body{margin:0;font-family:Arial;background:#f4f4f4}
.hero{height:70vh;background:url(hero.jpg) center/cover}
.overlay{background:rgba(0,0,0,.6);height:100%;color:#fff;display:flex;flex-direction:column;justify-content:center;align-items:center}
button{padding:10px 16px;border:none;border-radius:6px}