* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
section {
  height: 100vh;
  width: 100%;
  background-color: royalblue;
}
#sec-2 {
  background-color: black;
}
#sec-3 {
  background-color: yellowgreen;
}
#sec-4 {
  background-color: crimson;
}

.scroll-top {
  height: 60px;
  width: 60px;
  background-color: white;
  position: fixed;
  bottom: 10px;
  right: 10px;
  cursor: pointer;
  border-radius: 6px;
  box-shadow: 0px 0px 20px rgba(0, 0, 0, 0.336);
  /* hover effect default */
  transform: scale(0.9);
  transition: 0.3s ease-in-out transform;
  /* for centering the icon */
  display: flex;
  align-items: center;
  justify-content: center;
}
.scroll-top svg {
  width: 50%;
  color: black;
  pointer-events: none;
}

.scroll-top:hover {
  transform: scale(1);
}