:root{color-scheme:dark;background:#0d1521;color:#f3f5f8;font-family:system-ui}main{max-width:850px;margin:3rem auto;padding:1rem}nav{display:flex;gap:1rem}article{background:#1b293b;border:1px solid #8194af;padding:1.5rem;margin:1rem 0;border-radius:12px}a{color:#9fd4ff;margin-right:1rem}button{background:#234f78;color:white;padding:.7rem;margin:.3rem;border:1px solid #9fd4ff;border-radius:6px}a:focus,button:focus{outline:3px solid #ffdc70;outline-offset:3px}.mobile{display:none}@media(max-width:767px){.desktop{display:none}.mobile{display:block}}