title: Center text in link which is as block
body: <p>Ill start with showing you my problem in an image:
  <img src="https://i.stack.imgur.com/tq38S.png" alt="enter image description here"></p>
  
  <p>So i want to make a design for slider, now i want to make buttons for next and previous.
  yellow things in image are links with display: block. What do i need to do, to make text ( those arrows are unicode characters ) be positioned vertically and horizontally? Considering i still want whole yellow thing be clickable as a link.
  here is how yellow thing looks in css</p>
  
  <pre><code>    a.prev {
  width: 40px;
  height: 270px;
  display:block;
  float:left;
  background: yellow;
  -webkit-border-top-left-radius: 5px;
  -webkit-border-bottom-left-radius: 55px;
  -moz-border-radius-topleft: 5px;
  -moz-border-radius-bottomleft: 55px;
  border-top-left-radius: 5px;
  border-bottom-left-radius: 45px;
  </code></pre>
  
  <p>}</p>