feat(ui): loading overlay with instant mesh swap, no-store GLB, full-width viewport, ground grid, drop masthead title

1 files changed, 44 insertions, 1 deletions

diff --git a/public/styles.css b/public/styles.css
index d6cfbb1..bd4e3be 100644
--- a/public/styles.css
+++ b/public/styles.css
@@ -67,6 +67,10 @@ button:focus-visible {
   justify-content: space-between;
 }
 
+.masthead-compact {
+  justify-content: flex-end;
+}
+
 .masthead {
   gap: 24px;
   padding-bottom: 30px;
@@ -161,7 +165,7 @@ button:focus-visible {
 
 .workspace {
   display: grid;
-  grid-template-columns: minmax(200px, 0.72fr) minmax(360px, 1.8fr) minmax(220px, 0.82fr);
+  grid-template-columns: minmax(200px, 0.68fr) minmax(420px, 2.4fr);
   gap: 12px;
 }
 
@@ -780,3 +784,42 @@ button:focus-visible {
   cursor: pointer;
   pointer-events: auto;
 }
+
+/* ---- viewport loading overlay ---- */
+.viewport-loading {
+  position: absolute;
+  inset: 0;
+  display: grid;
+  place-items: center;
+  gap: 10px;
+  align-content: center;
+  background: rgba(8, 11, 13, 0.55);
+  backdrop-filter: blur(2px);
+  z-index: 3;
+}
+
+.viewport-loading.is-hidden {
+  display: none;
+}
+
+.loading-ring {
+  width: 42px;
+  height: 42px;
+  border: 2px solid rgba(210, 175, 95, 0.18);
+  border-top-color: #d2af5f;
+  border-radius: 50%;
+  animation: loading-spin 0.9s linear infinite;
+}
+
+.loading-text {
+  color: var(--muted);
+  font-family: "Fira Code", "SFMono-Regular", Consolas, monospace;
+  font-size: 0.62rem;
+  letter-spacing: 0.08em;
+}
+
+@keyframes loading-spin {
+  to {
+    transform: rotate(360deg);
+  }
+}