body { background: #2f2f2f;  }

.container {
  position: relative;
  width: 844px;
  height: 582px;
  margin: 50px auto 0 auto;
  background: url(../img/main-pic.jpg) no-repeat 0% 0%;
}

.container a.mail {
  position: absolute;
  top: 544px;
  left: 0;
  display: block;
  width: 148px;
  height: 20px;
  text-indent: -10000px;
  background: url(../img/email.jpg) no-repeat 0% 0%;
}

.container a.mail:hover { background-position: 0% -20px; }