/* ===== VARIABLES ===== */
:root {
    --navy-900: #0f2744;
    --navy-800: #1a3a5c;
    --navy-700: #234b73;
    --navy-600: #2d5f8a;
    --navy-500: #3d7ab3;
    --navy-400: #5a9fd4;
    --navy-300: #89bde5;
    --navy-200: #b8d9f2;
    --navy-100: #dcedf9;
    --navy-50: #f0f7fc;
    
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    
    --gold: #b8860b;
    
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Inter', -apple-system, sans-serif;
    
    --shadow-sm: 0 1px 3px rgba(15, 39, 68, 0.06);
    --shadow-md: 0 4px 16px rgba(15, 39, 68, 0.08);
    --shadow-lg: 0 12px 40px rgba(15, 39, 68, 0.12);
    
    --transition: 0.3s ease;
    --radius: 10px;
}

/* ===== RESET ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font-body);
    color: var(--gray-800);
    line-height: 1.65;
    font-size: 16px;
    background: var(--white);
}
a { color: var(--navy-600); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--navy-500); }

/* ===== HEADER ===== */
header {
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%; /* ← important */
}
.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
    flex-wrap: nowrap !important;
    justify-content: flex-start !important;   /* ← important */
    gap: 1.5rem !important;
}
.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-shrink: 0;    
}
.univ-logo {
    height: 40px;
    width: auto;
}
.logo {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--navy-800);
    text-decoration: none;
    white-space: nowrap;         /* ← AJOUT : le nom ne saute JAMAIS à la ligne */
    flex-shrink: 0;              /* ← AJOUT : le texte reste à sa taille */
}
nav ul {
    display: flex;
    gap: 2rem;
    list-style: none;
    align-items: center;
}
nav a {
    color: var(--gray-600);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
}
nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--navy-500);
    transition: var(--transition);
}
nav a:hover { color: var(--navy-700); }
nav a:hover::after { width: 100%; }
nav a.active { color: var(--navy-700); }
nav a.active::after { width: 100%; }
.nav-social {
    display: flex;
    gap: 0.75rem;
    margin-left: 1rem;
    padding-left: 1rem;
    border-left: 1px solid var(--gray-200);
}
.nav-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--gray-100);
    color: var(--gray-600);
}
.nav-social a:hover {
    background: var(--navy-600);
    color: var(--white);
}
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}
.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--navy-800);
    margin: 5px 0;
    transition: var(--transition);
}

/* ===== PAGE HEADER ===== */
.page-header {
    /* 1. Couleur de secours pour IE et les vieux navigateurs (Hexadécimal simple) */
    background-color: #f0f7fc; 
    
    /* 2. Dégradé avec couleurs en dur pour une compatibilité maximale */
    background: linear-gradient(160deg, #f0f7fc 0%, #ffffff 100%);
    
    /* 3. Ta version originale (pour les navigateurs modernes qui supportent les variables) */
    background: linear-gradient(160deg, var(--navy-50) 0%, var(--white) 100%);
    
    padding: 4rem 2rem;
    text-align: center;
}
.page-header-container {
    max-width: 1200px;
    margin: 0 auto;
}
.page-header h1 {
    font-family: var(--font-display);
    font-size: 2.2rem;
    font-weight: 600;
    color: var(--navy-900);
    margin-bottom: 0.75rem;
}
.page-header p {
    color: var(--navy-500);
    font-size: 1.05rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== SECTIONS ===== */
section { padding: 4rem 2rem; }
.section-container { max-width: 1200px; margin: 0 auto; }

/* ===== NEWS LIST (page actualités) ===== */
.news-section { background: var(--gray-50); }
.news-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}
.news-item {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 2rem;
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-100);
    transition: var(--transition);
}
.news-item:hover {
    box-shadow: var(--shadow-md);
    border-color: transparent;
}
.news-item-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}
.news-item-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.news-tag {
    position: absolute;
    top: 0.75rem;
    left: 0.75rem;
    padding: 0.3rem 0.65rem;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}
.news-tag.publication { background: var(--navy-600); color: var(--white); }
.news-tag.media { background: var(--gold); color: var(--white); }
.news-tag.tribune { background: var(--navy-500); color: var(--white); }
.news-tag.conference { background: var(--navy-800); color: var(--white); }
.news-item-content {
    padding: 1.5rem 1.5rem 1.5rem 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.news-date {
    font-size: 0.8rem;
    color: var(--gray-400);
    margin-bottom: 0.5rem;
}
.news-item-title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--navy-900);
    line-height: 1.4;
    margin-bottom: 0.75rem;
}
.news-item-title a { color: inherit; }
.news-item-title a:hover { color: var(--navy-600); }
.news-excerpt {
    color: var(--gray-600);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}
.news-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--navy-600);
    font-weight: 500;
    font-size: 0.9rem;
}
.news-link:hover { gap: 0.75rem; }
.empty-message {
    text-align: center;
    color: var(--gray-500);
    padding: 3rem;
}

/* ===== CV PAGE ===== */
.cv-section { background: var(--white); }
.cv-download {
    display: flex;
    justify-content: center;
    margin-bottom: 3rem;
}
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
    text-decoration: none;
}
.btn-primary {
    background: var(--navy-700);
    color: var(--white);
}
.btn-primary:hover {
    background: var(--navy-600);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.cv-block {
    margin-bottom: 3rem;
}
.cv-block h2 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--navy-900);
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--navy-200);
}
.cv-block h3 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--navy-800);
    margin: 1.5rem 0 0.75rem;
}
.cv-block ul {
    list-style: none;
    padding-left: 0;
}
.cv-block li {
    padding: 0.5rem 0 0.5rem 1.5rem;
    position: relative;
    color: var(--gray-700);
}
.cv-block li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--navy-500);
    font-weight: bold;
}
.cv-block .nested-list {
    margin-left: 1rem;
    margin-top: 0.5rem;
}
.cv-block .nested-list li {
    font-size: 0.9rem;
    color: var(--gray-600);
}
.cv-date {
    display: inline-block;
    background: var(--navy-100);
    color: var(--navy-700);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

/* ===== RESEARCH PAGE ===== */
.research-section { background: var(--white); }
.research-block {
    margin-bottom: 3rem;
}
.research-block h2 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--navy-900);
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--navy-200);
}
.publication-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}
.pub-item {
    padding: 1.25rem;
    background: var(--gray-50);
    border-radius: var(--radius);
    border-left: 4px solid var(--navy-500);
    transition: var(--transition);
}
.pub-item:hover {
    background: var(--navy-50);
    border-left-color: var(--navy-600);
}
.pub-item h3 {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 500;
    color: var(--navy-900);
    margin-bottom: 0.35rem;
    line-height: 1.4;
}
.pub-item h3 a { color: inherit; }
.pub-item h3 a:hover { color: var(--navy-600); }
.pub-meta {
    font-size: 0.9rem;
    color: var(--gray-500);
}
.pub-journal {
    font-style: italic;
    color: var(--navy-600);
}
.pub-year {
    display: inline-block;
    background: var(--navy-700);
    color: var(--white);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-right: 0.5rem;
}

/* ===== ENSEIGNEMENTS PAGE ===== */
.teaching-section { background: var(--white); }
.teaching-block {
    margin-bottom: 3rem;
}
.teaching-block h2 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--navy-900);
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--navy-200);
}
.teaching-block h3 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--navy-800);
    margin: 1.5rem 0 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}
.teaching-block h3 img {
    height: 30px;
    width: auto;
}
.teaching-list {
    list-style: none;
    padding-left: 0;
}
.teaching-list li {
    padding: 0.5rem 0 0.5rem 1.5rem;
    position: relative;
    color: var(--gray-700);
}
.teaching-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--navy-500);
}
.teaching-institution {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--gray-50);
    border-radius: var(--radius);
}
.teaching-institution-logo {
    width: 80px;
    height: 80px;
    object-fit: contain;
    flex-shrink: 0;
}
.teaching-institution-content h3 {
    margin-top: 0;
}

/* ===== EXPERTISE PAGE ===== */
.expertise-section { 
    background: var(--gray-50);
    min-height: 400px;
}
.expertise-placeholder {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--gray-500);
}

/* ===== FOOTER ===== */
footer {
    background: var(--navy-900);
    color: var(--white);
    padding: 3rem 2rem;
}
.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 3rem;
}
.footer-col h4 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}
.footer-col p, .footer-col a {
    color: var(--navy-300);
    font-size: 0.9rem;
    line-height: 1.8;
}
.footer-col a:hover { color: var(--white); }
.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}
.footer-social {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}
.footer-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--navy-700);
    border-radius: 50%;
    color: var(--white);
    transition: var(--transition);
}
.footer-social a:hover {
    background: var(--navy-600);
    transform: translateY(-3px);
}
.footer-bottom {
    max-width: 1200px;
    margin: 2rem auto 0;
    padding-top: 2rem;
    border-top: 1px solid var(--navy-700);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.footer-copy {
    color: var(--navy-400);
    font-size: 0.85rem;
}

/* ===== MOBILE NAV ===== */
.mobile-nav {
    display: none;
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    padding: 1rem 2rem;
}
.mobile-nav.active { display: block; }
.mobile-nav a {
    display: block;
    padding: 0.75rem 0;
    color: var(--gray-700);
    border-bottom: 1px solid var(--gray-100);
    font-weight: 500;
}
.mobile-nav a:last-child { border-bottom: none; }

/* ===== PAGE CONTENT (pages intérieures) ===== */
.page-content {
    padding: 3rem 2rem 4rem;
    background: var(--white);
}
.page-content .container {
    max-width: 1200px;
    margin: 0 auto;
}
.page-title {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--navy-900);
    margin-bottom: 0.5rem;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .footer-container { grid-template-columns: 1fr; gap: 2rem; text-align: center; }
    .footer-social { justify-content: center; }
    .footer-bottom { flex-direction: column; gap: 1rem; }
    .news-item { grid-template-columns: 1fr; }
    .news-item-image { height: 200px; }
    .news-item-content { padding: 1.5rem; }
}

@media (max-width: 768px) {
    nav ul { display: none; }
    .nav-toggle { display: block; }
    section { padding: 3rem 1.5rem; }
    .page-header { padding: 2rem 1.5rem; }
    .page-header h1 { font-size: 2rem; }
    .teaching-institution { flex-direction: column; align-items: center; text-align: center; }
}