* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: #f8fafc;
  color: #1e293b;
  line-height: 1.6;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px;
}

header {
  background: linear-gradient(135deg, #0f766e, #0d9488);
  color: white;
  padding: 24px 0;
  text-align: center;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

header h1 {
  font-size: 1.8rem;
  margin-bottom: 6px;
}

header p {
  opacity: 0.9;
  font-size: 0.95rem;
}

header a {
  color: white;
  text-decoration: none;
}

nav {
  background: #0f766e;
  padding: 12px 0;
  text-align: center;
}

nav a {
  color: white;
  text-decoration: none;
  margin: 0 12px;
  font-size: 0.95rem;
  opacity: 0.9;
}

nav a:hover {
  opacity: 1;
  text-decoration: underline;
}

.hero {
  text-align: center;
  padding: 40px 20px 20px;
}

.hero h2 {
  font-size: 1.6rem;
  margin-bottom: 10px;
  color: #0f766e;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
  margin: 30px 0 50px;
}

.tool-card {
  background: white;
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  transition: transform 0.2s, box-shadow 0.2s;
  border: 1px solid #e2e8f0;
}

.tool-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.1);
}

.tool-card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
  color: #0f766e;
}

.tool-card p {
  font-size: 0.9rem;
  color: #64748b;
  margin-bottom: 16px;
}

.tool-card a {
  display: inline-block;
  background: #0d9488;
  color: white;
  padding: 8px 16px;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}

.tool-card a:hover {
  background: #0f766e;
}

.calculator-box {
  background: white;
  border-radius: 12px;
  padding: 28px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
  margin: 20px 0 40px;
  border: 1px solid #e2e8f0;
}

.calculator-box h2 {
  color: #0f766e;
  margin-bottom: 8px;
  font-size: 1.4rem;
}

.calculator-box .desc {
  color: #64748b;
  margin-bottom: 24px;
  font-size: 0.95rem;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 6px;
  font-size: 0.95rem;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 1rem;
  background: #f8fafc;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: #0d9488;
  box-shadow: 0 0 0 3px rgba(13,148,136,0.15);
}

.btn {
  background: #0d9488;
  color: white;
  border: none;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  margin-top: 8px;
}

.btn:hover {
  background: #0f766e;
}

.result-box {
  margin-top: 24px;
  padding: 20px;
  background: #f0fdfa;
  border-radius: 10px;
  border: 1px solid #99f6e4;
  display: none;
}

.result-box h3 {
  color: #0f766e;
  margin-bottom: 12px;
}

.result-item {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid #ccfbf1;
  font-size: 1.05rem;
}

.result-item:last-child {
  border-bottom: none;
  font-weight: 600;
  font-size: 1.15rem;
  color: #0f766e;
}

.disclaimer {
  margin-top: 20px;
  font-size: 0.85rem;
  color: #64748b;
  background: #f1f5f9;
  padding: 12px 16px;
  border-radius: 8px;
}

footer {
  text-align: center;
  padding: 30px 20px;
  color: #64748b;
  font-size: 0.9rem;
  border-top: 1px solid #e2e8f0;
  margin-top: 40px;
}

.back-link {
  display: inline-block;
  margin-bottom: 20px;
  color: #0d9488;
  text-decoration: none;
  font-weight: 500;
}

.back-link:hover {
  text-decoration: underline;
}

@media (max-width: 600px) {
  header h1 {
    font-size: 1.4rem;
  }
  .tools-grid {
    grid-template-columns: 1fr;
  }
}