body {
  background: #000;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}
.box {
  position: relative;
  display: block;
  padding: 20px 30px;
  letter-spacing: 1px;
  text-decoration: none;
  text-transform: uppercase;
  width: 200px;
  text-align: center;
  margin: 100px 0 0;
  transition: 0.5s;
  color: #03f2ff;
  overflow: hidden;
}

.box:hover {
  background: #03f2ff;
  color: #000;
  box-shadow: 0 0 5px #03f2ff, 0 0 25px #03f2ff, 0 0 50px #03f2ff,
    0 0 200px #03f2ff;
  -webkit-box-reflect: below 1px linear-gradient(transparent, #000);
}

.box:nth-child(1):hover {
  width: 300px;
}
.box:nth-child(1) {
  filter: hue-rotate(270deg);
}
.box:nth-child(2) {
  filter: hue-rotate(110deg);
}

.box:nth-child(4) {
  background: rgba(15, 53, 76, 0.8);
  color: white;
  font-size: 12px;
}

/* 流光效果 */
.box span {
  position: absolute;
  display: block;
}
/* 从左到右 */
.box span:nth-child(1) {
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, transparent, #03f2ff);
  animation: animate1 1s linear infinite;
}
@keyframes animate1 {
  0% {
    left: -100%;
  }
  50%,
  100% {
    left: 100%;
  }
}

/* 从上到下 */
.box span:nth-child(2) {
  top: -100%;
  right: 0;
  width: 1px;
  height: 100%;
  background: linear-gradient(180deg, transparent, #03f2ff);
  animation: animate2 1s linear infinite;
  animation-delay: 0.25s;
}
@keyframes animate2 {
  0% {
    top: -100%;
  }
  50%,
  100% {
    top: 100%;
  }
}

/* 从右到左 */
.box span:nth-child(3) {
  right: -100%;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(270deg, transparent, #03f2ff);
  animation: animate3 1s linear infinite;
  animation-delay: 0.5s;
}
@keyframes animate3 {
  0% {
    right: -100%;
  }
  50%,
  100% {
    right: 100%;
  }
}

/* 从下到上 */
.box span:nth-child(4) {
  bottom: -100%;
  left: 0;
  width: 1px;
  height: 100%;
  background: linear-gradient(360deg, transparent, #03f2ff);
  animation: animate4 1s linear infinite;
  animation-delay: 0.75s;
}
@keyframes animate4 {
  0% {
    bottom: -100%;
  }
  50%,
  100% {
    bottom: 100%;
  }
}

/* 闪烁 */
.light {
  width: 100%;
  height: 100%;
  /* animation: glint 1.6s linear 0s infinite; */
  animation: glint 2s linear infinite;
  position: relative;
}
.light::after {
  content: "";
  position: absolute;
  width: 100%;
  height: 2px;
  bottom: 0;
  left: 0;
  background: linear-gradient(
    90deg,
    transparent,
    transparent,
    rgba(48, 251, 253),
    transparent,
    transparent
  );
  box-shadow: 0 -1px 10px #03f2ff;
}
/* 闪烁 start */
@keyframes glint {
  0% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.48),
        transparent
      )
      center bottom no-repeat;
  }
  10% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.44),
        transparent
      )
      center bottom no-repeat;
  }
  20% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.4),
        transparent
      )
      center bottom no-repeat;
  }
  30% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.36),
        transparent
      )
      center bottom no-repeat;
  }
  40% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.32),
        transparent
      )
      center bottom no-repeat;
  }
  50% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.28),
        transparent
      )
      center bottom no-repeat;
  }
  60% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.24),
        transparent
      )
      center bottom no-repeat;
  }
  70% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.32),
        transparent
      )
      center bottom no-repeat;
  }
  80% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.36),
        transparent
      )
      center bottom no-repeat;
  }
  90% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.4),
        transparent
      )
      center bottom no-repeat;
  }
  100% {
    background: linear-gradient(
        to right,
        transparent,
        rgba(48, 251, 253, 0.44),
        transparent
      )
      center bottom no-repeat;
  }
}