app.js

const tabs = Array.from(document.querySelectorAll('[role="tab"]'));
function selectTab(tab) {
  for (const item of tabs) {
    const selected = item === tab;
    item.setAttribute('aria-selected', String(selected));
    item.tabIndex = selected ? 0 : -1;
    const panel = document.getElementById(item.dataset.panel);
    panel.hidden = !selected;
    if (!selected) panel.querySelectorAll('video').forEach(video => video.pause());
  }
}
tabs.forEach((tab, index) => {
  tab.addEventListener('click', () => selectTab(tab));
  tab.addEventListener('keydown', event => {
    let next;
    if (event.key === 'ArrowRight') next = (index + 1) % tabs.length;
    if (event.key === 'ArrowLeft') next = (index + tabs.length - 1) % tabs.length;
    if (event.key === 'Home') next = 0;
    if (event.key === 'End') next = tabs.length - 1;
    if (next === undefined) return;
    event.preventDefault();
    selectTab(tabs[next]);
    tabs[next].focus();
  });
});
document.getElementById('copy-citation').addEventListener('click', async () => {
  const text = document.getElementById('bibtex').textContent;
  const status = document.getElementById('copy-status');
  try {
    await navigator.clipboard.writeText(text);
    status.textContent = 'BibTeX copied.';
  } catch {
    const selection = window.getSelection();
    const range = document.createRange();
    range.selectNodeContents(document.getElementById('bibtex'));
    selection.removeAllRanges();
    selection.addRange(range);
    status.textContent = 'Citation selected. Use your browser’s Copy command.';
  }
});