/* TechnoLearn - Big 4 Professional Theme */
:root {
  --primary: #008542; /* Professional Green (Deloitte/PwC inspired) */
  --primary-dark: #006633;
  --secondary: #1a1a1a; /* Near Black */
  --text-main: #333333;
  --text-muted: #666666;
  --bg-light: #ffffff;
  --bg-gray: #f8f9fa;
  --border-color: #e0e0e0;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  font-family: var(--font-sans);
  color: var(--text-main);
  background-color: var(--bg-light);
  line-height: 1.6;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--secondary);
  font-weight: 700;
  margin-top: 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Professional Navbar */
.tech-navbar {
  background-color: rgba(255, 255, 255, 0.95) !important;
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  color: var(--secondary) !important;
  height: 80px;
  display: flex;
  align-items: center;
}

.tech-brand {
  color: var(--primary) !important;
  font-size: 1.5rem !important;
  letter-spacing: -0.02em;
}

.tech-desktop-nav a {
  color: var(--secondary) !important;
  font-weight: 500 !important;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.5rem 0;
  border-bottom: 2px solid transparent;
  transition: all 0.3s ease;
}

.tech-desktop-nav a:hover, .tech-desktop-nav a.active {
  color: var(--primary) !important;
  border-bottom-color: var(--primary);
}

/* Hero Section - Clean & Impactful */
.hero-section {
  padding: 120px 0 80px;
  background-color: var(--bg-gray);
  text-align: center;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  line-height: 1.1;
  color: var(--secondary);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto 2.5rem;
}

.btn-primary {
  background-color: var(--primary) !important;
  color: white !important;
  padding: 1rem 2.5rem !important;
  font-weight: 600 !important;
  border-radius: 0 !important; /* Big 4 often uses sharp corners or very subtle rounding */
  text-transform: uppercase;
  letter-spacing: 0.1em;
  transition: all 0.3s ease !important;
  border: none !important;
}

.btn-primary:hover {
  background-color: var(--primary-dark) !important;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 133, 66, 0.2);
}

/* Cards & Sections */
.section-title {
  font-size: 2.5rem;
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
  padding-bottom: 1rem;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background-color: var(--primary);
}

.card {
  background: white;
  border: 1px solid var(--border-color);
  padding: 2rem;
  transition: all 0.3s ease;
}

.card:hover {
  border-color: var(--primary);
  box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

/* YouTube Section */
.youtube-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.video-card {
  position: relative;
  overflow: hidden;
  background: #000;
}

.video-card iframe {
  width: 100%;
  aspect-ratio: 16/9;
}

/* Footer */
footer {
  background-color: var(--secondary);
  color: white;
  padding: 4rem 0 2rem;
}

footer a {
  color: #ccc;
  text-decoration: none;
}

footer a:hover {
  color: white;
}