Html – Fade in border <hr> lines animation

On a simple static website I’m building (using Bootstrap 5) it has a full screen carousel, and the screen looks like this:

I’ve got some CSS animations running, so the Navbar, Title text & sub text fade in.
I’m trying to do the same for the 2 border lines (ideally they’ll be timed to appear last), but i’m having difficulty getting any animations to work on them.

Here’s the HTML for the Carousel:

<div id="carouselExampleIndicators" class="carousel slide carousel-fade" data-bs-ride="carousel">
                <!-- Indicators -->
                <ol class="carousel-indicators" style="color: transparent !important; z-index: 3;">
                    <li data-bs-target="#carouselExampleIndicators" data-bs-slide-to="0" class="active"></li>
                    <li data-bs-target="#carouselExampleIndicators" data-bs-slide-to="1"></li>
                    <li data-bs-target="#carouselExampleIndicators" data-bs-slide-to="2"></li>
                    <li data-bs-target="#carouselExampleIndicators" data-bs-slide-to="3"></li>
                </ol>
                <!-- Wrapper for slides -->
                <div class="carousel-inner">
                    <div class="carousel-item" data-bs-interval="1300">
                        <img class="d-block w-100" src="assets/images/Wiznu-40.jpg" data-color="lightblue" alt="First Image">
                    </div>
                    <div class="carousel-item" data-bs-interval="1300">
                        <img class="d-block w-100" src="assets/images/Wiznu-41.jpg" data-color="firebrick" alt="Second Image">
                    </div>
                    <div class="carousel-item" data-bs-interval="1300">
                        <img class="d-block w-100" src="assets/images/Wiznu-42.jpg" data-color="violet" alt="Third Image">
                    </div>
                    <div class="carousel-item" data-bs-interval="1300">
                        <img class="d-block w-100" src="assets/images/Wiznu-43.jpg" alt="Fourth Image">
                    </div>
                    <div class="carousel-caption d-flex flex-column justify-content-center h-100" style="top: 0; z-index: 2;">
                        <hr class="border border-white border-1 opacity-75 mx-lg-12 mx-sm-4 mb-1 fade-in-border">
                        <p class="display-2 text-white mb-1 mt-2 fade-in-Header"><span style="color: red;">W</span>IZNU FOR <span style="color:red">H</span>AIR</p>
                        <hr class="border border-white border-1 opacity-75 mx-lg-12 mx-sm-4 fade-in-border">
                        <p class="pt-3 lead text-white text-uppercase fade-in-Sub">The Hair Specialists</p>
                    </div>
                </div>
              </div>

And this is the what im currently using for the animations:

I first tried based on opacity (same as others), then the background-color, and then tried based on border, but nothing seems to be working.

<style>
        .fade-in-Header {
            animation: fadeIn 4s;
        }

        .fade-in-Sub {
            animation: fadeIn 5s;
        }

        .fade-in-border {
            animation: fadeInBorder 8s;
        }

        .fade-in-Nav {
            animation: fadeIn 7s;
        }

        @keyframes fadeInBorder {
             0% { border: 0px solid transparent;}
             100% {border: 1px solid #fff }
        }

        @-moz-keyframes fadeInBorder {
            0% {background-color: transparent;}
            100% {background-color: #fff;}
        }

        @-o-keyframes fadeInBorder {
            0% {background-color: transparent;}
            100% {background-color: #fff;}
        }

        @keyframes fadeIn {
            0% {opacity: 0;}
            100% {opacity: 1;}
        }

        @-moz-keyframes fadeIn {
        0% { opacity: 0; }
        100% { opacity: 1; }
        }

        @-webkit-keyframes fadeIn {
        0% { opacity: 0; }
        100% { opacity: 1; }
        }

        @-o-keyframes fadeIn {
        0% { opacity: 0; }
        100% { opacity: 1; }
        }

        @-ms-keyframes fadeIn {
        0% { opacity: 0; }
        100% { opacity: 1; }
        }

    </style>

Edit/Update
i have this JS code for the carousel so its full screen height on all devices

var $item = $('.carousel-item');
var $wHeight = $(window).height();

$item.height($wHeight); 
$item.addClass('full-screen');

var $numberofSlides = $('.carousel-item').length;
var $currentSlide = Math.floor((Math.random() * $numberofSlides));

$('.carousel-indicators li').each(function(){
    var $slideValue = $(this).attr('data-bs-slide-to');
    if($currentSlide == $slideValue) {
        $(this).addClass('active');
        $item.eq($slideValue).addClass('active');
    } else {
        $(this).removeClass('active');
        $item.eq($slideValue).removeClass('active');
    }
});

$('.carousel img').each(function() {
    var $src = $(this).attr('src');
    var $color = $(this).attr('data-color');
    $(this).parent().css({
        'background-image' : '-webkit-linear-gradient(top, rgba(0,0,0,0.5), rgba(0,0,0,0.5)),' + 'url(' + $src + ')',
        'background-color' : $color
    });
    $(this).remove();
});

$(window).on('resize', function (){
    $wHeight = $(window).height();
    $item.height($wHeight);
});