/* ============================================================
   base.css — Tipografia, layout base e utilidades
   ============================================================ */
body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--ink-950);
  background: var(--white);
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--green-950);
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

p { max-width: 68ch; }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: var(--section-y);
}

/* Superfície escura */
.on-dark {
  background: var(--surface-dark);
  color: rgba(245, 245, 241, 0.86);
}

.on-dark h1,
.on-dark h2,
.on-dark h3,
.on-dark h4 {
  color: var(--white);
}

.on-ivory {
  background: var(--surface-light);
}

/* Eyebrow */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--green-700);
  margin-bottom: 1rem;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--mint-500);
  flex: none;
}

.on-dark .eyebrow { color: var(--aqua-400); }

.section-lead {
  color: var(--muted-600);
  margin-top: 1rem;
}

.on-dark .section-lead { color: rgba(245, 245, 241, 0.75); }

/* Acessibilidade */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 200;
  background: var(--green-950);
  color: var(--white);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-btn);
  transition: top var(--dur) var(--ease);
}

.skip-link:focus { top: 1rem; }

:focus-visible {
  outline: 3px solid var(--mint-500);
  outline-offset: 2px;
  border-radius: 4px;
}

.on-dark :focus-visible,
.site-header :focus-visible {
  outline-color: var(--mint-500);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ============================================================
   Animações de entrada
   Performance: somente transform + opacity (compositor/GPU),
   sem layout shift (o espaço é reservado), IO com unobserve,
   sem will-change permanente e sem listeners de scroll.
   ============================================================ */

/* Bloco único (JS adiciona .is-visible) */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--dur-reveal) var(--ease-out), transform var(--dur-reveal) var(--ease-out);
}

/* Variações de direção para imagens/colunas */
.reveal.reveal-left { transform: translateX(-26px); }
.reveal.reveal-right { transform: translateX(26px); }

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* Grupo com stagger: os filhos entram em cascata */
.reveal-group > * {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--dur-reveal) var(--ease-out), transform var(--dur-reveal) var(--ease-out);
}

.reveal-group.is-visible > * {
  opacity: 1;
  transform: none;
}

.reveal-group.is-visible > :nth-child(1) { transition-delay: 0ms; }
.reveal-group.is-visible > :nth-child(2) { transition-delay: 70ms; }
.reveal-group.is-visible > :nth-child(3) { transition-delay: 140ms; }
.reveal-group.is-visible > :nth-child(4) { transition-delay: 210ms; }
.reveal-group.is-visible > :nth-child(5) { transition-delay: 280ms; }
.reveal-group.is-visible > :nth-child(6) { transition-delay: 350ms; }

/* Sem JS: conteúdo sempre visível */
.no-js .reveal,
.no-js .reveal-group > * {
  opacity: 1;
  transform: none;
}