diff --git a/style.css b/style.css
index 569446c..672d5bc 100644
--- a/style.css
+++ b/style.css
@@ -538,37 +538,44 @@
   box-shadow: 0 2px 4px rgba(0,0,0,0.05);
 }
 
-/* スマホ表示最適化 */
-@media (max-width: 600px) {
-  .banner {
-    font-size: 13px;
-    padding: 8px 10px;
-  }
-}
-.invite-cute-btn {
-  display: inline-block;
-  padding: 12px 20px;
-  font-size: 16px;
-  font-weight: bold;
-  border-radius: 25px;
-  border: none;
-  color: white;
-  background: linear-gradient(135deg, #6ea8ff, #3d7eff);
-  box-shadow: 0 4px 10px rgba(0, 100, 255, 0.3);
-  cursor: pointer;
-  transition: 0.25s ease;
-  letter-spacing: 0.5px;
+.share-modal, .qr-modal {
+  display:none;
+  position:fixed;
+  top:0; left:0;
+  width:100%; height:100%;
+  background:rgba(0,0,0,0.5);
+  justify-content:center;
+  align-items:center;
+  z-index:9999;
 }
 
-/* ホバー時にふわっと明るく */
-.invite-cute-btn:hover {
-  transform: translateY(-2px);
-  box-shadow: 0 8px 14px rgba(0, 100, 255, 0.35);
-  filter: brightness(1.1);
+.share-box, .qr-box {
+  background:white;
+  padding:20px;
+  border-radius:15px;
+  width:80%;
+  max-width:330px;
+  text-align:center;
+  box-shadow:0 4px 8px rgba(0,0,0,0.3);
 }
 
-/* 押した瞬間に“ぽよん” */
-.invite-cute-btn:active {
-  transform: scale(0.96);
-  box-shadow: 0 3px 8px rgba(0, 80, 200, 0.25);
+.share-btn {
+  width:100%;
+  padding:12px;
+  margin:10px 0;
+  background:#4a90ff;
+  color:white;
+  border:none;
+  border-radius:10px;
+  font-size:16px;
+}
+
+.close-btn {
+  margin-top:10px;
+  padding:10px;
+  background:#888;
+  color:white;
+  border:none;
+  border-radius:10px;
+  cursor:pointer;
 }