/* Variables de thème pour un design prestigieux et coloré (Science & Eau) */
:root {
  --bg-color: #ffffff;
  --bg-secondary: #f4f7f9;
  --text-color: #1e293b;
  --muted-text: #64748b;
  --border-color: #e2e8f0;
  --border-dark: #cbd5e1;
  --primary-color: #0f172a; /* Bleu très profond, élégant */
  --accent-color: #0284c7; /* Bleu d'eau pour l'Institut (Miquel/Eau) */
  --accent-hover: #0369a1;
  --font-serif: "Georgia", "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --transition-smooth: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* Réinitialisation de base */
* {
  box-sizing: border-box;
}

/* --- Scrollbar Personnalisée --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-color);
  border-left: 1px solid var(--border-color);
}

::-webkit-scrollbar-thumb {
  background: var(--border-dark);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-color);
}

/* Firefox */
html {
  scrollbar-width: thin;
  scrollbar-color: var(--border-dark) var(--bg-color);
}

body {
  font-family: var(--font-sans);
  color: var(--text-color);
  background-color: var(--bg-color);
  line-height: 1.8;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Page d'accueil - Sans Défilement --- */
body.home-page {
  overflow: hidden;
  height: 100vh;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: normal;
  color: var(--primary-color);
  margin-top: 0;
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: var(--transition-smooth);
}

/* --- Navbar --- */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2rem 4rem;
  border-bottom: 1px solid var(--border-color);
  background-color: rgba(255, 255, 255, 0.95);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  letter-spacing: 0.15em;
  color: var(--primary-color);
}

.nav-links a {
  margin-left: 3rem;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted-text);
  position: relative;
  padding-bottom: 0.3rem;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: var(--accent-color);
  transition: var(--transition-smooth);
}

.nav-links a:hover::after, .nav-links a.active::after {
  width: 100%;
}

.nav-links a.active, .nav-links a:hover {
  color: var(--primary-color);
}

/* --- Conteneurs --- */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2rem;
}

.page-content {
  padding-top: 4rem;
}

/* --- Hero Section (Page d'accueil) --- */
.hero {
  height: calc(100vh - 90px);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 2rem;
  background: radial-gradient(circle at center, #ffffff 0%, #f0f6fc 100%);
}

.hero-content {
  max-width: 850px;
}

.hero h1 {
  font-size: 3.8rem;
  line-height: 1.15;
  margin-bottom: 1.5rem;
  letter-spacing: 0.01em;
}

.subtitle {
  font-size: 1.3rem;
  color: var(--accent-color);
  margin-bottom: 4rem;
  font-family: var(--font-serif);
  font-style: italic;
  letter-spacing: 0.03em;
}

/* --- Boutons (Visuel Amélioré et Coloré) --- */
.btn {
  display: inline-block;
  padding: 1.2rem 3.5rem;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  background-color: var(--primary-color);
  color: #ffffff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.2);
  transition: var(--transition-smooth);
}

.btn:hover {
  background-color: var(--accent-color);
  color: #ffffff;
  transform: translateY(-4px);
  box-shadow: 0 15px 35px rgba(2, 132, 199, 0.3);
}

.btn:active {
  transform: translateY(0);
  box-shadow: 0 5px 15px rgba(2, 132, 199, 0.2);
}

/* --- En-tête des autres pages --- */
.page-header {
  text-align: center;
  padding: 6rem 0 5rem;
  position: relative;
}

.page-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 2px;
  background-color: var(--accent-color);
}

.page-header h1 {
  font-size: 2.8rem;
  letter-spacing: 0.02em;
  margin-bottom: 1.2rem;
  line-height: 1.2;
}

.page-header p.location {
  color: var(--muted-text);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-family: var(--font-sans);
}

/* --- Sections --- */
section {
  padding: 8rem 0;
  position: relative;
}

section:not(:last-of-type)::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 200px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

.section-title {
  font-size: 2rem;
  margin-bottom: 5rem;
  text-align: center;
  letter-spacing: 0.03em;
  color: var(--primary-color);
}

.subsection-title {
  font-size: 1.4rem;
  margin-bottom: 3rem;
  margin-top: 5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
  display: block;
  letter-spacing: 0.02em;
  color: var(--primary-color);
}

/* --- L'Équipe --- */
.team-grid {
  display: flex;
  flex-direction: column;
  gap: 4.5rem;
}

.team-member {
  text-align: center;
  padding: 2.5rem;
  border-radius: 8px;
  background-color: var(--bg-color);
  border: 1px solid transparent;
  transition: var(--transition-smooth);
}

.team-member:hover {
  background-color: var(--bg-secondary);
  border-color: var(--border-color);
  transform: translateY(-5px);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.03);
}

.team-member h3 {
  font-size: 1.5rem;
  margin-bottom: 0.8rem;
  letter-spacing: 0.02em;
}

.team-member p {
  color: var(--muted-text);
  font-size: 1.05rem;
  margin: 0;
  max-width: 600px;
  margin: 0 auto;
}

/* --- Profil & Écrits --- */
.profile-header {
  margin-bottom: 4rem;
  background-color: var(--primary-color);
  color: #ffffff;
  padding: 3.5rem;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.15);
}

.profile-header h3 {
  font-size: 1.8rem;
  margin-bottom: 2rem;
  text-align: center;
  color: #ffffff;
}

.contact-info {
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: 1rem;
  text-align: center;
}

.contact-info li {
  margin-bottom: 1rem;
}

.contact-info strong {
  font-weight: 500;
  color: #94a3b8;
  margin-right: 0.5rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-size: 0.85rem;
}

.contact-info a {
  color: #ffffff;
  border-bottom: 1px solid rgba(255, 255, 255, 0.3);
  padding-bottom: 2px;
}

.contact-info a:hover {
  border-bottom-color: #ffffff;
  color: #e0e7ff;
}

/* --- Éléments de la liste (Travaux) --- */
.work-item {
  margin-bottom: 4rem;
  padding: 2rem;
  border-left: 3px solid var(--border-dark);
  background: var(--bg-color);
  border-radius: 0 8px 8px 0;
  transition: var(--transition-smooth);
}

.work-item:hover {
  border-left-color: var(--accent-color);
  background-color: var(--bg-secondary);
  transform: translateX(10px);
  box-shadow: 5px 5px 20px rgba(0, 0, 0, 0.02);
}

.work-item h4 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  line-height: 1.4;
}

.work-item p {
  margin: 0.5rem 0;
  font-size: 0.95rem;
}

.meta-date {
  color: var(--accent-color);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 1rem !important;
  font-weight: 600;
}

.source {
  color: var(--muted-text);
  font-size: 0.85rem;
  font-style: italic;
  margin-top: 1.5rem !important;
  border-top: 1px dashed var(--border-color);
  padding-top: 0.5rem;
}

.doi {
  font-family: "Courier New", Courier, monospace;
  font-size: 0.9rem;
  background: var(--bg-secondary);
  padding: 0.2rem 0.5rem;
  display: inline-block;
  border-radius: 4px;
}

.doi a {
  border-bottom: none;
  color: var(--primary-color);
}

.doi a:hover {
  color: var(--accent-hover);
}

.contributors {
  color: var(--muted-text);
}

/* --- Pied de page (Footer) --- */
footer {
  text-align: center;
  padding: 5rem 0;
  color: var(--muted-text);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-top: 1px solid var(--border-color);
}