.btn-oreca{
  border: none;
  position: relative;
  border-bottom: 2px solid var(--rouge)!important;
  padding: 0 0 .2em;
  color: var(--noir)!important;
  display: inline-block;
  text-decoration: none;
  font-size: 1.30344vw;
}

.btn-oreca::before{
    content: "+";
    color: var(--rouge);
    display: inline-block;
    position: absolute;
    font-size: 3.6em;
    font-weight: 300;
    top: -0.7em;
    left: 0.15em;
    margin: 0;
}

.btn-oreca:hover::after{
  content: ' ';
  position: absolute;
  display: block;
  bottom: -0.1em;
  right: 0;
  width: 100%;
  height: 1px;
  z-index: 1;
  background: var(--rouge);
  mix-blend-mode: multiply;
  opacity: 0;
  transform: scaleY(0);
  transform-origin: center bottom;
  animation: overButton 0.4s ease-in-out both;
}

@keyframes overButton{
  100%{
    opacity: 1;
    transform: scaleY(15);
  }
}

@media screen and (max-width: 991px){
  .btn-oreca{
    font-size: 2vw;
  }
}