* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
  margin: 0;
}
body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  background: #f7f7fb;
  color: #222;
}
.container {
  max-width: 720px;
  margin: 8vh auto;
  padding: 24px;
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.08);
  text-align: center;
}
button {
  padding: 10px 16px;
  border: 0;
  border-radius: 10px;
  cursor: pointer;
}