/* Global */

:root {
  --focus-color: forestgreen;
}

html, body {
	height: 100%;
	margin: 0;
}

body {
  font: 21px sans-serif;
}

form {
  width: 100%;
}

/* Styling of simple elements */

#content {
	height: 100%;
  max-width: 20em;
	margin-left: auto;
	margin-right: auto;

	display: flex;
	align-items: center;
	justify-content: center;
	flex-direction: column;
}

#title {
	font-size: 2em;
	font-weight: bold;
}

#content input {
  border: 0;
  border-bottom: 1px solid grey;
  padding: 0.4em;
  padding-left: 0;
  width: 100%;
  box-sizing: border-box;
  font-size: inherit;
  margin-bottom: 0.5em;
}

#content #submit-btn {
	border: 2px solid black;
	border-radius: 0.4em;
	box-sizing: border-box;
	width: 100%;
	margin-top: 0.5em;
  font-size: 0.8em;
  padding: 0.3em;
}

input:focus, button:focus {
  outline: 0;
}

#content hr {
	width: 100%;
	border: 1px solid black;
	box-sizing: border-box;
}

/* Where the magic happens */

#submit-btn {
  transition: 0.2s;
  background-color: black;
  color: white;
  text-align: center;
}

#submit-btn:hover {
  cursor: pointer;
  border-color: var(--focus-color) !important;
  color: var(--focus-color);
  background-color: white;
}

#submit-btn:active {
  transition: 0s;
  transform: scale(0.9);
}

.input-selection {
  position: relative;
  margin-top: 0.7em;
}

.input-selection label {
  transition: 0.2s;
  width: inherit;
  height: inherit;
  position: absolute;
  margin-top: 0.4em;
  scale: 1em;
  color: grey;
  left: 0;
}

.input-selection input::-webkit-input-placeholder {
  /* Don't show the placeholder when the label is on top */
  opacity: 0;
}

.input-selection:hover > label, 
.input-selection > input:not(:placeholder-shown) + label,
.input-selection > input:focus + label {
  /* When hovering, typing or having typed something in an input, 
   * make the label smaller, color it and then move it up
   */
  font-size: 0.7em;
  color: var(--focus-color);
  transform: translate(0, -1.2em);
}

.input-selection:hover > input::-webkit-input-placeholder, 
.input-selection > input:focus::-webkit-input-placeholder {
  opacity: 1;
}

.input-selection:hover > input, 
.input-selection > input:focus {
  border-color: var(--focus-color) !important;
  caret-color: var(--focus-color);
  border-width: 2px !important;
  margin-top: -1px !important;
}