/* ============================================================
   TuteurIA — Landing page moderne
   Palette : Navy #17356e + Blanc/craie #fbfaf7
   Typo : Bricolage Grotesque (titres) + Public Sans (corps)
   Mobile-first, sections alternées, photos plein cadre.
   ============================================================ */

:root {
  --navy: #17356e;
  --navy-dark: #0f2350;
  --navy-soft: #1f4a8f;
  --navy-tint: #e9eef7;
  --chalk: #fbfaf7;
  --chalk-2: #f3f1ea;
  --ink: #0f1b33;
  --muted: #566079;
  --line: #e6e3da;
  --white: #ffffff;
  --radius: 18px;
  --radius-lg: 28px;
  --shadow: 0 18px 50px rgba(15, 35, 80, 0.12);
  --shadow-soft: 0 8px 24px rgba(15, 35, 80, 0.08);
  --font-head: "Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --font-body: "Public Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--chalk);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0;
}

p { margin: 0; }

a { color: var(--navy); text-decoration: none; }
a:hover { text-decoration: underline; }

img { display: block; max-width: 100%; }

.wrap { max-width: 1200px; margin: 0 auto; padding: 0 1.25rem; }

/* ============================================================
   Boutons
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 999px;
  padding: 0.95rem 1.8rem;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 1.02rem;
  text-decoration: none;
  border: 0;
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
  white-space: nowrap;
}
.btn-primary {
  background: var(--navy);
  color: var(--chalk);
  box-shadow: 0 10px 24px rgba(23, 53, 110, 0.28);
}
.btn-primary:hover {
  background: var(--navy-dark);
  color: var(--chalk);
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(23, 53, 110, 0.36);
  text-decoration: none;
}
.btn-ghost {
  background: transparent;
  color: var(--chalk);
  border: 2px solid rgba(251, 250, 247, 0.55);
}
.btn-ghost:hover {
  background: rgba(251, 250, 247, 0.12);
  color: var(--chalk);
  text-decoration: none;
}
.btn-outline {
  background: transparent;
  color: var(--navy);
  border: 2px solid var(--navy);
}
.btn-outline:hover {
  background: var(--navy-tint);
  text-decoration: none;
}
.btn-lg { padding: 1.1rem 2.2rem; font-size: 1.1rem; }

/* ============================================================
   Navigation
   ============================================================ */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  background: rgba(251, 250, 247, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid rgba(230, 227, 218, 0.7);
}
.nav-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
}
.brand {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--navy);
  letter-spacing: -0.02em;
  text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand span { color: var(--navy-soft); }
.nav-links {
  display: none;
  gap: 1.6rem;
  margin-left: 2.5rem;
}
.nav-links a {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.96rem;
  text-decoration: none;
}
.nav-links a:hover { color: var(--navy); text-decoration: none; }
.nav-cta { margin-left: auto; }
@media (min-width: 900px) {
  .nav-links { display: flex; }
}

/* ============================================================
   Hero plein écran
   ============================================================ */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  color: var(--chalk);
  overflow: hidden;
  padding: 6rem 0 3rem;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    105deg,
    rgba(15, 35, 80, 0.92) 0%,
    rgba(23, 53, 110, 0.78) 45%,
    rgba(23, 53, 110, 0.35) 100%
  );
}
.hero-inner {
  position: relative;
  z-index: 2;
  max-width: 760px;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(251, 250, 247, 0.14);
  border: 1px solid rgba(251, 250, 247, 0.3);
  color: var(--chalk);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.4rem 0.95rem;
  border-radius: 999px;
  margin-bottom: 1.4rem;
}
.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  line-height: 1.05;
  margin: 0 0 1.4rem;
  color: var(--chalk);
}
.hero h1 .accent { color: #ffd27a; }
.hero .lead {
  font-size: clamp(1.08rem, 2vw, 1.3rem);
  color: rgba(251, 250, 247, 0.9);
  max-width: 620px;
  margin: 0 0 2rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
}
.hero-scroll {
  position: absolute;
  bottom: 1.8rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  color: rgba(251, 250, 247, 0.7);
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
}
.hero-scroll::after {
  content: "";
  width: 1px;
  height: 28px;
  background: rgba(251, 250, 247, 0.5);
}

/* ============================================================
   Sections génériques
   ============================================================ */

section.block { padding: 5rem 0; }
section.block.navy {
  background: var(--navy);
  color: var(--chalk);
}
section.block.navy h2,
section.block.navy h3 { color: var(--chalk); }
section.block.navy p { color: rgba(251, 250, 247, 0.85); }
section.block.chalk { background: var(--chalk); }
section.block.chalk-2 { background: var(--chalk-2); }

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 3rem;
}
.section-eyebrow {
  display: inline-block;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--navy-soft);
  margin-bottom: 0.8rem;
}
section.block.navy .section-eyebrow { color: #ffd27a; }
.section-title {
  font-size: clamp(1.9rem, 4vw, 2.9rem);
  margin: 0 0 0.8rem;
}
.section-sub {
  font-size: 1.1rem;
  color: var(--muted);
}
section.block.navy .section-sub { color: rgba(251, 250, 247, 0.82); }

/* ============================================================
   "Comment ça marche" — 3 étapes
   ============================================================ */

.steps {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: 1fr;
}
@media (min-width: 860px) {
  .steps { grid-template-columns: repeat(3, 1fr); }
}
.step {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 2rem 1.8rem;
  box-shadow: var(--shadow-soft);
  position: relative;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}
.step-num {
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: var(--navy);
  color: var(--chalk);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.2rem;
}
.step-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 1rem;
  color: var(--navy);
}
.step h3 {
  font-size: 1.3rem;
  margin-bottom: 0.6rem;
}
.step p { color: var(--muted); font-size: 1rem; }

/* ============================================================
   Split feature (photo plein cadre + texte)
   ============================================================ */

.split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}
@media (min-width: 900px) {
  .split { grid-template-columns: 1fr 1fr; gap: 4rem; }
  .split.reverse .split-media { order: 2; }
}
.split-media {
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  box-shadow: var(--shadow);
  background: var(--navy-tint);
}
.split-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.split-text h2 {
  font-size: clamp(1.7rem, 3.5vw, 2.5rem);
  margin-bottom: 1rem;
}
.split-text p {
  font-size: 1.1rem;
  color: var(--muted);
  margin-bottom: 1.6rem;
}
section.block.navy .split-text p { color: rgba(251, 250, 247, 0.85); }
.split-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1rem;
}
.split-list li {
  display: flex;
  gap: 0.9rem;
  align-items: flex-start;
  font-size: 1.02rem;
}
.split-list .tick {
  flex: 0 0 28px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--navy);
  color: var(--chalk);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.85rem;
  margin-top: 2px;
}
section.block.navy .split-list .tick {
  background: var(--chalk);
  color: var(--navy);
}
.split-list strong { font-weight: 700; }
.split-list span { color: var(--muted); }
section.block.navy .split-list span { color: rgba(251, 250, 247, 0.8); }

/* ============================================================
   Grille avantages (4 cartes) — "Pourquoi TuteurIA"
   ============================================================ */

.adv-grid {
  display: grid;
  gap: 1.4rem;
  grid-template-columns: 1fr;
}
@media (min-width: 600px) { .adv-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .adv-grid { grid-template-columns: repeat(4, 1fr); } }
.adv {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.8rem 1.5rem;
  box-shadow: var(--shadow-soft);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
section.block.navy .adv {
  background: rgba(251, 250, 247, 0.06);
  border-color: rgba(251, 250, 247, 0.16);
}
.adv:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.adv-icon {
  width: 44px;
  height: 44px;
  color: var(--navy);
  margin-bottom: 1rem;
}
section.block.navy .adv-icon { color: #ffd27a; }
.adv h3 { font-size: 1.18rem; margin-bottom: 0.5rem; }
.adv p { color: var(--muted); font-size: 0.97rem; }
section.block.navy .adv p { color: rgba(251, 250, 247, 0.8); }

/* ============================================================
   Bannière photo pleine largeur (parallax léger)
   ============================================================ */

.banner {
  position: relative;
  min-height: 420px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--chalk);
  overflow: hidden;
}
.banner-bg {
  position: absolute;
  inset: 0;
  background-attachment: fixed;
  background-size: cover;
  background-position: center;
}
.banner-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(15, 35, 80, 0.72);
}
.banner-inner {
  position: relative;
  z-index: 2;
  max-width: 760px;
  padding: 0 1.5rem;
}
.banner h2 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 1rem;
}
.banner p {
  font-size: 1.15rem;
  color: rgba(251, 250, 247, 0.9);
  margin-bottom: 1.8rem;
}
@media (max-width: 600px) {
  .banner-bg { background-attachment: scroll; }
}

/* ============================================================
   CTA final
   ============================================================ */

.cta-final {
  background: var(--navy);
  color: var(--chalk);
  border-radius: var(--radius-lg);
  padding: 4rem 2rem;
  text-align: center;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.cta-final::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 80% 20%, rgba(255, 210, 122, 0.18), transparent 50%);
}
.cta-final h2 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 1rem;
  position: relative;
}
.cta-final p {
  font-size: 1.12rem;
  color: rgba(251, 250, 247, 0.88);
  max-width: 560px;
  margin: 0 auto 2rem;
  position: relative;
}
.cta-final .btn-primary {
  background: var(--chalk);
  color: var(--navy);
  position: relative;
}
.cta-final .btn-primary:hover {
  background: #fff;
  color: var(--navy-dark);
}

/* ============================================================
   Footer
   ============================================================ */

footer {
  background: var(--navy-dark);
  color: rgba(251, 250, 247, 0.78);
  padding: 3rem 0 2rem;
  font-size: 0.95rem;
}
.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr;
  margin-bottom: 2rem;
}
@media (min-width: 760px) {
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
}
.footer-brand {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--chalk);
  margin-bottom: 0.6rem;
}
.footer-col h4 {
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--chalk);
  margin-bottom: 0.9rem;
}
.footer-col a {
  display: block;
  color: rgba(251, 250, 247, 0.78);
  text-decoration: none;
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}
.footer-col a:hover { color: var(--chalk); text-decoration: none; }
.footer-bottom {
  border-top: 1px solid rgba(251, 250, 247, 0.14);
  padding-top: 1.4rem;
  text-align: center;
  font-size: 0.88rem;
  color: rgba(251, 250, 247, 0.65);
}
.footer-bottom strong { color: var(--chalk); font-weight: 700; }

/* ============================================================
   Accessibilité / réduction d'animation
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
  .banner-bg { background-attachment: scroll; }
}