<style>
.calculator {
  background: #fff;
  padding: 20px;
  border-radius: 8px;
  max-width: 600px;
  margin: auto;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  font-family: "Segoe UI", sans-serif;
}

.calculator h3 {
  margin-bottom: 20px;
  color: #005fa3;
  text-align: center;
}

input[type="number"], button {
  width: 100%;
  padding: 10px;
  margin-bottom: 15px;
  font-size: 1em;
  border: 1px solid #ccc;
  border-radius: 4px;
}

button {
  background-color: #0078d4;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

.result {
  background: #eef6ff;
  padding: 15px;
  border-left: 4px solid #0078d4;
  border-radius: 4px;
}
.result h4 {
  margin-top: 0;
  color: #005fa3;
}
.result p {
  margin: 8px 0;
  font-size: 1em;
}
.calculator button {
  display: block;
  margin: 20px auto;
  padding: 10px 20px;
  font-size: 18px;
  font-weight: bold;
  background-color: #007acc;
  color: #fff;
  border: 2px dashed red;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
  transition: background-color 0.3s ease;
}

.calculator button:hover {
  background-color: #005fa3;
}
</style>