JSFiddle - React, Tailwind, and code Playground
by master1991
HTML
<p class="form-input form-input__password">
<label class="password label password__input-label" for="password">Пароль</label>
<input class="password input password__input password__input-first" maxlength="250" type="password" name="user-password" id="password" required="">
</p>
<div class="password-rules">
<h4 class="rules-heading">Password should have</h4>
<ul class="list-reset rules-list">
<li class="rule rule__length"> at least 10 symbols</li>
<li class="rule rule__capital">a capital letter</li>
</ul>
</div>
JavaScript
let reg = /[A-Z]/;
let pInput = document.querySelector(".password__input");
let ruleLenght= document.querySelector(".rule__length");
let ruleCapital= document.querySelector(".rule__capital");
pInput.addEventListener("keyup", function(){
if(pInput.value.length < 10) {
ruleLenght.style.color = "red";
ruleCapital.style.color = "red";
}else{
ruleLenght.style.color = "green";
if(!reg.test(pInput.value)){
ruleCapital.style.color = "red";
}else{
ruleCapital.style.color = "green";
}
}
});