body {
  font-family: Arial, sans-serif;
  max-width: 760px;
  margin: 40px auto;
  padding: 0 20px;
  text-align: center;
  color: #222;
  line-height: 1.5;
  background: #fafafa;
}

h1 {
  font-size: 40px;
  margin-bottom: 10px;
}

h2 {
  margin-top: 35px;
}

p {
  color: #555;
}

input {
  padding: 12px;
  margin: 10px 0 16px 0;
  width: 260px;
  max-width: 100%;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 16px;
}

button {
  padding: 14px 22px;
  font-size: 16px;
  border: none;
  border-radius: 8px;
  background: #222;
  color: white;
  cursor: pointer;
}

button:hover {
  opacity: 0.92;
}

#result {
  margin-top: 24px;
  font-size: 22px;
  font-weight: bold;
}

.calculator-box {
  background: white;
  border: 1px solid #e5e5e5;
  border-radius: 14px;
  padding: 30px 20px;
  margin-top: 25px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.04);
}

.ad-space {
  width: 100%;
  height: 90px;
  background-color: #f5f5f5;
  margin: 20px 0;
}

footer {
  margin-top: 40px;
  font-size: 14px;
}