/* ============================================================
   DDTApps Design System — Base
   Reset, document, typography, layout primitives, utilities.
   ============================================================ */

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--text-md);
  background: var(--ink-900);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  min-height: 100vh;
}

/* Film-grain ambience */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.05'/%3E%3C/svg%3E");
}

img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
input, textarea, select { font: inherit; }

::selection { background: var(--accent); color: #fff; }

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

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

/* --- Typography --- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--text-hi);
  line-height: var(--lh-tight);
  letter-spacing: var(--tracking-display);
  font-weight: 600;
  text-wrap: balance;
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); line-height: var(--lh-snug); }
h4 { font-size: 1.05rem; }

p { max-width: 65ch; }

.lead {
  font-size: var(--fs-lead);
  line-height: 1.55;
  color: var(--text-md);
}

.text-gradient {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-micro);
  font-weight: 600;
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--accent-hi);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--accent);
}

/* --- Layout primitives --- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
  position: relative;
  z-index: 1;
}

.container--narrow { max-width: var(--container-narrow); }

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

.section-head {
  max-width: 640px;
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}

.section-head h2 { margin-top: var(--sp-3); }
.section-head .lead { margin-top: var(--sp-4); }

.section-head--center {
  margin-inline: auto;
  text-align: center;
}
.section-head--center .eyebrow { justify-content: center; }
.section-head--center .eyebrow::before { display: none; }
.section-head--center p { margin-inline: auto; }

.grid {
  display: grid;
  gap: var(--sp-5);
}

@media (min-width: 700px) {
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1000px) {
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* --- Utilities --- */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  clip-path: inset(50%);
  overflow: hidden;
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--sp-4);
  z-index: 200;
  padding: var(--sp-3) var(--sp-4);
  background: var(--accent);
  color: #fff;
  border-radius: var(--r-sm);
  transition: top var(--dur-fast) var(--ease-out);
}
.skip-link:focus { top: var(--sp-4); color: #fff; }

/* Scroll-reveal baseline (JS animates; visible without JS) */
.reveal { opacity: 1; }
.js .reveal { opacity: 0; transform: translateY(28px); }
.js .reveal.is-inview {
  opacity: 1;
  transform: none;
  transition: opacity var(--dur-slow) var(--ease-out),
              transform var(--dur-slow) var(--ease-out);
}
@media (prefers-reduced-motion: reduce) {
  .js .reveal { opacity: 1; transform: none; }
}