.neon

html {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #010101;  
}

.neon {
  width: 400px;
  height: 200px;
  border: 4px solid #fff;
  border-radius: 12px;
  box-shadow:
    0 0 8px #fff,
    inset 0 0 8px #fff,
    0 0 16px #37f713,
    inset 0 0 16px #37f713,
    0 0 32px #37f713,
    inset 0 0 32px #37f713; 
}