* {
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
  transition: all 0.3s ease-out ;
}
body {
  background-color: cornflowerblue;
}
.timeline {
  max-width: 1200px;
  margin: auto;
  position: relative;
}
.timeline:after {
  content: "";
  position: absolute;
  background-color: white;
  width: 6px;
  top: 0;
  bottom: 0;
  left: 50%;
  margin-left: -3px;
}
.container {
  width: 50%;
  padding: 10px 30px;
  position: relative;
}
.container:after {
  content: "";
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: white;
  border: 5px solid rgb(37, 37, 121);
  position: absolute;
  right: -17px;
  top: 40px;
  z-index: 2;
}
.left {
  left: 0;
}
.left:before {
  content: "";
  width: 0;
  height: 0;
  border-right: 10px solid transparent;
  border-top: 10px solid transparent;
  border-left: 10px solid #fff;
  border-bottom: 10px solid transparent;
  position: absolute;
  right: 10;
  top: 45;
}

.right {
  left: 50%;
}
.right:before {
  content: "";
  width: 0;
  height: 0;
  border-right: 10px solid #fff;
  border-top: 10px solid transparent;
  border-left: 10px solid transparent;
  border-bottom: 10px solid transparent;
  position: absolute;
  left: 10px;
  top: 44px;
}

.right:after {
  left: -17px;
}
.content {
  background-color: white;
  padding: 20px 30px;
  border-radius: 5px;
}

@media (max-width: 600px) {
  .timeline:after {
    left: 20px;
  }

  .container {
    width: 100%;
    padding-left: 50px;
  }

  .container:after {
    left: 5;
  }
  .right {
    left: 0%;
  }

  .right:before,
  .left:before {
    content: "";
    width: 0;
    height: 0;
    border-right: 10px solid #fff;
    border-top: 10px solid transparent;
    border-left: 10px solid transparent;
    border-bottom: 10px solid transparent;
    position: absolute;
    left: 30;
    top: 45;
  }
}