body{font-family:Arial,sans-serif;margin:0;background:#f5f7fa;color:#222}main{max-width:900px;margin:30px auto;padding:20px;background:#fff;border-radius:12px;box-shadow:0 2px 12px #0001}input,button{display:block;width:100%;box-sizing:border-box;padding:12px;margin:8px 0}button{cursor:pointer}#map{height:500px;margin-top:15px}.online{color:green}.offline{color:#999}