*{box-sizing:border-box}
body{margin:0;font-family:system-ui,Arial;background:#fff;color:#111}
.header{background:#007aff;color:#fff;text-align:center;padding:2rem}
.section{padding:1.5rem;max-width:900px;margin:0 auto}
ul{padding-left:20px}
a.btn{display:inline-block;padding:10px 18px;background:#007aff;color:#fff;border-radius:6px;text-decoration:none;margin-top:10px}
.banners{display:flex;flex-direction:column;gap:1rem;padding:1rem}
.banners img{width:100%;border-radius:10px}
@media(min-width:768px){.banners{flex-direction:row}}
footer{text-align:center;padding:1rem;font-size:14px;color:#555}