#ph-calculator {
  background: linear-gradient(to right, #c2e9fb, #a1c4fd);
  padding: 20px;
  max-width: 350px;
  border-radius: 15px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.2);
  font-family: Arial, sans-serif;
  margin: 20px auto;
}

#ph-calculator h2 {
  text-align: center;
  color: #333;
  margin-bottom: 15px;
}

.input-row {
  margin-bottom: 12px;
}

.input-row label {
  display: block;
  margin-bottom: 5px;
  color: #333;
}

#ph-calculator input,
#ph-calculator select {
  width: 100%;
  padding: 8px;
  border: 1px solid #aaa;
  border-radius: 8px;
  box-sizing: border-box;
}

#ph-calculator button {
  width: 100%;
  padding: 10px;
  background-color: #5a67d8;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 16px;
  margin-top: 10px;
}

#ph-calculator button:hover {
  background-color: #434190;
}

#result {
  margin-top: 15px;
  padding: 10px;
  background: #f0f4f8;
  border-left: 4px solid #5a67d8;
  border-radius: 6px;
  color: #333;
}