How to make image adaptivnoi?

<section class="offer">
 <div class="owl-carousel slider">
 <?php foreach(getSlider() as $sliderpost): ?>

 <div class="item slider-wrapper" style="background-image: url(<?php //echo get_the_post_thumbnail_url( $sliderpost->ID); ?>);">
 <img src="<?get_the_post_thumbnail_url php echo( $sliderpost->ID); ?>">
 <a class="slide-btn" onclick="popup_callback();">Order</a>

 <?php endforeach; ?>

item slider-wrapper a fixed height like 200px to make the image show as a whole but it was visiteu unit item slider-wrapper. Probyval cover half of the image on the sides not. Tried contain izobrajenia stood in the center of the block is not at all the height of item slider-wrapper
March 20th 20 at 11:48
1 answer
March 20th 20 at 11:50
Necessary background to enter the exact width and height.
Here look:

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