diff --git a/css/styles.css b/css/styles.css
index e7a63dd..b10913e 100644
--- a/css/styles.css
+++ b/css/styles.css
@@ -743,34 +743,17 @@ section { padding: 46px 0; }
 
 /* ---------- Diagram-style project thumb ---------- */
 .project-card .thumb-diagram {
-  background: #101820;
   display: flex;
   align-items: center;
   justify-content: center;
-  padding: 18px 8px 8px;
-  position: relative;
-  border-color: #263746;
-  box-shadow: 0 4px 14px rgba(16, 38, 61, 0.10);
-}
-
-.project-card .thumb-diagram::before {
-  content: "";
-  position: absolute;
-  top: 7px;
-  left: 10px;
-  width: 34px;
-  height: 5px;
-  border-radius: 999px;
-  background: rgba(255,255,255,.24);
 }
 
 .project-card .thumb-diagram img {
   width: 100%;
   height: 100%;
   object-fit: contain;
-  background: #eef2f6;
-  padding: 8px;
-  border: 1px solid #c7d2dc;
+  background: #13283c;
+  border: 1px solid rgba(255,255,255,.10);
 }
 .project-card .card-link { display: block; color: inherit; }
 .project-card .card-link:hover { text-decoration: none; }
diff --git a/index.html b/index.html
index 963f6d8..ef573c0 100644
--- a/index.html
+++ b/index.html
@@ -90,7 +90,7 @@
 
           <article class="project-card">
             <a class="card-link" href="homelab.html" aria-label="View ByteGeist Windows Server Lab details">
-              <div class="thumb thumb-diagram">
+              <div class="thumb screenshot-frame thumb-diagram">
                 <img src="assets/images/homelab-topology.svg"
                      alt="ByteGeist AD homelab topology diagram — DC01, FILE01, OPNsense, WIN11-01" />
               </div>