/* Modern Unit Converter Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --secondary-color: #f8fafc;
  --accent-color: #06b6d4;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-light: #94a3b8;
  --background: #ffffff;
  --surface: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --radius: 12px;
  --radius-lg: 16px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--background);
  scroll-behavior: smooth;
}

/* Navigation */
nav {
  background: var(--background);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.95);
}

nav ul {
  display: flex;
  align-items: center;
  list-style: none;
  padding: 0 2rem;
  margin: 0;
  height: 70px;
}

nav ul:first-child {
  flex: 1;
}

nav a {
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 500;
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

nav a:hover {
  background: var(--surface);
  color: var(--primary-color);
}

nav a.active {
  background: var(--primary-color);
  color: white;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--primary-color);
}

.menu-button {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--radius);
  transition: var(--transition);
}

.menu-button:hover {
  background: var(--surface);
}

/* Sidebar */
.sidebar {
  position: fixed;
  top: 0;
  right: -300px;
  height: 100vh;
  width: 300px;
  background: var(--background);
  box-shadow: var(--shadow-xl);
  list-style: none;
  padding: 2rem 0;
  transition: var(--transition);
  z-index: 200;
  border-left: 1px solid var(--border);
}

.sidebar.active {
  right: 0;
}

.sidebar li {
  margin: 0;
}

.sidebar a {
  display: flex;
  align-items: center;
  padding: 1rem 2rem;
  color: var(--text-primary);
  text-decoration: none;
  transition: var(--transition);
  border-left: 3px solid transparent;
}

.sidebar a:hover {
  background: var(--surface);
  border-left-color: var(--primary-color);
  color: var(--primary-color);
}

.sidebar a.active {
  background: var(--primary-color);
  color: white;
  border-left-color: var(--primary-dark);
}

.close-sidebar {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--radius);
  transition: var(--transition);
}

.close-sidebar:hover {
  background: var(--surface);
}

/* Main Content */
.main-content {
  min-height: calc(100vh - 70px);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  position: relative;
  overflow: hidden;
}

.main-content::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  pointer-events: none;
}

.hero-section {
  text-align: center;
  color: white;
  max-width: 800px;
  z-index: 1;
  position: relative;
}

.hero-section h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero-section p {
  font-size: 1.25rem;
  margin-bottom: 3rem;
  opacity: 0.9;
}

.converter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  width: 100%;
  margin-top: 3rem;
}

.converter-card {
  background: var(--background);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-xl);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  cursor: pointer;
  border: 1px solid var(--border);
}

.converter-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.converter-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 25px 50px -12px rgb(0 0 0 / 0.25);
}

.converter-card h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.converter-card p {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.converter-card a {
  text-decoration: none;
  color: inherit;
}

.converter-icon {
  width: 60px;
  height: 60px;
  background: var(--surface);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  font-size: 1.5rem;
  color: var(--primary-color);
}

/* Footer */
.preFooter {
  background: var(--surface);
  padding: 2rem;
  text-align: center;
  border-top: 1px solid var(--border);
}

.tech-stack {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.tech-item {
  background: var(--background);
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  font-weight: 500;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.keywords-footer {
  background: var(--surface);
  padding: 2rem;
  border-top: 1px solid var(--border);
}

.keywords-footer h3 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.keywords-footer p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

footer {
  background: var(--text-primary);
  color: white;
  text-align: center;
  padding: 3rem 2rem;
}

footer h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

footer p {
  opacity: 0.8;
  font-size: 1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
  .hideOnMobile {
    display: none;
  }
  
  .menu-button {
    display: block;
  }
  
  nav ul {
    padding: 0 1rem;
  }
  
  .main-content {
    padding: 1rem;
  }
  
  .converter-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .converter-card {
    padding: 1.5rem;
  }
  
  .tech-stack {
    gap: 1rem;
  }
  
  .tech-item {
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .hero-section h1 {
    font-size: 2rem;
  }
  
  .hero-section p {
    font-size: 1rem;
  }
  
  .converter-card {
    padding: 1rem;
  }
  
  .converter-card h3 {
    font-size: 1.25rem;
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.converter-card {
  animation: fadeInUp 0.6s ease-out;
}

.converter-card:nth-child(1) { animation-delay: 0.1s; }
.converter-card:nth-child(2) { animation-delay: 0.2s; }
.converter-card:nth-child(3) { animation-delay: 0.3s; }
.converter-card:nth-child(4) { animation-delay: 0.4s; }
.converter-card:nth-child(5) { animation-delay: 0.5s; }

/* Focus states for accessibility */
a:focus,
button:focus,
select:focus,
input:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  :root {
    --background: #0f172a;
    --surface: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-light: #64748b;
    --border: #334155;
  }
  
  nav {
    background: rgba(15, 23, 42, 0.95);
  }
  
  .converter-card {
    background: var(--surface);
  }
}