body{
background-color: #DBF9FC;
  background-image: radial-gradient( circle 933.4px at 0.9% -2.6%,  rgba(1,220,215,1) 0%, rgba(171,196,251,1) 47.6%, rgba(224,188,253,1) 72.8%, rgba(255,182,194,1) 100.3% );
  margin: 0;
  padding: 0;
}
.container{
  text-align: center;
  margin-top: 100px;
}
.btn{
  border: 1px solid #3498db;
  background: none;
  padding: 10px 20px;
  font-size: 30px;
  font-family: "montserrat";
  cursor: pointer;
  margin: 10px;
  transition: 0.8s;
  position: relative;
  overflow: hidden;
}
.btn1,.btn2,.btn3,.btn4,.btn5,.btn6,.btn7,.btn8,.btn9{
  color: #3498db;
}
.btn10,.btn11,.btn12{
  color: #fff;
}
.btn1:hover,.btn2:hover,.btn3:hover,.btn4:hover,.btn5:hover,.btn6:hover,.btn7:hover,.btn8:hover,.btn9:hover{
  color: #fff;
}
.btn10:hover,.btn11:hover,.btn12:hover{
  color: #3498db;
}
.btn::before{
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 0%;
  background: #3498db;
  z-index: -1;
  transition: 0.8s;
}
.btn1::before,.btn2::before,.btn3::before,.btn4::before,.btn5::before,.btn6::before,.btn7::before,.btn8::before,.btn9::before{
  top: 0;
  border-radius: 0 0 50% 50%;
}
.btn10::before,.btn11::before,.btn12::before{
  bottom: 0;
  border-radius: 50% 50% 0 0;
}
.btn10::before,.btn11::before,.btn12::before{
  height: 180%;
}
.btn1:hover::before,.btn2:hover::before,.btn3:hover::before,.btn4:hover::before,.btn5:hover::before,.btn6:hover::before,.btn7:hover::before,.btn8:hover::before,.btn9:hover::before{
  height: 180%;
}
.btn10:hover::before,.btn11:hover::before,.btn12:hover::before{
  height: 0%;
}