let input = document.getElementById("string");
let counter = document.getElementById("counterFooter")
let button = document.getElementById("btn");
input.addEventListener("input", () => {
let left = 140 - input.value.length;
left < 21 ? counter.style.color = "red" : counter.style.color = "white";
left < 0 ? button.classList.add("buttonDisabled") : button.classList.remove("buttonDisabled");;
counter.innerHTML = left + "/140";
})
button.addEventListener("click", () => {
let text = input.value;
window.open("https://twitter.com/intent/tweet?text=" + text);
});