:root {
  --bg-color: #0f172a;
  --surface-color: rgba(30, 41, 59, 0.7);
  --surface-border: rgba(255, 255, 255, 0.1);
  --primary-color: #0ea5e9;
  --accent-color: #f59e0b;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --success-color: #10b981;
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-image: radial-gradient(circle at top right, rgba(14, 165, 233, 0.1), transparent 40%),
                    radial-gradient(circle at bottom left, rgba(245, 158, 11, 0.05), transparent 40%);
}

/* Typography */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(to right, var(--text-primary), var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
  margin-bottom: 0.5rem;
}

h2 { font-size: 2rem; color: var(--primary-color); margin-top: 2rem; }
h3 { font-size: 1.5rem; margin-top: 1.5rem; }
p { margin-bottom: 1rem; color: var(--text-secondary); }
a { color: var(--primary-color); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-color); }

/* Layout */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.main-content {
  flex: 1;
  padding: 3rem 0;
}

/* Header & Footer */
header, footer {
  background: rgba(15, 23, 42, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--surface-border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

footer {
  border-bottom: none;
  border-top: 1px solid var(--surface-border);
  margin-top: auto;
  padding: 2rem 0;
  text-align: center;
}

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

.logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  position: relative;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--text-primary);
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: var(--primary-color);
  transition: var(--transition);
}

.nav-links a:hover::after, .nav-links a.active::after {
  width: 100%;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 0.875rem;
}

/* Calculator UI (Glassmorphism) */
.calculator-card {
  background: var(--surface-color);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--surface-border);
  border-radius: 1.5rem;
  padding: 2.5rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  margin-bottom: 4rem;
  animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

@media (max-width: 768px) {
  .calc-grid { grid-template-columns: 1fr; gap: 2rem; }
  h1 { font-size: 2rem; }
}

.input-group {
  margin-bottom: 1.5rem;
}

.input-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.input-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

input[type="number"], select {
  width: 100%;
  background: rgba(15, 23, 42, 0.5);
  border: 1px solid var(--surface-border);
  color: var(--text-primary);
  padding: 0.875rem 1rem;
  border-radius: 0.75rem;
  font-size: 1rem;
  font-family: var(--font-family);
  transition: var(--transition);
  appearance: none;
}

input[type="number"]:focus, select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.2);
}

input[type="number"]::-webkit-inner-spin-button {
  opacity: 1;
}

.select-wrapper {
  position: relative;
}

.select-wrapper::after {
  content: '▼';
  font-size: 0.8rem;
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
}

/* Results Section */
.results-container {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.result-card {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--surface-border);
  border-radius: 1rem;
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.result-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--primary-color);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.result-card:hover::before {
  transform: scaleX(1);
}

.result-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
  border-color: rgba(255, 255, 255, 0.2);
}

.result-name {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.result-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-color);
  font-variant-numeric: tabular-nums;
}

.witr-card {
  display: none; /* Controlled by JS */
}

/* SEO Content Section */
.seo-content {
  background: var(--surface-color);
  border: 1px solid var(--surface-border);
  border-radius: 1.5rem;
  padding: 3rem;
  margin-top: 2rem;
}

.seo-content ul {
  list-style-position: inside;
  margin-bottom: 1.5rem;
  color: var(--text-secondary);
}

.seo-content li {
  margin-bottom: 0.5rem;
}

/* Text Pages (About, Terms, Privacy) */
.page-content {
  background: var(--surface-color);
  border: 1px solid var(--surface-border);
  border-radius: 1.5rem;
  padding: 3rem;
  max-width: 800px;
  margin: 0 auto;
}

.page-content h2 {
  border-bottom: 1px solid var(--surface-border);
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
}

/* Sitemap */
.sitemap-list {
  list-style: none;
  font-size: 1.25rem;
}

.sitemap-list li {
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--surface-border);
}

.sitemap-list a {
  display: flex;
  align-items: center;
}

.sitemap-list a::before {
  content: '→';
  margin-right: 0.5rem;
  color: var(--primary-color);
}

/* Blog Styles */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.blog-card {
  background: var(--surface-color);
  border: 1px solid var(--surface-border);
  border-radius: 1rem;
  padding: 2rem;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.blog-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-color);
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}

.blog-title {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-bottom: 1rem;
  line-height: 1.3;
}

.blog-excerpt {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.blog-read-more {
  display: inline-block;
  color: var(--primary-color);
  font-weight: 600;
  margin-top: auto;
}

.blog-read-more::after {
  content: ' →';
  transition: var(--transition);
}

.blog-read-more:hover::after {
  margin-left: 0.5rem;
}