styles3.css

body {
  margin: 0;
  width: 100vw;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

label {
  width: 500px;
  height: 200px;
  position: relative;
  display: block;
  background: #ebebeb;
  border-radius: 200px;
  box-shadow: inset 0px 5px 15px rgba(0, 0, 0, 0.4),
	inset 0px -5px 15px rgba(255, 255, 255, 0.4);
  cursor: pointer;
  transition: 0.3s;
}

label:after {
  content: "";
  width: 180px;
  height: 180px;
  position: absolute;
  top: 40px;
  right: 20px;
  background: linear-gradient(180deg, #ffcc89, #d8860b);
  border-radius: 180px;
  box-shadow: 0px 5px 10px rgba(0,0,0,0.2);
  transition: 0.3s;
}

input {
  width: 0;
  height: 0;
  visibility: hidden;
}

input:checked + label {
  background: #242424;
}

input:checked + label:after {
  left: 490px;
  transform: translateX(-100);
  background: linear-gradient(180deg, #777777, #3a3a3a); 
}

label:active:after {
  width: 260px;
}

.background {
  width: 100vw;
  height: 100vh;
  background: #fff;
  z-index: -1;
  position: absolute;
  transition: 0.3s;
}

input:checked + label + .background {
  background: #242424;
}

label svg {
  position: absolute;
  width: 120px;
  top: 40px;
  z-index: 100;
}

label svg.sun {
  left: 40px;
  fill: #fff;
  transition: 0.3s;
}

label svg.moon {
  left: 340px;
  fill: #7e7e7e;
  transition: 0.3s;
}

input:checked + label svg.sun {
  fill: #7e7e7e
}

input:checked + label svg.mooon {
  fill: #ffffff
}