.contenedores {
  position: relative;
}
.base2 {
  position: fixed;
  top: 300px;
  left: 50%;
  transform: translateX(-50%);
  scroll-behavior: smooth;
  background: linear-gradient(rgba(242, 254, 1, 0.8), rgba(20, 80, 160, 0.8));
  width: 65%;
  height: 600px;
   -webkit-box-shadow: 14px 12px 5px 0px rgba(0,0,0,0.75);
  -moz-box-shadow: 14px 12px 5px 0px rgba(0,0,0,0.75);
  box-shadow: 14px 12px 5px 0px rgba(0,0,0,0.75);
  border-radius:60px;
  z-index:999;
}
.linearoja{
  text-decoration-line:underline;
  text-decoration-color:red;
  }
.lineanegra{
    text-decoration-line:underline;
    text-decoration-color:black;
 }