* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #111827;
  color: #e5e7eb;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.container {
  text-align: center;
  padding: 2rem 2.5rem;
  border-radius: 1rem;
  background: #1f2937;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
  max-width: 320px;
  width: 100%;
}

h1 {
  margin-top: 0;
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

.countdown {
  font-size: 3rem;
  font-weight: bold;
  margin: 1rem 0 1.5rem;
}

button {
  padding: 0.6rem 1.6rem;
  border-radius: 999px;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  background: #3b82f6;
  color: white;
  font-weight: 600;
}

button:disabled {
  opacity: 0.6;
  cursor: default;
}

button + button {
  margin-left: 0.5rem;
}

.hidden {
  display: none;
}

.hint {
  margin-top: 1.5rem;
  font-size: 0.85rem;
  color: #9ca3af;
}