const html = document.querySelector('html');
const focoBt = document.querySelector('.app__card-button--foco');
const curtoBt = document.querySelector('.app__card-button--curto');
const longoBt = document.querySelector('.app__card-button--longo');
focoBt.addEventListener('click', function() {
html.setAttribute('data-contexto', 'foco')
});
curtoBt.addEventListener('click', function() {
html.setAttribute('data-contexto', 'descanso-curto')
});
longoBt.addEventListener('click', function() {
html.setAttribute('data-contexto', 'descanso-longo')
});
