:root {
  --primary: #0a74da;
  --background: #ffffff;
  --text: #333333;
  --card-bg: #f2f6fc;
  --transition: 0.3s ease;
}

body.dark {
  --background: #0d1117;
  --text: #e6edf3;
  --card-bg: #161b22;
  --primary: #418aff;
}

body {
  margin: 0;
  font-family: "Poppins", sans-serif;
  background: var(--background);
  color: var(--text);
  scroll-behavior: smooth;
  transition: background var(--transition), color var(--transition);
}

/* Navbar */
.navbar {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--primary);
  color: white;
  padding: 10px 20px;
  z-index: 10;
}

.navbar .logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo img {
  width: 36px;
  height: 36px;
  border-radius: 50%;
}

.nav-links {
  display: flex;
  gap: 20px;
}

.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: opacity var(--transition);
}

.nav-links a:hover {
  opacity: 0.8;
}

.menu-toggle {
  display: none;
  font-size: 24px;
  cursor: pointer;
}

.theme-btn {
  background: transparent;
  border: none;
  color: white;
  font-size: 20px;
  cursor: pointer;
}

/* Sections */
.section {
  padding: 60px 20px;
  text-align: center;
}

.cards {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  margin-top: 20px;
}

.card {
  background: var(--card-bg);
  padding: 20px;
  border-radius: 12px;
  width: 280px;
  box-shadow: 0 3px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
}

/* Footer */
footer {
  text-align: center;
  padding: 20px;
  background: var(--primary);
  color: white;
  margin-top: 40px;
}

/* Mobile */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    background: var(--primary);
    width: 100%;
    position: absolute;
    top: 60px;
    left: 0;
    padding: 10px 0;
    text-align: center;
  }

  .nav-links.active {
    display: flex;
    animation: slideDown 0.3s ease;
  }

  @keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .menu-toggle {
    display: block;
  }
}