html,
body {
  margin: 0;
  padding: 0;
  background: #ffffff;
  color: #000000;
  font-family: Arial, "Microsoft YaHei", sans-serif;
}

body {
  min-height: 100vh;
}

.page {
  width: 100%;
  max-width: 760px;
  margin: 170px auto 0;
  text-align: center;
}

h1 {
  margin: 0 0 22px;
  font-size: 24px;
  font-weight: 700;
}

.input-row {
  display: inline-flex;
  align-items: center;
  gap: 14px;
}

#secretInput {
  width: 320px;
  height: 40px;
  padding: 0 12px;
  border: 1px solid #999999;
  border-radius: 0;
  font-size: 15px;
  outline: none;
}

button {
  height: 40px;
  padding: 0 16px;
  border: 1px solid #999999;
  background: #f3f3f3;
  color: #000000;
  font-size: 15px;
  cursor: pointer;
}

.result-panel {
  margin-top: 24px;
}

.label {
  margin: 0 0 18px;
  font-size: 22px;
  font-weight: 700;
}

.code {
  margin: 0;
  font-size: 58px;
  line-height: 1;
  color: #ff0000;
}

.countdown {
  margin: 18px 0 12px;
  font-size: 15px;
  color: #777777;
}

.error {
  margin-top: 18px;
  font-size: 14px;
  color: #cc0000;
}

@media (max-width: 640px) {
  .page {
    margin-top: 90px;
    padding: 0 16px;
  }

  .input-row {
    display: flex;
    flex-direction: column;
    gap: 10px;
  }

  #secretInput {
    width: 100%;
  }

  button {
    width: 100%;
  }

  .label {
    font-size: 20px;
  }

  .code {
    font-size: 48px;
  }
}