Detect TLD links

tld-detect.js

var links = document.getElementsByTagName("a");
document.head.insertAdjacentHTML("beforeend", `<style>@keyframes intraT { 50% { opacity: 0; }}</style>`)
for (var i = 0; i < links.length; i++) {
    let temp_url = ""
    try {
        temp_url = new URL(links[i].href);
    } catch(err) {
        temp_url = "err"
    }
    if (temp_url != "err") {
        let a1 = temp_url.hostname.match(/\./g)
        if (a1 == null && temp_url.hostname.length != 0 ){
            links[i].style.color = "tomato"
            links[i].style.animation= "intraT 1s linear infinite"
            console.log(temp_url.hostname)
        }
    }   
}