div.logo {
  width: 200px;
  height: 200px;
  background-size: 200px 200px;
  display: inline-block;
  overflow: hidden;
}

span.tooltip {
  background-color: rgba(255, 255, 155, 0.9);
  border: 1px dotted black;
  display: none;
  font-size: 90%;
  font-weight: bold;
  padding: 2px;
  position: relative;
  top: 179px;
}
div.logo:hover > span.tooltip {
  display: inline;
}
a{
  color: black;
  text-decoration: none;
}

#pfe {
  background-image: url("images/colorless/pfe.svg");
}
#pfe:hover {
  background-image: url("images/colorless/pfe-invert.svg");
}

#webmail {
  background-image: url("images/colorless/webmail.svg");
}
#webmail:hover {
  background-image: url("images/colorless/webmail-invert.svg");
}
#cv {
  background-image: url("images/colorless/cv.svg");
}
#cv:hover {
  background-image: url("images/colorless/cv-invert.svg");
}
/*#photos {
  background-image: url("images/colorless/logo-photo.svg");
}
#photos:hover {
  background-image: url("images/colorless/logo-photo-invert.svg");
}
#seeks {
  background-image: url("images/colorless/logo.svg");
}
#seeks:hover {
  background-image: url("images/colorless/logo-invert.svg");
}
#blog {
  background-image: url("images/colorless/logo-blog.svg");
}
#blog:hover {
  background-image: url("images/colorless/logo-blog-invert.svg");
}*/