<div class="radikalwp-form-validate" data-validate><label class="radikalwp-form-validate-label" for="radikalwp-val-email">ایمیل<//label><input class="radikalwp-form-validate-input" id="radikalwp-val-email" type="email" placeholder="you@example.com"><p class="radikalwp-form-validate-msg" hidden>فرمت ایمیل صحیح نیست<//p><//div>

.radikalwp-form-validate { max-width: 320px; }
.radikalwp-form-validate-label {
  display: block;
  margin-bottom: 6px;
  font-size: 12.5px;
  font-weight: 700;
  color: #334155;
}
.radikalwp-form-validate-input {
  width: 100%;
  padding: 12px 15px;
  font-family: inherit;
  font-size: 14px;
  color: #1e293b;
  background: #fff;
  border: 1.5px solid #e2e8f0;
  border-radius: 12px;
  outline: none;
  transition: border-color .25s ease, box-shadow .25s ease;
}
.radikalwp-form-validate-input.is-valid {
  border-color: #10b981;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, .12);
}
.radikalwp-form-validate-input.is-invalid {
  border-color: #ef4444;
  box-shadow: 0 0 0 3px rgba(239, 68, 68, .12);
}
.radikalwp-form-validate-msg {
  margin: 6px 2px 0;
  font-size: 11.5px;
  color: #ef4444;
}

// اعتبارسنجی زنده فرمت ایمیل با تغییر کلاس وضعیت
document.querySelectorAll('[data-validate]').forEach(function (wrap) {
  var input = wrap.querySelector('input');
  var msg = wrap.querySelector('.radikalwp-form-validate-msg');
  input.addEventListener('input', function () {
    var ok = /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(input.value);
    input.classList.toggle('is-valid', ok);
    input.classList.toggle('is-invalid', !ok && input.value.length > 2);
    msg.hidden = ok || input.value.length <= 2;
  });
});