/* === STYLE GLOBAL === */
html, body {
  margin: 0; padding: 0; height: 100%;
  background: black; overflow: hidden;
  font-family: 'Segoe UI', sans-serif; color: white;
}

/* === HEADER === */
header {
  position: absolute; top: 0; width: 100%;
  background-color: rgba(17, 17, 17, 0.8);
  border-bottom: 2px solid #34febb;
  padding: 15px 0; z-index: 1000;
  backdrop-filter: blur(5px);
  box-sizing: border-box;
}
nav { display: flex; justify-content: center; gap: 30px; font-size: 1.1em; flex-wrap: wrap; padding: 0 10px; }
nav a { color: white; text-decoration: none; transition: 0.3s; }
nav a:hover { color: #34febb; text-decoration: underline; }
.nav-separator { color: #555; }
.nav-en { font-weight: bold; color: #34febb; }

/* === CANVAS MATRIX === */
canvas { position: absolute; top: 0; left: 0; z-index: 0; }

/* === CONTENU CENTRAL === */
.content {
  position: relative; z-index: 1; height: 100vh;
  display: flex; flex-direction: column; justify-content: center; align-items: center;
  padding: 0 15px; box-sizing: border-box;
}

/* === BOÎTE CENTRALE === */
.overlay-box {
  background-color: rgba(0, 0, 0, 0.3);
  padding: 40px 60px; border-radius: 20px;
  box-shadow: 0 0 25px rgba(52, 254, 187, 0.25);
  text-align: center;
  animation: zoomIn 1s ease-out, pulse 3s infinite ease-in-out;
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  width: 100%; max-width: 600px; box-sizing: border-box;
}

/* === ANIMATIONS === */
@keyframes zoomIn { 0% { transform: scale(0.9); opacity: 0; } 100% { transform: scale(1); opacity: 1; } }
@keyframes pulse {
  0%, 100% { transform: scale(1); box-shadow: 0 0 25px rgba(52, 254, 187, 0.25); }
  50% { transform: scale(1.03); box-shadow: 0 0 35px rgba(52, 254, 187, 0.5); }
}

/* === TYPOGRAPHIE === */
.matrix-text { font-size: 2.8em; font-weight: bold; opacity: 0; transition: opacity 1s ease-in-out; }
.subtitle { font-size: 1.2em; margin-top: 15px; opacity: 0; transition: opacity 1s ease-in-out; }

/* === BOUTON === */
.btn {
  margin-top: 30px; background-color: #34febb; color: black;
  padding: 12px 30px; border: none; border-radius: 8px;
  cursor: pointer; font-weight: bold; font-size: 1em;
  display: none; transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.btn:hover { transform: scale(1.05); box-shadow: 0 0 12px rgba(52, 254, 187, 0.6); }

/* === UTILITAIRES POUR JS (Sécurité CSP A+) === */
.opacity-100 { opacity: 1 !important; }
.show-inline-block { display: inline-block !important; }

/* === RESPONSIVE TABLETTE === */
@media (max-width: 768px) {
  nav { gap: 15px; font-size: 0.95em; }
  .overlay-box { padding: 30px 30px; }
  .matrix-text { font-size: 2em; }
  .subtitle { font-size: 1em; }
  .btn { padding: 12px 25px; font-size: 0.95em; }
}

/* === RESPONSIVE MOBILE === */
@media (max-width: 480px) {
  nav { gap: 10px; font-size: 0.82em; }
  .overlay-box { padding: 25px 20px; border-radius: 12px; }
  .matrix-text { font-size: 1.4em; }
  .subtitle { font-size: 0.9em; margin-top: 10px; }
  .btn { width: 100%; padding: 12px; font-size: 0.9em; margin-top: 20px; }
}