diff --git a/app/expo/page.tsx b/app/expo/page.tsx
index 05033b6..b8b7075 100644
--- a/app/expo/page.tsx
+++ b/app/expo/page.tsx
@@ -1,7 +1,7 @@
 "use client";
 import { useState, useRef, useEffect } from "react";
 import { motion, AnimatePresence } from "framer-motion";
-import { X } from "lucide-react";
+import { X, Maximize2, Minimize2 } from "lucide-react";
 import clsx from "clsx";
 
 // 展台四模块视频配置（请将对应 mp4/webm 文件放入 public/videos/ 下）
@@ -39,8 +39,10 @@ interface VideoStateRef {
 
 export default function ExpoPage() {
   const [active, setActive] = useState<string | null>(null);
+  const [isFullscreen, setIsFullscreen] = useState(false);
   const timeRefs = useRef<Record<string, VideoStateRef>>({});
   const containerRefs = useRef<Record<string, HTMLVideoElement | null>>({});
+  const mainRef = useRef<HTMLElement | null>(null);
 
   // 记录时间用于在放大时继续播放（非严格同步，够展示用）
   const handleBeforeExpand = (key: string) => {
@@ -83,8 +85,53 @@ export default function ExpoPage() {
     return () => window.removeEventListener("keydown", onKey);
   }, [active]);
 
+  // Fullscreen 监听
+  useEffect(() => {
+    const handler = () => {
+      const fsEl = document.fullscreenElement || (document as any).webkitFullscreenElement;
+      setIsFullscreen(!!fsEl);
+    };
+    document.addEventListener("fullscreenchange", handler);
+    document.addEventListener("webkitfullscreenchange", handler as any);
+    return () => {
+      document.removeEventListener("fullscreenchange", handler);
+      document.removeEventListener("webkitfullscreenchange", handler as any);
+    };
+  }, []);
+
+  const enterFs = async () => {
+    const el = mainRef.current;
+    if (!el) return;
+    try {
+      if (el.requestFullscreen) await el.requestFullscreen();
+      else if ((el as any).webkitRequestFullscreen) (el as any).webkitRequestFullscreen();
+    } catch (_) {
+      /* ignore */
+    }
+  };
+  const exitFs = async () => {
+    try {
+      if (document.exitFullscreen) await document.exitFullscreen();
+      else if ((document as any).webkitExitFullscreen) (document as any).webkitExitFullscreen();
+    } catch (_) {
+      /* ignore */
+    }
+  };
+  const toggleFs = () => {
+    if (isFullscreen) exitFs(); else enterFs();
+  };
+
   return (
-    <main className="relative min-h-screen w-full bg-[#05080b] text-slate-100 overflow-hidden select-none">
+    <main ref={mainRef} className="relative min-h-screen w-full bg-[#05080b] text-slate-100 overflow-hidden select-none">
+
+      {/* 全屏按钮 */}
+      <button
+        onClick={toggleFs}
+        className="fixed z-[60] top-2 left-2 md:top-3 md:left-3 w-9 h-9 md:w-10 md:h-10 flex items-center justify-center rounded-full bg-black/60 hover:bg-black/80 border border-white/10 text-slate-200 backdrop-blur-sm transition"
+        aria-label={isFullscreen ? "退出全屏" : "进入全屏"}
+      >
+        {isFullscreen ? <Minimize2 className="w-4 h-4 md:w-5 md:h-5" /> : <Maximize2 className="w-4 h-4 md:w-5 md:h-5" />}
+      </button>
 
       {/* 2x2 全屏栅格 */}
       <div className="grid grid-cols-1 grid-rows-4 md:grid-cols-2 md:grid-rows-2 w-full h-screen">
@@ -109,9 +156,9 @@ export default function ExpoPage() {
               preload="auto"
             />
             {/* 角标信息，默认半透明，悬停/触摸更亮 */}
-            <div className="absolute left-0 top-0 p-2 md:p-3 bg-black/35 backdrop-blur-sm rounded-br-xl md:rounded-br-2xl text-[10px] md:text-xs leading-snug transition group-hover:bg-black/55">
+            <div className="absolute left-0 top-0 p-2 md:p-3 bg-black/35 backdrop-blur-sm rounded-br-xl md:rounded-br-2xl text-[12px] md:text-xs leading-snug transition group-hover:bg-black/55">
               <p className="font-semibold text-slate-100/95 mb-0.5 md:mb-1 truncate max-w-[10rem] md:max-w-[14rem]">{v.title}</p>
-              <p className="text-[9px] md:text-[10px] text-slate-300/80 line-clamp-2 md:line-clamp-2 max-w-[12rem] md:max-w-[16rem]">{v.desc}</p>
+              <p className="text-[10px] md:text-[10px] text-slate-300/80 line-clamp-2 md:line-clamp-2 max-w-[12rem] md:max-w-[16rem]">{v.desc}</p>
             </div>
             <div className="absolute inset-0 opacity-0 group-hover:opacity-100 transition bg-black/25 flex items-center justify-center text-[11px] tracking-wide font-medium">点击放大</div>
           </motion.div>
@@ -138,10 +185,11 @@ export default function ExpoPage() {
                 exit={{ opacity: 0, scale: 0.95 }}
                 transition={{ type: "spring", stiffness: 180, damping: 22 }}
               >
-                <div className="relative flex-1 bg-black">
+                <div className="relative flex-1 bg-black flex items-center justify-center min-h-0">
+                  {/* 居中容器：使用 max-* 避免视频固有尺寸撑大父容器 */}
                   <video
                     ref={expandedVideoRef}
-                    className="w-full h-full object-contain bg-black"
+                    className="max-w-full max-h-full w-auto h-auto object-contain bg-black select-none"
                     src={v.src}
                     playsInline
                     muted
@@ -149,24 +197,19 @@ export default function ExpoPage() {
                     loop
                     controls
                   />
-                  <div className="absolute top-0 left-0 right-0 p-3 md:p-5 flex flex-col gap-2 bg-gradient-to-b from-black/70 to-transparent pointer-events-none">
+                  {/* 叠加标题描述层，置于上方 */}
+                  <div className="absolute top-0 left-0 right-0 z-10 p-3 md:p-5 flex flex-col gap-2 bg-gradient-to-b from-black/70 to-transparent pointer-events-none">
                     <h2 className="text-base md:text-2xl font-semibold tracking-tight drop-shadow">{v.title}</h2>
                     <p className="text-[10px] md:text-sm text-slate-300 max-w-4xl leading-relaxed">{v.desc}</p>
                   </div>
                   <button
                     onClick={handleRestore}
-                    className="absolute top-2 right-2 md:top-4 md:right-4 w-9 h-9 rounded-full bg-black/60 hover:bg-black/80 text-slate-200 flex items-center justify-center border border-white/10 backdrop-blur-sm transition"
+                    className="absolute z-10 top-2 right-2 md:top-4 md:right-4 w-9 h-9 rounded-full bg-black/60 hover:bg-black/80 text-slate-200 flex items-center justify-center border border-white/10 backdrop-blur-sm transition"
                     aria-label="关闭放大"
                   >
                     <X className="w-5 h-5" />
                   </button>
                 </div>
-                <div className="p-2 md:p-3 flex justify-end gap-3 items-center text-[10px] md:text-xs text-slate-400 bg-[#0e1419]/90 border-t border-white/5">
-                  <button
-                    onClick={handleRestore}
-                    className="px-3 py-1 rounded-md bg-sky-600/25 hover:bg-sky-600/40 text-sky-200 font-medium tracking-wide"
-                  >返回</button>
-                </div>
               </motion.div>
             ))}
           </>
diff --git a/app/page.tsx b/app/page.tsx
index d3bcf06..2b6c02f 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -12,8 +12,8 @@ const Scene = dynamic(() => import("@/components/Scene"), { ssr: false });
 const moduleLinks = [
   { title: "力学实验模块", href: "#mechanics", icon: Waves, desc: "单摆精密测量 / 大摆角与阻尼修正 / 傅科摆进动 / 多参数智能拟合" },
   { title: "电路实验模块", href: "#circuit", icon: CircuitBoard, desc: "YOLO 电路识别 → 拓扑重建 → 虚拟仿真 → AI 智能辅导闭环" },
-  { title: "电磁学实验模块", href: "#electromag", icon: Atom, desc: "气垫导轨 + 视觉测量 + BO/RL 迭代优化电磁能量转换效率" },
-  { title: "光学实验模块", href: "#optics", icon: Camera, desc: "分光计视觉十字像追踪 + PID/步骤引导提升调节精度与效率" },
+  { title: "电磁学实验模块", href: "#electromag", icon: Atom, desc: "气垫导轨 + 视觉测量 + 后续 BO/RL 迭代优化电磁能量转换效率" },
+  { title: "光学实验模块", href: "#optics", icon: Camera, desc: "分光计视觉十字像追踪 + 步骤引导提升调节精度与效率" },
 ];
 
 export default function Home() {
diff --git a/public/videos/optics.mp4 b/public/videos/optics.mp4
new file mode 100644
index 0000000..acc6462
Binary files /dev/null and b/public/videos/optics.mp4 differ