* {
  box-sizing: border-box
}

body,
html {
  width: 100%;
  max-width: 100vw;
  height: 100vh;
  height: -webkit-fill-available;
  height: -moz-available;
  height: -fill-available;
  margin: 0;
  padding: 0;
  background-color: #136a8a;
  background-image: linear-gradient(135deg, #136a8a, #267871);
  overflow-x: hidden;
  overflow-y: auto;
  font-size: 18px;
  font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Helvetica, Arial, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol;
  line-height: 1.4;
  color: #072530
}

@media screen and (max-width:768px) {
  body,
  html {
    font-size: 14px
  }
}

body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 1rem;
}

h1 {
  font-size: 4rem;
  color: #0d485d;
  line-height: 1
}

h1,
p {
  font-family: inherit;
  margin: 0 0 1rem;
  padding: 0
}

p {
  font-size: inherit;
  line-height: inherit;
  color: inherit;
  font-weight: 400
}

.container {
  margin: 150px auto;
  width: 100%;
  max-width: 728px;
  background-color: #fafafa;
  border-radius: .5rem;
  padding: 1rem;
  text-align: center
}

.form {
  display: block;
  margin: 0;
  padding: 0
}

.form .form__input {
  display: block;
  width: 100%;
  max-width: 400px;
  margin: 0 auto 1rem;
  font-family: inherit;
  font-size: 2rem;
  padding: .5rem;
  text-align: center;
  border: 2px solid #136a8a;
  border-radius: .5rem
}

.form .form__input:active,
.form .form__input:focus {
  outline: none;
  box-shadow: 0 0 10px 1px rgba(0, 0, 0, .5)
}

.form .form__input:invalid {
  border-color: #de0001
}

.form .form__input:placeholder-shown {
  border-color: #136a8a
}

.form .form__input:valid {
  border-color: #136a8a
}

.form .form__label {
  display: block;
  text-align: left;
  width: 100%;
  max-width: 400px;
  margin: 0 auto .25rem;
  font-weight: 700;
  color: #0d485d
}

.form .form__submit {
  display: block;
  margin: 0 auto 1rem;
  width: auto;
  max-width: auto;
  color: #fff;
  background-color: #136a8a;
  border: none;
  border-radius: .5rem;
  font-family: inherit;
  font-size: 2rem;
  padding: .5rem 1rem
}

.form .form__submit:focus,
.form .form__submit:hover {
  cursor: pointer;
  background-image: linear-gradient(135deg, #136a8a, #267871)
}

.form .form__submit:active,
.form .form__submit:focus {
  outline: none;
  box-shadow: 0 0 10px 1px #000
}

.form .form__result {
  font-size: 1.25rem
}