html { scroll-behavior: smooth; }
body { font-family: system-ui, sans-serif; }
/* Paleta: azul, branco, cinza */
:root {
  --primary:#1d4ed8; /* azul principal */
  --primary-light:#3b82f6;
  --bg:#f8fafc; /* quase branco */
  --text:#1f2937; /* cinza escuro */
  --muted:#64748b; /* cinza médio */
}

.fade-in { opacity:0; transform: translateY(12px); transition: opacity .6s ease, transform .6s ease; }
.fade-in.visible { opacity:1; transform: translateY(0); }

.nav-active { display:block !important; }

.btn-base { transition: background-color .25s ease, color .25s ease, transform .25s ease; }
.btn-base:hover { transform: translateY(-2px); }
.btn-primary { background: var(--primary); color:#fff; }
.btn-primary:hover { background: var(--primary-light); }

.card-skill { transition: box-shadow .25s ease, transform .25s ease; }
.card-skill:hover { box-shadow: 0 8px 24px -8px rgba(0,0,0,0.25); transform: translateY(-4px); }

header { backdrop-filter: blur(6px); }

/* Botão hambúrguer estados */
#btnMenu { transition: color .25s ease, background-color .25s ease; }
#btnMenu[data-icon-state="closed"] { color: var(--primary); }
#btnMenu[data-icon-state="open"] { color: var(--primary-light); }

/* Mobile menu overlay (progressivo) */
#mobileMenu { display:none; }
@media (max-width: 767px) {
  #mobileMenu { background:rgba(255,255,255,0.95); position:fixed; top:64px; left:0; right:0; padding:1rem 1.25rem 2rem; box-shadow:0 4px 16px -4px rgba(0,0,0,.15); }
  #mobileMenu a { display:block; padding:.75rem 0; border-bottom:1px solid #e2e8f0; }
  #mobileMenu a:last-child { border-bottom:none; }
}