body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  background: #0f1115;
  color: #ffffff;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  width: 100%;
  max-width: 360px;
  padding: 24px;
  box-sizing: border-box;
  text-align: center;
}

h1 {
  margin-bottom: 24px;
  font-size: 1.6rem;
}

label {
  display: block;
  margin-bottom: 6px;
  font-size: 0.9rem;
  opacity: 0.85;
}

input {
  width: 100%;
  padding: 14px;
  font-size: 1.1rem;
  border-radius: 8px;
  border: none;
  margin-bottom: 16px;
  box-sizing: border-box;
  text-align: center;
}

.result {
  margin-top: 24px;
  margin-bottom: 24px;
  font-size: 1.4rem;
  font-weight: bold;
}

.calibration {
  margin-top: 20px;
}

.toggle {
  background: transparent;
  border: none;
  color: #9ca3af;
  font-size: 1rem;
  cursor: pointer;
}

.calibration-content {
  display: none;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid #2a2f3a;
}

.calibration-content label {
  font-size: 0.8rem;
  opacity: 0.8;
}

.calibration-content.open {
  display: block;
}

.hint {
  margin-top: 6px;
  margin-bottom: 16px;
  font-size: 0.8rem;
  color: #9ca3af;
}