html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    font-family: Arial, sans-serif;
}
body {
    position: relative;
    width: 100vw;
    height: 100vh;
}
.bg-image {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    object-fit: cover;
    z-index: 0;
    transition: transform 2s linear, filter 1.5s linear;
    will-change: transform, filter;
}
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0,0,0,0.5);
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.content {
    z-index: 2;
    color: #fff;
    text-align: center;
}
/* Botones del mismo tamaño */
.btn {
    display: inline-block;
    margin: 10px 20px;
    padding: 12px 32px;
    background: #007bff;
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 1.1rem;
    cursor: pointer;
    text-decoration: none;
    transition: background 0.2s;
    min-width: 180px;
    text-align: center;
    box-sizing: border-box;
}