text centered on img with responsive and within a link

I have a problem and that is that I can not leave a text that goes inside an image and is inside a link, when I start to do the responsive the text goes too up, some way to power fix it?

<div class="container">
  <a href="url">

    <img class="img" src="D:\prueba.jpg">

    <div class="texto">
        Texto Centrado 
    </div>

  </a>
</div>

.container {
    position: relative;
}

.img {
    float: left;
    object-fit: cover;
    width: 100%;
    height: 1080px;

}

.texto {
    position: absolute;
    text-align: center;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    font-size: 50px;
    color: white;
    font-weight: 800;
    margin-top: 25%;
}