Implement 'internal submit button' to the 'Textbox' component. Remove separate submit to the Headcode search card.

Adjust the hover and active styles of the 'TrainService' expandable cards.

src/lib/components/ui/cards/HeadcodeSearchCard.svelte

@@ -6,8 +6,7 @@
 
 	let headcode = $state('');
 
-	function handleSearch(e: SubmitEvent) {
-		e.preventDefault();
+	function handleSearch(headcode: string) {
 		if (!headcode.trim()) return;
 
 		const searchParams = new URLSearchParams();
@@ -18,10 +17,9 @@
 </script>
 
 <BaseCard header={'Search Train & PIS'}>
-	<form onsubmit={handleSearch} class="card-content">
-		<Textbox placeholder="Enter Headcode" bind:value={headcode} maxLength={4} />
-		<Button type="submit" disabled={!headcode}>Search</Button>
-	</form>
+	<div class="card-content">
+		<Textbox placeholder="Enter Headcode" bind:value={headcode} maxLength={4} onsubmit={handleSearch} />
+	</div>
 </BaseCard>
 
 <style>
@@ -29,7 +27,7 @@
 		text-align: center;
 		width: 90%;
 		margin: auto;
-		padding: 10px 0 0 0;
+		padding: 10px 0 0.5rem 0;
 		display: flex;
 		flex-direction: column;
 		gap: 0.75rem;