body {
  max-width: 960px;
  margin: auto;
  font-family: sans-serif;
  text-align: center;
  padding: 2rem;
}

#timer {
  font-size: 2rem;
  margin: 1rem 0;
}

button {
  padding: 0.6rem 1.2rem;
  font-size: 1.1rem;
  cursor: pointer;
  border: 1px solid #ccc;
  background: #f8f8f8;
  border-radius: 8px;
  margin: 0.4rem;
  width: 90%;
  max-width: 320px;
}

button:hover {
  background-color: #ddd;
}

canvas {
  max-width: 100%;
  height: auto;
  margin-top: 1rem;
}

@media (max-width: 600px) {
  body {
    padding: 1rem;
  }

  #timer {
    font-size: 1.5rem;
  }

  button {
    font-size: 1rem;
  }
}

#auth {
  margin-bottom: 1rem;
}

#auth input {
  padding: 0.3rem;
  margin: 0.2rem;
  font-size: 1rem;
}

#auth button {
  margin: 0.2rem;
}