diff --git a/js/app.js b/js/app.js
index 1317273..9c01436 100644
--- a/js/app.js
+++ b/js/app.js
@@ -297,7 +297,8 @@
       let a = null, bd = 1e9;
       sc.querySelectorAll('[id]').forEach(el => {
         const r = el.getBoundingClientRect();
-        if (r.height < 60 || r.bottom <= top) return;
+        if (r.height < 60 || r.height > sc.clientHeight * 4 || r.bottom <= top) return;
+        for (let x = el; x && x !== sc; x = x.parentElement) { const ps = getComputedStyle(x).position; if (ps === 'fixed' || ps === 'absolute' || ps === 'sticky') return; }   /* 浮层 / 吸顶不跟着滚，不能当锚点 */
         const d = Math.abs(r.top - top);
         if (d < bd) { bd = d; a = { id: el.id, off: r.top - top }; }
       });