/* https://codepen.io/RobertAron/pen/gOLLXLo */

*,
::before,
::after {
  font-family: "Roboto", sans-serif;
  box-sizing: border-box;
  margin: 0;
}

:root {
  --spacing: 8px;
  --hue: 400;
  --background1: hsl(214, 14%, 20%);
  --background2: hsl(214, 14%, 13%);
  --background3: hsl(214, 14%, 5%);
  --brand1: hsl(var(--hue) 80% 60%);
  --text1: hsl(0, 0%, 100%);
  --text2: hsl(0, 0%, 90%);
}

code {
  background: var(--background3);
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: conic-gradient(at 100% 100%, white, rgb(43, 110, 58), rgb(49, 49, 105));
  background-repeat: no-repeat;
  background-size: cover;
  color: var(--text1);
  gap: var(--spacing);
  padding: calc(var(--spacing) * 2);
  font-size: 1.5rem;
}

@media only screen and (max-width: 600px) {
  body {
    font-size: 1rem;
  }
}

a {
  color: var(--brand1);
  text-decoration: none;
}

.number-code>div {
  display: flex;
}

.number-code>div>input:not(:last-child) {
  margin-right: calc(var(--spacing) * 2);
}

.content-area {
  display: flex;
  flex-direction: column;
  gap: calc(var(--spacing) * 2);
  background: var(--background2);
  padding: var(--spacing);
  border-radius: var(--spacing);
  max-width: min(100%, 50rem);
}

.content-area p {
  color: var(--text2);
  font-size: 0.8em;
}

form {
  background-color: grey;
}

form input.code-input {
  font-size: 1.5em;
  width: 2em;
  text-align: center;
  flex: 1 0 1em;
}

form input[type=submit] {
  margin-left: auto;
  display: block;
  font-size: 1em;
  cursor: pointer;
  transition: all cubic-bezier(0.4, 0, 0.2, 1) 0.1s;
}

form input[type=submit]:hover {
  background: var(--background3);
}

form input {
  padding: var(--spacing);
  border-radius: calc(var(--spacing) / 2);
  color: var(--text1);
  background: var(--background1);
  border: 0;
  border: 4px solid transparent;
}

form input:invalid {
  box-shadow: none;
}

form input:focus {
  outline: none;
  border: 4px solid var(--brand1);
  background: var(--background3);
}