     left: -100%;
     opacity: 0;
@@ -1314,7 +1340,8 @@ footer {
   cursor: pointer;
   opacity: 0;
   bottom: -20px;
-  pointer-events: none; /* non cliccabile quando invisibile */
+  pointer-events: none;
+  /* non cliccabile quando invisibile */
   transition:
     transform 0.3s,
     opacity 0.4s ease,
@@ -1368,11 +1395,13 @@ footer {
     opacity: 0;
     transform: translateY(20px);
   }
+
   to {
     opacity: 1;
     transform: translateY(0);
   }
 }
+
 .page-404 > * {
   animation: fadeInUp 0.8s ease-out both;
 }
@@ -1426,6 +1455,7 @@ footer {
   transform: scale(1.05);
   transition: transform 0.5s;
 }
+
 .btn-glow:active {
   transform: scale(0.95);
   transition: transform 0.1s;
@@ -1777,6 +1807,7 @@ footer {
   border-radius: 50%;
   aspect-ratio: 1;
 }
+
 .color-input::-webkit-color-swatch-wrapper {
   padding: 0;
   border: none;
@@ -1817,9 +1848,9 @@ footer {
 .top-nav-sim {
   position: relative;
   display: flex;
-  align-items: stretch;
+  align-items: center;
   width: 100%;
-  margin-top: 5rem;
+  margin-top: 6rem;
 }
 
 .top-nav-sim-inner {
@@ -1833,6 +1864,7 @@ footer {
   box-sizing: border-box;
   max-width: 80%;
   margin: 0 auto;
+  padding-left: 10px;
   flex-wrap: wrap;
 }
 
@@ -1848,7 +1880,96 @@ footer {
 }
 
 .top-nav-sim-filler {
-  width: 20%;
+  width: 30%;
+  transition:
+    opacity 0.4s ease,
+    transform 0.4s ease;
+  align-items: center;
+  justify-content: center;
+}
+
+.top-nav-sim-filler.hide {
+  opacity: 0;
+  transform: translateX(20px);
+  pointer-events: none;
+}
+
+.fun-fact {
+  position: relative;
+  max-width: 460px;
+  overflow: hidden;
+  border-radius: 16px;
+  padding: 18px 20px;
+  background: var(--card-bg);
+  border: 1px solid rgba(45, 212, 191, 0.35);
+  box-shadow:
+    0 0 0 1px rgba(45, 212, 191, 0.08),
+    0 8px 24px rgba(0, 0, 0, 0.35);
+}
+
+.fun-fact-header {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  margin-bottom: 12px;
+}
+
+.fun-fact-icon {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  width: 30px;
+  height: 30px;
+  border-radius: 9px;
+  background: rgba(45, 212, 191, 0.12);
+  border: 1px solid rgba(45, 212, 191, 0.3);
+  color: var(--accent);
+}
+
+.fun-fact-label {
+  font-size: 11px;
+  font-weight: 500;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--accent);
+}
+
+.fun-fact-text {
+  margin: 0;
+  font-size: 14.5px;
+  line-height: 1.65;
+  color: var(--text);
+}
+
+.fun-fact {
+  position: relative;
+}
+
+.fun-fact-close {
+  position: absolute;
+  top: 12px;
+  right: 12px;
+}
+
+.btn-close {
+  width: 28px;
+  height: 28px;
+  border: none;
+  border-radius: 50%;
+  background: transparent;
+  color: #5eead4;
+  font-size: 16px;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  transition: all 0.2s ease;
+}
+
+.btn-close:hover {
+  background: rgba(45, 212, 191, 0.15);
+  transform: scale(1.1);
 }
 
 /* Wind icon for Ball Gravity Simulation*/
@@ -1880,6 +2001,7 @@ footer {
   from {
     transform: translateY(0);
   }
+
   to {
     transform: translateY(-3px);
   }
@@ -2257,11 +2379,13 @@ footer {
     opacity: 0.6;
     transform: scale(1);
   }
+
   50% {
     opacity: 1;
     transform: scale(1.05);
   }
 }
+
 .animate-pulse-strong {
   animation: pulse-strong 1.2s ease-in-out infinite;
 }
@@ -2272,11 +2396,13 @@ footer {
     opacity: 0;
     transform: translateY(20px);
   }
+
   to {
     opacity: 1;
     transform: translateY(0);
   }
 }
+
 .animate-fadeInUp {
   animation: fadeInUp 0.6s ease forwards;
 }
@@ -2292,7 +2418,8 @@ footer {
   font-size: 0.7rem;
   padding: 0.7rem;
   border-radius: var(--border-radius);
-  pointer-events: auto; /* serve per cliccare i bottoni */
+  pointer-events: auto;
+  /* serve per cliccare i bottoni */
   transition:
     padding 0.3s ease,
     width 0.3s ease,
@@ -2350,6 +2477,7 @@ footer {
     height 0.3s ease;
   overflow: hidden;
 }
+
 .sim-info-panel.collapsed .sim-info-header {
   margin: 0.3rem 0;
   justify-content: center;
@@ -2403,7 +2531,8 @@ footer {
     padding: 0.5rem;
     border-radius: var(--border-radius);
     overflow-y: auto;
-    max-height: 40vh; /* pannello non troppo alto */
+    max-height: 40vh;
+    /* pannello non troppo alto */
   }
 
   .sim-info-header {
@@ -2428,7 +2557,8 @@ footer {
 
   .sim-info-btn,
   .sim-info-toggle {
-    font-size: 1rem; /* più grandi per touch */
+    font-size: 1rem;
+    /* più grandi per touch */
     padding: 0.2rem 0.4rem;
   }
 }
@@ -2941,7 +3071,8 @@ footer {
 /* --- MOBILE: Menu a tendina --- */
 @media (max-width: 767px) {
   .simulation-controls {
-    flex-direction: column; /* Colonna per ospitare il menu sotto */
+    flex-direction: column;
+    /* Colonna per ospitare il menu sotto */
     gap: 0;
   }
 
@@ -2955,9 +3086,11 @@ footer {
   }
 
   .extra-controls-wrapper {
-    display: none; /* Nascondi di base */
+    display: none;
+    /* Nascondi di base */
     width: 100%;
-    flex-direction: column; /* O "row wrap" se preferisci i tasti piccoli */
+    flex-direction: column;
+    /* O "row wrap" se preferisci i tasti piccoli */
     gap: 0.5rem;
     padding: 1rem 0;
     border-top: 1px solid rgba(255, 255, 255, 0.1);
@@ -2989,7 +3122,8 @@ footer {
   border: 1px solid color-mix(in oklab, var(--accent-color), transparent 75%);
   font-weight: 500;
   margin-left: 1rem;
-  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2); /* subtle shadow */
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
+  /* subtle shadow */
 }
 
 /* Blogs section page */
diff --git a/tsconfig.json b/tsconfig.json
index e81a500..1045bf8 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -32,7 +32,8 @@
     "**/*.mts",
     "app/hooks/useSimInfo.ts",
     "app/components/LandingPart.jsx",
-    "app/(pages)/blog/[slug]/page.jsx"
+    "app/(pages)/blog/[slug]/page.jsx",
+    "app/(core)/components/Funfact.jsx"
   ],
   "exclude": ["node_modules"]
 }