how to apply css to particular column of gridview columns in yii2

Question

I am new to yii2.. how to apply css to column, column heading of yii2 gridview??

<?php 

    $gridColumns = [
                     ['class' => 'yii\grid\SerialColumn'],
                     ['class' => 'yii\grid\CheckboxColumn'],  

                    'name',
                    'company_mail', //change the color of heading
                    'no_employees',
                    'email:email', 
                    .
                    .
                    .];
            echo GridView::widget([
            'dataProvider' => $dataProvider,
            'filterModel' => $searchModel,
            'columns' => $gridColumns,
    ]); 
    ?>

Answer 1

You can set particular column style/css using this way.

$columns = [
   'onenormalcolumn',
   'anothercolumn',
   [
       'format'=>"ntext", // or other formatter
       'attribute' => 'theattributeofmodel',
       'contentOptions' => ['style' => 'width:50px'], // For TD
       'headerOptions' => ['class' => 'ur-class'] // For TH

   ]
]

Answer 2

You have to set your column in detailed mode:

<?php 
$columns = [
   'onenormalcolumn',
   'anothercolumn',
   [
       'format'=>"ntext", // or other formatter
       'attribute' => 'theattributeofmodel',
       'options'=>[ 'style'=>'your rules here' ]
   ]
]
?>

See Yii2 Gridview column options

Answer 3

if you want change the column header css properties you should use headerOptions column propreties eg:

'columns' => [
    ['class' => 'yii\grid\SerialColumn'],

    .......
    'anothercolumn',
       [
        'format'=>"ntext", // or other formatter
        'attribute' => 'theattributeofmodel',
        'headerOptions'=>[ 'style'=>'background-color:#ccf8fe' ]
       ], 

],