.nav-buttons {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    margin-bottom: 20px;
}

.nav-btn {
    background-color: #003366;   /* bleu foncé par défaut */
    color: white;                /* texte blanc */
    padding: 8px 16px;
    border-radius: 6px;
    text-decoration: none;
    font-family: 'Roboto', sans-serif;
    font-weight: 600;
    border: 2px solid #003366;  /* contour bleu */
    transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-btn:hover {
    background-color: white;    /* fond blanc au survol */
    color: #003366;             /* texte bleu */
}

/* Centrage du bouton Sommaire */
.center-btn {
    margin: 0 auto;
}

@media (max-width: 600px) {
  .container {
    margin: 1rem;
    padding: 1.3rem;
  }

  h1 {
    font-size: 1.6rem;
  }

  .nav-buttons a {
    font-size: 0.9rem;
    padding: 0.5rem 0.8rem;
  }
}


/* ------------------------------ */
/*   BANDE SUPÉRIEURE / HEADER    */
/* ------------------------------ */

.header-banner {
  width: 100%;
  background-color: #ffffff;
  padding: 1.2rem 0;
  text-align: center;
  font-family: 'Montserrat', sans-serif;
  font-weight: 600;
  font-size: 1.5rem;
  color: #001933;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);

  display: flex;                /* → mise en ligne */
  align-items: center;          /* → centrage vertical */
  justify-content: center;      /* → centre horizontal */
  gap: 1rem;                    /* → espace entre image et texte */
}

.banner-logo {
  height: 50px;                 /* → taille de l’image */
  width: auto;
  object-fit: contain;
}

/* ------------------------------ */
/*          FOND GLOBAL           */
/* ------------------------------ */

body {
  background-color: #001933; /* bleu foncé */
  margin: 0;
  padding: 0;
  color: #1a1a1a;
  font-family: 'Rubik', sans-serif;
  line-height: 1.7;
}

.image-centree {
  width: 100%;
  max-width: 600px;
  height: auto;
  display: block;
  margin: 0 auto; /* pour centrer */
}

.image-centree_petite {
  max-width: 150px;
  height: auto;
  display: block;
  margin: 0 auto; /* pour centrer */
}

.video-container {
  position: relative;
  width: 100%;
  max-width: 560px; /* largeur maximale de la vidéo */
  margin: 0 auto;   /* centre horizontalement */
  padding-bottom: 56.25%; /* ratio 16:9 */
  height: 0;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
@media (max-width: 600px) {
  .video-container {
    width: 100%;       /* prend toute la largeur du conteneur sur mobile */
    height: auto;
  }
}

/* ------------------------------ */
/*       CONTENEUR PRINCIPAL      */
/* ------------------------------ */

.container {
  max-width: 800px;
  margin: 2rem auto;
  padding: 2rem;
  background-color: #f5faff; /* bleu clair très doux */
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
  position: relative;
}

/* ------------------------------ */
/*             TITRES             */
/* ------------------------------ */

h1, h2, h3 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 600;
  margin-top: 2rem;
  margin-bottom: 1rem;
}

h1 {
  text-align: center;
  font-size: 2rem;
  color: #003f5c;
  margin-top: 0;
}

h2 {
  color: #003f5c;
  border-bottom: 2px solid #003f5c;
  padding-bottom: 4px;
}

h3 {
  background-color: #003f5c; /* bleu foncé */
  color: white;              /* texte blanc */
  padding: 0.5rem 1rem;      /* un peu d’espace autour du texte */
  border-radius: 4px;        /* coins arrondis */
  margin-top: 2rem;
  margin-bottom: 1rem;
}

/* ------------------------------ */
/*     PARAGRAPHES & LISTES       */
/* ------------------------------ */

p, li {
  font-size: 1.1rem;
  color: #222;
  margin-bottom: 1.2rem;
}

/* ------------------------------ */
/*              LIENS             */
/* ------------------------------ */

a {
  color: #003f5c;
  font-weight: 500;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ------------------------------ */
/*             ASTUCES            */
/* ------------------------------ */

.astuce {
  background-color: #e0f7ff;
  border-left: 4px solid #004d66;
  padding: 1rem;
  margin: 1.5rem 0;
  border-radius: 6px;

}

/* ------------------------------ */
/*               CODE             */
/* ------------------------------ */

code {
  background-color: #f4f4f4;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: monospace;
}

pre {
  background-color: #f4f4f4;
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  font-family: monospace;
}

#backToTop {
  position: absolute;  /* au lieu de fixed */
  bottom: 30px;
  right: 30px;
  padding: 10px 15px;
  font-size: 16px;
  background-color: #003366;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
  transition: background-color 0.2s;
  display: none;       /* caché par défaut, on l’affichera au scroll */
}

#backToTop:hover {
  background-color: #0055aa;
}


/* ------------------------------ */
/*              FOOTER            */
/* ------------------------------ */

footer {
  text-align: center;
  font-size: 0.9rem;
  color: #d0d7e0;
  margin-top: 3rem;
  padding: 2rem 0 1rem 0;
}