/* --------------------------------------------------------------------------
   2. Reset e Configurações Globais
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  overflow-x: hidden;
  overflow-x: clip;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--depth-6);
  color: var(--color-cream);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  overflow-x: clip;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --------------------------------------------------------------------------
   Coluna d'água global
   Um único campo fixo atrás de todas as seções. A opacidade de cada camada
   é função de --depth, de modo que a água escurece conforme o scroll desce.
   As seções ficam transparentes e apenas somam brilhos locais.
   -------------------------------------------------------------------------- */
.ocean-field {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
  background-color: var(--depth-6);
}

.ocean-field__layer {
  position: absolute;
  inset: 0;
  transition: opacity 120ms linear;
}

.ocean-field__layer--abyss {
  background:
    radial-gradient(ellipse 70% 42% at 50% 108%, rgba(0, 200, 196, 0.06) 0%, transparent 64%),
    radial-gradient(ellipse 40% 30% at 82% 88%, rgba(81, 193, 230, 0.035) 0%, transparent 70%),
    linear-gradient(180deg, var(--depth-5) 0%, var(--depth-6) 100%);
}

.ocean-field__layer--deep {
  background: linear-gradient(180deg, var(--depth-4) 0%, var(--depth-5) 100%);
  opacity: calc(1 - var(--depth, 0) * var(--depth-deep-fade));
}

.ocean-field__layer--mid {
  background:
    radial-gradient(ellipse 90% 60% at 18% 8%, rgba(0, 200, 196, 0.07) 0%, transparent 62%),
    linear-gradient(180deg, var(--depth-3) 0%, var(--depth-4) 100%);
  opacity: calc(1 - var(--depth, 0) * var(--depth-mid-fade));
}

.ocean-field__layer--shallow {
  background:
    radial-gradient(ellipse 130% 70% at 50% -18%, rgba(0, 200, 196, 0.18) 0%, transparent 58%),
    radial-gradient(ellipse 70% 45% at 18% 4%, rgba(81, 193, 230, 0.10) 0%, transparent 60%),
    linear-gradient(180deg, var(--depth-0) 0%, var(--depth-1) 42%, var(--depth-2) 100%);
  opacity: calc(1 - var(--depth, 0) * var(--depth-shallow-fade));
}

/* Feixes de luz da superfície — somem nos primeiros metros */
.ocean-field__light {
  position: absolute;
  inset: -20% 0 auto 0;
  height: 95%;
  background:
    linear-gradient(103deg, transparent 18%, rgba(98, 220, 228, 0.06) 26%, transparent 34%),
    linear-gradient(96deg, transparent 46%, rgba(81, 193, 230, 0.05) 56%, transparent 66%),
    linear-gradient(111deg, transparent 68%, rgba(98, 220, 228, 0.045) 76%, transparent 86%);
  opacity: calc(1 - var(--depth, 0) * 3.2);
  filter: blur(2px);
  transform-origin: top center;
  animation: ocean-field-light-drift 28s ease-in-out infinite alternate;
}

@keyframes ocean-field-light-drift {
  0%   { transform: translate3d(-1.4%, 0, 0) scaleX(1); }
  100% { transform: translate3d(1.4%, 1.4%, 0) scaleX(1.04); }
}

/* Cáusticas: reflexos difusos da luz na superfície, visíveis só nos
   primeiros metros. Somem antes da zona crepuscular. */
.ocean-field__caustics {
  position: absolute;
  inset: -18% -12% 0;
  background-image:
    radial-gradient(ellipse 12% 4% at 15% 20%, rgba(98, 220, 228, 0.16) 0%, transparent 70%),
    radial-gradient(ellipse 16% 5% at 42% 34%, rgba(81, 193, 230, 0.12) 0%, transparent 70%),
    radial-gradient(ellipse 10% 4% at 70% 18%, rgba(98, 220, 228, 0.14) 0%, transparent 72%),
    radial-gradient(ellipse 18% 6% at 88% 40%, rgba(0, 200, 196, 0.10) 0%, transparent 70%);
  background-size: 70% 55%;
  background-position: 0 0, 30% 20%, 60% 10%, 80% 30%;
  opacity: calc(0.9 - var(--depth, 0) * 2.6);
  filter: blur(5px);
  mix-blend-mode: screen;
  transform-origin: center top;
  animation: ocean-caustics-drift 30s ease-in-out infinite alternate;
  will-change: transform, opacity;
}

@keyframes ocean-caustics-drift {
  0%   { transform: translate3d(-1.2%, 0, 0) scale(1); }
  100% { transform: translate3d(1.2%, 1.6%, 0) scale(1.035); }
}

main {
  position: relative;
  z-index: 1;
}

/* Acessibilidade: Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1.5rem;
  background-color: var(--color-amber);
  color: var(--color-primary);
  font-weight: 700;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  z-index: 9999;
  text-decoration: none;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 1rem;
  outline: 3px solid var(--color-turquoise);
}

/* Foco visível acessível */
:focus-visible {
  outline: 2px solid var(--color-aqua);
  outline-offset: 3px;
}

/* --------------------------------------------------------------------------
   Utilitário para conteúdo disponível apenas a leitores de tela
   -------------------------------------------------------------------------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   Animações de entrada coordenadas por IntersectionObserver
   -------------------------------------------------------------------------- */
html.js .reveal-item {
  opacity: 0;
  transform: translateY(32px);
  transition:
    opacity 0.75s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.75s cubic-bezier(0.16, 1, 0.3, 1);
  transition-delay: calc(var(--reveal-i, 0) * 70ms);
}

html.js .reveal-item.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Variante editorial: o bloco sobe por trás de uma máscara,
   em vez de simplesmente deslizar. Usada nos cabeçalhos de seção. */
html.js .reveal-mask.reveal-item {
  opacity: 0;
  transform: translateY(16px);
  /* Mantém uma faixa mínima "visível" para o IntersectionObserver não
     considerar o bloco totalmente recortado (o que impediria o reveal). */
  clip-path: inset(0 0 72% 0);
  transition:
    opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.9s cubic-bezier(0.16, 1, 0.3, 1),
    clip-path 1s cubic-bezier(0.16, 1, 0.3, 1);
  transition-delay: calc(var(--reveal-i, 0) * 70ms);
}

html.js .reveal-mask.reveal-item.is-visible {
  opacity: 1;
  transform: translateY(0);
  clip-path: inset(0 0 -12% 0);
}