style.css

@import url("https://fonts.googleapis.com/css2?family=Muli&display=swap");

* {
  box-sizing: border-box; /* to avoid width problems if padding */
}

body {
  font-family: "Muli", sans-serif;  /*  adding font family  */
  display: flex;  /* it will set the items in a row */
  align-items: center;  /* centre the items in a row */
  justify-content: center; /* centre the items in a columns */
  height: 100vh; /* take the whole display of device */
  overflow: hidden; /* to hide scrollbars */
  margin: 0; 
}

.container {
  display: flex; /* set the all items in a rows */
  width: 90vw; /* it take only 90% of the width of device and 10% will be empty */
}

.panel {
  background-size: auto 100%; /* adjusting size of the background image */
  background-position: center; 
  background-repeat: no-repeat; 
  height: 80vh;
  border-radius: 50px; /* by this we can set how much curve should be there of an image */
  color: #fff; /* font color */
  cursor: pointer; /* when we put our cursor on it will change to pointer */
  flex: 0.5; 
  margin: 10px;
  position: relative;
  transition: all 0.7s ease-in;
  -webkit-transition: all 700ms ease-in; 
}

.panel h3 {
  font-size: 24px;
  position: absolute;
  bottom: 20px;
  left: 40px;
  margin: 0;
  opacity: 0;
}

.panel.active {
  flex: 5;
}

.panel.active h3 {
  opacity: 1;
  transition: opacity 0.3s ease-in 0.4s;
}

@media (max-width: 480px) {
  .container {
    width: 100vw;
  }

  .panel:nth-of-type(4),
  .panel:nth-of-type(5) {
    display: none;
  }
}