/*Button*/
.inputfile-6 + label {
    color: #d3394c;
}

.inputfile-6 + label {
    border: 1px solid #d3394c;
    background-color: #f1e5e6;
    padding: 0;
}

    .inputfile-6:focus + label,
    .inputfile-6.has-focus + label,
    .inputfile-6 + label:hover {
        border-color: #722040;
    }

    .inputfile-6 + label span,
    .inputfile-6 + label strong {
        padding: 0.625rem 1.25rem;
        /* 10px 20px */
    }

    .inputfile-6 + label span {
        width: 200px;
        min-height: 2em;
        display: inline-block;
        text-overflow: ellipsis;
        white-space: nowrap;
        overflow: hidden;
        vertical-align: top;
    }

    .inputfile-6 + label strong {
        height: 100%;
        color: #f1e5e6;
        background-color: #d3394c;
        display: inline-block;
    }

    .inputfile-6:focus + label strong,
    .inputfile-6.has-focus + label strong,
    .inputfile-6 + label:hover strong {
        background-color: #722040;
    }

@media screen and (max-width: 50em) {
    .inputfile-6 + label strong {
        display: block;
    }

input[type='file']{
    display:none;
}
/*HTML*/
	<div class="box">
		<input type="file" name="file1" id="file1" class="inputfile inputfile-6" multiple="multiple"/>
        <label for="file1"> <strong><svg xmlns="http://www.w3.org/2000/svg" width="17" height="17" viewBox="0 0 20 17"><path d="M10 0l-5.2 4.9h3.3v5.1h3.8v-5.1h3.3l-5.2-4.9zm9.3 11.5l-3.2-2.1h-2l3.4 2.6h-3.5c-.1 0-.2.1-.2.1l-.8 2.3h-6l-.8-2.2c-.1-.1-.1-.2-.2-.2h-3.6l3.4-2.6h-2l-3.2 2.1c-.4.3-.7 1-.6 1.5l.6 3.1c.1.5.7.9 1.2.9h16.3c.6 0 1.1-.4 1.3-.9l.6-3.1c.1-.5-.2-1.2-.7-1.5z"/></svg> Wybierz pliki&hellip;</strong></label>
    </div>

/*JS*/

'use strict';

;( function ( document, window, index )
{
	var inputs = document.querySelectorAll( '.inputfile' );
	Array.prototype.forEach.call( inputs, function( input )
	{
		var label	 = input.nextElementSibling,
			labelVal = label.innerHTML;

		input.addEventListener( 'change', function( e )
		{
			var fileName = '';
			if( this.files && this.files.length > 1 )
				fileName = ( this.getAttribute( 'data-multiple-caption' ) || '' ).replace( '{count}', this.files.length );
			else
				fileName = e.target.value.split( '\\' ).pop();

			if( fileName )
				label.querySelector( 'span' ).innerHTML = fileName;
			else
				label.innerHTML = labelVal;
		});

		// Firefox bug fix
		input.addEventListener( 'focus', function(){ input.classList.add( 'has-focus' ); });
		input.addEventListener( 'blur', function(){ input.classList.remove( 'has-focus' ); });
	});
}( document, window, 0 ));