:root {
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color: #111;
  background: #f6f6f6;
}

* { box-sizing: border-box; }

.page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.card {
  width: 100%;
  max-width: 520px;
  background: #fff;
  border: 1px solid #e7e7e7;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 10px 24px rgba(0,0,0,0.06);
  text-align: center;
}

.logo {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  border: 2px solid #111;
  display: grid;
  place-items: center;
  font-weight: 800;
  margin: 0 auto 12px;
}

.title {
  margin: 0 0 16px;
  font-size: 28px;
  text-align: center;
}

.btn {
  width: 100%;
  border: 1px solid #111;
  background: #111;
  color: white;
  padding: 12px 14px;
  border-radius: 12px;
  font-weight: 700;
  cursor: pointer;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.error {
  margin: 12px 0 0;
  color: #b00020;
  background: #ffe7ea;
  padding: 10px;
  border-radius: 12px;
  border: 1px solid #ffcad2;
  text-align: left;
}

.result {
  margin-top: 14px;
  padding: 12px;
  border-radius: 14px;
  border: 1px solid #eee;
  background: #fafafa;
  text-align: left;
}

.label {
  font-size: 13px;
  opacity: 0.7;
  margin-bottom: 6px;
}

.desc {
  font-size: 18px;
  font-weight: 800;
}