/* ------------------------------------------------------------------
   Structure : barre de navigation, sections, grilles, pied de page
   ------------------------------------------------------------------ */

.shell {
  width: min(100% - var(--gutter) * 2, var(--shell));
  margin-inline: auto;
}
.shell--wide {
  width: min(100% - var(--gutter) * 2, var(--shell-wide));
}
.prose {
  max-width: var(--measure);
}

/* ---------- Barre supérieure ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 60;
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  background: color-mix(in srgb, var(--bg-deep) 74%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-2) var(--ease),
    background var(--dur-2) var(--ease);
}
.topbar[data-stuck='true'] {
  border-bottom-color: var(--line);
  background: color-mix(in srgb, var(--bg-deep) 90%, transparent);
}

.topbar__inner {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  min-height: 60px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--step--1);
  letter-spacing: 0.02em;
  color: var(--ink);
  text-decoration: none;
  flex: none;
}
.brand:hover {
  color: var(--ink);
}
.brand__mark {
  width: 22px;
  height: 22px;
  flex: none;
}
.brand__sub {
  color: var(--ink-4);
  font-weight: 400;
  letter-spacing: 0;
}

.topnav {
  display: flex;
  gap: 0.15rem;
  margin-left: auto;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}
.topnav::-webkit-scrollbar {
  display: none;
}
.topnav a {
  --_c: var(--ink-3);
  position: relative;
  padding: 0.42rem 0.72rem;
  border-radius: 999px;
  font-size: var(--step--1);
  color: var(--_c);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur-1) var(--ease), background var(--dur-1) var(--ease);
}
.topnav a:hover {
  --_c: var(--ink);
  background: var(--surface);
}
.topnav a[aria-current='true'] {
  --_c: var(--ink);
  background: var(--surface-2);
}

.topbar__cta {
  flex: none;
  margin-left: 0.4rem;
}

/* Jauge de progression de lecture */
.progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  height: 2px;
  width: 100%;
  transform-origin: 0 50%;
  transform: scaleX(var(--p, 0));
  background: linear-gradient(90deg, var(--pos), var(--neg) 55%, var(--geo));
  will-change: transform;
}

@media (max-width: 1080px) {
  .topnav {
    display: none;
  }
}

/* ---------- Sections ---------- */

.section {
  position: relative;
  padding-block: clamp(4rem, 2rem + 8vw, 8.5rem);
  scroll-margin-top: 72px;
}
.section + .section {
  padding-top: 0;
}
.section--tight {
  padding-block: clamp(2.5rem, 1.5rem + 4vw, 5rem);
}

.section__head {
  display: grid;
  gap: 1rem;
  margin-bottom: clamp(2rem, 1rem + 3vw, 3.4rem);
  max-width: var(--measure);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-4);
}
.eyebrow::before {
  content: '';
  width: 1.6rem;
  height: 1px;
  background: currentColor;
  opacity: 0.6;
}

.lede {
  font-size: var(--step-1);
  line-height: 1.55;
  color: var(--ink-2);
  max-width: 62ch;
}

.section__body > * + * {
  margin-top: 1.05em;
}

/* ---------- Grilles ---------- */

.grid {
  display: grid;
  gap: clamp(1rem, 0.5rem + 1.6vw, 1.75rem);
}
.grid--2 {
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 22rem), 1fr));
}
.grid--3 {
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 16.5rem), 1fr));
}
.grid--split {
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
}
@media (min-width: 62rem) {
  .grid--split {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: clamp(2rem, 1rem + 3vw, 4rem);
  }
  /* Texte dominant : la colonne de lecture garde la priorité. */
  .grid--split.grid--text {
    grid-template-columns: minmax(0, 1.22fr) minmax(0, 0.78fr);
  }
  .grid--split.is-reversed > :first-child {
    order: 2;
  }
}

.stack > * + * {
  margin-top: var(--gap, 1rem);
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  min-height: min(100svh, 56rem);
  display: grid;
  align-items: center;
  overflow: clip;
  isolation: isolate;
}
.hero__canvas {
  position: absolute;
  inset: 0;
  z-index: -1;
}
/* Voile de lisibilité : la grille passe derrière le titre, il faut
   l'assombrir là où le texte se trouve — en haut et à gauche. */
.hero__canvas::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(
      105deg,
      color-mix(in srgb, var(--bg-deep) 82%, transparent) 0%,
      color-mix(in srgb, var(--bg-deep) 52%, transparent) 42%,
      transparent 74%
    ),
    linear-gradient(
      to bottom,
      color-mix(in srgb, var(--bg-deep) 62%, transparent) 0%,
      transparent 30%,
      transparent 60%,
      var(--bg-deep) 100%
    );
  pointer-events: none;
}
.hero__inner {
  padding-block: clamp(5rem, 3rem + 10vw, 9rem);
  display: grid;
  gap: 1.6rem;
  max-width: 60rem;
}
.hero h1 {
  max-width: 16ch;
}
.hero__sub {
  font-size: var(--step-1);
  color: var(--ink-2);
  max-width: 54ch;
  line-height: 1.55;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 0.5rem;
}
.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.6rem;
  margin-top: 1.2rem;
  font-size: var(--step--1);
  color: var(--ink-4);
  font-family: var(--font-mono);
}

.scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 1.6rem;
  translate: -50% 0;
  display: grid;
  justify-items: center;
  gap: 0.45rem;
  font-size: var(--step--2);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-4);
  font-family: var(--font-mono);
}
.scroll-cue__line {
  width: 1px;
  height: 2.2rem;
  background: linear-gradient(to bottom, var(--line-strong), transparent);
  animation: cue 2.4s var(--ease) infinite;
}
@keyframes cue {
  0%,
  100% {
    opacity: 0.25;
    transform: scaleY(0.6);
    transform-origin: top;
  }
  50% {
    opacity: 1;
    transform: scaleY(1);
    transform-origin: top;
  }
}
@media (prefers-reduced-motion: reduce) {
  .scroll-cue__line {
    animation: none;
  }
}

/* ---------- Rail de navigation latéral ---------- */

.rail {
  position: fixed;
  right: max(1rem, calc((100vw - var(--shell-wide)) / 2 - 2.2rem));
  top: 50%;
  translate: 0 -50%;
  z-index: 50;
  display: grid;
  gap: 0.1rem;
  padding: 0.35rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--bg-deep) 62%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-2) var(--ease);
}
.rail[data-visible='true'] {
  opacity: 1;
  pointer-events: auto;
}
.rail a {
  position: relative;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
}
.rail a::after {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--ink-4);
  transition: background var(--dur-1) var(--ease), scale var(--dur-1) var(--ease);
}
.rail a:hover::after {
  background: var(--ink-2);
  scale: 1.25;
}
.rail a[aria-current='true']::after {
  background: var(--geo);
  scale: 1.35;
  box-shadow: 0 0 0 4px var(--geo-glow);
}
.rail a span {
  position: absolute;
  right: calc(100% + 0.6rem);
  padding: 0.25rem 0.6rem;
  border-radius: var(--r-sm);
  background: var(--surface-solid);
  border: 1px solid var(--line);
  font-size: var(--step--2);
  color: var(--ink-2);
  white-space: nowrap;
  opacity: 0;
  translate: 6px 0;
  pointer-events: none;
  transition: opacity var(--dur-1) var(--ease), translate var(--dur-1) var(--ease);
}
.rail a:hover span,
.rail a:focus-visible span {
  opacity: 1;
  translate: 0 0;
}
@media (max-width: 1180px) {
  .rail {
    display: none;
  }
}

/* ---------- Pied de page ---------- */

.footer {
  border-top: 1px solid var(--line);
  margin-top: clamp(4rem, 2rem + 6vw, 7rem);
  padding-block: clamp(2.5rem, 1.5rem + 3vw, 4rem) 3rem;
  font-size: var(--step--1);
  color: var(--ink-4);
}
.footer__grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
}
.footer h4 {
  color: var(--ink-3);
  font-size: var(--step--2);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  font-weight: 500;
  margin-bottom: 0.85rem;
}
.footer ul {
  list-style: none;
  padding: 0;
}
.footer li {
  margin-block: 0.4em;
}
.footer a {
  color: var(--ink-3);
  text-decoration: none;
}
.footer a:hover {
  color: var(--ink);
}
.footer__note {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  max-width: 78ch;
  color: var(--ink-4);
  font-size: var(--step--2);
  line-height: 1.7;
}

/* ---------- Révélation au défilement ---------- */

[data-reveal] {
  opacity: 0;
  translate: 0 18px;
  transition: opacity 0.7s var(--ease-out), translate 0.7s var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}
[data-reveal].is-in {
  opacity: 1;
  translate: 0 0;
}
@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    translate: none;
    transition: none;
  }
}

/* ---------- Canvas du héros ---------- */

.hero__canvas canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

/* ---------- Curseur de manipulation ---------- */

.viz__stage.is-grabbing {
  cursor: grabbing;
}