* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  background: linear-gradient(135deg, #0f172a, #1e293b);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.container {
  background: white;
  width: 100%;
  max-width: 600px;
  padding: 30px;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

h1 {
  text-align: center;
  color: #0f172a;
  margin-bottom: 10px;
}

.subtitle {
  text-align: center;
  color: #64748b;
  margin-bottom: 25px;
}

.calculator label {
  display: block;
  margin-bottom: 8px;
  margin-top: 15px;
  font-weight: 600;
}

input,
select {
  width: 100%;
  padding: 12px;
  border: 1px solid #cbd5e1;
  border-radius: 10px;
  font-size: 16px;
}

button {
  width: 100%;
  margin-top: 20px;
  padding: 14px;
  background: #2563eb;
  color: white;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  font-size: 16px;
  font-weight: bold;
}

button:hover {
  background: #1d4ed8;
}

.results {
  margin-top: 25px;
  display: grid;
  gap: 15px;
}

.result-box {
  background: #f8fafc;
  padding: 15px;
  border-radius: 12px;
  border-left: 5px solid #2563eb;
}

.result-box span {
  color: #64748b;
}

.result-box h3 {
  margin-top: 5px;
  color: #0f172a;
}

.footer {
  margin-top: 30px;
  text-align: center;
  border-top: 1px solid #e2e8f0;
  padding-top: 20px;
}

.footer p {
  margin-bottom: 8px;
}

.dh-btn {
  background: #16a34a;
}

.dh-btn:hover {
  background: #15803d;
}