frontend/src/components/script-editor/ScriptBodyEditor.tsx

@@ -37,7 +37,7 @@ export function ScriptBodyEditor({ value, onChange, disabled }: Props) {
     <div className="relative rounded-xl border border-border overflow-hidden">
       {/* Highlighted overlay (read-only visual layer) — scroll synced to textarea */}
       <div ref={overlayRef} className="absolute inset-0 pointer-events-none overflow-hidden p-4">
-        <PowerShellHighlighter script={value || ' '} className="font-label text-sm leading-[1.5] whitespace-pre-wrap break-words m-0" />
+        <PowerShellHighlighter script={value || ' '} className="font-label text-sm leading-[21px] whitespace-pre m-0 p-0 border-0" />
       </div>
 
       {/* Editable textarea (transparent text, visible caret) */}
@@ -48,8 +48,9 @@ export function ScriptBodyEditor({ value, onChange, disabled }: Props) {
         onScroll={handleScroll}
         onKeyDown={handleTab}
         disabled={disabled}
+        wrap="off"
         spellCheck={false}
-        className="relative z-10 w-full min-h-[300px] resize-y font-label text-sm leading-[1.5] bg-transparent text-transparent caret-foreground p-4 whitespace-pre-wrap break-words focus:outline-none focus:ring-1 focus:ring-[rgba(6,182,212,0.2)] disabled:cursor-not-allowed disabled:opacity-50"
+        className="relative z-10 w-full min-h-[300px] resize-y font-label text-sm leading-[21px] bg-transparent text-transparent caret-foreground p-4 whitespace-pre overflow-auto focus:outline-none focus:ring-1 focus:ring-[rgba(6,182,212,0.2)] disabled:cursor-not-allowed disabled:opacity-50"
         placeholder="# Enter your PowerShell script here…&#10;# Use {{ param_name }} for parameter placeholders"
       />
     </div>

frontend/src/lib/scriptParameterDetector.ts

@@ -155,11 +155,12 @@ function findScriptLevelParamBlock(script: string): { start: number; end: number
 
     if (functionBraceDepth === 0 && /^param\s*\(/i.test(trimmed) && paramStart === -1) {
       paramStart = i
+      let foundOpen = false
       for (let j = i; j < lines.length; j++) {
         for (const ch of lines[j]) {
-          if (ch === '(') parenDepth++
+          if (ch === '(') { parenDepth++; foundOpen = true }
           if (ch === ')') parenDepth--
-          if (parenDepth === 0 && paramStart !== -1) {
+          if (foundOpen && parenDepth === 0) {
             return { start: paramStart, end: j }
           }
         }