:root {
  --primary-color: #2c3e50;
  --secondary-color: #27ae60;
  --accent-color: #f39c12;
  --text-color: #333;
  --bg-color: #ecf0f1;
  --card-bg: #fff;
  --header-bg: #fff;
  --footer-bg: #2c3e50;
  --footer-text: #ecf0f1;
  --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --spacing-base: 1rem;
  --radius-base: 8px;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-base);
}

/* Header */
.site-header {
  background: var(--header-bg);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  text-decoration: none;
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-color);
  font-weight: 500;
}

.nav-links a:hover {
  color: var(--secondary-color);
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--primary-color), #34495e);
  color: #fff;
  text-align: center;
  padding: 4rem 1rem;
  margin-bottom: 2rem;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.2rem;
  max-width: 600px;
  margin: 0 auto 2rem;
  opacity: 0.9;
}

.cta-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  border-radius: var(--radius-base);
  text-decoration: none;
  font-weight: bold;
  transition: transform 0.2s, background-color 0.2s;
  border: none;
  cursor: pointer;
  font-size: 1rem;
}

.btn-primary {
  background-color: var(--secondary-color);
  color: #fff;
}

.btn-secondary {
  background-color: transparent;
  border: 2px solid #fff;
  color: #fff;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary:hover {
  background-color: #219150;
}

.btn-secondary:hover {
  background-color: rgba(255,255,255,0.1);
}

/* Calculator Grid */
.calculator-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 4rem;
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius-base);
  padding: 1.5rem;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.card h2 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
}

.card p {
  color: #666;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.card .btn-link {
  color: var(--secondary-color);
  text-decoration: none;
  font-weight: bold;
  align-self: flex-start;
}

.card .btn-link:hover {
  text-decoration: underline;
}

/* SEO Content */
.seo-content {
  background: var(--card-bg);
  padding: 3rem;
  border-radius: var(--radius-base);
  margin-bottom: 4rem;
}

.seo-content h2 {
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.seo-content p {
  margin-bottom: 1rem;
}

/* Footer */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 3rem 0;
  margin-top: auto;
}

.footer-content {
  text-align: center;
}

.footer-links {
  margin-bottom: 1.5rem;
}

.footer-links a {
  color: var(--footer-text);
  text-decoration: none;
  margin: 0 1rem;
  opacity: 0.8;
}

.footer-links a:hover {
  opacity: 1;
}

.disclaimer {
  font-size: 0.8rem;
  opacity: 0.6;
  max-width: 600px;
  margin: 1rem auto 0;
}

/* Calculator Page Specifics */
.calculator-page {
  padding: 2rem 0;
}

.calc-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  background: var(--card-bg);
  padding: 2rem;
  border-radius: var(--radius-base);
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}

@media (max-width: 768px) {
  .calc-container {
    grid-template-columns: 1fr;
  }
}

.input-group {
  margin-bottom: 1rem;
}

.input-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--primary-color);
}

.input-group input,
.input-group select {
  width: 100%;
  padding: 0.8rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 1rem;
}

.input-group input:focus,
.input-group select:focus {
  outline: none;
  border-color: var(--secondary-color);
  box-shadow: 0 0 0 3px rgba(39, 174, 96, 0.1);
}

.result-area {
  background: var(--bg-color);
  padding: 1.5rem;
  border-radius: var(--radius-base);
}

.result-item {
  display: flex;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.result-item:last-child {
  border-bottom: none;
}

.result-value {
  font-weight: bold;
  color: var(--primary-color);
}

.highlight {
  font-size: 1.5rem;
  color: var(--secondary-color);
}

.calc-description {
  margin-top: 2rem;
  line-height: 1.8;
}