/* Ai4Energy www — JuliaLang-inspired style (Bootstrap 5 + custom) */
:root {
  --julia-purple: #9558b2;
  --julia-blue: #4063d8;
  --julia-red: #cb3c33;
  --julia-green: #389826;
  --brand-primary: #4063d8;
  --brand-secondary: #9558b2;
  --bg-light: #f8f9fa;
}
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: #222;
  line-height: 1.7;
}
/* Navbar */
.navbar {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #eee;
}
.navbar .nav-link {
  font-weight: 500;
  font-size: 0.95rem;
  color: #444 !important;
  border-radius: 8px;
  transition: color .2s, background .2s;
}
.navbar .nav-link:hover {
  color: var(--brand-primary) !important;
  background: rgba(64,99,216,0.06);
}
.btn-primary {
  background: var(--brand-primary);
  border-color: var(--brand-primary);
  border-radius: 8px;
  font-weight: 600;
  padding: 0.6rem 1.5rem;
  transition: all .2s;
}
.btn-primary:hover {
  background: #3553c0;
  border-color: #3553c0;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(64,99,216,0.3);
}
.btn-outline-primary {
  border-color: var(--brand-primary);
  color: var(--brand-primary);
  border-radius: 8px;
  font-weight: 600;
  padding: 0.6rem 1.5rem;
  transition: all .2s;
}
.btn-outline-primary:hover {
  background: var(--brand-primary);
  color: #fff;
  transform: translateY(-1px);
}
/* Hero */
.hero-section {
  padding: 80px 0 60px;
  background: linear-gradient(135deg, #f0f4ff 0%, #f5f0ff 50%, #f0fff4 100%);
  text-align: center;
}
.hero-section h1 {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--brand-primary) 0%, var(--brand-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
}
.hero-section .tagline {
  font-size: 1.2rem;
  color: #666;
  max-width: 600px;
  margin: 0 auto 2rem;
}
.hero-section .hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}
/* Feature cards */
.feature-section {
  padding: 60px 0;
}
.feature-section h2 {
  text-align: center;
  font-weight: 700;
  font-size: 1.8rem;
  margin-bottom: 3rem;
  color: #333;
}
.feature-card {
  padding: 24px;
  border: 1px solid #eee;
  border-radius: 12px;
  transition: all .3s ease;
  height: 100%;
  background: #fff;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
  border-color: var(--brand-primary);
}
.feature-card .icon {
  font-size: 2rem;
  margin-bottom: 12px;
}
.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.feature-card p {
  font-size: 0.9rem;
  color: #666;
  line-height: 1.6;
  margin: 0;
}
/* Content */
.content-section {
  padding: 40px 0;
}
.content-section h2 {
  font-weight: 700;
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
  color: #333;
}
.content-section p {
  color: #444;
  line-height: 1.8;
}
/* Footer */
.site-footer {
  background: #1a1a2e;
  color: #ccc;
}
.site-footer h5, .site-footer h6 {
  color: #fff;
  font-weight: 700;
}
.site-footer a {
  color: #aaa;
  text-decoration: none;
  transition: color .2s;
}
.site-footer a:hover {
  color: #fff;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  background: rgba(0,0,0,0.2);
}
.footer-bottom a {
  color: #999;
}
.footer-bottom a:hover {
  color: #fff;
}
/* Responsive */
@media (max-width: 768px) {
  .hero-section { padding: 48px 0; }
  .hero-section h1 { font-size: 2.2rem; }
  .hero-section .tagline { font-size: 1rem; }
}