body{margin:0;font-family:Arial;background:#f5f5f5;color:#333}
header{background:#20232a;color:#fff;text-align:center;padding:1rem}
.logo{max-height:60px;margin:0 auto .5rem;display:block}
nav ul{list-style:none;margin:0;padding:0;display:flex;justify-content:center;background:#333}
nav a{color:#fff;text-decoration:none;padding:1rem}
nav a.active,nav a:hover{background:#555}
main{padding:2rem}
.slogan{font-size:.9rem;font-style:italic;margin-top:.5rem;color:#ccc}
.file-thumb{width:100px;border-radius:4px;margin-right:.5rem}
.file-item{display:flex;align-items:center;background:#fff;padding:.5rem 1rem;border-radius:6px;box-shadow:0 1px 4px rgba(0,0,0,.08);margin-bottom:.5rem}
.screen-card{background:#fff;border-radius:8px;padding:1rem;margin:.5rem;box-shadow:0 1px 6px rgba(0,0,0,.1);text-align:center;width:200px}
.screen-card button{margin:.25rem;padding:.3rem .7rem;border:none;border-radius:4px;cursor:pointer}