/* ======================   VARIABLES ET RÉINITIALISATION   ====================== */
:root {
    --primary-color: #1A417E;
    --secondary-color: #62CEE6;
    --text-color: #1A417E;
    --light-bg: #fff;
    --dark-bg: #1A417E;
    --border-color: #dddddd;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--light-bg);
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

img {
    max-width: 100%;
    height: auto;
}

main {
    padding-top: 120px;
}

section {
    padding: 2rem 0;
}

/* ======================
   EN-TÊTE ET NAVIGATION (version corrigée et isolée)
   ====================== */

.navbar {
    background-color: var(--dark-bg);
    padding: 1rem 0;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.header-banner {
    /* Full-bleed banner: s' tend d'un bord   l'autre de la fen tre */
    width: 100vw; /* largeur de la fen tre */
    margin-left: calc(50% - 50vw); /* recentre l'élément quand il est dans un flux centré */
    overflow: hidden; /* emp che tout débordement si on souhaite couper */
    background: transparent;
}
.header-banner img {
    display: block;
    width: 100%; /* remplit la largeur du parent (100vw) */
    height: auto;
    max-width: none; /* supprime la contrainte précédente */
    object-fit: contain; /* conserve les proportions */
}

.navbar-flex {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.navbar ul {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-right: 7rem;
}

.navbar a {
    color: #fff;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.navbar a:hover {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    text-decoration: none;
}

.navbar a.nav-link-active {
    position: relative;
}

.navbar a.nav-link-active::after {
    content: "";
    display: block;
    position: absolute;
    left: 25%;
    right: 25%;
    bottom: 0.2em;
    height: 3px;
    background: #dc3545;
    border-radius: 2px;
}

.lang-switch {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    margin-right: 2.5rem;
    display: flex;
    align-items: center;
    z-index: 2;
}

/* ===== MENU BURGER ===== */
.burger-menu {
    display: none;
    position: fixed;
    left: 16px;
    top: 16px;
    z-index: 2000;
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    border: none;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.10);
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.2s;
}

.burger-menu span,
.burger-menu span::before,
.burger-menu span::after {
    display: block;
    background: #fff;
    height: 4px;
    width: 28px;
    border-radius: 2px;
    position: absolute;
    transition: 0.3s;
    content: '';
}

.burger-menu span {
    position: relative;
}

.burger-menu span::before {
    content: '';
    position: absolute;
    top: -10px;
    left: 0;
    width: 28px;
}

.burger-menu span::after {
    content: '';
    position: absolute;
    top: 10px;
    left: 0;
    width: 28px;
}

.burger-menu.open span {
    background: transparent;
}

.burger-menu.open span::before {
    background: white !important;
    transform: translateY(10px) rotate(45deg);
    display: block !important;
}

.burger-menu.open span::after {
    background: white !important;
    transform: translateY(-10px) rotate(-45deg);
    display: block !important;
}

.mobile-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: var(--dark-bg);
    z-index: 2000;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 2rem;
    transition: opacity 0.2s;
    overflow-y: auto;
    padding-top: 100px;
    padding-bottom: 40px;
}

.mobile-nav.open {
    display: flex;
}

.mobile-nav ul {
    flex-direction: column;
    gap: 2rem;
    display: flex;
    align-items: center;
}

.mobile-nav a {
    color: #fff;
    font-size: 1.3rem;
    padding: 0.7rem 1.5rem;
    border-radius: 8px;
    transition: background 0.2s, color 0.2s;
}

.mobile-nav a.nav-link-active::after {
    left: 20%;
    right: 20%;
    bottom: 0.1em;
}

.mobile-nav .lang-switch {
    position: static;
    margin: 2rem 0 0 0;
    transform: none;
    justify-content: center;
}

@media (max-width: 900px) {
    .navbar-flex {
        flex-direction: row;
    }
    .lang-switch {
        margin-right: 1rem;
    }
    .navbar ul {
        margin-right: 0;
    }
}

@media (max-width: 768px) {
    .navbar-flex {
        display: none;
    }
    .burger-menu {
        display: flex;
        position: fixed;
        left: 16px;
        top: 16px;
    }
    .mobile-nav {
        display: none;
    }
    main {
        padding-top: 90px;
    }
    .lang-switch {
        position: static;
        margin: 1rem 0 0 0;
        transform: none;
        justify-content: center;
    }
}

/* ======================   SECTIONS COMMUNES   ====================== */
section {
    padding: 3rem 0;
    border-bottom: 1px solid var(--border-color);
}

section h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
    text-align: center;
}

.section-title {
    text-align: center;
    margin-bottom: 2rem;
}

/* ======================   SECTION "ABOUT" (HOME)   ====================== */
.about-content {
    margin-bottom: 2rem;
}

.about-content ul {
    margin: 1rem 0 1.5rem 2rem;
}

/* ======================   SECTION "PROGRAMME" (mis à jour)   ====================== */
.program-unavailable {
    font-size: 0.9rem;
    color: #666;
    margin: 1.5rem auto;
    max-width: 80%;
    text-align: center;
}

.program-unavailable-header {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0rem;
}

.program-unavailable i {
    margin-right: 0.5rem;
}

.program-unavailable-message {
    margin: 0;
    font-style: italic;
}

.keynote-speakers {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin: 2rem auto;
    flex-wrap: wrap;
    max-width: 800px;
}

.speaker {
    text-align: center;
    max-width: 200px;
}

.speaker-image {
    width: 150px;
    height: 150px;
    margin: 0 auto 1rem;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid #ddd; /* Cercle gris clair */
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.speaker-image:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.speaker-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

.speaker-name {
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 0.3rem;
}

.speaker-affiliation {
    font-size: 0.9rem;
    color: #666;
    font-style: italic;
}

/* Responsive : empile les images sur mobile */
@media (max-width: 768px) {
    .keynote-speakers {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
    }
}


.program-timeline .program-break {
    font-style: italic;
    color: black;
    margin: 1.5rem 0;
    padding: 0.5rem;
    background-color: rgba(52, 219, 130, 0.1);
    border-radius: 4px;
    text-align: center;
    display: block;
    width: calc(100% + 5rem);
    margin-left: -5rem;
    padding-left: 5rem;
    box-sizing: border-box;
}

.program-timeline .program-special {
    font-style: italic;
    font-weight: bold;
    color: black;
    margin: 1.5rem 0;
    padding: 0.5rem 1rem;
    background-color: rgba(52, 152, 219, 0.1);
    border-radius: 4px;
    display: block;
    width: calc(100% + 5rem);
    margin-left: -5rem;
    padding-left: 5rem;
    box-sizing: border-box;
}

.program-timeline .program-session {
    color: black;
    margin: 1.5rem 0;
    padding: 0.5rem 1rem;
    background-color: rgba(219, 216, 52, 0.1);
    border-radius: 4px;
    display: block;
    width: calc(100% + 5rem);
    margin-left: -5rem;
    padding-left: 5rem;
    box-sizing: border-box;
}

.program-timeline {
    list-style: none;
    padding: 0;
    margin: 0;
}

.program-timeline li {
    margin-bottom: 0.7rem;
    padding-left: 5rem;
    position: relative;
}

.program-timeline strong {
    color: var(--dark-color);
}

/* ======================   SECTION "APPEL À CONTRIBUTIONS"   ====================== */
.contribution-types {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.contribution-type {
    background-color: var(--light-bg);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
}

.contribution-type h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.contribution-type i {
    color: var(--secondary-color);
    margin-right: 0.5rem;
}

.important-dates {
    margin: 2rem 0;
    overflow-x: auto;
}

.important-dates table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.important-dates td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.important-dates td:first-child {
    font-weight: bold;
    width: 60%;
}

.submission-link {
    text-align: center;
    margin: 2rem 0;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: #fff;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: bold;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: var(--secondary-color);
    color: var(--primary-color);
}

.btn i {
    margin-right: 0.5rem;
}

.note {
    font-size: 0.9rem;
    color: #666;
    margin-top: 0.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.note i {
    margin-right: 0.5rem;
}

/* ======================   SECTION "INSCRIPTIONS"   ====================== */
.registration-info ul {
    margin: 1rem 0 1.5rem 2rem;
}

.registration-faq {
    margin-top: 2rem;
    background-color: var(--light-bg);
    padding: 1.5rem;
    border-radius: 8px;
}

.registration-link {
    text-align: center;
    margin: 2rem 0;
}

.faq-item {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.faq-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0;
}

.faq-item h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
}

.faq-item h4 i {
    margin-right: 0.5rem;
    color: var(--secondary-color);
}

/* ======================   SECTION "ORGANISATION"   ====================== */
.committee-members {
    margin: 2rem 0;
    padding: 1.5rem;
    background-color: var(--light-bg);
    border-radius: 8px;
}

/* ======================   SECTION "CONTACT"   ====================== */
.contact-info {
    max-width: 600px;
    margin: 0 auto;
}

.contact-email {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 1.5rem 0;
    padding: 1rem;
    background-color: var(--light-bg);
    border-radius: 8px;
}

.contact-email i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-right: 1rem;
}

.social-icons {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-top: 1rem;
}

.social-icon {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1rem;
    border-radius: 8px;
    width: 100px;
    text-align: center;
    background-color: #f0f0f0;
    color: #aaa;
}

.social-icon i {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.temporary-contact {
    background-color: #e7f3fe;
    padding: 1rem;
    border-radius: 4px;
    margin: 1.5rem 0;
}

.temporary-contact i {
    margin-right: 0.5rem;
    color: var(--primary-color);
}

/* ======================   SECTION "INFORMATIONS PRATIQUES"   ====================== */
.practical-info-content {
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.7;
}

.practical-info-content ul {
    margin: 1rem 0 1.5rem 2rem;
}

.practical-info-content li {
    margin-bottom: 0.7rem;
}

.map-container {
    text-align: center;
    width: 100%;
    max-width: 800px;
    margin: 1.5rem auto;
    border-radius: 8px;
    overflow: hidden;
}
.map-container iframe {
    border: none;
    border-radius: 8px;
}


/* ======================   PIED DE PAGE   ====================== */
.site-footer {
    background-color: var(--dark-bg);
    color: #fff;
    padding: 2rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: #fff;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.footer-section p,
.footer-section li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.footer-section a {
    color: #62CEE6;
}

.footer-section a:hover {
    color: #fff;
}

.footer-partner-logos {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 1rem auto;
}

.footer-partner-logos img {
    height: 115px;
    border-radius: 4%;
    transition: transform 0.3s ease;
}

.footer-partner-logos img:hover {
    transform: scale(1.4); /* Agrandit de 5% */
}

.logo-blanc {
    height: 50px !important;
    filter: brightness(0) invert(1);
}


/* Responsive : empile les images sur mobile */
@media (max-width: 768px) {
    .footer-partner-logos {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
    }
}

.footer-legal {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 1rem;
    text-align: center;
    font-size: 0.9rem;
    color: #ccc;
}

.footer-links {
    list-style: none;
    padding: 0;
    display: flex;
    gap: 2rem;
    justify-content: center;
}

.footer-links li {
    display: inline-block;
}

/* ======================   RESPONSIVE DESIGN   ====================== */
@media (max-width: 768px) {
    .header-banner {
        width: 100%;
    }
    .header-banner img {
        width: 100%;
        height: auto;
        min-height: 180px; /* Remplace max-height par min-height */
        object-fit: contain; /* Conserve les proportions */
        background: white; /* Fond blanc pour les espaces vides */
    }
    .contribution-types {
        grid-template-columns: 1fr;
    }
    .navbar ul {
        flex-direction: column;
        align-items: center;
    }
    .navbar-flex {
        flex-direction: column;
        align-items: stretch;
    }
    .lang-switch {
        position: static;
        margin: 1rem 0 0 0;
        transform: none;
        justify-content: center;
    }
}

/* ======================   SWITCH LANGUE   ====================== */
.btn-lang {
    background: var(--secondary-color);
    color: var(--primary-color);
    padding: 0.4em 1em;
    border-radius: 20px;
    font-weight: bold;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    text-decoration: none;
    box-shadow: 0 2px 6px rgba(0,0,0,0.08);
    transition: background 0.2s;
}

.btn-lang:hover {
    background: var(--primary-color);
    color: #fff;
}

html {
    scroll-behavior: smooth;
}

/* ======================   BOUTON REMONTER EN HAUT   ====================== */
#scroll-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    z-index: 1200;
    background: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    cursor: pointer;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}

#scroll-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}

#scroll-to-top:hover {
    background: var(--secondary-color);
    color: var(--primary-color);
}