<input type="email" id="main-input" placeholder='Your email?' />
<br />
<input type="number" min="1" max="10" value="20" />

body {
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  font-family: Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1rem;
  line-height: 3.5rem;
}
input {
  font-size: 1.5rem;
  padding: 0.5rem;
  border-radius: 0.5rem;
}
#main-input:invalid {
  border: 2px solid red;
  box-shadow: 0 0 2px red;
  outline: red;
}
#main-input:valid {
  border: 2px solid green;
  box-shadow: 0 0 2px green;
  outline: green;
}
input:in-range {
  border: 2px solid green;
  box-shadow: 0 0 2px green;
  outline: green;
}