diff --git a/static/style.css b/static/style.css
index 96fd0b9d3..cb0215c88 100644
--- a/static/style.css
+++ b/static/style.css
@@ -2399,6 +2399,9 @@
   .mermaid-viewer-viewport{position:relative;overflow:hidden;max-width:100%;border:1px solid var(--border);border-radius:8px;background:var(--code-bg);cursor:grab;touch-action:none;user-select:none;-webkit-user-select:none;}
   .mermaid-viewer-viewport.is-panning{cursor:grabbing;}
   .mermaid-viewer--inline .mermaid-viewer-viewport{width:100%;max-height:70vh;}
+  @media (max-width: 640px){
+    .mermaid-viewer--inline .mermaid-viewer-viewport{min-height:min(200px,70vh);}
+  }
   .mermaid-viewer--lightbox .mermaid-viewer-viewport{max-width:90vw;max-height:90vh;border:none;box-shadow:0 8px 48px rgba(0,0,0,.6);}
   .mermaid-viewer-canvas{position:absolute;left:0;top:0;transform-origin:0 0;will-change:transform;}
   .mermaid-viewer-svg{display:block;width:100%;height:100%;}