@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&display=swap');
@import url('https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.1/font/bootstrap-icons.css');

:root {
  --bg-color: #0b0f19;
  --bg-secondary: #111827;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-green: #10b981;
  --accent-gradient: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  --glass-bg: rgba(17, 24, 39, 0.6);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  --surface-color: #1f2937;
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --nav-height: 80px;
}

[data-theme='light'] {
  --bg-color: #f1f5f9;
  --bg-secondary: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(0, 0, 0, 0.05);
  --glass-shadow: 0 8px 32px 0 rgba(148, 163, 184, 0.15);
  --surface-color: #ffffff;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
  padding-top: var(--nav-height);
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
}

a:hover {
  color: var(--accent-blue);
}

ul {
  list-style: none;
}

/* Typography */
.text-gradient {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

.heading-1 {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.2;
}

/* Code Blocks Fix for Light Mode */
pre, pre code {
  color: #d4d4d4 !important;
}

.heading-2 {
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.heading-3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

/* Glassmorphism */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  border-radius: 16px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 50px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  outline: none;
  font-size: 1rem;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.6);
  color: white;
}

.btn-outline {
  background: transparent;
  border: 1px solid var(--accent-blue);
  color: var(--accent-blue);
}

.btn-outline:hover {
  background: var(--accent-blue);
  color: white;
}

.btn-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
}

.btn-icon:hover {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: white;
}

/* Container */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Layout Utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }

/* Grid Utils */
.grid { display: grid; gap: 2rem; }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 1000;
  transition: var(--transition);
  border-bottom: 1px solid var(--glass-border);
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.navbar .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand i {
  color: var(--accent-blue);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

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

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.mobile-menu-btn {
  display: none;
  font-size: 1.5rem;
  background: none;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
}

.mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  width: 100%;
  background: var(--bg-color);
  padding: 2rem;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  border-bottom: 1px solid var(--glass-border);
  flex-direction: column;
  gap: 1.5rem;
  z-index: 999;
}

.mobile-menu.active {
  display: flex;
}

/* Sections */
.section-padding {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.section-subtitle {
  color: var(--accent-blue);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
  display: block;
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--glass-border);
  padding: 4rem 0 2rem;
  margin-top: 5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-col h4 {
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  font-size: 1.25rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  color: var(--text-secondary);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--glass-border);
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Ad Placeholders */
.ad-container {
  display: flex;
  justify-content: center;
  margin: 2rem 0;
  width: 100%;
}

.ad-placeholder {
  background: rgba(59, 130, 246, 0.05);
  border: 1px dashed rgba(59, 130, 246, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-blue);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-radius: 8px;
  position: relative;
  overflow: hidden;
}

.ad-placeholder::before {
  content: 'Test Ad - Sponsored';
  opacity: 0.9;
}

.ad-leaderboard { width: 100%; max-width: 728px; height: 90px; }
.ad-sidebar-slot { width: 100%; max-width: 300px; height: 600px; margin: 0 auto; }
.ad-square { width: 100%; max-width: 300px; height: 250px; margin: 0 auto; }

/* Cards */
.course-card {
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
  height: 100%;
  display: flex;
  flex-direction: column;
}

.course-card:hover {
  transform: translateY(-5px);
  border-color: rgba(139, 92, 246, 0.3);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
}

.course-icon {
  width: 70px;
  height: 70px;
  border-radius: 20px;
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin: 0 auto 1.5rem;
  transition: var(--transition);
}

.course-card:hover .course-icon {
  background: var(--accent-gradient);
  color: white;
}

.course-card h3 {
  margin-bottom: 1rem;
}

.course-card p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

/* Badges */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
}

/* Forms & Inputs */
.input-group {
  margin-bottom: 1.5rem;
}

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

.input {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--bg-color);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  color: var(--text-primary);
  font-family: inherit;
  transition: var(--transition);
}

.input:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

textarea.input {
  resize: vertical;
  min-height: 120px;
}

/* Sidebar Items */
.sidebar { position: sticky; top: 100px; }
.sidebar-widget { padding: 1.5rem; margin-bottom: 1.5rem; }
.sidebar-links { display: flex; flex-direction: column; gap: 0.8rem; }
.sidebar-links a { display: flex; justify-content: space-between; color: var(--text-secondary); padding: 0.5rem 0; border-bottom: 1px dashed var(--glass-border); align-items: center; }
.sidebar-links a:hover { color: var(--accent-blue); padding-left: 0.5rem; }

/* Media Queries */
@media (max-width: 992px) {
  .grid-cols-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-cols-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links, .nav-actions .btn-primary { display: none; }
  .mobile-menu-btn { display: block; }
  .grid-cols-2 { grid-template-columns: 1fr; }
  .heading-1 { font-size: 2.5rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
}