diff --git a/themes/Ying/assets/css/main.css b/themes/Ying/assets/css/main.css
index 216e6e37..3ba5b819 100644
--- a/themes/Ying/assets/css/main.css
+++ b/themes/Ying/assets/css/main.css
@@ -501,7 +501,7 @@ ul {
 
 /*默认 box-shadow 数值：rgba(236, 236, 236, 0.86)*/
 .main {
-    max-width: 630px;
+    max-width: 618px; /* Reduced from 680px based on user feedback "narrower again" */
     overflow: hidden;
     margin: 60px auto;
     padding: 50px;
@@ -515,8 +515,16 @@ ul {
     -webkit-backdrop-filter: blur(10px);
     /* Optimized transition: removed box-shadow and backdrop-filter for performance */
     transition: background-color 0.35s ease, color 0.35s ease;
+    will-change: transform; /* Promote to layer for smoother scrolling */
 }
 
+/* Optimize article content rendering */
+/* Removed content-visibility to fix clipping issue with overflowing elements (e.g. friend circle shadows/transform) */
+/* .post-content {
+    content-visibility: auto;
+    contain-intrinsic-size: 1000px;
+} */
+
 /* Mobile Optimization: Remove expensive effects */
 @media (max-width: 767px) {
     .main, 
@@ -2817,10 +2825,15 @@ input[type=submit] {
     opacity: 0;
     visibility: hidden;
     height: 0;
-    width: 0;
+    width: 40px;
     margin: 0;
+    padding: 0;
     overflow: hidden;
-    transform: scale(0);
+    transform: scale(0.8) translateY(10px);
+    pointer-events: none;
+    border-width: 0;
+    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s, height 0.3s ease, border-width 0.3s ease;
+    will-change: opacity, transform, height;
 }
 
 #back-to-top.show {
@@ -2829,7 +2842,9 @@ input[type=submit] {
     height: 40px;
     width: 40px;
     margin-top: 0;
-    transform: scale(1);
+    transform: scale(1) translateY(0);
+    pointer-events: auto;
+    border-width: 1px;
 }
 
 #back-to-top.show:hover {