:root {
  --fundo: #fbfbfd;
  --texto: #1d1d1f;
  --suave: #6e6e73;
  --linha: rgba(0, 0, 0, 0.08);
  --destaque: #0066cc;
  --barra: rgba(251, 251, 253, 0.72);
  color-scheme: light;
  font: 100%/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fundo: #000;
    --texto: #f5f5f7;
    --suave: #a1a1a6;
    --linha: rgba(255, 255, 255, 0.12);
    --destaque: #2997ff;
    --barra: rgba(0, 0, 0, 0.72);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--fundo);
  color: var(--texto);
  -webkit-text-size-adjust: 100%;
}

.barra {
  position: sticky;
  top: 0;
  z-index: 1;
  padding: calc(env(safe-area-inset-top, 0px) + 0.75rem) 1.25rem 0.75rem;
  background: var(--barra);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--linha);
}

.barra nav {
  max-width: 44rem;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  font-size: 0.875rem;
  letter-spacing: 0.01em;
}

.barra a { color: var(--suave); text-decoration: none; }
.barra a[aria-current="page"] { color: var(--texto); font-weight: 600; }

main {
  max-width: 44rem;
  margin: 0 auto;
  padding: 2.5rem 1.25rem calc(env(safe-area-inset-bottom, 0px) + 4rem);
}

h1 {
  font-size: clamp(2rem, 6vw, 2.75rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
}

.data { color: var(--suave); font-size: 0.9375rem; margin: 0 0 2.5rem; }

h2 {
  font-size: 1.375rem;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin: 2.5rem 0 0.75rem;
}

h3 { font-size: 1.0625rem; line-height: 1.3; margin: 1.75rem 0 0.5rem; }

p, li { font-size: 1.0625rem; letter-spacing: 0; }
ul { padding-left: 1.25rem; }
li { margin: 0.375rem 0; }

a { color: var(--destaque); }
a:active { opacity: 0.6; }

.caixa {
  border: 1px solid var(--linha);
  border-radius: 1rem;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
}

.caixa p { margin: 0.25rem 0; }

.ingles {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--linha);
}

footer {
  color: var(--suave);
  font-size: 0.875rem;
  margin-top: 4rem;
}

@media (prefers-reduced-transparency: reduce) {
  .barra { background: var(--fundo); backdrop-filter: none; -webkit-backdrop-filter: none; }
}

@media (prefers-contrast: more) {
  :root { --suave: var(--texto); --linha: currentColor; }
  .barra { background: var(--fundo); backdrop-filter: none; -webkit-backdrop-filter: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}