function setShare(pct) {
  const el = document.getElementById('a_share');
  if (el) el.value = Number(pct).toFixed(4);
}

function onKindChange(kind) {
  const shareWrap = document.getElementById('share-wrap');
  const presets   = document.getElementById('presets');
  if (!shareWrap || !presets) return;
  if (kind === 'transfer') {
    shareWrap.style.display = 'none';
    presets.style.display = 'none';
  } else {
    shareWrap.style.display = '';
    presets.style.display = '';
  }
}

document.addEventListener('DOMContentLoaded', () => {
  // default your share to 2/3
  setShare(66.6667);
  // wire presets
  const p50 = document.getElementById('p50');
  const p66 = document.getElementById('p66');
  const p33 = document.getElementById('p33');
  if (p50) p50.addEventListener('click', () => setShare(50));
  if (p66) p66.addEventListener('click', () => setShare(66.6667));
  if (p33) p33.addEventListener('click', () => setShare(33.3333));

  // wire kind radios
  const bill = document.getElementById('k_bill');
  const xfer = document.getElementById('k_xfer');
  if (bill) bill.addEventListener('change', () => onKindChange('bill'));
  if (xfer) xfer.addEventListener('change', () => onKindChange('transfer'));
  onKindChange((xfer && xfer.checked) ? 'transfer' : 'bill');
});