Adjust logo sizing, header height, and font style on main landing page

app/static/styles.css

@@ -16,7 +16,7 @@
   --muted:         #627590;
   --success:       #127a46;
   --danger:        #b91c1c;
-  --header-h:      110px;
+  --header-h:      55px;
 }
 
 /* ── 리셋 & 기본 ─────────────────────────────────── */
@@ -88,9 +88,8 @@ a { color: inherit; text-decoration: none; }
 .brand-logo-mark svg { color: #fff; }
 
 .brand-logo-img {
-  width: 100px;
-  height: 100px;
-  object-fit: contain;
+  width: auto;
+  height: auto;
 }
 
 .brand-logo-img--full {
@@ -341,8 +340,8 @@ a { color: inherit; text-decoration: none; }
 .header-logo-mark svg { color: #fff; }
 
 .header-logo-img {
-  width: 100px;
-  height: 100px;
+  height: 55px;
+  width: auto;
   object-fit: contain;
   flex-shrink: 0;
 }
@@ -361,9 +360,10 @@ a { color: inherit; text-decoration: none; }
 }
 
 .header-portal {
-  font-size: 11px;
-  color: rgba(255,255,255,.45);
-  font-weight: 400;
+  font-size: 24px;
+  font-weight: 700;
+  color: #ffffff;
+  letter-spacing: -0.5px;
 }
 
 .header-user {