* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #f6f7fb;
  display: grid;
  place-items: center;
  height: 100vh;
}

.card{
  width: min(560px, 92vw);
  background: #fff;
  border-radius: 16px;
  padding: 28px;
  box-shadow: 0 10px 30px rgba(0,0,0,.08);
}

h1 { margin: 0 0 10px; }
p { margin: 0 0 14px; color: #333; line-height: 1.6; }

button{
  border: 0;
  padding: 12px 16px;
  border-radius: 10px;
  cursor: pointer;
  background: #1677ff;
  color: #fff;
  font-size: 16px;
}

.tip{ margin-top: 12px; color: #666; }
footer{ margin-top: 18px; color: #999; font-size: 12px; }