:out-of-range

/* Selects any <input>, but only when it has a range */
/* specified, and its value is outside that range */
input:out-of-range {
  background-color: rgba(255, 0, 0, 0.25);
}

:out-of-range

<form action="" id="form1">
??? <ul>Values between 1 and 10 are valid.
??????? <li>
??????????? <input id="value1" name="value1" type="number" placeholder="1 to 10" min="1" max="10" value="12">
??????????? <label for="value1">Your value is </label>
??????? </li>
</form>

li {
??? list-style: none;
??? margin-bottom: 1em;
}
input {
??? border: 1px solid black;
}
input:in-range {
??? background-color: rgba(0, 255, 0, 0.25);
}
input:out-of-range {
??? background-color: rgba(255, 0, 0, 0.25);
??? border: 2px solid red;
}
input:in-range + label::after {
??? content:' OK';
}
input:out-of-range + label::after {
??? content:'out of range!';
}