diff --git a/src/styles/signup.scss b/src/styles/signup.scss
index 794d304..93c7a3e 100644
--- a/src/styles/signup.scss
+++ b/src/styles/signup.scss
@@ -47,4 +47,15 @@
 }
 
 @media only screen and (max-width: 430px) {
+  .signup-sub-container {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    margin-top: 45px;
+    width: 420px;
+    padding: 12px;
+    border-radius: 10px;
+    background-color: rgb(240, 247, 250);
+    border: 1px solid #e9e9e9;
+  }
 }