/* AI with Samuel — système de design (prototype v0)
   Référence d'inspiration : site sombre, typo légère, accent vert.
   Tout passe par les variables ci-dessous : changer ici = changer partout. */

:root {
  --bg: #080808;
  --bg-halo: #0e1b1b;
  --surface: #0f1212;
  --line: rgba(237, 236, 228, 0.12);
  --text: #edece4;
  --text-dim: #898a86;
  --mint: #b8eeda;
  --green: #15c686;
  --green-soft: #38cf98;
  --white: #ffffff;
  --warn: #e8b04a;

  --font-body: "Poppins", Arial, sans-serif;
  --font-label: "JetBrains Mono", ui-monospace, monospace;

  --radius: 4px;
  --gutter: 24px;
  --max: 1120px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 300;
  font-size: 18px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Halo teal en haut + diagonales discrètes + grain */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: -2;
  background:
    radial-gradient(120% 60% at 50% -10%, var(--bg-halo) 0%, transparent 70%),
    repeating-linear-gradient(115deg, transparent 0 220px, rgba(255,255,255,0.018) 220px 221px);
}
body::after {
  content: "";
  position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: .07;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }
section { padding: 112px 0; }

/* Titres : légers, grands, dégradé blanc-menthe -> vert sur la phrase clé */
h1, h2, h3 { font-weight: 300; line-height: 1.1; letter-spacing: -0.02em; }
h1 { font-size: clamp(40px, 7vw, 72px); }
h2 { font-size: clamp(30px, 4.4vw, 48px); }
h3 { font-size: 22px; font-weight: 400; letter-spacing: -0.01em; }
.grad {
  background: linear-gradient(90deg, var(--mint) 0%, var(--green) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.label {
  font-family: var(--font-label); font-weight: 500;
  font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--text-dim);
}
.lead { font-size: 20px; color: var(--text); max-width: 640px; }
.dim { color: var(--text-dim); }

/* Boutons : strictement noir et blanc, coins 4px.
   Repos : blanc, texte noir, pas de flèche.
   Survol / focus clavier : s'inverse (noir, texte blanc, filet blanc) et une flèche glisse depuis la gauche. */
.btn {
  display: inline-flex; align-items: center; gap: 0;
  background: var(--white); color: #000; text-decoration: none;
  border: 1px solid var(--white);
  font-family: var(--font-label); font-weight: 500; font-size: 13px;
  letter-spacing: 0.1em; text-transform: uppercase;
  padding: 14px 22px; border-radius: var(--radius);
  transition: background .3s ease, color .3s ease;
}
.btn::after {
  content: "\2192";                       /* → */
  content: "\2192" / "";                  /* idem, sans texte alternatif pour les lecteurs d'écran */
  display: inline-block; overflow: hidden; white-space: nowrap;
  max-width: 0; margin-left: 0; opacity: 0; transform: translateX(-10px);
  transition: max-width .35s cubic-bezier(.22,.8,.3,1), margin-left .35s cubic-bezier(.22,.8,.3,1),
              opacity .25s ease, transform .35s cubic-bezier(.22,.8,.3,1);
}
.btn:hover, .btn:focus-visible { background: #000; color: var(--white); }
.btn:hover::after, .btn:focus-visible::after { max-width: 1.4em; margin-left: 10px; opacity: 1; transform: none; }
a:focus-visible, summary:focus-visible { outline: 2px solid var(--green); outline-offset: 3px; }
.btn:focus-visible { outline: 2px solid var(--white); outline-offset: 3px; }

/* Wordmark provisoire */
.wordmark { font-weight: 400; font-size: 20px; letter-spacing: -0.02em; color: var(--white); text-decoration: none; }
.wordmark i { font-style: normal; color: var(--green); }

/* Étiquette de contenu d'exemple (à retirer quand le contenu est réel) */
.sample {
  display: inline-block; font-family: var(--font-label); font-size: 10px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--warn); border: 1px dashed var(--warn);
  padding: 2px 8px; border-radius: 2px;
}

@media (max-width: 640px) {
  section { padding: 72px 0; }
  body { font-size: 17px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }