헤더, 인증키 스타일 수정

src/main/resources/static/sass/layout/_header.scss

@@ -46,14 +46,8 @@
 // Modern Header Structure
 // ===========================
 .global-header {
-  position: fixed;
-  top: 0;
-  left: 0;
-  right: 0;
-  //background-color: #C3DFEA;
+  position: relative;
   background-color: #ffffff;
-  backdrop-filter: blur(10px);
-  -webkit-backdrop-filter: blur(10px);
   z-index: $z-index-header;
   height: 112px;
   transition: all 0.3s ease;
@@ -63,6 +57,13 @@
   &.index-header {
     background-color: #E5F8FF;
   }
+  .container {
+    height: 100%;
+
+    .header-content {
+      height: 100%;
+    }
+  }
 }
 
 .header-content {
@@ -73,7 +74,6 @@
   max-width: 1920px;
   margin: 0 auto;
   padding: 0 20px;
-  margin-top: 20px;
 }
 
 // ===========================
@@ -999,9 +999,7 @@
 // ===========================
 // Body Layout Compensation
 // ===========================
-body {
-  padding-top: 112px; // Compensate for fixed header (112px height)
-}
+// body padding-top removed - header is no longer fixed on PC
 
 // ===========================
 // Mobile Responsive Design
@@ -1033,10 +1031,7 @@ body {
     }
   }
 
-  body {
-    // 헤더 높이와 동일하게 반응형 적용
-    padding-top: clamp(44px, 11.73vw, 60px);
-  }
+  // body padding-top removed - header is no longer fixed
 }
 
 // ===========================