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

body {
  width: 100vw;
  height: 100vh;
  font-family: sans-serif;
  background: url(img/terra.jpeg);
  background-size: cover;
  background-position: center;
}

.login-box {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 400px;
  padding: 40px;
  background: rgba(0, 0, 0, 0.6);
  border: 1px solid #523e1e;
  backdrop-filter: blur(30px);
  box-shadow: 0 15px 25px rgba(0, 0, 0, 0.6);
  border-radius: 10px;
}

.login-box h2 {
  margin: 0 0 30px;
  color: #523e1e;
  text-align: center;
  font-size: 40px;
}

.user-box {
  position: relative;
}

input {
  width: 100%;
  padding: 10px 0;
  font-size: 16px;
  color: #fff;
  margin-bottom: 30px;
  border: none;
  outline: none;
  background: transparent;
  border-bottom: 1px solid #fff;
}

label {
  position: absolute;
  top: 0;
  left: 0;
  padding: 10px 0;
  font-size: 16px;
  color: #fff;
  pointer-events: none;
  transition: 0.5s;
}

input:focus ~ label,
input:valid ~ label {
  top: -20px;
  left: 0;
  color: #523e1e;
  font-size: 12px;
}

form a {
  position: relative;
  display: inline-block;
  padding: 10px 20px;
  color: #523e1e;
  font-size: 16px;
  text-decoration: none;
  text-transform: uppercase;
  overflow: hidden;
  transition: 0.5s;
  letter-spacing: 4px;
}

form a:hover {
  background-color: #523e1e;
  color: #fff;
  border-radius: 5px;
  box-shadow: 0 0 5px #523e1e, 0 0 25px #523e1e, 0 0 50px #523e1e,
    0 0 100px #523e1e;
}

a span {
  position: absolute;
  display: block;
}

a span:nth-child(1) {
  top: 0;
  left: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, #523e1e);
  animation: btn-anim1 1s linear infinite;
}

@keyframes btn-anim1 {
  0% {
    left: -100%;
  }
  50%,
  100% {
    left: 100%;
  }
}

a span:nth-child(2) {
  top: -100%;
  right: 0;
  width: 2px;
  height: 100%;
  background: linear-gradient(180deg, transparent, #523e1e);
  animation: btn-anim2 1s linear infinite;
  animation-delay: 0.25s;
}

@keyframes btn-anim2 {
  0% {
    top: -100%;
  }
  50%,
  100% {
    top: 100%;
  }
}

a span:nth-child(3) {
  bottom: 0;
  right: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(270deg, transparent, #523e1e);
  animation: btn-anim3 1s linear infinite;
  animation-delay: 0.5s;
}

@keyframes btn-anim3 {
  0% {
    right: -100%;
  }
  50%,
  100% {
    right: 100%;
  }
}

a span:nth-child(4) {
  bottom: -100%;
  left: 0;
  width: 2px;
  height: 100%;
  background: linear-gradient(360deg, transparent, #523e1e);
  animation: btn-anim4 1s linear infinite;
  animation-delay: 0.75s;
}

@keyframes btn-anim4 {
  0% {
    bottom: -100%;
  }
  50%,
  100% {
    bottom: 100%;
  }
}