form(onsubmit="return false")
  .form-item
    label Username
    .input-wrapper
      input(type="text" id="username" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" data-lpignore="true")
  .form-item
    label Password
    .input-wrapper
      input(type="password" id="password" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" data-lpignore="true")
      button(type="button" id="eyeball")
        .eye
      #beam
  button(id="submit") Sign in

:root {
  --bgColor: white;
  --inputColor: black;
  --outlineColor: dodgerblue;
  --beamColor: yellow;
  --spacer: 1rem;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  display: grid;
  place-items: center;
  background: var(--bgColor);
  
  &.show-password {
    --bgColor: black;
    --inputColor: white;
    --outlineColor: var(--beamColor);
  }
}

form {
  transform: translate3d(0,0,0);
  padding: var(--spacer);
  
  > * + * {
    margin-top: var(--spacer);
  }
}

.form-item {
  > * + * {
    margin-top: 0.5rem;
  }
}

label,
input,
button {
  font-size: 1.5rem;
  font-family: monospace;
  color: var(--inputColor);
  
  &:focus {
    outline: 3px solid var(--outlineColor);
    outline-offset: 2px;
  }
  
  &::-moz-focus-inner {
    border: none;
  }
  
  &[id="password"] {
    color: black;
  }
}

button {
  border: none;
}

[id="submit"] {
  cursor: pointer;
  margin: calc(var(--spacer) * 2) 0 0 2px;
  padding: 0.75rem 1.25rem;
  color: var(--bgColor);
  background-color: var(--inputColor);
  box-shadow: 4px 4px 0 rgba(dodgerblue, 0.2);
  
  &:active {
    transform: translateY(1px);
  }
}

.input-wrapper {
  position: relative;
}

input {
  padding: 0.75rem 4rem 0.75rem 0.75rem;
  width: 100%;
  border: 2px solid transparent;
  border-radius: 0;
  background-color: transparent;
  box-shadow: 
    inset 0 0 0 2px black,
    inset 6px 6px 0 rgba(dodgerblue, 0.2),
    3px 3px 0 rgba(dodgerblue, 0.2);
  -webkit-appearance: none;

  &:focus {
    outline-offset: 1px;
  }
  
  .show-password & {
    box-shadow: inset 0 0 0 2px black;
    border: 2px dashed white;
    
    &:focus {
      outline: none;
      border-color: var(--beamColor);
    }
  }
}

[id="eyeball"] {
  --size: 1.25rem;
  
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  outline: none;
  position: absolute;
  top: 50%;
  right: 0.75rem;
  border: none;
  background-color: transparent;
  transform: translateY(-50%);
  
  &:active {
    transform: translateY(calc(-50% + 1px));
  }
}

.eye {
  width: var(--size);
  height: var(--size);
  border: 2px solid var(--inputColor);
  border-radius: calc(var(--size) / 1.5) 0;
  transform: rotate(45deg);
  
  &:before,
  &:after {
    content: '';  
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    margin: auto;
    border-radius: 100%;
  }
  
  &:before {
    width: 35%;
    height: 35%;
    background-color: var(--inputColor);
  }
  
  &:after {
    width: 65%;
    height: 65%;
    border: 2px solid var(--inputColor);
    border-radius: 100%;
  }
}

[id="beam"] {  
  position: absolute;
  top: 50%;
  right: 1.75rem;
  clip-path: polygon(100% 50%, 100% 50%, 0 0, 0 100%);
  width: 100vw;
  height: 25vw;
  z-index: 1;
  mix-blend-mode: multiply;
  transition: transform 200ms ease-out;
  transform-origin: 100% 50%;
  transform: translateY(-50%) rotate(var(--beamDegrees, 0));
  pointer-events: none;
  
  .show-password & {
    background: var(--beamColor);
  }
}

const root = document.documentElement;
const eye = document.getElementById('eyeball');
const beam = document.getElementById('beam');
const passwordInput = document.getElementById('password');

root.addEventListener('mousemove', (e) => {
  let rect = beam.getBoundingClientRect();
  let mouseX = rect.right + (rect.width / 2); 
  let mouseY = rect.top + (rect.height / 2);
  let rad = Math.atan2(mouseX - e.pageX, mouseY - e.pageY);
  let degrees = (rad * (20 / Math.PI) * -1) - 350;

  root.style.setProperty('--beamDegrees', `${degrees}deg`);
});

eye.addEventListener('click', e => {
  e.preventDefault();
  document.body.classList.toggle('show-password');
  passwordInput.type = passwordInput.type === 'password' ? 'text' : 'password'
  passwordInput.focus();
});