{{-- Formateo + validación de RUT en el frontend. Aplica a cualquier <input data-rut>. --}}
<script>
(function () {
    if (window.__rutInit) { return; }
    window.__rutInit = true;
    function cleanRut(v){return (v||'').replace(/[^0-9kK]/g,'').toUpperCase();}
    function computeDv(num){var s=0,m=2;for(var i=num.length-1;i>=0;i--){s+=parseInt(num.charAt(i),10)*m;m=(m===7)?2:m+1;}var r=11-(s%11);if(r===11)return '0';if(r===10)return 'K';return String(r);}
    function isValidRut(v){var c=cleanRut(v);if(c.length<2)return false;var dv=c.slice(-1),n=c.slice(0,-1);if(!/^[0-9]+$/.test(n)||parseInt(n,10)<=0)return false;return computeDv(n)===dv;}
    function formatRut(v){var c=cleanRut(v);if(c.length===0)return '';if(c.length===1)return c;var dv=c.slice(-1),n=c.slice(0,-1).replace(/\B(?=(\d{3})+(?!\d))/g,'.');return n+'-'+dv;}
    function ensureError(input){var n=input.nextElementSibling;if(n&&n.classList&&n.classList.contains('rut-js-error'))return n;var el=document.createElement('p');el.className='rut-js-error';el.style.cssText='margin:6px 0 0;font-size:12px;color:#dc2626;display:none;';el.textContent='El RUT ingresado no es válido.';input.parentNode.insertBefore(el,input.nextSibling);return el;}
    function attach(input){if(input.dataset.rutBound)return;input.dataset.rutBound='1';var err=ensureError(input);
        input.addEventListener('input',function(){input.value=formatRut(input.value);err.style.display='none';input.style.borderColor='';});
        input.addEventListener('blur',function(){if(input.value.trim()===''){err.style.display='none';input.style.borderColor='';return;}var ok=isValidRut(input.value);err.style.display=ok?'none':'block';input.style.borderColor=ok?'':'#dc2626';});
        if(input.value.trim()!=='')input.value=formatRut(input.value);
        if(input.form){input.form.addEventListener('submit',function(e){if(input.value.trim()==='')return;if(!isValidRut(input.value)){e.preventDefault();err.style.display='block';input.style.borderColor='#dc2626';input.focus();}});}
    }
    document.addEventListener('DOMContentLoaded',function(){var i=document.querySelectorAll('input[data-rut]');for(var k=0;k<i.length;k++)attach(i[k]);});
})();
</script>