Сайт в разработке

<h1 class='my-heading'>Just some HTML</h1><?php echo 'The year is ' . date('Y'); ?>

[].forEach.call(document.querySelectorAll("input[type='tel']"), function (input) {
        let keyCode;
        function mask(event) {
            event.keyCode && (keyCode = event.keyCode);
            let pos = this.selectionStart;
            if (pos < 3) event.preventDefault()
            let matrix = "+7 (___) ___-__-__",
                i = 0,
                def = matrix.replace(/\D/g, ""),
                val = this.value.replace(/\D/g, ""),
                newValue = matrix.replace(/[_\d]/g, function (a) {
                    return i < val.length ? val.charAt(i++) || def.charAt(i) : a;
                });
            i = newValue.indexOf("_");
            if (i != -1) {
                i < 5 && (i = 3);
                newValue = newValue.slice(0, i);
            }
            let reg = matrix.substr(0, this.value.length).replace(/_+/g,
                function (a) {
                    return "\\d{1," + a.length + "}";
                }).replace(/[+()]/g, "\$&");
            reg = new RegExp("^" + reg + "$");
            if (!reg.test(this.value) || this.value.length < 5 || keyCode > 47 && keyCode < 58) this.value = newValue;
            if (event.type == "blur" && this.value.length < 5) this.value = "";
        }

        input.addEventListener("input", mask, false);
        input.addEventListener("focus", mask, false);
        input.addEventListener("blur", mask, false);
        input.addEventListener("keydown", mask, false);
        input.addEventListener('mouseup', event => {
          event.preventDefault()
          if (input.value.length < 4) {
            input.setSelectionRange(4, 4)
          } else {
            input.setSelectionRange(input.value.length, input.value.length)
          }
        })
    });