/* =================================================================
   DESIGN SYSTEM · BASE
   ----------------------------------------------------------------
   Reset, tipografia base, container, helpers de layout.
   ================================================================= */

@layer reset {
  *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
  body { min-height: 100dvh; }
  img, svg, video, canvas, picture { display: block; max-width: 100%; }
  button { cursor: pointer; font: inherit; background: none; border: none; color: inherit; }
  input, textarea, select { font: inherit; color: inherit; }
  a { color: inherit; text-decoration: none; }
  ul, ol { list-style: none; }
  table { border-collapse: collapse; border-spacing: 0; }
  :focus-visible { outline: 2px solid var(--color-border-focus); outline-offset: 2px; }
  ::selection { background: var(--color-brand); color: var(--color-text-on-brand); }

  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
      scroll-behavior: auto !important;
    }
  }
}

@layer base {
  body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-relaxed);
    color: var(--color-text);
    background-color: var(--color-bg-base);
    background-image:
      radial-gradient(ellipse 60% 50% at 10% 0%, var(--color-accent-muted), transparent 60%),
      radial-gradient(ellipse 50% 40% at 90% 100%, var(--color-brand-muted), transparent 60%);
    background-attachment: fixed;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    transition:
      background-color var(--duration-slow) var(--ease-out),
      color var(--duration-slow) var(--ease-out);
  }

  /* Grain texture sobre todo o app, opcional */
  body::after {
    content: "";
    position: fixed;
    inset: 0;
    z-index: var(--z-max);
    pointer-events: none;
    opacity: 0.025;
    mix-blend-mode: multiply;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='256' height='256'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.72' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='256' height='256' filter='url(%23g)'/%3E%3C/svg%3E");
  }
  [data-theme="dark"] body::after { opacity: 0.04; mix-blend-mode: screen; }

  /* Headings padrão */
  h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: var(--weight-regular);
    line-height: var(--leading-tight);
    color: var(--color-text);
    letter-spacing: var(--tracking-tight);
    text-wrap: balance;
  }
  h1 { font-size: var(--text-4xl); }
  h2 { font-size: var(--text-3xl); }
  h3 { font-size: var(--text-2xl); }
  h4 { font-size: var(--text-xl); }
  h5 { font-size: var(--text-lg); font-family: var(--font-sans); font-weight: var(--weight-semibold); }
  h6 { font-size: var(--text-base); font-family: var(--font-sans); font-weight: var(--weight-semibold); text-transform: uppercase; letter-spacing: var(--tracking-wider); }
  em { font-style: italic; color: var(--color-brand); }

  p { text-wrap: pretty; max-width: 70ch; }
  code, kbd, samp, pre {
    font-family: var(--font-mono);
    font-size: 0.9em;
    color: var(--color-text);
    background: var(--color-bg-muted);
    padding: 0.15em 0.45em;
    border-radius: var(--radius-xs);
    border: 1px solid var(--color-border-subtle);
  }
  pre {
    padding: var(--space-4);
    overflow-x: auto;
    line-height: var(--leading-snug);
  }
  pre code { padding: 0; background: transparent; border: 0; }

  /* Skip link */
  .skip-link {
    position: absolute;
    top: -100%;
    left: var(--space-3);
    z-index: var(--z-max);
    background: var(--color-brand);
    color: var(--color-text-on-brand);
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm);
    border-radius: var(--radius-sm);
    transition: top var(--duration-fast) var(--ease-out);
  }
  .skip-link:focus { top: var(--space-3); }
}

@layer layout {
  .container { width: min(calc(100% - 2 * var(--container-padding)), var(--container-lg)); margin-inline: auto; }
  .container-narrow { width: min(calc(100% - 2 * var(--container-padding)), var(--container-md)); margin-inline: auto; }
  .container-wide { width: min(calc(100% - 2 * var(--container-padding)), var(--container-xl)); margin-inline: auto; }

  .stack { display: flex; flex-direction: column; gap: var(--space-4); }
  .stack-sm { display: flex; flex-direction: column; gap: var(--space-2); }
  .stack-lg { display: flex; flex-direction: column; gap: var(--space-6); }
  .stack-xl { display: flex; flex-direction: column; gap: var(--space-10); }

  .row { display: flex; flex-wrap: wrap; gap: var(--space-3); align-items: center; }
  .row-tight { display: flex; flex-wrap: wrap; gap: var(--space-2); align-items: center; }

  .grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-6); }
  .grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-5); }
  .grid-4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-4); }
  .grid-auto { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: var(--space-4); }
  .grid-auto-lg { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: var(--space-5); }

  @media (max-width: 900px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  }
  @media (max-width: 768px) {
    .grid-3-tablet { grid-template-columns: repeat(2, 1fr); }
  }

  .section {
    padding-block: var(--space-section);
    border-top: 1px solid var(--color-divider);
  }
  .section:first-of-type { border-top: 0; }
  .section--alt { background: var(--color-bg-subtle); }
  .section--dark {
    background: var(--raw-neutral-950);
    color: oklch(96% 0.012 200);
    --color-text: oklch(96% 0.012 200);
    --color-text-secondary: oklch(78% 0.020 200);
    --color-border-subtle: oklch(35% 0.030 205 / 0.5);
  }
}

@layer utilities {
  .eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-family: var(--font-sans);
    font-size: var(--text-2xs);
    font-weight: var(--weight-bold);
    letter-spacing: var(--tracking-widest);
    text-transform: uppercase;
    color: var(--color-accent-hover);
  }
  .eyebrow::before {
    content: "";
    width: var(--space-6);
    height: 1px;
    background: currentColor;
    opacity: 0.6;
  }

  .lede {
    font-size: var(--text-md);
    color: var(--color-text-secondary);
    max-width: 64ch;
    line-height: var(--leading-relaxed);
  }

  .divider {
    width: var(--space-12);
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent), var(--color-accent-active));
    border: 0;
    margin-block: var(--space-6);
  }

  .text-muted { color: var(--color-text-tertiary); }
  .text-secondary { color: var(--color-text-secondary); }
  .text-brand { color: var(--color-brand); }
  .text-accent { color: var(--color-accent-hover); }
  .text-mono { font-family: var(--font-mono); font-size: var(--text-xs); }
  .text-center { text-align: center; }

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

  /* Reveal on scroll */
  .reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--duration-slower) var(--ease-premium),
                transform var(--duration-slower) var(--ease-premium);
    transition-delay: calc(min(var(--i, 0), 6) * 80ms);
  }
  .reveal.is-visible { opacity: 1; transform: translateY(0); }
}