Антон

<li>
    <a href="#" class="active">Item-4</a>
  </li>

$(document).ready(function(e){
  offsetleft = $('.active').scroll()[0].offsetLeft;
  $('.main-list').scrollLeft(offsetleft);
})

$new_arr = array();
$arr = array(
  '0' => 
    array (
      0 => '305',
      1 => '308',
      2 => '508',
      3 => '509',
      4 => '510',
      ),
  '1' =>          
    array (   
      0 => '305',
      1 => '308',
      2 => '508',
      3 => '515',
      4 => '516',
      ),
  '2' =>          
    array ( 
      0 => '305',
      1 => '308',
      2 => '541',
      3 => '542',
      4 => '543',
      ),
  '3' =>          
    array (    
      0 => '305',
      1 => '308',
      2 => '541',
      3 => '548',
      4 => '549',
      ),
  '4' =>          
    array (  
      0 => '305',
      1 => '308',
      2 => '554',
      3 => '555',
      4 => '556',
      ),
  '5' =>          
    array (  
      0 => '305',
      1 => '308',
      2 => '554',
      3 => '561',
      4 => '562',
      ),
  );
  
foreach($arr as $key => $item){
    $item = array_reverse($item);
    foreach($item as $key2 => $sub){
        
        $new_arr[$key]['val']= $sub;
        $new_arr[$key] = ['0' => $new_arr[$key]];
    }

}

&_visible &{    
    &__item{ 
      color:#0f0;
    }
    
  }

<?php
$var = '{
  "features": [
    {
      "id": 0,
      "category": [ 6, 7,  8 ]
    },
    {
      "id": 1,
      "category": [ 1, 2, 3 ]
    }
  ]
}';

$decoded = json_decode($var, true);


foreach($decoded['features'] as $item) {
    
    foreach($item['category'] as $cat) {
        echo $cat;
    }
}
// 678123

for(i = 1; i < 100; i++) {
x = 100 / i;
console.log(i + ' = ' + x + '%');
}