css轻松实现固定比例的块级容器

        .banner-wrapper {
            position: relative;
            width: 100%;
            padding-top: 50%;
        }

        .banner {
            position: absolute;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
        }
        
        <div class="banner-wrapper">
            <img class="banner" src="./img/portfolio/cabin.png" alt="">
        </div>