Update SNS quick login design

Match the requested SNS quick login layout with a title and circular provider icons for Naver/Kakao/Google.

Co-authored-by: Cursor <cursoragent@cursor.com>

index.html

@@ -73,6 +73,7 @@
           </div>
           <div class="sns-login" id="snsLogin" hidden>
             <span class="sns-label">SNS 간편로그인</span>
+            <div class="sns-row">
               <button class="sns-btn sns-naver" id="btnNaver" type="button" hidden aria-label="네이버로 로그인">
                 <span class="sns-letter">N</span>
               </button>
@@ -83,6 +84,7 @@
                 <span class="sns-google-g">G</span>
               </button>
             </div>
+          </div>
           <button class="btn" id="btnLogin" type="button">로그인</button>
           <button class="btn" id="btnLogout" type="button" hidden>로그아웃</button>
         </div>

styles.css

@@ -182,26 +182,34 @@ html[data-theme="light"] .topbar {
 
 .sns-login {
   display: inline-flex;
+  flex-direction: column;
   align-items: center;
   gap: 10px;
-  padding: 8px 10px;
-  border-radius: 14px;
+  padding: 10px 12px;
+  border-radius: 18px;
   border: 1px solid var(--border);
   background: rgba(255, 255, 255, 0.03);
 }
 
+.sns-row {
+  display: inline-flex;
+  align-items: center;
+  gap: 14px;
+}
+
 .sns-label {
-  font-size: 12px;
-  color: var(--muted2);
-  margin-right: 4px;
+  font-size: 15px;
+  font-weight: 800;
+  letter-spacing: -0.02em;
+  color: var(--text);
   white-space: nowrap;
 }
 
 .sns-btn {
-  width: 42px;
-  height: 42px;
+  width: 56px;
+  height: 56px;
   border-radius: 999px;
-  border: 1px solid rgba(0, 0, 0, 0.08);
+  border: 2px solid rgba(0, 0, 0, 0.08);
   display: grid;
   place-items: center;
   cursor: pointer;
@@ -231,7 +239,7 @@ html[data-theme="light"] .topbar {
 
 .sns-letter {
   font-weight: 900;
-  font-size: 18px;
+  font-size: 24px;
   color: #fff;
   letter-spacing: -0.02em;
 }
@@ -242,32 +250,32 @@ html[data-theme="light"] .topbar {
 }
 
 .sns-kakao-bubble {
-  width: 16px;
-  height: 13px;
+  width: 20px;
+  height: 16px;
   background: rgba(0, 0, 0, 0.82);
-  border-radius: 6px;
+  border-radius: 8px;
   position: relative;
 }
 
 .sns-kakao-bubble::after {
   content: "";
   position: absolute;
-  bottom: -4px;
-  left: 4px;
+  bottom: -5px;
+  left: 6px;
   width: 0;
   height: 0;
-  border: 4px solid transparent;
+  border: 5px solid transparent;
   border-top-color: rgba(0, 0, 0, 0.82);
 }
 
 .sns-google {
   background: #ffffff;
-  border-color: rgba(66, 133, 244, 0.35);
+  border-color: rgba(66, 133, 244, 0.4);
 }
 
 .sns-google-g {
   font-weight: 900;
-  font-size: 18px;
+  font-size: 24px;
   background: conic-gradient(from 210deg, #ea4335 0 25%, #fbbc05 25% 50%, #34a853 50% 75%, #4285f4 75% 100%);
   -webkit-background-clip: text;
   background-clip: text;