.pen {
  max-width: 1100px;
  width: 100%;
  margin: 50px auto 0;
  opacity: 0;
  position: relative;
  -webkit-transition: all 0.25s ease-in-out;
  -moz-transition: all 0.25s ease-in-out;
  -ms-transition: all 0.25s ease-in-out;
  -o-transition: all 0.25s ease-in-out;
  transition: all 0.25s ease-in-out;
  -webkit-animation: 1s appear 1 forwards;
  -moz-animation: 1s appear 1 forwards;
  -o-animation: 1s appear 1 forwards;
  animation: 1s appear 1 forwards;
}

.stage {
  max-width: 1100px;
  width: 100%;
  height: 400px;
  -webkit-transition: all 0.25s ease-in-out;
  -moz-transition: all 0.25s ease-in-out;
  -ms-transition: all 0.25s ease-in-out;
  -o-transition: all 0.25s ease-in-out;
  transition: all 0.25s ease-in-out;
}

.element {
  background: green;
  width: 150px;
  -webkit-transform-origin: 50% 50%;
  height: inherit;
  margin: 0 7px 0 0;
  display: inline-block;
  -webkit-transition: all 0.25s ease-in-out;
  -moz-transition: all 0.25s ease-in-out;
  -ms-transition: all 0.25s ease-in-out;
  -o-transition: all 0.25s ease-in-out;
  transition: all 0.25s ease-in-out;
  -webkit-transform: translate3d(0, 0, 0);
  -moz-transform: translate3d(0, 0, 0);
  -ms-transform: translate3d(0, 0, 0);
  -o-transform: translate3d(0, 0, 0);
  transform: translate3d(0, 0, 0);
}

.element.active {
  width: 200px;
  -webkit-transition: all 0.25s ease-in-out;
  -moz-transition: all 0.25s ease-in-out;
  -ms-transition: all 0.25s ease-in-out;
  -o-transition: all 0.25s ease-in-out;
  transition: all 0.25s ease-in-out;
}

.element.inactive {
  width: 162px;
  -webkit-transition: all 0.25s ease-in-out;
  -moz-transition: all 0.25s ease-in-out;
  -ms-transition: all 0.25s ease-in-out;
  -o-transition: all 0.25s ease-in-out;
  transition: all 0.25s ease-in-out;
  opacity: 0.4;
}

.element.sec2 {
  background: url('https://www.octagondev.com/wp-content/uploads/2023/07/OCTA-slide-4-2.jpg') 45% 0 no-repeat;
  background-size: cover;
}

.element.sec1 {
  background: url('https://www.octagondev.com/wp-content/uploads/2023/07/OCTA-slide-4-1-copy.jpg') 45% 0 no-repeat;
  background-size: cover;
}

.element.sec3 {
  background: url('https://www.octagondev.com/wp-content/uploads/2023/07/OCTA-slide-4-3.jpg') 45% 0 no-repeat;
  background-size: cover;
}

.element.sec4 {
  background: url('https://www.octagondev.com/wp-content/uploads/2023/07/OCTA-slide-4-4.jpg') 45% 0 no-repeat;
  background-size: cover;
}

.element:last-of-type {
  margin: 0;
}

@media all and (min-width: 900px) {
  .pen {
    max-width: 1200px;
  }
}

@media all and (min-width: 900px) {
  .element {
    width: 250px;
  }
}

@media all and (min-width: 900px) {
  .element.inactive {
    width: 200px;
  }
}

@media all and (min-width: 900px) {
  .element.active {
    width: 242px;
  }
}

@media all and (min-width: 900px) {
  .stage {
    max-width: 1200px;
    height: 600px;
  }
}

@media all and (max-width: 660px) {
  .pen {
    max-width: 335px;
  }
}

@media all and (max-width: 660px) {
  .element {
    width: 101px;
  }
}

@media all and (max-width: 660px) {
  .element.inactive {
    width: 61px;
  }
}

@media all and (max-width: 660px) {
  .element.active {
    width: 181px;
  }
}

@media all and (max-width: 660px) {
  .stage {
    max-width: 335px;
  }
}

@keyframes appear {
  15% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}