diff --git a/styles.css b/styles.css
index 635acfc..a6a5a3e 100644
--- a/styles.css
+++ b/styles.css
@@ -22,6 +22,43 @@
   border-bottom: 4px solid #4b0082; /* 深い紫のアクセント */
 }
 
+.modal {
+  display: none;
+  position: fixed;
+  z-index: 1000;
+  left: 0;
+  top: 0;
+  width: 100%;
+  height: 100%;
+  overflow: auto;
+  background-color: rgba(0, 0, 0, 0.8);
+}
+
+.modal-content {
+  margin: auto;
+  display: block;
+  max-width: 80%;
+  max-height: 80%;
+  border-radius: 8px;
+}
+
+.close {
+  position: absolute;
+  top: 10px;
+  right: 25px;
+  color: white;
+  font-size: 35px;
+  font-weight: bold;
+  cursor: pointer;
+}
+
+.close:hover,
+.close:focus {
+  color: #ccc;
+  text-decoration: none;
+  cursor: pointer;
+}
+
 /* ポップアップのカスタムスタイル */
 .popup-content {
   width: 300px; /* 幅を広く設定 */