Hide textbox when the fields are empty

Hello everyone,
I’ve created a textbox called “Dettagli” where inside I put some custom fields.
when fields are not compiled, they are not displayed in the front-end.
Until this point everything works fine.
Example 1 – fields filled in:
http://oltretutto.altervista.org/motori-a-idrogeno/

The problem is that the textbox is not hidden when all fields are empty.
Example 2 – empty fields:
http://oltretutto.altervista.org/lornitorinco/

This is the code I used:

<?php
// Inizio - Campo immagine
?>
<?php 

$image = get_field('immagine');

if( !empty($image) ): 

	// vars
	$url = $image['url'];
	$title = $image['title'];
	$alt = $image['alt'];
	$caption = $image['caption'];

	// thumbnail
	$size = 'large';
	$thumb = $image['sizes'][ $size ];
	$width = $image['sizes'][ $size . '-width' ];
	$height = $image['sizes'][ $size . '-height' ];

	if( $caption ): ?>

		<div class="wp-caption">

	<?php endif; ?>

	<div class="box-image"><a href="<?php echo $url; ?>" title="<?php echo $title; ?>">

		<img src="<?php echo $thumb; ?>" alt="<?php echo $alt; ?>" width="<?php echo $width; ?>" height="<?php echo $height; ?>" />

	</a></div>

	<?php if( $caption ): ?>

			<p class="wp-caption-text"><?php echo $caption; ?></p>

		</div>

	<?php endif; ?>

<?php endif; ?>
<div class="box-dettagli">
<div class="hd-box">Dettagli</div>
<div class="box-testo">

<?php
// parte 1
?>

<?php

if(get_field('storia'))
{
	echo '<div class="box-tipo"><div class="box-campo">Storia: </div><div class="box-risultato">' . get_field('storia') . '</div></div>';
}

?>

<?php
// parte 2
?>

<?php

if(get_field('disegni'))
{
	echo '<div class="box-tipo"><div class="box-campo">Disegni:</div><div class="box-risultato"> ' . get_field('disegni') . '</div></div>';
}

?>

<?php
// parte 3
?>

<?php 

$terms = get_field('genere');

if( $terms ): ?>

	<div class="box-tipo"><div class="box-campo">Genere:</div><div class="box-risultato"><ul class="box-voci">

	<?php foreach( $terms as $term ): ?>

		<li><a href="<?php echo get_term_link( $term ); ?>"><?php echo $term->name; ?></a></li>

	<?php endforeach; ?></ul></div>

	</div>

<?php endif; ?>

<?php
// parte 4
?>

<br>
<?php
if( get_field('correlati') )
{
echo "<div>Correlati: " . implode(', ', get_field('correlati')) . "</div>";
}

?></div></div>

<?php
// Fine
?>

Sorry for my bad English… I understand very little English

https://wordpress.org/plugins/advanced-custom-fields/