feat: 沉浸模式底栏长度变化增加回弹动画

src/assets/main.css

@@ -258,9 +258,10 @@ html.platform-macos #root {
   opacity: 1;
   transform: translateX(-50%) translateY(0) scale(1);
   transition:
+    width 420ms cubic-bezier(0.2, 1.2, 0.26, 1),
     opacity 200ms ease,
-    transform 260ms cubic-bezier(0.22, 1, 0.36, 1);
-  will-change: opacity, transform;
+    transform 320ms cubic-bezier(0.2, 1.2, 0.26, 1);
+  will-change: width, opacity, transform;
 }
 
 .ss-immersive-toolbar.is-hidden {

src/components/Home.tsx

@@ -118,6 +118,8 @@ export const Home: React.FC<HomeProps> = ({
   const groupRefs = useRef<Record<string, HTMLDivElement | null>>({})
   const searchAreaRef = useRef<HTMLDivElement>(null)
   const immersiveToolbarRef = useRef<HTMLDivElement>(null)
+  const immersiveToolbarContentRef = useRef<HTMLDivElement>(null)
+  const [immersiveToolbarWidth, setImmersiveToolbarWidth] = useState<number | null>(null)
 
   const [selectedStudent, setSelectedStudent] = useState<student | null>(null)
   const [batchMode, setBatchMode] = useState(false)
@@ -321,6 +323,33 @@ export const Home: React.FC<HomeProps> = ({
     return () => document.removeEventListener("mousedown", onDocumentClick)
   }, [])
 
+  useEffect(() => {
+    if (!immersiveMode) return
+    const contentEl = immersiveToolbarContentRef.current
+    if (!contentEl) return
+
+    let frameId: number | null = null
+    const updateToolbarWidth = () => {
+      if (frameId !== null) cancelAnimationFrame(frameId)
+      frameId = requestAnimationFrame(() => {
+        const contentWidth = Math.ceil(contentEl.getBoundingClientRect().width)
+        const nextWidth = contentWidth + 20
+        setImmersiveToolbarWidth((prev) => (prev === nextWidth ? prev : nextWidth))
+      })
+    }
+
+    updateToolbarWidth()
+    const observer = new ResizeObserver(updateToolbarWidth)
+    observer.observe(contentEl)
+    window.addEventListener("resize", updateToolbarWidth)
+
+    return () => {
+      observer.disconnect()
+      window.removeEventListener("resize", updateToolbarWidth)
+      if (frameId !== null) cancelAnimationFrame(frameId)
+    }
+  }, [immersiveMode])
+
   useEffect(() => {
     return () => {
       if (longPressTimerRef.current !== null) {
@@ -2481,9 +2510,8 @@ export const Home: React.FC<HomeProps> = ({
           position: "fixed",
           left: "50%",
           bottom: isPortraitMode ? "12px" : "16px",
-          transform: "translateX(-50%)",
           zIndex: 1100,
-          width: "max-content",
+          width: immersiveToolbarWidth ? `${immersiveToolbarWidth}px` : "max-content",
           maxWidth: "calc(100vw - 20px)",
           borderRadius: "999px",
           border: "1px solid color-mix(in srgb, var(--ss-border-color) 80%, transparent)",
@@ -2497,7 +2525,10 @@ export const Home: React.FC<HomeProps> = ({
         }}
       >
           <div
-            ref={searchAreaRef}
+            ref={(node) => {
+              searchAreaRef.current = node
+              immersiveToolbarContentRef.current = node
+            }}
             style={{
               display: "flex",
               alignItems: "center",