body {
    background-color : #121B29;
    width: 100%;
    margin: auto;
    color: white;
    font-family: 'roboto';
}

header {
    background-color: #EEEBFF;
    color: #121B29;
    padding: -20px;
}

header .logo-nird {
    height: 60px;
    margin-right: 15px;
}

header nav {
    display: flex;
    align-items: center;
    /* justify-content: space-between */
}

header nav ul {
    display: flex;
    gap: 50px;
    align-items: center;
    list-style-type: none;
}

header nav ul li a {
    font-size: 18px;
    font-weight: bold;
    text-decoration: none;
    color: inherit; 
}
/* style nav-item */
.nav-item {
    display: inline-block;
    padding: 8px 12px;
    border-radius: 6px;
    color: inherit;
    text-decoration: none;
    font-weight: 700;
    cursor: pointer;
    user-select: none;
    transition: transform 180ms cubic-bezier(.2,.8,.2,1), box-shadow 180ms cubic-bezier(.2,.8,.2,1);
    box-shadow: 0 6px 0 rgba(0,0,0,0.35), inset 0 -2px 0 rgba(0,0,0,0.12);
    background-image: linear-gradient(rgba(255,255,255,0.02), rgba(0,0,0,0.04));
}

/* Effet natif tactile / :active */
.nav-item:active {
    transform: translateY(6px);
    box-shadow: 0 2px 0 rgba(0,0,0,0.35), inset 0 6px 12px rgba(0,0,0,0.30);
}

/* Classe appliquée par JS pour animation contrôlée */
.nav-item.sunk {
    transform: translateY(6px);
    box-shadow: 0 2px 0 rgba(0,0,0,0.35), inset 0 6px 12px rgba(0,0,0,0.30);
}

/* Focus clavier visible */
.nav-item:focus {
    outline: 3px solid rgba(255, 212, 64, 0.25);
    outline-offset: 3px;
}

/* Respecter prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
    .nav-item,
    .nav-item:active,
    .nav-item.sunk {
    transition: none !important;
    transform: none !important;
    box-shadow: 0 6px 0 rgba(0,0,0,0.35) !important;
    }
}


/* FIN HEADER -----------------------------------------------------------------------------------------------------------------------------------------------*/

.titre, .partiegauche, .partiedroite {
    display: block;
    position: absolute;
    width: 400px;
}

/* Titre et texte gauche */
.titre {
    left: 240px;
    top: 190px;
}

.partiegauche {
    left: 240px;
    top: 240px;
    font-size: 18px;
}

/* Texte droite */
.partiedroite {
    right: 240px;
    top: 200px;
    font-size: 18px;
}

/* Image centrale */
.pc {
    display: block;
    margin: auto;
}

/* .pc {
    display: block;
    margin: auto;
    position: sticky;
    top: 100px;
    z-index: -1;
    max-width: 500px;
} */

/* 2e partie ----------------------------------------*/

.e2partie p {
    position: absolute;
    width: 900px;
    font-size: 18px;
    left: 240px;
    top: 1100px;
}

.e2partie .pc {
    display: block;
    margin: auto;
    position: absolute;
    top: 1100px;
    right: 240px;
    max-width: 500px;
}


/* troisième partie _______________________________________________*/


.e3partie p {
    font-size: 18px;
    position: absolute;
    width : 900px;
    top : 1600px;
    margin : auto;
    left : 240px;
}


/* Formulaire simulation */
form {
    margin: 50px auto;
    width: 400px;
}

form div {
    margin-bottom: 15px;
}

form div label {
    color: #AA8C50;
    font-weight: bold;
}

form div input[type="text"],
form div input[type="number"],
form div input[type="range"],
form div select {
    width: 100%;
    height: 34px;
    padding: 8px;
    box-sizing: border-box;
    border: 3px solid #AA8C50;
    border-radius: 17px;
}

form div input[type="radio"] {
    width: auto;
    height: auto;
    margin-right: 8px;
}

.periode label {
    display: inline-flex;
    align-items: center;
    margin-right: 15px;
    color: white;
}

footer {
  text-align: center;
  padding: 16px;
  background-color: #1e2a3a;
  margin-top: 32px;
}