diff --git a/app/newsletter/components/WeeklyImpulsesHero.tsx b/app/newsletter/components/WeeklyImpulsesHero.tsx
index d69bbe4..3fbdc3a 100644
--- a/app/newsletter/components/WeeklyImpulsesHero.tsx
+++ b/app/newsletter/components/WeeklyImpulsesHero.tsx
@@ -116,7 +116,14 @@ export function WeeklyImpulsesHero() {
               </p>
             ) : (
               <form onSubmit={handleSubmit} className="flex flex-col gap-3 items-start w-full">
-                <div className="flex gap-3 items-start w-full sm:w-auto">
+                {/* flex-col sm:flex-row, no items-start at the base tier —
+                    stacks full-width below sm: (default align-items:
+                    stretch is what makes the button fill the row once
+                    stacked), same pattern as /challenge's EmailCapture.
+                    Was a fixed row at every width before, squeezing input
+                    + button together on a narrow phone (fixed 2026-07-24,
+                    consistency with the other mail CTAs). */}
+                <div className="flex flex-col sm:flex-row sm:items-start gap-3 w-full">
                   <input
                     ref={emailRef}
                     type="email"