* {
  box-sizing: border-box;
}

:root {
  --red: hsl(0, 100%, 74%);
  --green: hsl(154, 59%, 51%);
  --blue: hsl(248, 32%, 49%);
  --dark-blue: hsl(249, 10%, 26%);
  --grayish-blue: hsl(246, 25%, 77%);

  --box-shadow: 0 0.5rem 1px 0 hsla(249, 10%, 26%, 0.2);

  font-size: 16px;
  font-family: 'Poppins', Tahoma, Geneva, Verdana, sans-serif;
  color: white;
  background: var(--red);
}

body {
  margin: 0 50px;
  min-height: 100vh;
  background: url(../images/bg-intro-desktop.png);
  background-repeat: repeat;
  background-size: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 50px;
}

header {
  max-width: 500px;
}

main {
  width: 600px;
}

header h1 {
  font-size: 3.1rem;
}

header p {
  color: whitesmoke;
}

main form {
  display: flex;
  flex-flow: column nowrap;
  background-color: #FFF;
  padding: 40px;
  border-radius: 10px;
  box-shadow: var(--box-shadow);
}

main > p:first-child {
  background-color: var(--blue);
  padding: 1rem 5rem;
  margin-bottom: 1.5rem;
  border-radius: 0.5rem;
  text-align: center;
  box-shadow: var(--box-shadow);
}

input, button {
  display: block;
  height: 3.5rem;
  font-weight: bold;
  margin-top: 1.4rem;
  border-radius: 5px;
  font-size: 1rem;
  font-weight: 600;
  font-family: 'Poppins', 'Segoe UI', Verdana, Geneva, Tahoma, sans-serif;
}

input:nth-child(1) {
  margin-top: 0;
}

input:focus, input:active {
  outline: unset;
  border: 1px solid var(--dark-blue);
}

input {
  color: var(--dark-blue);
  border: 1px solid hsla(246, 25%, 77%, 0.5);
  padding: 0 3rem 0 2rem;
}

input::placeholder {
  opacity: 0.8;
}


input.error {
  display: block;
  color: var(--red);
  border-color: var(--red);
}

input.error + p.error {
  margin: 0.3rem 0 0 0;
  color: var(--red);
  text-align: right;
  font-size: 0.8rem;
  font-style: italic;
  position: relative;
}

input + p.error > .error-icon {
  content: url(../images/icon-error.svg);
  position: absolute;
  top: -2.7rem;
  right: 1rem;
}

button, button:active {
  border: unset;
  background-color: var(--green);
  text-transform: uppercase;
  color: white;
  font-weight: 500;
  cursor: pointer;
  transition: opacity 0.2s;
  border-bottom: 3px solid hsla(249, 10%, 26%, 0.2);
}

button:hover {
  opacity: 0.8;
}

form p {
  font-size: 0.8rem;
  color: var(--grayish-blue);
  text-align: center;
}

a:link, a:visited {
  text-decoration: none;
  color: var(--red);
  font-weight: 700;
}

@media screen and (max-width: 850px) {
  body {
    display: block;
    margin: 24px;
    background: url(../images/bg-intro-mobile.png);
    background-repeat: repeat;
    padding-top: 50px;
  }

  header {
    text-align: center;
    max-width: fit-content;
  }

  header h1 {
    font-size: 1.6rem;
  }

  main {
    width: auto;
    margin: 40px 0;
  }

  main > p:first-child {
    padding: 1rem 3rem;
  }

  main form {
    padding: 20px;
  }
}