language flags (Image links) with css not work in WordPress costum theme

I try to add a language flags (like a images with links) in my wordpress custom theme. Images work correctly, but their links did not work.

My code: header.php

<div class='container'>
  <div class="flags-holder">
   <div class="flag">
     <a href="http://example.com"><img src="http://example.com/imgs/en-english.png"></a>
     <a href="http://example.com/en"><img src="http://example.com/imgs/ru-ruskaq.png"></a></div>
   </div>

Stylesheet.css

#top .flags-holder {
  float: right !important;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  font-size: 11px;
  height: 20px;
  position: relative;
  padding: 0;
  left: 10%;
  z-index: 100;
}
#header .container{
  z-index: 99;
  padding-top: 4px;
  padding-left: 73% !important;
}
.flag {
  height: 20px;
  float: right !important;
  overflow: hidden;
  display: block;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  position: relative;
  right: 0;
  top: -1px;
}