/* ========= LUMI — Design System ========= */
:root {
  --bg: #0f1329;
  --bg-2: #1a1f3a;
  --bg-3: #242a4a;
  --surface: #1e2440;
  --border: rgba(255, 255, 255, 0.08);
  --text: #ecedf7;
  --text-dim: #a8aec9;
  --text-muted: #7a80a0;
  --accent: #a78bfa;      /* lavande */
  --accent-2: #60a5fa;    /* bleu lune */
  --accent-warm: #fbbf24; /* étoile */
  --success: #4ade80;
  --danger: #f87171;
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
  --max: 1200px;
  --space: clamp(1rem, 2.5vw, 2rem);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a { color: var(--accent); text-decoration: none; transition: color .2s; }
a:hover { color: var(--accent-2); }

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: #fff;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.5rem); margin-bottom: 1rem; }
h3 { font-size: 1.25rem; margin-bottom: .5rem; }

p { color: var(--text-dim); }

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--space);
}

/* ========= Starfield background ========= */
.stars {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse at top, rgba(167, 139, 250, 0.15), transparent 60%),
    radial-gradient(ellipse at bottom right, rgba(96, 165, 250, 0.1), transparent 60%),
    var(--bg);
  pointer-events: none;
}
.stars::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(1px 1px at 20% 30%, #fff, transparent),
    radial-gradient(1px 1px at 40% 70%, #fff, transparent),
    radial-gradient(1px 1px at 80% 20%, #fff, transparent),
    radial-gradient(1px 1px at 90% 60%, #fff, transparent),
    radial-gradient(1.5px 1.5px at 33% 85%, #fff, transparent),
    radial-gradient(1px 1px at 65% 45%, #fff, transparent),
    radial-gradient(1px 1px at 10% 90%, #fff, transparent);
  background-size: 100% 100%;
  opacity: 0.4;
  animation: twinkle 4s ease-in-out infinite alternate;
}
@keyframes twinkle { to { opacity: 0.8; } }

/* ========= Header ========= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(15, 19, 41, 0.75);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  padding-bottom: 1rem;
}
.logo {
  display: flex;
  align-items: center;
  gap: .6rem;
  font-weight: 800;
  font-size: 1.25rem;
  color: #fff;
  letter-spacing: -0.02em;
}
.logo img { width: 34px; height: 34px; border-radius: 8px; }
.nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}
.nav a {
  color: var(--text-dim);
  font-size: 0.95rem;
  font-weight: 500;
}
.nav a:hover, .nav a.active { color: #fff; }
.lang-switch {
  display: flex;
  gap: .3rem;
  padding: .25rem;
  background: var(--bg-3);
  border-radius: 999px;
  font-size: 0.8rem;
}
.lang-switch a {
  padding: .3rem .7rem;
  border-radius: 999px;
  color: var(--text-muted);
  font-weight: 600;
}
.lang-switch a.active {
  background: var(--accent);
  color: #fff;
}

/* Mobile nav */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
  padding: .5rem;
}
@media (max-width: 820px) {
  .nav-toggle { display: block; }
  .nav {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg-2);
    padding: 2rem;
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%);
    transition: transform .3s;
    gap: 1.5rem;
  }
  .nav.open { transform: translateY(0); }
}

/* ========= Buttons ========= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .85rem 1.5rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .2s;
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(167, 139, 250, 0.3);
  color: #fff;
}
.btn-ghost {
  background: transparent;
  color: #fff;
  border-color: var(--border);
}
.btn-ghost:hover {
  background: var(--surface);
  color: #fff;
}
.btn-disabled {
  background: var(--bg-3);
  color: var(--text-muted);
  cursor: not-allowed;
  pointer-events: none;
}

/* ========= Hero ========= */
.hero {
  padding: clamp(3rem, 8vw, 6rem) 0 clamp(3rem, 6vw, 5rem);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}
@media (max-width: 820px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .4rem 1rem;
  background: rgba(167, 139, 250, 0.1);
  border: 1px solid rgba(167, 139, 250, 0.2);
  border-radius: 999px;
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 1.25rem;
}
.hero h1 {
  margin-bottom: 1.25rem;
}
.hero h1 .accent {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.lead {
  font-size: 1.15rem;
  color: var(--text-dim);
  margin-bottom: 2rem;
  max-width: 520px;
}
@media (max-width: 820px) {
  .hero p.lead { margin: 0 auto 2rem; }
}
.hero-ctas {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}
@media (max-width: 820px) {
  .hero-ctas { justify-content: center; }
}
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}
.hero-visual img {
  max-width: 300px;
  border-radius: 38px;
  box-shadow: var(--shadow-lg);
  filter: drop-shadow(0 30px 60px rgba(167, 139, 250, 0.2));
}

/* ========= Sections ========= */
section { padding: clamp(3rem, 6vw, 5rem) 0; }

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 3rem;
}
.section-header .eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: .75rem;
}
.section-header p { font-size: 1.05rem; }

/* ========= Feature grid ========= */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  transition: transform .3s, border-color .3s;
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(167, 139, 250, 0.4);
}
.feature-icon {
  display: inline-flex;
  width: 52px;
  height: 52px;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(167, 139, 250, 0.2), rgba(96, 165, 250, 0.2));
  border-radius: 12px;
  font-size: 1.6rem;
  margin-bottom: 1rem;
}
.feature-card h3 { color: #fff; }
.feature-card p { font-size: 0.95rem; }

/* ========= Feature showcase (alternating) ========= */
.showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
  margin-bottom: 4rem;
}
.showcase.reverse .showcase-text { order: 2; }
@media (max-width: 820px) {
  .showcase, .showcase.reverse { grid-template-columns: 1fr; }
  .showcase.reverse .showcase-text { order: unset; }
}
.showcase-text h2 { margin-bottom: 1rem; }
.showcase-text .eyebrow {
  color: var(--accent);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  font-size: 0.8rem;
  margin-bottom: .75rem;
  display: block;
}
.showcase-text ul {
  list-style: none;
  margin-top: 1.25rem;
}
.showcase-text li {
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: .6rem;
  color: var(--text-dim);
}
.showcase-text li::before {
  content: '✦';
  position: absolute;
  left: 0;
  color: var(--accent);
}
.showcase-visual {
  display: flex;
  justify-content: center;
}
.showcase-visual img {
  max-width: 260px;
  border-radius: 34px;
  box-shadow: var(--shadow);
}

/* ========= Science section ========= */
.science-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.5rem;
  margin: 3rem 0;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  text-align: center;
}
.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: block;
  line-height: 1;
}
.stat-label {
  margin-top: .75rem;
  font-size: 0.9rem;
  color: var(--text-dim);
}

.science-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(1.5rem, 3vw, 2.5rem);
  margin-bottom: 1.5rem;
}
.science-block h3 {
  color: #fff;
  margin-bottom: .75rem;
  display: flex;
  align-items: center;
  gap: .6rem;
}
.science-block p { margin-bottom: 1rem; }
.science-block p:last-child { margin-bottom: 0; }

/* ========= Ebook cards ========= */
.ebook-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}
.ebook-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform .3s, border-color .3s;
  display: flex;
  flex-direction: column;
}
.ebook-card:hover {
  transform: translateY(-6px);
  border-color: rgba(167, 139, 250, 0.4);
}
.ebook-cover {
  aspect-ratio: 2 / 3;
  overflow: hidden;
  background: var(--bg-3);
}
.ebook-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .5s;
}
.ebook-card:hover .ebook-cover img { transform: scale(1.03); }
.ebook-body {
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}
.ebook-body h3 { color: #fff; }
.ebook-body p { font-size: 0.92rem; flex: 1; margin: .5rem 0 1.25rem; }
.ebook-stores {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
}
.store-chip {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  font-size: 0.85rem;
  font-weight: 600;
  padding: .55rem 1rem;
  background: linear-gradient(135deg, rgba(167, 139, 250, 0.15), rgba(96, 165, 250, 0.1));
  border-radius: 999px;
  color: #fff;
  border: 1px solid rgba(167, 139, 250, 0.35);
  text-decoration: none;
  transition: all .2s ease;
}
a.store-chip:hover {
  background: linear-gradient(135deg, rgba(167, 139, 250, 0.3), rgba(96, 165, 250, 0.2));
  border-color: rgba(167, 139, 250, 0.6);
  transform: translateY(-1px);
  color: #fff;
}
.store-chip.placeholder {
  opacity: 0.55;
  background: var(--bg-3);
  color: var(--text-dim);
  border-color: var(--border);
  font-weight: 500;
  cursor: default;
}

/* ========= Contact / form ========= */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 3rem;
}
@media (max-width: 820px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-info h3 { color: #fff; margin-bottom: .5rem; }
.contact-info p { margin-bottom: 1.5rem; }
.contact-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  margin-bottom: 1.25rem;
}
.contact-item .icon {
  width: 44px;
  height: 44px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.2rem;
}
.contact-item strong { color: #fff; display: block; margin-bottom: .2rem; }
.contact-item span { color: var(--text-dim); font-size: 0.92rem; }

form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}
.form-row { margin-bottom: 1.25rem; }
label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: .5rem;
}
input, textarea {
  width: 100%;
  padding: .85rem 1rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: #fff;
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color .2s;
}
input:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
}
textarea { resize: vertical; min-height: 140px; }

/* ========= CTA banner ========= */
.cta-banner {
  background: linear-gradient(135deg, rgba(167, 139, 250, 0.12), rgba(96, 165, 250, 0.08));
  border: 1px solid rgba(167, 139, 250, 0.25);
  border-radius: var(--radius-lg);
  padding: clamp(2rem, 5vw, 3.5rem);
  text-align: center;
  margin: 3rem auto;
}
.cta-banner h2 { margin-bottom: 1rem; }
.cta-banner p { max-width: 560px; margin: 0 auto 2rem; font-size: 1.05rem; }

/* ========= Footer ========= */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
  background: rgba(15, 19, 41, 0.5);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}
@media (max-width: 820px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
.footer-col h4 {
  color: #fff;
  font-size: 0.95rem;
  margin-bottom: 1rem;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: .5rem; }
.footer-col a {
  color: var(--text-dim);
  font-size: 0.9rem;
}
.footer-col a:hover { color: #fff; }
.footer-brand p {
  font-size: 0.9rem;
  margin-top: .75rem;
  max-width: 280px;
}
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ========= Utilities ========= */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }

/* fade-in on load */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn .8s ease forwards;
}
.fade-in.delay-1 { animation-delay: .1s; }
.fade-in.delay-2 { animation-delay: .2s; }
.fade-in.delay-3 { animation-delay: .3s; }
@keyframes fadeIn {
  to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}