diff --git a/static/css/base.css b/static/css/base.css
index 8dc5f0f1..22e351bf 100644
--- a/static/css/base.css
+++ b/static/css/base.css
@@ -65,6 +65,7 @@ body {
 
     --lora-accent: var(--color-accent);
     --lora-surface: var(--bg-elevated);
+    --lora-surface-solid: var(--bg-elevated-solid);
     --lora-border: var(--border-subtle);
     --lora-text: var(--text-primary);
     --lora-error: var(--color-error);
@@ -93,6 +94,7 @@ body {
 
     --lora-accent: var(--color-accent);
     --lora-surface: var(--bg-elevated);
+    --lora-surface-solid: var(--bg-elevated-solid);
     --lora-border: var(--border-subtle);
     --lora-text: var(--text-primary);
     --lora-error: var(--color-error);
diff --git a/static/css/components/import-modal.css b/static/css/components/import-modal.css
index 2af575ce..81cf1fe5 100644
--- a/static/css/components/import-modal.css
+++ b/static/css/components/import-modal.css
@@ -24,7 +24,10 @@
     position: sticky;
     bottom: 0;
     z-index: 1;
-    background: var(--lora-surface);
+    /* Solid surface: must fully mask the step content scrolling underneath;
+       the translucent --lora-surface would double-composite over the modal
+       surface and show a seam in light themes. */
+    background: var(--lora-surface-solid);
     border-top: 1px solid var(--lora-border);
     padding-top: var(--space-2);
     padding-bottom: var(--space-1);
diff --git a/static/css/components/metadata-refresh-result.css b/static/css/components/metadata-refresh-result.css
index b33bf85d..40077614 100644
--- a/static/css/components/metadata-refresh-result.css
+++ b/static/css/components/metadata-refresh-result.css
@@ -100,7 +100,9 @@
 .failure-table th {
     position: sticky;
     top: 0;
-    background: var(--lora-surface);
+    /* Solid surface: the sticky header must fully mask the rows scrolling
+       underneath; translucent --lora-surface would let them bleed through. */
+    background: var(--lora-surface-solid);
     border-bottom: 1px solid var(--lora-border);
     padding: var(--space-1) var(--space-2);
     text-align: left;
@@ -163,7 +165,7 @@
 }
 
 [data-theme="dark"] .failure-table th {
-    background: var(--lora-surface);
+    background: var(--lora-surface-solid);
 }
 
 [data-theme="dark"] .failure-table td {
diff --git a/static/css/components/modal/_base.css b/static/css/components/modal/_base.css
index bd37b52b..5161f913 100644
--- a/static/css/components/modal/_base.css
+++ b/static/css/components/modal/_base.css
@@ -37,7 +37,10 @@ body.modal-open {
     height: auto;
     max-height: calc(100vh - var(--header-height, 48px) - 5.5rem); /* Subtract header height and modal margins */
     margin: 1rem auto; /* Keep reduced top margin */
-    background: var(--lora-surface);
+    /* Opaque surface: the modal stacks above the backdrop, and sticky layers
+       inside (action footers, table headers) share this same solid token so
+       they cannot double-composite into a visible seam (light themes). */
+    background: var(--lora-surface-solid);
     border-radius: var(--border-radius-base);
     padding: var(--space-3);
     border: 1px solid var(--lora-border);
@@ -174,7 +177,7 @@ body.modal-open {
 
 /* Dark theme unified styles */
 [data-theme="dark"] .modal-content {
-    background: var(--lora-surface);
+    background: var(--lora-surface-solid);
     border: 1px solid var(--lora-border);
 }
 
diff --git a/static/css/components/modal/download-modal.css b/static/css/components/modal/download-modal.css
index 1ea968ff..0258942c 100644
--- a/static/css/components/modal/download-modal.css
+++ b/static/css/components/modal/download-modal.css
@@ -789,7 +789,10 @@
     position: sticky;
     bottom: 0;
     z-index: 1;
-    background: var(--lora-surface);
+    /* Solid surface: must fully mask the step content scrolling underneath;
+       the translucent --lora-surface would double-composite over the modal
+       surface and show a seam in light themes. */
+    background: var(--lora-surface-solid);
     border-top: 1px solid var(--lora-border);
     padding-top: var(--space-2);
     padding-bottom: var(--space-1);
diff --git a/static/css/tokens/colors.css b/static/css/tokens/colors.css
index 6310a347..61d95094 100644
--- a/static/css/tokens/colors.css
+++ b/static/css/tokens/colors.css
@@ -82,6 +82,17 @@
   --favorite-glow: oklch(65% 0.15 85 / 0.5);
 }
 
+/* Opaque variants of the elevated surfaces. The elevated tokens are
+   translucent; a layer stacked on top of an elevated surface (sticky modal
+   footers, sticky table headers) must use the solid variant, otherwise the
+   translucent layer double-composites over the surface and shows as a
+   visible seam in light themes. Derived here so every theme/preset override
+   of the source tokens is picked up automatically. */
+:root {
+  --bg-elevated-solid: oklch(from var(--bg-elevated) l c h / 1);
+  --surface-elevated-solid: oklch(from var(--surface-elevated) l c h / 1);
+}
+
 :root[data-theme="dark"] {
   --bg-base: #1a1a1a;
   --bg-elevated: oklch(25% 0.02 256 / 0.98);