Add header

src/main/resources/static/css/styles.css

@@ -268,6 +268,58 @@ body {
     flex-direction: column;
 }
 
+.admin-body {
+    background: radial-gradient(circle at 0% 30%, rgba(59, 130, 246, 0.12), transparent 32%),
+                radial-gradient(circle at 90% 5%, rgba(124, 58, 237, 0.1), transparent 30%),
+                #0f172a;
+}
+
+.admin-shell {
+    max-width: 1200px;
+    width: 100%;
+    margin: 0 auto;
+    padding: 28px 18px 56px;
+    display: flex;
+    flex-direction: column;
+    gap: 18px;
+}
+
+.admin-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 16px;
+    padding: 18px 22px;
+    background: rgba(15, 23, 42, 0.92);
+    border: 1px solid #1f2937;
+    border-radius: 16px;
+    box-shadow: 0 18px 50px rgba(0, 0, 0, 0.4);
+}
+
+.admin-header h1 {
+    margin: 6px 0 8px;
+}
+
+.admin-identity {
+    display: flex;
+    gap: 14px;
+    align-items: center;
+}
+
+.header-actions.tight {
+    gap: 8px;
+}
+
+.header-actions.horizontal {
+    flex-direction: row;
+    align-items: center;
+    gap: 10px;
+}
+
+.header-actions.horizontal form {
+    margin: 0;
+}
+
 .dashboard-body {
     min-height: 100vh;
     background: radial-gradient(circle at 0% 30%, rgba(59, 130, 246, 0.14), transparent 30%),
@@ -397,6 +449,7 @@ body {
     gap: 24px;
     padding: 16px;
     background: #0b1220;
+    border-radius: 12px;
 }
 
 .controls-full {
@@ -450,10 +503,13 @@ body {
 .overlay {
     position: relative;
     flex: 1;
-    min-height: 420px;
-    height: calc(100vh - 260px);
+    min-height: 520px;
+    height: calc(100vh - 220px);
     background: black;
     overflow: hidden;
+    border: 1px solid #1f2937;
+    border-radius: 16px;
+    box-shadow: 0 16px 45px rgba(0, 0, 0, 0.45);
 }
 
 .overlay iframe {