let gradientAngle = 45; let gradientSpinElems = document.getElementsByClassName('gradient-spin'); const gradientInterval = setInterval(function() { updateGradientAngle(); }, 50); function updateGradientAngle() { gradientAngle += 1 if (gradientAngle > 360) { gradientAngle = 0; } for (let i=0; i<gradientSpinElems.length; i++) { gradientSpinElems[i].style.background = `linear-gradient(${gradientAngle}deg, #1a9fff, #946beb)`; } }