* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: #10202b;
}

.tabs input {
  visibility: hidden;
  display: none;
}

.buttons {
  position: relative;
  display: flex;
  gap: 80px;
  padding: 30px 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  background-color: #182d3c;
  overflow: hidden;
  border-radius: 20px;
}

.buttons label {
  width: 20%;
  font-size: 1.75em;
  -webkit-text-stroke: 1px #fff;
  color: transparent;
  opacity: 0.3;
  cursor: pointer;
  transition: 0.5s;
}

.buttons label:hover {
  opacity: 1;
  filter: drop-shadow(0 0 10px #fff) drop-shadow(0 0 20px #fff);
}

.tabs input:nth-child(1):checked ~ .buttons label:nth-child(1),
.tabs input:nth-child(2):checked ~ .buttons label:nth-child(2),
.tabs input:nth-child(3):checked ~ .buttons label:nth-child(3),
.tabs input:nth-child(4):checked ~ .buttons label:nth-child(4),
.tabs input:nth-child(5):checked ~ .buttons label:nth-child(5) {
  color: #fff;
  opacity: 1;
  filter: drop-shadow(0 0 10px #fff) drop-shadow(0 0 20px #fff);
}

.underline {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 20%;
  height: 5px;
  transition: 0.5s;
}

.underline::before {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  border-radius: 4px;
  height: 100%;
  background-color: #fff;
  filter: drop-shadow(0 0 10px #fff) drop-shadow(0 0 20px #fff)
    drop-shadow(0 0 30px #fff) drop-shadow(0 0 50px #fff);
}

.underline::after {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  border-radius: 4px;
  height: 100%;
  background-color: #fff;
  filter: drop-shadow(0 0 10px #fff) drop-shadow(0 0 20px #fff)
    drop-shadow(0 0 30px #fff) drop-shadow(0 0 50px #fff) blur(5px);
}

.tabs input:nth-child(1):checked ~ .buttons .underline {
  left: 0;
}

.tabs input:nth-child(2):checked ~ .buttons .underline {
  left: 20%;
}

.tabs input:nth-child(3):checked ~ .buttons .underline {
  left: 40%;
}

.tabs input:nth-child(4):checked ~ .buttons .underline {
  left: 60%;
}
.tabs input:nth-child(5):checked ~ .buttons .underline {
  left: 80%;
}