h1 { font-size: var(--font-fluid-4xl); }
h2 { font-size: var(--font-fluid-3xl); }
h3 { font-size: var(--font-fluid-2xl); }
h4 { font-size: var(--font-fluid-xl); }

a {
  transition: color var(--transition-fast);
}

.text-primary { color: var(--color-primary); }
.text-center { text-align: center; }

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

.theme-toggle__icon--sun { display: none; }
.theme-toggle__icon--moon { display: block; }

html.dark .theme-toggle__icon--sun { display: block; }
html.dark .theme-toggle__icon--moon { display: none; }

.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }
.delay-5 { transition-delay: 0.5s; }
.delay-6 { transition-delay: 0.6s; }

@media (prefers-reduced-motion: reduce) {
  .fade-in { opacity: 1; transform: none; transition: none; }
}