How to Integrate Live search in WordPress?

I tried most of the available plugins to integrate Live Search in WordPress, but all of them messed up my theme layout.

The search function in my site is from a small search box at the top right using the following code in header.php:

<div id="search">
    <div class="search-content">
        <form method="get" id="searchform" action="/">
            <input class="form-control search-input" type="text" placeholder="<?php _e('Search..', 'demotheme'); ?>" name="s" id="s" value="<?php echo get_search_query(); ?>">
        <button type="submit"><i class="fa fa-search"></i></button>
    </form>
    </div>
</div>

So far I have tested these plugins:

• Dave's WordPress Live Search
• Ajax Search for WooCommerce
• Ajax Search Lite
• SearchWP Live Ajax Search
• Advanced Woo Search
• Ivory Search – WordPress Search Plugin

Every time I try to replace the default search function <?php echo get_search_query(); ?> in the header file with the plugin shortcode, I got the following mess in my theme:

Thanks.