:root {
  --bg: #0d0d1a;
  --bg-2: #16162a;
  --bg-3: #1e1e30;
  --surface: rgba(30, 30, 48, 0.82);
  --text: #f8fafc;
  --text-2: #c8c8d8;
  --text-3: #8c8ca5;
  --border: rgba(255,255,255,.1);
  --cyan: #22d3ee;
  --cyan-dark: #0891b2;
  --pink: #ff2d78;
  --purple: #9b6cff;
  --yellow: #f9c846;
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 32px;
  --radius-pill: 999px;
  --shadow: 0 22px 60px rgba(0,0,0,.32);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: Poppins, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.65;
  overflow-x: hidden;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    radial-gradient(circle at 8% 8%, rgba(255,45,120,.14), transparent 28rem),
    radial-gradient(circle at 92% 22%, rgba(34,211,238,.12), transparent 30rem),
    var(--bg);
}
a { color: inherit; }
img { display: block; max-width: 100%; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { line-height: 1.12; }
h1 { max-width: 770px; margin-bottom: 1.35rem; font-size: clamp(2rem, 4.2vw, 3.4rem); letter-spacing: -.045em; }
h2 { margin-bottom: 1.15rem; font-size: clamp(2rem, 4vw, 3.35rem); letter-spacing: -.04em; }
h3 { font-size: 1.14rem; }
p { color: var(--text-2); }
.container { width: min(1160px, calc(100% - 40px)); margin-inline: auto; }
.section { padding: clamp(5rem, 10vw, 8.5rem) 0; }
.section-heading { max-width: 760px; margin-bottom: 3rem; }
.concrete-section .section-heading,
.uses-section .section-heading { max-width: 1000px; }
.section-heading > p:not(.kicker) { max-width: 680px; font-size: 1.06rem; }
.concrete-section .section-heading > p:not(.kicker) { max-width: 1000px; }
.kicker, .eyebrow { margin-bottom: .75rem; color: var(--cyan); font-size: .76rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
.skip-link { position: fixed; top: 8px; left: 8px; z-index: 100; padding: .7rem 1rem; border-radius: 8px; background: white; color: #111; transform: translateY(-150%); }
.skip-link:focus { transform: none; }

.site-header { position: sticky; top: 0; z-index: 30; border-bottom: 1px solid var(--border); background: rgba(13,13,26,.82); backdrop-filter: blur(18px); }
.nav-shell { min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; }
.brand { display: inline-flex; align-items: center; gap: .65rem; color: var(--text); font-size: 1.25rem; font-weight: 800; text-decoration: none; }
.brand-mark, .mini-logo { display: grid; place-items: center; width: 38px; aspect-ratio: 1; border-radius: 11px; background: linear-gradient(135deg, var(--pink), #ff7cab); color: white; box-shadow: 0 8px 25px rgba(255,45,120,.28); }
.nav-links { display: flex; gap: 1.7rem; }
.nav-links a, .site-footer nav a { color: var(--text-2); font-size: .9rem; font-weight: 600; text-decoration: none; }
.nav-links a:hover, .site-footer nav a:hover { color: var(--cyan); }
.button { display: inline-flex; min-height: 52px; align-items: center; justify-content: center; padding: .85rem 1.5rem; border: 0; border-radius: var(--radius-pill); background: linear-gradient(135deg, var(--cyan), var(--cyan-dark)); color: #071318; font-weight: 800; text-decoration: none; box-shadow: 0 12px 30px rgba(34,211,238,.2); transition: transform .18s ease, box-shadow .18s ease; }
.button:hover { transform: translateY(-2px); box-shadow: 0 17px 36px rgba(34,211,238,.28); }
.button:active { transform: scale(.98); }
.button-small { min-height: 42px; padding: .65rem 1.1rem; font-size: .83rem; }
.button-ghost { border: 1px solid rgba(255,255,255,.22); background: rgba(255,255,255,.05); color: var(--text); box-shadow: none; }
.text-link { color: var(--text); font-weight: 700; text-decoration: none; }
.text-link span { color: var(--cyan); }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 1.2rem; }

.hero { position: relative; min-height: calc(100vh - 74px); display: grid; align-items: center; padding: clamp(4rem, 8vw, 7rem) 0; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(390px, .9fr); align-items: center; gap: clamp(3rem, 7vw, 7rem); }
.badge { display: inline-flex; padding: .45rem .8rem; border: 1px solid rgba(249,200,70,.3); border-radius: var(--radius-pill); background: rgba(249,200,70,.09); color: var(--yellow); font-size: .76rem; font-weight: 800; letter-spacing: .05em; text-transform: uppercase; }
.hero-lead { max-width: 690px; margin-bottom: 2rem; font-size: clamp(1.05rem, 2vw, 1.26rem); }
.microcopy { margin: 1.25rem 0 0; color: var(--text-3); font-size: .78rem; }
.hero-demo { position: relative; display: grid; gap: .8rem; padding: 2.3rem 1.35rem 1.35rem; border: 1px solid var(--border); border-radius: var(--radius-lg); background: linear-gradient(160deg, rgba(30,30,48,.95), rgba(22,22,42,.8)); box-shadow: var(--shadow); }
.hero-demo::before { content: ""; position: absolute; inset: -1px; z-index: -1; border-radius: inherit; background: linear-gradient(150deg, rgba(34,211,238,.4), transparent 35%, rgba(255,45,120,.3)); filter: blur(18px); opacity: .7; }
.hero-mascot { position: absolute; top: -76px; right: 20px; width: 125px; filter: drop-shadow(0 12px 15px rgba(0,0,0,.25)); }
.hero-london { display: flex; min-height: 560px; align-self: stretch; align-items: center; justify-content: center; margin: -2rem 0; }
.hero-london img { width: min(430px, 100%); max-height: 650px; object-fit: contain; filter: drop-shadow(0 28px 34px rgba(0,0,0,.38)); }
.demo-card { padding: 1.25rem; border: 1px solid var(--border); border-radius: var(--radius-md); background: rgba(13,13,26,.74); }
.brick-row, .brick-stack { display: flex; flex-wrap: wrap; gap: .55rem; }
.brick { display: inline-flex; padding: .6rem .85rem; border-radius: 10px; color: #10101a; font-size: .88rem; font-weight: 800; box-shadow: 0 6px 14px rgba(0,0,0,.22); }
.brick-blue { background: #6ba3d6; }.brick-yellow { background: var(--yellow); }.brick-pink { background: #ff7aa9; }.brick-purple { background: #b49aff; }
.demo-transform { display: grid; grid-template-columns: auto 1fr; column-gap: .75rem; align-items: center; padding: .3rem .8rem; }
.demo-transform span:last-child { grid-column: 2; color: var(--text-3); font-size: .72rem; }
.mini-logo { grid-row: span 2; width: 34px; border-radius: 9px; font-size: .8rem; }
.game-label { display: inline-block; margin-bottom: .75rem; color: var(--pink); font-size: .74rem; font-weight: 800; }
.sentence { margin: 0; color: var(--text); font-size: 1.18rem; font-weight: 700; }
.sentence mark { padding: .1rem .3rem; border-radius: 5px; background: rgba(34,211,238,.16); color: var(--cyan); }

.concrete-section, .uses-section, .faq-section { background: var(--bg-2); }
.flow-grid, .three-grid, .benefit-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.info-card, .benefit-card { position: relative; padding: 1.6rem; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); }
.flow-card { position: relative; padding: 1.6rem; border: none; background: transparent; text-align: center; }
.flow-card { min-height: 290px; }
.flow-card-accent { background: transparent; }
.step-number { display: block; margin-bottom: 1rem; color: var(--text-3); font-size: .72rem; font-weight: 800; letter-spacing: .1em; }
.phone-mockup {
  position: relative;
  width: min(215px, 86%);
  margin: 1.5rem auto;
  padding: 7px;
  border: 1px solid rgba(255,255,255,.17);
  border-radius: 34px;
  background: #05050b;
  box-shadow: 0 22px 38px rgba(0,0,0,.42), 0 0 0 4px rgba(255,255,255,.035);
}
.phone-mockup::after {
  content: "";
  position: absolute;
  right: -4px;
  top: 24%;
  width: 3px;
  height: 58px;
  border-radius: 0 3px 3px 0;
  background: #353546;
}
.phone-mockup img {
  width: 100%;
  border-radius: 27px;
}
.phone-speaker {
  position: absolute;
  top: 13px;
  left: 50%;
  z-index: 1;
  width: 42px;
  height: 5px;
  border-radius: var(--radius-pill);
  background: rgba(0,0,0,.72);
  transform: translateX(-50%);
}
.brick-stack { align-items: flex-start; }
.check-list, .compare-card ul { margin: 0; padding: 0; list-style: none; }
.check-list li, .compare-card li { position: relative; margin-bottom: .8rem; padding-left: 1.5rem; color: var(--text-2); }
.check-list li::before, .zebrik-card li::before { content: "✓"; position: absolute; left: 0; color: var(--cyan); font-weight: 800; }
.sentence-list p { padding: .75rem; border-radius: 10px; background: rgba(255,255,255,.04); color: var(--text); font-size: .86rem; }
.three-grid { counter-reset: steps; }
.info-card { min-height: 245px; }
.icon-chip { display: grid; place-items: center; width: 45px; aspect-ratio: 1; margin-bottom: 2rem; border-radius: 13px; background: rgba(34,211,238,.14); color: var(--cyan); font-weight: 800; }
.icon-pink { background: rgba(255,45,120,.14); color: var(--pink); }.icon-purple { background: rgba(155,108,255,.14); color: #b89cff; }
.info-card p, .benefit-card p, .audience-grid p { margin-bottom: 0; font-size: .92rem; }

.benefit-grid { grid-template-columns: repeat(3, 1fr); }
.benefit-card > span { display: block; margin-bottom: 1.3rem; font-size: 1.6rem; }
.benefit-card > .benefit-mascot { display: block; width: 64px; height: auto; margin-bottom: 1rem; }
.visual-section { position: relative; }
.floating-mascot {
  position: absolute;
  z-index: 2;
  filter: drop-shadow(0 14px 18px rgba(0,0,0,.28));
}
.floating-mascot-a { top: 4px; right: 3%; width: 78px; transform: rotate(5deg); }
.floating-mascot-n { top: -40px; right: 3%; width: 138px; transform: rotate(-5deg); }
.flow-card { position: relative; }
.flow-mascot { position: absolute; bottom: 30px; right: -10px; z-index: 3; width: 178px; transform: rotate(-8deg); filter: drop-shadow(0 14px 18px rgba(0,0,0,.32)); pointer-events: none; }

.difference-section { background: linear-gradient(180deg, var(--bg), #111124); }
.difference-intro {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 350px;
  column-gap: 4rem;
  align-items: center;
}
.difference-demo { width: 100%; margin: 3.5rem 0 3rem; }
.compare-grid { display: grid; grid-template-columns: 1fr 1fr; max-width: 900px; margin-inline: auto; }
.compare-card { position: relative; padding: 1.7rem 2rem 1.35rem; }
.compare-card + .compare-card { border-left: 1px solid var(--border); }
.compare-card h3 { margin-bottom: 1.1rem; }
.muted-card { opacity: .72; }
.muted-card li::before { content: "—"; position: absolute; left: 0; color: var(--text-3); }
.zebrik-card h3 { color: var(--cyan); }
.audience-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--border); }
.audience-grid article { padding: 2rem; background: var(--bg-2); }
.test-section { padding-top: 2rem; }
.test-card { position: relative; overflow: hidden; display: grid; grid-template-columns: 1fr 250px; align-items: end; min-height: 300px; padding: clamp(1.75rem, 4vw, 3rem); border: 1px solid rgba(34,211,238,.25); border-radius: var(--radius-lg); background: linear-gradient(130deg, rgba(8,145,178,.22), rgba(155,108,255,.15) 60%, rgba(255,45,120,.16)); }
.test-card > div { max-width: 720px; }
.test-card img { align-self: end; width: 230px; margin-bottom: -4.5rem; filter: drop-shadow(0 18px 20px rgba(0,0,0,.35)); }
.test-card .actions { margin-top: 2rem; }

.faq-layout { display: grid; grid-template-columns: .65fr 1fr; gap: 5rem; }
.faq-list details { border-top: 1px solid var(--border); }
.faq-list details:last-child { border-bottom: 1px solid var(--border); }
.faq-list summary { position: relative; padding: 1.4rem 2.5rem 1.4rem 0; cursor: pointer; color: var(--text); font-weight: 700; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: .3rem; color: var(--cyan); font-size: 1.4rem; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { padding-right: 2rem; }
.site-footer { padding: 2.4rem 0; border-top: 1px solid var(--border); }
.footer-grid { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 2rem; }
.site-footer nav { display: flex; gap: 1.4rem; }
.site-footer p { margin: 0; text-align: right; color: var(--text-3); font-size: .75rem; }

@media (max-width: 900px) {
  .nav-links { display: none; }
  .hero { min-height: auto; }
  .hero-grid, .pedagogy-grid, .faq-layout { grid-template-columns: 1fr; }
  .hero-london { min-height: 480px; margin: -1rem 0; }
  .flow-grid, .three-grid, .benefit-grid { grid-template-columns: repeat(2, 1fr); }
  .pedagogy-grid, .faq-layout { gap: 2.5rem; }
  .section-mascot { display: none; }
  .difference-intro { grid-template-columns: minmax(0, 1fr) 300px; column-gap: 2rem; }
  .test-card { grid-template-columns: 1fr 180px; }
  .footer-grid { grid-template-columns: 1fr; text-align: center; }
  .site-footer nav { justify-content: center; flex-wrap: wrap; }
  .site-footer p { text-align: center; }
}

@media (max-width: 620px) {
  .container { width: min(100% - 28px, 1160px); }
  .site-header .button-small { display: none; }
  .nav-shell { min-height: 64px; }
  .section { padding: 4.5rem 0; }
  .hero { padding-top: 3rem; }
  h1 { font-size: clamp(2.4rem, 13vw, 3.7rem); }
  .hero-grid { display: block; }
  .hero-london { min-height: 390px; margin: 0; }
  .hero-london img { width: min(300px, 86vw); max-height: 430px; }
  .hero-mascot { width: 105px; top: -70px; }
  .flow-grid, .three-grid, .benefit-grid, .compare-grid, .audience-grid { grid-template-columns: 1fr; }
  .floating-mascot { position: static; margin: -1.5rem 0 1rem auto; }
  .floating-mascot-a { width: 68px; }
  .floating-mascot-n { width: 96px; }
  .flow-mascot { width: 132px; bottom: 40px; right: -6px; }
  .difference-intro { grid-template-columns: 1fr; }
  .difference-demo { width: min(100%, 390px); margin: 5rem auto 2.5rem; }
  .compare-grid { border: 0; }
  .compare-card { padding: 1.5rem 0; border-top: 1px solid var(--border); }
  .compare-card + .compare-card { border-left: 0; border-bottom: 1px solid var(--border); }
  .flow-card { min-height: auto; }
  .audience-grid { gap: 1px; }
  .test-card { display: block; min-height: 0; }
  .test-card img { width: 150px; margin: 2rem auto -4.5rem; }
  .button { width: 100%; }
  .actions .text-link { width: 100%; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}

/* ---- Thème clair (opt-in, n'affecte rien sans la classe .theme-light) ---- */
html.theme-light {
  --bg: #f4f3ee;
  --bg-2: #ecebe4;
  --bg-3: #e3e1d8;
  --surface: #ffffff;
  --text: #1a1a2e;
  --text-2: #4d4d5e;
  --text-3: #8a8a9a;
  --border: rgba(0,0,0,.12);
  --cyan-dark: #0e7d99;
}
html.theme-light body::before {
  background:
    radial-gradient(circle at 8% 8%, rgba(255,45,120,.10), transparent 28rem),
    radial-gradient(circle at 92% 22%, rgba(34,211,238,.12), transparent 30rem),
    var(--bg);
}
html.theme-light .site-header { background: rgba(244,243,238,.82); }
html.theme-light .difference-section { background: linear-gradient(180deg, var(--bg), #e7e5dd); }
html.theme-light .hero-demo { background: linear-gradient(160deg, #ffffff, #f1f0ea); }
html.theme-light .button-ghost { border-color: rgba(0,0,0,.18); background: rgba(0,0,0,.04); color: var(--text); }
html.theme-light .button { color: #ffffff; }

/* Bouton de bascule de thème (discret) */
.theme-toggle { margin-top: 1rem; padding: 0; border: 0; background: none; color: var(--text-3); font: inherit; font-size: .72rem; font-weight: 600; letter-spacing: .04em; cursor: pointer; opacity: .55; transition: opacity .15s, color .15s; }
.theme-toggle:hover { opacity: 1; color: var(--text-2); }