* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: #f5f5f5;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.container {
  width: 100%;
  max-width: 600px;
}

.door-opener {
  background: white;
  border-radius: 8px;
  padding: 60px 40px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  text-align: center;
}

h1 {
  color: #1a1a1a;
  margin-bottom: 60px;
  font-size: 2.5rem;
  font-weight: 500;
  letter-spacing: -0.5px;
}

.open-btn {
  background: #2563eb;
  color: white;
  border: none;
  padding: 32px 48px;
  font-size: 1.75rem;
  font-weight: 500;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.2s ease;
  width: 100%;
  min-height: 100px;
}

.open-btn:hover {
  background: #1d4ed8;
}

.open-btn:active {
  background: #1e40af;
}

.open-btn:disabled {
  background: #9ca3af;
  cursor: not-allowed;
  opacity: 0.7;
}

.message {
  margin-top: 32px;
  min-height: 32px;
  font-size: 1.125rem;
  font-weight: 400;
  color: #6b7280;
}

.message.success {
  color: #059669;
}

.message.error {
  color: #dc2626;
}

.message.loading {
  color: #2563eb;
}

/* Mobile optimizations */
@media (max-width: 768px) {
  .door-opener {
    padding: 50px 30px;
  }

  h1 {
    font-size: 2rem;
    margin-bottom: 50px;
  }

  .open-btn {
    padding: 28px 40px;
    font-size: 1.5rem;
    min-height: 90px;
  }

  .message {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  body {
    padding: 16px;
  }

  .door-opener {
    padding: 40px 24px;
  }

  h1 {
    font-size: 1.75rem;
    margin-bottom: 40px;
  }

  .open-btn {
    padding: 24px 32px;
    font-size: 1.375rem;
    min-height: 80px;
  }

  .message {
    font-size: 0.9375rem;
    margin-top: 24px;
  }
}