body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  max-width: 800px;
  margin: 0 auto;
  padding: 10px;
  background-color: #f5f5f5;
  font-size: 16px;
  line-height: 1.5;
}

.container {
  background: white;
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.message-box {
  height: 300px;
  border: 1px solid #ddd;
  padding: 10px;
  overflow-y: auto;
  margin-bottom: 10px;
  background-color: #fafafa;
}

.input-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

input[type="text"],
textarea {
  flex: 1;
  min-width: 200px;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 16px;
  box-sizing: border-box;
}

button {
  padding: 12px 16px;
  background-color: #007bff;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 16px;
  font-weight: 500;
  min-height: 44px;
  white-space: nowrap;
}

button:hover {
  background-color: #0056b3;
}

.main-btn {
  background-color: #28a745;
}

.main-btn:hover {
  background-color: #218838;
}

.chemical-btn {
  background-color: #ffc107;
  color: #212529;
}

.chemical-btn:hover {
  background-color: #e0a800;
}

.tank-btn {
  background-color: #17a2b8;
}

.tank-btn:hover {
  background-color: #138496;
}

.sieng-btn {
  background-color: #6f42c1;
}

.sieng-btn:hover {
  background-color: #5a32a3;
}

.message-main {
  border-left: 4px solid #28a745;
  background-color: #f8fff9;
}

.message-chemical {
  border-left: 4px solid #ffc107;
  background-color: #fffdf5;
}

.message-tank {
  border-left: 4px solid #17a2b8;
  background-color: #f5feff;
}

.message-sieng {
  border-left: 4px solid #6f42c1;
  background-color: #faf8ff;
}

.message {
  padding: 5px;
  margin: 2px 0;
  border-radius: 3px;
}

.status {
  padding: 10px;
  margin-bottom: 10px;
  border-radius: 4px;
  font-weight: bold;
}

.connected {
  background-color: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.disconnected {
  background-color: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

textarea {
  width: 100%;
  resize: vertical;
  font-size: 16px;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 6px;
  box-sizing: border-box;
}

h1 {
  font-size: 1.5rem;
  margin-bottom: 20px;
  text-align: center;
  color: #333;
}

h3 {
  margin-top: 20px;
  margin-bottom: 15px;
  color: #333;
  font-size: 1.2rem;
}

/* 모바일 반응형 스타일 */
@media (max-width: 768px) {
  body {
    padding: 5px;
    font-size: 16px;
  }

  .container {
    padding: 10px;
    border-radius: 0;
    box-shadow: none;
  }

  h1 {
    font-size: 1.3rem;
    margin-bottom: 15px;
  }

  .input-group {
    flex-direction: column;
    gap: 8px;
  }

  input[type="text"],
  textarea {
    min-width: auto;
    width: 100%;
    font-size: 16px;
  }

  button {
    width: 100%;
    padding: 14px 16px;
    font-size: 16px;
    min-height: 48px;
  }

  .message-box {
    height: 250px;
    font-size: 14px;
  }

  .status {
    text-align: center;
    font-size: 14px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 8px;
  }

  h1 {
    font-size: 1.2rem;
  }

  .message-box {
    height: 200px;
  }

  textarea {
    min-height: 80px;
  }
}