Fix mobile overflow with viewport width units

- Use 100vw for snippets-container to constrain to viewport width
- Calculate max-width for snippet boxes: calc(100vw - 2rem)
- Calculate max-width for code blocks: calc(100vw - 4rem)
- Ensure content never overflows even on very small screens (< 590px)

Author: codebude

public/styles.css

@@ -152,13 +152,19 @@ pre.relative {
 }
 
 /* Mobile responsive snippet styles */
+#snippets-container {
+    max-width: 100vw;
+    width: 100vw;
+    box-sizing: border-box;
+}
+
 #snippets-container > div {
-    max-width: 100%;
+    max-width: calc(100vw - 2rem); /* Account for container padding */
     box-sizing: border-box;
 }
 
 #snippets-container pre {
-    max-width: 100%;
+    max-width: calc(100vw - 4rem); /* Account for container + snippet padding */
     box-sizing: border-box;
 }