/* ============================================================
   Satio — base layout, reset, brand motifs (grain, pattern, rail, watermark)
   ============================================================ */

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

body {
  margin: 0;
  font-family: var(--f-mono);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--dark);
  background: var(--bg-light);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { font-family: var(--f-head); margin: 0; }
p { margin: 0 0 1em; }
a { color: inherit; }
img, svg { display: block; max-width: 100%; }
button { font-family: inherit; cursor: pointer; }

.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---------- grain texture overlay (SVG feTurbulence, whole document) ---------- */
.grain-overlay {
  position: fixed;
  inset: 0;
  z-index: 999;
  pointer-events: none;
  opacity: 0.05;
  mix-blend-mode: overlay;
}
.grain-overlay svg { width: 100%; height: 100%; }

/* ---------- section rhythm: dark / light sandwich ---------- */
.section {
  position: relative;
  overflow: hidden;
  padding: 4.5rem 0;
}
.section--light { background: var(--bg-light); color: var(--dark); }
.section--dark { background: var(--dark); color: var(--white); }
.section--card { background: var(--card-light); }

.section-inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 3.5rem 1fr;
  gap: 1.5rem;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}
@media (max-width: 720px) {
  .section-inner { grid-template-columns: 1fr; }
}

/* ---------- rail: arrow + rotated vertical section label ---------- */
.rail {
  position: sticky;
  top: 1.5rem;
  align-self: start;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  height: fit-content;
}
.rail__arrow {
  font-size: 1.1rem;
  color: var(--text-muted);
  opacity: 0.7;
}
.section--dark .rail__arrow { color: var(--text-muted-dark); }
.rail__label {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-family: var(--f-cond);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  color: var(--orange);
  white-space: nowrap;
}
.section--dark .rail__label { color: var(--amber); }
@media (max-width: 720px) {
  .rail { flex-direction: row; position: static; margin-bottom: 1rem; }
  .rail__label { writing-mode: horizontal-tb; transform: none; }
}

/* ---------- giant pale watermark word, per-section, clipped by section bounds ---------- */
.watermark {
  position: absolute;
  top: 50%;
  right: -2vw;
  transform: translateY(-50%);
  font-family: var(--f-cond);
  font-weight: 700;
  font-size: 42vh;
  line-height: 1;
  letter-spacing: 0.02em;
  color: rgba(0, 0, 0, 0.05);
  z-index: 1;
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
}
.section--dark .watermark { color: rgba(255, 255, 255, 0.045); }
@media (max-width: 720px) {
  .watermark { font-size: 22vh; }
}

/* ---------- tiled icon pattern background (dark sections only) ---------- */
.pattern-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.05;
  background-repeat: repeat;
  background-size: 84px 84px;
}

/* ---------- header / footer ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(236, 233, 228, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.4rem 0.8rem;
  min-height: 4.2rem;
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
}
.site-header__logo { height: 1.8rem; width: auto; flex-shrink: 0; }
.site-header__nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.site-header__sep {
  color: var(--line);
  font-size: 0.8rem;
}
.site-header__back,
.site-header__platform {
  font-family: var(--f-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  white-space: nowrap;
}
.site-header__platform { color: var(--orange); font-weight: 600; }
.site-header__back:hover { color: var(--orange); }
.site-header__platform:hover { color: var(--dark); }
@media (max-width: 480px) {
  .site-header__back,
  .site-header__platform { font-size: 0.72rem; }
  .site-header__nav { gap: 0.35rem; }
}

.site-footer {
  padding: 2.5rem 0;
  background: var(--dark);
  color: var(--text-muted-dark);
}
.site-footer .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--f-mono);
  font-size: 0.8rem;
  flex-wrap: wrap;
  gap: 0.8rem;
}
.site-footer img { height: 1.4rem; opacity: 0.85; }

/* ---------- eyebrow / kicker ---------- */
.eyebrow {
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 0.6rem;
  display: block;
}
.section--dark .eyebrow { color: var(--amber); }

.title-xl {
  font-family: var(--f-head);
  font-weight: 700;
  font-size: clamp(1.8rem, 4vw, 3rem);
  line-height: 1.1;
  margin-bottom: 1rem;
}
.title-lg {
  font-family: var(--f-head);
  font-weight: 700;
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  line-height: 1.2;
  margin-bottom: 0.8rem;
}
.lede {
  font-family: var(--f-head);
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 42rem;
}
.section--dark .lede { color: var(--text-muted-dark); }

/* ---------- reveal-on-scroll ---------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }