/* ═══════════════════════════════════════════════════
   H2-HYDROGENE.COM — Feuille de style partagée v2
   ═══════════════════════════════════════════════════ */
@import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;600;900&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;1,9..40,300&display=swap');

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

:root {
  --bg:        #050d1a;
  --bg2:       #071525;
  --bg3:       #0a1e30;
  --green:     #00ffb3;
  --green2:    #00c98a;
  --green-dim: rgba(0,255,179,0.08);
  --green-glow:rgba(0,255,179,0.18);
  --blue:      #1a9fff;
  --blue-dim:  #1a4a6e;
  --text:      #e8f4f8;
  --text-muted:#7aa8c0;
  --text-faint:#3a6a84;
  --border:    rgba(0,255,179,0.12);
  --border2:   rgba(0,255,179,0.06);
  --card-bg:   rgba(10,30,48,0.85);
  --radius:    4px;
  --nav-h:     72px;
}

html { scroll-behavior: smooth; }
body {
  background: var(--bg); color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-weight: 300; line-height: 1.75; overflow-x: hidden;
}
body::before {
  content:''; position:fixed; inset:0;
  background-image:url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");
  pointer-events:none; z-index:0; opacity:.4;
}

/* ── NAVBAR ── */
.site-nav {
  position:fixed; top:0; left:0; right:0; z-index:200;
  display:flex; align-items:center; justify-content:space-between;
  padding:0 3rem; height:var(--nav-h);
  background:rgba(5,13,26,0.92); backdrop-filter:blur(24px);
  border-bottom:1px solid var(--border);
}
.nav-logo {
  display:flex; align-items:center; gap:.7rem;
  font-family:'Orbitron',monospace; font-size:1.2rem; font-weight:900;
  letter-spacing:.1em; color:var(--text); text-decoration:none;
}
.nav-logo span { color:var(--green); }
.logo-atom { width:32px; height:32px; animation:spin-slow 12s linear infinite; flex-shrink:0; }
.logo-atom svg { width:100%; height:100%; }
.nav-links { display:flex; gap:2rem; list-style:none; }
.nav-links a {
  color:var(--text-muted); text-decoration:none;
  font-size:.82rem; font-weight:400;
  letter-spacing:.08em; text-transform:uppercase; transition:color .2s;
}
.nav-links a:hover, .nav-links a.active { color:var(--green); }
.nav-hamburger {
  display:none; flex-direction:column; gap:5px;
  cursor:pointer; padding:.5rem; background:none; border:none;
}
.nav-hamburger span {
  display:block; width:24px; height:2px;
  background:var(--green); border-radius:2px; transition:transform .3s,opacity .3s;
}

/* ── FOOTER ── */
.site-footer {
  padding:3rem; background:var(--bg);
  border-top:1px solid var(--border); position:relative; z-index:1;
}
.footer-inner {
  max-width:1200px; margin:0 auto;
  display:grid; grid-template-columns:2fr 1fr 1fr 1fr; gap:3rem;
}
.footer-brand p { font-size:.85rem; color:var(--text-muted); line-height:1.8; margin-top:.8rem; max-width:280px; }
.footer-col h4 {
  font-family:'Orbitron',monospace; font-size:.68rem; font-weight:700;
  letter-spacing:.2em; text-transform:uppercase; color:var(--green); margin-bottom:1rem;
}
.footer-col ul { list-style:none; }
.footer-col ul li { margin-bottom:.5rem; }
.footer-col ul a { font-size:.82rem; color:var(--text-muted); text-decoration:none; transition:color .2s; }
.footer-col ul a:hover { color:var(--text); }
.footer-bottom {
  max-width:1200px; margin:2rem auto 0; padding-top:1.5rem;
  border-top:1px solid var(--border2);
  display:flex; justify-content:space-between; align-items:center;
  font-size:.72rem; color:var(--text-faint);
}
.footer-h2-tag { font-family:'Orbitron',monospace; font-size:.62rem; letter-spacing:.22em; color:var(--green); }

/* ── BREADCRUMB ── */
.breadcrumb {
  display:flex; align-items:center; gap:.5rem;
  font-size:.75rem; color:var(--text-muted);
  font-family:'Orbitron',monospace; letter-spacing:.06em; flex-wrap:wrap;
}
.breadcrumb a { color:var(--text-muted); text-decoration:none; transition:color .2s; }
.breadcrumb a:hover { color:var(--green); }
.breadcrumb-sep { color:var(--text-faint); font-size:.65rem; }
.breadcrumb-current { color:var(--green); }

/* ── SECTION TAG ── */
.section-tag {
  display:inline-block; font-family:'Orbitron',monospace;
  font-size:.62rem; font-weight:600; letter-spacing:.3em; text-transform:uppercase;
  color:var(--green); margin-bottom:.8rem;
}

/* ── BUTTONS ── */
.btn-primary {
  display:inline-flex; align-items:center; gap:.5rem;
  padding:.8rem 1.8rem; background:var(--green); color:var(--bg);
  border:none; border-radius:var(--radius);
  font-family:'Orbitron',monospace; font-size:.72rem; font-weight:700;
  letter-spacing:.12em; text-transform:uppercase;
  cursor:pointer; text-decoration:none;
  transition:transform .2s,box-shadow .2s;
  box-shadow:0 0 24px rgba(0,255,179,.22);
}
.btn-primary:hover { transform:translateY(-2px); box-shadow:0 0 40px rgba(0,255,179,.38); }
.btn-ghost {
  display:inline-flex; align-items:center; gap:.5rem;
  padding:.8rem 1.8rem; background:transparent; color:var(--text);
  border:1px solid var(--border); border-radius:var(--radius);
  font-family:'Orbitron',monospace; font-size:.72rem; font-weight:600;
  letter-spacing:.12em; text-transform:uppercase;
  cursor:pointer; text-decoration:none; transition:border-color .2s,color .2s;
}
.btn-ghost:hover { border-color:var(--green); color:var(--green); }

/* ── CARD ── */
.card {
  background:var(--card-bg); border:1px solid var(--border);
  border-radius:var(--radius); overflow:hidden;
  transition:transform .3s,border-color .3s,box-shadow .3s;
}
.card:hover {
  transform:translateY(-4px); border-color:rgba(0,255,179,.28);
  box-shadow:0 16px 48px rgba(0,0,0,.4),0 0 30px rgba(0,255,179,.05);
}

/* ── AD SLOTS — Revive Adserver ── */
.ad-slot {
  display:flex; align-items:center; justify-content:center;
  overflow:hidden; flex-shrink:0;
}
/* Skyscraper 160×600 */
.ad-160x600 { width:160px; min-height:600px; }
/* Carré 250×250 */
.ad-250x250 { width:250px; min-height:250px; }
/* Rectangle 330×280 */
.ad-330x280 { width:330px; max-width:100%; min-height:280px; }
/* Leaderboard 728×90 */
.ad-728x90  { width:728px; max-width:100%; min-height:90px; }

/* ── FADE-UP ── */
.fade-up { opacity:0; transform:translateY(28px); transition:opacity .6s ease,transform .6s ease; }
.fade-up.visible { opacity:1; transform:none; }

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width:5px; }
::-webkit-scrollbar-track { background:var(--bg); }
::-webkit-scrollbar-thumb { background:var(--blue-dim); border-radius:3px; }
::-webkit-scrollbar-thumb:hover { background:var(--green); }

/* ── KEYFRAMES ── */
@keyframes spin-slow  { to { transform:rotate(360deg); } }
@keyframes pulse-glow {
  0%,100%{ opacity:1; transform:translate(-50%,-50%) scale(1); }
  50%    { opacity:.5; transform:translate(-50%,-50%) scale(1.08); }
}

/* ── RESPONSIVE ── */
@media(max-width:1024px){
  .site-nav { padding:0 1.5rem; }
  .footer-inner { grid-template-columns:1fr 1fr; }
  .ad-728x90 { width:100%; }
}
@media(max-width:768px){
  .nav-links { display:none; }
  .nav-links.open {
    display:flex; flex-direction:column; gap:1.2rem;
    position:fixed; top:var(--nav-h); left:0; right:0;
    background:rgba(5,13,26,.97); backdrop-filter:blur(20px);
    padding:2rem 1.5rem; border-bottom:1px solid var(--border);
    z-index:199;
  }
  .nav-hamburger { display:flex; }
  .footer-inner { grid-template-columns:1fr; gap:2rem; }
  .footer-bottom { flex-direction:column; gap:.8rem; text-align:center; }
  .ad-330x280 { width:100%; }
  .ad-160x600 { display:none; }
}


/* ── RESPONSIVE AD SYSTEM ──
   Desktop : .ad-728x90 visible, .ad-mobile-rect hidden
   Mobile  : .ad-728x90 hidden,  .ad-mobile-rect visible
   ─────────────────────────────────────────────── */
.ad-mobile-rect { display:none; }

@media(max-width:768px) {
  /* Hide leaderboard, show rectangle replacement */
  .ad-leaderboard-wrap .ad-728x90 { display:none !important; }
  .ad-leaderboard-wrap .ad-mobile-rect { display:flex; width:100%; max-width:330px; min-height:280px; margin:0 auto; }
  /* Hero images: reduce height on mobile */
  .article-hero { height:200px !important; }
  .cat-featured-img { height:180px !important; }
  .art-card-img { height:140px; }
  .cat-card-img { height:160px; }
}

@media(max-width:480px) {
  .article-hero { height:170px !important; }
}