diff --git a/style.css b/style.css
index e64d7cf..113db37 100644
--- a/style.css
+++ b/style.css
@@ -579,24 +579,14 @@
   border-radius:10px;
   cursor:pointer;
 }
+/* 退出ボタンの隣に置く共有ボタン（小さめ） */
 #shareBtn {
-  position: fixed;
-  bottom: 100px;
-  right: 15px;
-
-  width: 48px;
-  height: 48px;
-
+  padding: 6px 12px;
+  font-size: 13px;
   background: #4a90ff;
-  border-radius: 50%;
-
   color: white;
-  font-size: 20px;
-  text-align: center;
-  line-height: 48px;
-
   border: none;
-  box-shadow: 0 3px 6px rgba(0,0,0,0.2);
-
-  z-index: 9999;
+  border-radius: 8px;
+  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
+  cursor: pointer;
 }