/* ========================================================================
   astrochimie.fr — Le Carnet du Cosmos
   Système de design principal
   ======================================================================== */

/* ---------- RESET ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul[role="list"], ol[role="list"] { list-style: none; padding: 0; margin: 0; }
img, picture, svg, video { max-width: 100%; display: block; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 3px; border-radius: 2px; }

/* ---------- DESIGN TOKENS ---------- */
:root {
  /* Palette — mode nuit (par défaut) */
  --color-bg:        #0a0e1a;       /* encre profonde */
  --color-bg-soft:   #131826;       /* parchemin nocturne */
  --color-bg-elev:   #1a2033;       /* surface élevée */
  --color-ink:       #f1ead8;       /* texte principal — vélin */
  --color-ink-soft:  #b8b09a;       /* texte secondaire */
  --color-ink-mute:  #6b6557;       /* texte estompé */
  --color-rule:      #2a3148;       /* filets, séparateurs */
  --color-rule-soft: #1f253a;
  --color-accent:    #d4a574;       /* or stellaire */
  --color-accent-2:  #5fcfa3;       /* aurore */
  --color-accent-3:  #c64869;       /* plasma */
  --color-accent-4:  #6ba3e8;       /* hydrogène ionisé */

  /* Typographie */
  --font-display: 'Cormorant Garamond', 'EB Garamond', 'Iowan Old Style', 'Palatino Linotype', Palatino, Georgia, serif;
  --font-body:    'Spectral', 'Source Serif Pro', 'Iowan Old Style', 'Palatino Linotype', Georgia, serif;
  --font-sans:    'Söhne', 'Söhne Buch', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial, sans-serif;
  --font-mono:    'JetBrains Mono', 'SF Mono', 'Fira Code', Menlo, Consolas, monospace;

  /* Échelle modulaire — ratio 1.25 */
  --fs-xs:   0.75rem;
  --fs-sm:   0.875rem;
  --fs-base: 1rem;
  --fs-md:   1.125rem;
  --fs-lg:   1.375rem;
  --fs-xl:   1.75rem;
  --fs-2xl:  2.25rem;
  --fs-3xl:  3rem;
  --fs-4xl:  4rem;
  --fs-5xl:  5.5rem;

  /* Espacement */
  --sp-1: 0.25rem; --sp-2: 0.5rem; --sp-3: 0.75rem; --sp-4: 1rem;
  --sp-5: 1.5rem; --sp-6: 2rem; --sp-7: 3rem; --sp-8: 4rem;
  --sp-9: 6rem;   --sp-10: 8rem;

  /* Mise en page */
  --measure: 68ch;
  --container: 1240px;
  --container-narrow: 880px;
  --radius: 4px;
  --radius-lg: 12px;

  /* Transitions */
  --ease: cubic-bezier(0.65, 0, 0.35, 1);
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --t-fast: 180ms;
  --t-mid:  360ms;
  --t-slow: 720ms;
}

/* ---------- THÈME JOUR — "carnet de laboratoire" ---------- */
[data-theme="day"] {
  --color-bg:        #f5efe0;       /* parchemin */
  --color-bg-soft:   #ece5d2;       /* parchemin marqué */
  --color-bg-elev:   #ffffff;
  --color-ink:       #1a1d24;
  --color-ink-soft:  #4a4d56;
  --color-ink-mute:  #8a8474;
  --color-rule:      #c9c0a8;
  --color-rule-soft: #ddd5bc;
  --color-accent:    #8a5a1f;
  --color-accent-2:  #2a7a5f;
  --color-accent-3:  #a32f4a;
  --color-accent-4:  #2a5a9a;
}

/* ---------- BASE ---------- */
html, body { background: var(--color-bg); color: var(--color-ink); }
body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.65;
  font-feature-settings: "kern", "liga", "onum";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color var(--t-mid) var(--ease), color var(--t-mid) var(--ease);
}

/* ---------- TYPOGRAPHIE ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--color-ink);
}
h1 { font-size: clamp(2.5rem, 5vw + 1rem, var(--fs-5xl)); font-weight: 400; letter-spacing: -0.025em; }
h2 { font-size: clamp(1.875rem, 3vw + 0.5rem, var(--fs-3xl)); font-weight: 400; }
h3 { font-size: var(--fs-xl); }
h4 { font-size: var(--fs-lg); }

p { max-width: var(--measure); }

a { text-decoration: none; transition: color var(--t-fast) var(--ease); }
.prose a, p a { color: var(--color-accent); border-bottom: 1px solid currentColor; }
.prose a:hover, p a:hover { color: var(--color-accent-2); }

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

/* Petites caps & numéros stylisés */
.smallcaps {
  font-family: var(--font-sans);
  font-size: 0.78em;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 500;
}

.eyebrow {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-accent);
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: var(--sp-3);
}
.eyebrow::before {
  content: "";
  width: 28px; height: 1px; background: currentColor;
}

.lead {
  font-size: var(--fs-md);
  line-height: 1.55;
  color: var(--color-ink-soft);
  max-width: 56ch;
}

/* Formules chimiques */
.formula, var, .mono {
  font-family: var(--font-mono);
  font-style: normal;
  font-feature-settings: "ss01";
}

/* ---------- LAYOUT ---------- */
.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1rem, 4vw, 2.5rem);
}
.container--narrow { max-width: var(--container-narrow); }

section { padding-block: clamp(3rem, 8vw, var(--sp-10)); position: relative; }

.divider {
  border: 0;
  border-top: 1px solid var(--color-rule);
  margin-block: var(--sp-7);
}
.divider--ornament {
  text-align: center;
  border: 0;
  height: 24px;
  margin-block: var(--sp-8);
  position: relative;
}
.divider--ornament::before {
  content: "✦";
  color: var(--color-accent);
  font-size: 1.1rem;
  background: var(--color-bg);
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}
.divider--ornament::after {
  content: "";
  position: absolute;
  inset: 50% 0 auto 0;
  height: 1px;
  background: var(--color-rule);
}

/* ---------- HEADER / NAVIGATION ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(14px);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease);
}
.site-header.is-scrolled { border-bottom-color: var(--color-rule); }

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-5);
  padding-block: var(--sp-4);
}
.brand {
  display: inline-flex; align-items: center; gap: var(--sp-3);
  font-family: var(--font-display);
  font-size: var(--fs-lg);
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--color-ink);
}
.brand__mark {
  width: 32px; height: 32px;
  display: inline-block;
}
.brand__name { white-space: nowrap; }
.brand__name em {
  font-style: italic;
  color: var(--color-accent);
}

.nav__list {
  display: flex; gap: var(--sp-2);
  list-style: none; padding: 0; margin: 0;
  align-items: center;
}
.nav__link {
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  letter-spacing: 0.02em;
  color: var(--color-ink-soft);
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius);
  position: relative;
  transition: color var(--t-fast) var(--ease);
}
.nav__link:hover, .nav__link[aria-current="page"] { color: var(--color-ink); }
.nav__link[aria-current="page"]::after {
  content: ""; position: absolute;
  bottom: 4px; left: var(--sp-3); right: var(--sp-3);
  height: 1px; background: var(--color-accent);
}

.nav__actions { display: flex; gap: var(--sp-2); align-items: center; }

.theme-toggle, .menu-toggle {
  background: transparent;
  border: 1px solid var(--color-rule);
  border-radius: var(--radius);
  width: 38px; height: 38px;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer;
  color: var(--color-ink-soft);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}
.theme-toggle:hover, .menu-toggle:hover { color: var(--color-ink); border-color: var(--color-accent); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-sun { display: none; }
[data-theme="day"] .theme-toggle .icon-sun { display: block; }
[data-theme="day"] .theme-toggle .icon-moon { display: none; }

.menu-toggle { display: none; }
.menu-toggle__bars {
  display: inline-flex; flex-direction: column; gap: 4px;
}
.menu-toggle__bars span {
  display: block; width: 18px; height: 1.5px; background: currentColor;
  transition: transform var(--t-fast) var(--ease), opacity var(--t-fast) var(--ease);
}

/* ---------- BOUTONS ---------- */
.btn {
  display: inline-flex; align-items: center; gap: var(--sp-3);
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  letter-spacing: 0.05em;
  padding: var(--sp-3) var(--sp-5);
  border: 1px solid var(--color-ink);
  background: transparent;
  color: var(--color-ink);
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--t-fast) var(--ease);
  text-decoration: none;
}
.btn:hover {
  background: var(--color-ink); color: var(--color-bg);
}
.btn--primary {
  background: var(--color-accent); border-color: var(--color-accent); color: var(--color-bg);
}
.btn--primary:hover {
  background: transparent; color: var(--color-accent);
}
.btn--ghost { border-color: var(--color-rule); color: var(--color-ink-soft); }
.btn--ghost:hover { color: var(--color-ink); border-color: var(--color-ink); background: transparent; }

.btn .arrow {
  display: inline-block;
  transition: transform var(--t-fast) var(--ease);
}
.btn:hover .arrow { transform: translateX(4px); }

/* ---------- HERO ---------- */
.hero {
  position: relative;
  min-height: clamp(620px, 92vh, 880px);
  display: flex; align-items: center;
  overflow: hidden;
  isolation: isolate;
}
.hero__canvas {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  z-index: -1;
}
.hero__veil {
  position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(ellipse at 30% 40%, rgba(212, 165, 116, 0.10), transparent 60%),
    radial-gradient(ellipse at 70% 70%, rgba(198, 72, 105, 0.08), transparent 55%),
    linear-gradient(180deg, transparent 70%, var(--color-bg) 100%);
  pointer-events: none;
}
.hero__content {
  position: relative;
  z-index: 1;
  padding-block: var(--sp-9);
  max-width: 980px;
}
.hero__title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 7rem);
  line-height: 0.98;
  font-weight: 400;
  letter-spacing: -0.035em;
  margin-block: var(--sp-5) var(--sp-6);
}
.hero__title em {
  font-style: italic;
  color: var(--color-accent);
  font-weight: 300;
}
.hero__title-row {
  display: block;
  opacity: 0;
  animation: heroLine var(--t-slow) var(--ease-out) forwards;
}
.hero__title-row:nth-child(1) { animation-delay: 100ms; }
.hero__title-row:nth-child(2) { animation-delay: 250ms; }
.hero__title-row:nth-child(3) { animation-delay: 400ms; }
@keyframes heroLine {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero__lead {
  max-width: 56ch;
  font-size: var(--fs-md);
  color: var(--color-ink-soft);
  line-height: 1.55;
  opacity: 0;
  animation: heroLine var(--t-slow) var(--ease-out) 600ms forwards;
}
.hero__cta {
  display: flex; gap: var(--sp-4); flex-wrap: wrap;
  margin-top: var(--sp-7);
  opacity: 0;
  animation: heroLine var(--t-slow) var(--ease-out) 800ms forwards;
}
.hero__meta {
  position: absolute;
  bottom: var(--sp-6); left: 0; right: 0;
  display: flex; justify-content: space-between; align-items: end;
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
  opacity: 0;
  animation: heroLine var(--t-slow) var(--ease-out) 1000ms forwards;
}
.hero__meta-item { display: flex; align-items: center; gap: var(--sp-3); }
.hero__meta-item::before {
  content: ""; width: 6px; height: 6px;
  border-radius: 50%; background: var(--color-accent-2);
  box-shadow: 0 0 12px var(--color-accent-2);
}

/* ---------- SECTION HEADER ---------- */
.section-header {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-5);
  margin-bottom: var(--sp-8);
  max-width: 100%;
}
@media (min-width: 760px) {
  .section-header { grid-template-columns: 1fr 1fr; gap: var(--sp-7); }
}
.section-header__title { font-size: clamp(2rem, 4vw, 3.25rem); }
.section-header__intro { color: var(--color-ink-soft); }

/* ---------- "FEATURED" GRID ---------- */
.feature-grid {
  display: grid; gap: var(--sp-5);
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.feature {
  position: relative;
  padding: var(--sp-6);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-lg);
  background: var(--color-bg-soft);
  transition: transform var(--t-mid) var(--ease), border-color var(--t-mid) var(--ease);
  overflow: hidden;
  isolation: isolate;
}
.feature:hover { transform: translateY(-4px); border-color: var(--color-accent); }
.feature::before {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(circle at top right, rgba(212, 165, 116, 0.08), transparent 50%);
  opacity: 0; transition: opacity var(--t-mid) var(--ease);
  z-index: -1;
}
.feature:hover::before { opacity: 1; }
.feature__num {
  font-family: var(--font-display);
  font-size: var(--fs-2xl);
  color: var(--color-accent);
  font-style: italic;
  display: block;
  margin-bottom: var(--sp-3);
  font-weight: 300;
}
.feature__title { font-size: var(--fs-lg); margin-bottom: var(--sp-3); }
.feature__text { color: var(--color-ink-soft); font-size: var(--fs-sm); line-height: 1.6; }
.feature__link {
  display: inline-flex; align-items: center; gap: 6px;
  margin-top: var(--sp-4);
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
}
.feature__link:hover { color: var(--color-ink); }

/* ---------- PROSE / ARTICLE ---------- */
.prose {
  max-width: var(--measure);
}
.prose > * + * { margin-top: var(--sp-5); }
.prose h2 { margin-top: var(--sp-8); font-size: var(--fs-2xl); }
.prose h3 { margin-top: var(--sp-7); }
.prose p { font-size: var(--fs-md); line-height: 1.75; }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li { margin-block: 0.4em; line-height: 1.65; }
.prose figure { margin-block: var(--sp-7); }
.prose figcaption {
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  color: var(--color-ink-mute);
  margin-top: var(--sp-3);
  font-style: italic;
}
.prose blockquote {
  border-left: 2px solid var(--color-accent);
  padding-left: var(--sp-5);
  font-family: var(--font-display);
  font-style: italic;
  font-size: var(--fs-lg);
  color: var(--color-ink-soft);
  margin-block: var(--sp-6);
}

.prose .pullquote {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  line-height: 1.25;
  color: var(--color-ink);
  text-align: center;
  padding: var(--sp-7) 0;
  border-top: 1px solid var(--color-rule);
  border-bottom: 1px solid var(--color-rule);
  font-style: italic;
  font-weight: 400;
  max-width: none;
}

.prose .callout {
  background: var(--color-bg-soft);
  border: 1px solid var(--color-rule);
  border-left: 3px solid var(--color-accent-2);
  padding: var(--sp-5) var(--sp-6);
  border-radius: var(--radius);
  font-size: var(--fs-base);
}
.prose .callout strong { color: var(--color-accent-2); }

/* ---------- ARTICLE PAGE LAYOUT ---------- */
.article-hero {
  padding-block: var(--sp-8) var(--sp-7);
  border-bottom: 1px solid var(--color-rule);
}
.article-hero__date {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent);
  display: block;
  margin-bottom: var(--sp-4);
}
.article-hero__title {
  font-size: clamp(2rem, 4.5vw, 3.5rem);
  max-width: 22ch;
  margin-bottom: var(--sp-5);
}
.article-hero__deck {
  font-size: var(--fs-md);
  color: var(--color-ink-soft);
  max-width: 60ch;
  line-height: 1.55;
}
.article-meta {
  display: flex; gap: var(--sp-5);
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
  margin-top: var(--sp-6);
}

.article-body { padding-block: var(--sp-8); }

/* ---------- FOOTER ---------- */
.site-footer {
  padding: var(--sp-9) 0 var(--sp-6);
  border-top: 1px solid var(--color-rule);
  background: var(--color-bg-soft);
  margin-top: var(--sp-9);
  font-size: var(--fs-sm);
}
.footer__grid {
  display: grid;
  gap: var(--sp-7);
  grid-template-columns: 1fr;
  margin-bottom: var(--sp-7);
}
@media (min-width: 720px) {
  .footer__grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; }
}
.footer__brand p {
  color: var(--color-ink-soft);
  margin-top: var(--sp-3);
  font-size: var(--fs-sm);
  max-width: 30ch;
}
.footer__title {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
  margin-bottom: var(--sp-4);
}
.footer__list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: var(--sp-2); }
.footer__list a { color: var(--color-ink-soft); transition: color var(--t-fast) var(--ease); }
.footer__list a:hover { color: var(--color-accent); }

.footer__bottom {
  border-top: 1px solid var(--color-rule);
  padding-top: var(--sp-5);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--sp-3);
  color: var(--color-ink-mute);
  font-size: var(--fs-xs);
  letter-spacing: 0.05em;
}

/* ---------- TIMELINE (DÉCOUVERTES) ---------- */
.timeline {
  position: relative;
  padding-left: clamp(1.5rem, 4vw, 3rem);
}
.timeline::before {
  content: ""; position: absolute;
  top: 0; bottom: 0; left: 0;
  width: 1px; background: var(--color-rule);
}
.timeline__item {
  position: relative;
  padding-bottom: var(--sp-7);
}
.timeline__item::before {
  content: ""; position: absolute;
  left: calc(-1 * clamp(1.5rem, 4vw, 3rem));
  top: 0.5em;
  width: 11px; height: 11px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid var(--color-accent);
  transform: translateX(-5px);
}
.timeline__year {
  font-family: var(--font-display);
  font-size: var(--fs-2xl);
  color: var(--color-accent);
  font-weight: 400;
  font-style: italic;
  display: block;
  line-height: 1;
}
.timeline__title { font-size: var(--fs-lg); margin: var(--sp-3) 0 var(--sp-2); }
.timeline__text { color: var(--color-ink-soft); font-size: var(--fs-sm); line-height: 1.65; max-width: 60ch; }

/* ---------- MOLECULE EXPLORER ---------- */
.explorer {
  display: grid;
  gap: var(--sp-6);
  grid-template-columns: 1fr;
}
@media (min-width: 940px) {
  .explorer { grid-template-columns: 1fr 1.4fr; gap: var(--sp-7); align-items: start; }
}
.explorer__sidebar {
  position: sticky; top: 80px;
  background: var(--color-bg-soft);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-lg);
  padding: var(--sp-5);
}
.explorer__filters {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  margin-bottom: var(--sp-4);
}
.filter-pill {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--color-rule);
  background: transparent;
  color: var(--color-ink-soft);
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--t-fast) var(--ease);
}
.filter-pill:hover { color: var(--color-ink); border-color: var(--color-ink); }
.filter-pill[aria-pressed="true"] {
  background: var(--color-accent); border-color: var(--color-accent); color: var(--color-bg);
}
.search-input {
  width: 100%;
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  color: var(--color-ink);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  margin-bottom: var(--sp-3);
}
.search-input:focus { border-color: var(--color-accent); outline: none; }

.molecule-grid {
  display: grid;
  gap: var(--sp-3);
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
}
.molecule-tile {
  position: relative;
  aspect-ratio: 1;
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius);
  cursor: pointer;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center;
  padding: var(--sp-3);
  transition: all var(--t-fast) var(--ease);
  font-family: var(--font-mono);
}
.molecule-tile:hover, .molecule-tile.is-active {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px -8px rgba(212, 165, 116, 0.4);
}
.molecule-tile.is-active { background: var(--color-bg-elev); }
.molecule-tile__formula {
  font-size: var(--fs-md);
  color: var(--color-ink);
  margin-bottom: var(--sp-2);
}
.molecule-tile__name {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--color-ink-mute);
  line-height: 1.3;
}
.molecule-tile__cat {
  position: absolute; top: 6px; right: 8px;
  width: 6px; height: 6px;
  border-radius: 50%;
}
.molecule-tile__cat[data-cat="diatomique"]   { background: var(--color-accent-4); }
.molecule-tile__cat[data-cat="organique"]    { background: var(--color-accent-2); }
.molecule-tile__cat[data-cat="prebiotique"]  { background: var(--color-accent-3); }
.molecule-tile__cat[data-cat="ion"]          { background: var(--color-accent); }
.molecule-tile__cat[data-cat="hydrocarbure"] { background: #b889e8; }
.molecule-tile__cat[data-cat="exotique"]     { background: #e8c468; }

.molecule-detail {
  background: var(--color-bg-soft);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-lg);
  padding: var(--sp-6);
  min-height: 480px;
  position: sticky; top: 80px;
}
.molecule-detail__formula {
  font-family: var(--font-mono);
  font-size: var(--fs-3xl);
  color: var(--color-accent);
  margin-bottom: var(--sp-2);
}
.molecule-detail__name {
  font-family: var(--font-display);
  font-size: var(--fs-xl);
  margin-bottom: var(--sp-4);
}
.molecule-detail__viz {
  background: var(--color-bg);
  border-radius: var(--radius);
  height: 240px;
  margin-block: var(--sp-5);
  display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
}
.molecule-detail__viz canvas { width: 100%; height: 100%; }
.molecule-detail__facts {
  display: grid; gap: var(--sp-3);
  grid-template-columns: 1fr 1fr;
  margin-top: var(--sp-5);
}
.fact {
  padding: var(--sp-3);
  background: var(--color-bg);
  border-radius: var(--radius);
}
.fact__label {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
  margin-bottom: 4px;
}
.fact__value {
  font-family: var(--font-display);
  font-size: var(--fs-md);
  color: var(--color-ink);
}
.molecule-detail__desc {
  margin-top: var(--sp-5);
  color: var(--color-ink-soft);
  font-size: var(--fs-sm);
  line-height: 1.65;
}

.legend {
  display: flex; flex-wrap: wrap; gap: var(--sp-4);
  margin-top: var(--sp-4);
  padding-top: var(--sp-4);
  border-top: 1px solid var(--color-rule);
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
}
.legend-item { display: inline-flex; align-items: center; gap: 6px; }
.legend-dot { width: 7px; height: 7px; border-radius: 50%; display: inline-block; }

/* ---------- ACTUALITES LIST ---------- */
.news-list { display: grid; gap: var(--sp-6); }
.news-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-3);
  padding-block: var(--sp-6);
  border-bottom: 1px solid var(--color-rule);
}
@media (min-width: 720px) {
  .news-item { grid-template-columns: 180px 1fr; gap: var(--sp-6); align-items: start; }
}
.news-item__date {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent);
  padding-top: 8px;
}
.news-item__title { font-size: var(--fs-xl); margin-bottom: var(--sp-3); }
.news-item__title a { color: var(--color-ink); border-bottom: 0; }
.news-item__title a:hover { color: var(--color-accent); }
.news-item__excerpt { color: var(--color-ink-soft); font-size: var(--fs-base); line-height: 1.6; max-width: 64ch; }
.news-item__tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
  margin-top: var(--sp-3);
}

/* ---------- GLOSSAIRE ---------- */
.gloss-nav {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  margin-bottom: var(--sp-7);
  padding-bottom: var(--sp-5);
  border-bottom: 1px solid var(--color-rule);
}
.gloss-nav a {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  width: 32px; height: 32px;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--color-rule);
  border-radius: var(--radius);
  color: var(--color-ink-soft);
  transition: all var(--t-fast) var(--ease);
}
.gloss-nav a:hover { background: var(--color-accent); color: var(--color-bg); border-color: var(--color-accent); }

.gloss-letter {
  font-family: var(--font-display);
  font-size: var(--fs-4xl);
  color: var(--color-accent);
  font-style: italic;
  font-weight: 300;
  margin-top: var(--sp-7);
  margin-bottom: var(--sp-4);
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--color-rule);
  line-height: 1;
}
.gloss-entry { margin-bottom: var(--sp-5); }
.gloss-term {
  font-family: var(--font-display);
  font-size: var(--fs-lg);
  color: var(--color-ink);
  margin-bottom: var(--sp-2);
  font-weight: 500;
}
.gloss-term__formula {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-accent);
  margin-left: var(--sp-3);
}
.gloss-def { color: var(--color-ink-soft); font-size: var(--fs-base); line-height: 1.65; max-width: 70ch; }

/* ---------- FORMULAIRE ---------- */
.contact-form {
  display: grid; gap: var(--sp-5);
  max-width: 540px;
  margin-top: var(--sp-6);
}
.field { display: flex; flex-direction: column; gap: var(--sp-2); }
.field label {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-ink-mute);
}
.field input, .field textarea, .field select {
  background: var(--color-bg-soft);
  border: 1px solid var(--color-rule);
  color: var(--color-ink);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  transition: border-color var(--t-fast) var(--ease);
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--color-accent);
}
.field textarea { min-height: 140px; resize: vertical; }

/* ---------- 404 ---------- */
.error-page {
  min-height: 80vh;
  display: flex; align-items: center; justify-content: center;
  text-align: center;
  padding: var(--sp-8);
}
.error-page__code {
  font-family: var(--font-display);
  font-size: clamp(6rem, 18vw, 14rem);
  color: var(--color-accent);
  font-style: italic;
  font-weight: 300;
  line-height: 0.9;
  letter-spacing: -0.04em;
}

/* ---------- UTILITAIRES ---------- */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}
.text-center { text-align: center; }
.mt-auto { margin-top: auto; }

/* Reveal au scroll */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 800ms var(--ease-out), transform 800ms var(--ease-out);
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* ---------- RESPONSIVE ---------- */
@media (max-width: 760px) {
  .menu-toggle { display: inline-flex; }
  .nav__list {
    position: fixed;
    inset: 64px 0 0 0;
    background: var(--color-bg);
    flex-direction: column;
    padding: var(--sp-7);
    gap: var(--sp-3);
    align-items: flex-start;
    transform: translateX(100%);
    transition: transform var(--t-mid) var(--ease);
    border-top: 1px solid var(--color-rule);
  }
  .nav__list.is-open { transform: translateX(0); }
  .nav__link { font-size: var(--fs-md); padding: var(--sp-3) 0; }
  .hero__meta { flex-direction: column; gap: var(--sp-3); align-items: flex-start; }
  .explorer__sidebar { position: static; }
  .molecule-detail { position: static; }
  .article-meta { flex-direction: column; gap: var(--sp-2); }
}

/* ---------- ACCESSIBILITÉ : MOTION ---------- */
@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;
  }
  .hero__canvas { display: none; }
  .hero__veil {
    background:
      radial-gradient(ellipse at 30% 40%, rgba(212, 165, 116, 0.12), transparent 60%),
      radial-gradient(ellipse at 70% 70%, rgba(198, 72, 105, 0.10), transparent 55%),
      var(--color-bg);
  }
}

/* Print */
@media print {
  .site-header, .site-footer, .hero__canvas { display: none; }
  body { background: white; color: black; }
}

/* ============================================================
   APPENDIX — supplementary styles for inner pages
   ============================================================ */

/* Allow `.container.narrow` as well as `.container--narrow` */
.container.narrow { max-width: var(--container-narrow); }

/* ---------- Page hero (used on inner pages) ---------- */
.page-hero {
  padding-top: clamp(5rem, 12vh, 8rem);
  padding-bottom: clamp(2.5rem, 6vh, 4rem);
  border-bottom: 1px solid var(--color-rule);
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: "";
  position: absolute;
  inset: -40% -20% auto auto;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle at center, color-mix(in srgb, var(--color-accent) 10%, transparent) 0%, transparent 60%);
  pointer-events: none;
  opacity: 0.6;
  z-index: -1;
}
.page-hero__title {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(2.4rem, 5.2vw, 4rem);
  line-height: 1.05;
  letter-spacing: -0.012em;
  margin-block: var(--sp-3) var(--sp-5);
  max-width: 24ch;
}
.page-hero__lede {
  font-family: var(--font-body);
  font-size: var(--fs-lg);
  line-height: 1.6;
  color: var(--color-ink-soft);
  max-width: 60ch;
}

/* ---------- Section variant ---------- */
.section { padding-block: clamp(3rem, 8vh, 6rem); }
.section--alt { background: var(--color-bg-alt); border-top: 1px solid var(--color-rule); border-bottom: 1px solid var(--color-rule); }

/* ---------- Inline link arrow ---------- */
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  border-bottom: 0;
  transition: gap var(--t-fast) var(--ease);
}
.link-arrow:hover { gap: 0.7em; color: var(--color-accent-2); }

/* ---------- News list extras ---------- */
.news-item__lede {
  color: var(--color-ink-soft);
  font-size: var(--fs-base);
  line-height: 1.65;
  max-width: 64ch;
  margin-block: var(--sp-3);
}
.news-item__hint {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-ink-faint, var(--color-ink-soft));
  font-style: italic;
  opacity: 0.7;
}

/* ---------- Form modifiers ---------- */
.field--checkbox {
  flex-direction: row;
  align-items: flex-start;
  gap: var(--sp-3);
}
.field--checkbox label {
  font-size: var(--fs-sm);
  line-height: 1.55;
  text-transform: none;
  letter-spacing: 0;
  color: var(--color-ink-soft);
  font-weight: 400;
  font-family: var(--font-body);
}
.field--checkbox input[type="checkbox"] {
  width: 18px;
  height: 18px;
  margin-top: 3px;
  flex-shrink: 0;
  accent-color: var(--color-accent);
}
.field--actions {
  flex-direction: row;
  align-items: center;
  gap: var(--sp-3);
  margin-top: var(--sp-2);
}
.form-hint {
  font-size: var(--fs-xs);
  color: var(--color-ink-soft);
  margin-top: var(--sp-3);
  font-style: italic;
}

/* ---------- Article meta line ---------- */
.article-meta {
  font-size: var(--fs-sm);
  color: var(--color-ink-soft);
  border-top: 1px solid var(--color-rule);
  padding-top: var(--sp-5);
  margin-top: var(--sp-7);
}
hr.rule {
  border: 0;
  height: 1px;
  background: var(--color-rule);
  margin-block: var(--sp-7);
}

/* ---------- Explorer layout (molecules page) ---------- */
.explorer__controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
  align-items: center;
  justify-content: space-between;
  padding-block: var(--sp-4);
  border-bottom: 1px solid var(--color-rule);
  margin-bottom: var(--sp-6);
}
.explorer__filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}
.explorer__filters button {
  background: transparent;
  border: 1px solid var(--color-rule);
  color: var(--color-ink-soft);
  padding: 0.45em 0.95em;
  border-radius: 999px;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  transition: all var(--t-fast) var(--ease);
}
.explorer__filters button:hover { color: var(--color-ink); border-color: var(--color-ink-soft); }
.explorer__filters button[aria-pressed="true"] {
  background: var(--color-accent);
  color: var(--color-bg);
  border-color: var(--color-accent);
}
.explorer__search input {
  width: min(28ch, 100%);
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  color: var(--color-ink);
  padding: 0.55em 0.95em;
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
}
.explorer__search input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent) 20%, transparent);
}
.explorer__layout {
  display: grid;
  gap: var(--sp-6);
  grid-template-columns: 1fr;
}
@media (min-width: 900px) {
  .explorer__layout { grid-template-columns: 1.4fr 1fr; align-items: start; }
}

/* ---------- Molecule grid ---------- */
.explorer__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--sp-3);
}
.molecule-tile {
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  padding: var(--sp-4);
  border-radius: 6px;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  color: inherit;
  transition: all var(--t-fast) var(--ease);
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  min-height: 130px;
}
.molecule-tile:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
}
.molecule-tile[aria-pressed="true"] {
  border-color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 6%, transparent);
}
.molecule-tile__formula {
  font-family: var(--font-mono);
  font-size: var(--fs-lg);
  color: var(--color-accent);
  letter-spacing: 0.02em;
}
.molecule-tile__name {
  font-family: var(--font-display);
  font-size: var(--fs-base);
  color: var(--color-ink);
  font-style: italic;
  font-weight: 400;
  line-height: 1.3;
}
.molecule-tile__meta {
  margin-top: auto;
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  display: flex;
  justify-content: space-between;
  gap: 0.5em;
}
.molecule-tile__year { color: var(--color-accent); }

/* ---------- Detail panel ---------- */
.explorer__detail {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-rule);
  border-radius: 6px;
  padding: var(--sp-5);
  position: sticky;
  top: 90px;
  min-height: 300px;
}
.detail__placeholder {
  color: var(--color-ink-soft);
  font-style: italic;
  font-size: var(--fs-sm);
  line-height: 1.6;
}
.detail__placeholder p { margin-block: var(--sp-2); }
.detail__formula {
  font-family: var(--font-mono);
  font-size: var(--fs-2xl);
  color: var(--color-accent);
  letter-spacing: 0.03em;
}
.detail__name {
  font-family: var(--font-display);
  font-size: var(--fs-xl);
  font-style: italic;
  margin-block: var(--sp-2) var(--sp-3);
  line-height: 1.2;
}
.detail__canvas {
  width: 100%;
  height: 220px;
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  border-radius: 4px;
  margin-block: var(--sp-3);
  display: block;
}
.detail__row {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  margin-block: var(--sp-2);
  align-items: baseline;
}
.detail__row dt {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
}
.detail__row dd { margin: 0; color: var(--color-ink); line-height: 1.5; }
.detail__description {
  margin-top: var(--sp-4);
  padding-top: var(--sp-4);
  border-top: 1px solid var(--color-rule);
  color: var(--color-ink-soft);
  font-size: var(--fs-sm);
  line-height: 1.7;
}

/* ---------- Error page ---------- */
.error-page {
  min-height: calc(100vh - 200px);
  display: flex;
  align-items: center;
  padding-block: var(--sp-8);
}
.error-page__code {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(7rem, 22vw, 14rem);
  font-weight: 300;
  color: var(--color-accent);
  line-height: 0.9;
  letter-spacing: -0.04em;
  opacity: 0.85;
}
.error-page__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 500;
  margin-block: var(--sp-4) var(--sp-5);
  max-width: 24ch;
}
.error-page__lede {
  font-size: var(--fs-md);
  line-height: 1.65;
  color: var(--color-ink-soft);
  max-width: 60ch;
}
.error-page__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  margin-top: var(--sp-6);
}

/* ============================================================
   Molecule explorer — additional styles to match JS
   ============================================================ */

/* filter pill buttons (created by JS) */
.filter-pill {
  background: transparent;
  border: 1px solid var(--color-rule);
  color: var(--color-ink-soft);
  padding: 0.45em 1em;
  border-radius: 999px;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  transition: all var(--t-fast) var(--ease);
}
.filter-pill:hover { color: var(--color-ink); border-color: var(--color-ink-soft); }
.filter-pill[aria-pressed="true"] {
  background: var(--color-accent);
  color: var(--color-bg);
  border-color: var(--color-accent);
}

/* molecule tile category indicator (small colored dot top-right) */
.molecule-tile { position: relative; }
.molecule-tile__cat {
  position: absolute;
  top: var(--sp-3);
  right: var(--sp-3);
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--color-ink-soft);
}
.molecule-tile__cat[data-cat="diatomique"]   { background: var(--color-accent-4); }
.molecule-tile__cat[data-cat="organique"]    { background: var(--color-accent-2); }
.molecule-tile__cat[data-cat="prebiotique"]  { background: var(--color-accent-3); }
.molecule-tile__cat[data-cat="ion"]          { background: var(--color-accent); }
.molecule-tile__cat[data-cat="hydrocarbure"] { background: #b889e8; }
.molecule-tile__cat[data-cat="exotique"]     { background: #e8c468; }

.molecule-tile.is-active {
  border-color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 8%, transparent);
  box-shadow: 0 0 0 1px var(--color-accent);
}

/* detail panel (matches JS class names) */
.molecule-detail__formula {
  font-family: var(--font-mono);
  font-size: var(--fs-2xl);
  color: var(--color-accent);
  letter-spacing: 0.03em;
  line-height: 1.1;
}
.molecule-detail__name {
  font-family: var(--font-display);
  font-size: var(--fs-xl);
  font-style: italic;
  font-weight: 500;
  margin-block: var(--sp-2) var(--sp-4);
  line-height: 1.2;
  color: var(--color-ink);
}
.molecule-detail__viz {
  margin-block: var(--sp-3) var(--sp-4);
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  border-radius: 4px;
  padding: var(--sp-2);
  height: 240px;
  position: relative;
}
.molecule-detail__viz canvas {
  width: 100%;
  height: 100%;
  display: block;
}
.molecule-detail__facts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-3) var(--sp-4);
  margin-block: var(--sp-4);
  padding-block: var(--sp-4);
  border-block: 1px solid var(--color-rule);
}
.fact { display: flex; flex-direction: column; gap: 2px; }
.fact__label {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
}
.fact__value {
  font-family: var(--font-display);
  font-style: italic;
  font-size: var(--fs-base);
  color: var(--color-ink);
  line-height: 1.3;
}
.molecule-detail__desc {
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
  margin-top: var(--sp-3);
}

@media (max-width: 899px) {
  .explorer__detail { position: static; }
  .molecule-detail__facts { grid-template-columns: 1fr 1fr; }
}