/* ========================================
   VARIABLES CSS
   ======================================== */
:root {
    /* Couleurs principales - Basées sur le logo ICASB officiel */
    --primary-blue: #00447C;
    --primary-gold: #F7A81B;
    --white: #ffffff;
    --light-gray: #f8f9fa;
    --medium-gray: #e9ecef;
    --dark-gray: #6c757d;
    --text-dark: #2d3748;
    --text-light: #4a5568;
    
    /* Ombres */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
    
    /* Espacements */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;
    
    /* Bordures */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    /* Transitions */
    --transition: all 0.3s ease;
}

/* ========================================
   RESET ET BASE
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--white);
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

ul {
    list-style: none;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* ========================================
   CONTAINER
   ======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ========================================
   HEADER
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: var(--transition);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo {
    height: 60px;
    width: auto;
    object-fit: contain;
}

/* Navigation desktop */
.nav-desktop {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-dark);
    position: relative;
    padding: var(--spacing-xs) 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-gold);
    transition: var(--transition);
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--primary-blue);
}

/* Menu toggle (mobile) */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-xs);
}

.menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background: var(--primary-blue);
    border-radius: 2px;
    transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Navigation mobile */
.nav-mobile {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-md);
    flex-direction: column;
    gap: var(--spacing-sm);
    z-index: 999;
    transform: translateY(-100%);
    opacity: 0;
    transition: var(--transition);
}

.nav-mobile.active {
    transform: translateY(0);
    opacity: 1;
}

.nav-mobile .nav-link {
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
}

.nav-mobile .nav-link:hover {
    background: var(--light-gray);
}

/* ========================================
   HERO SECTION
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-blue) 0%, #0a3557 100%);
    margin-top: 70px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(210, 154, 45, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(210, 154, 45, 0.15) 0%, transparent 50%);
    pointer-events: none;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><rect width="1" height="1" fill="rgba(255,255,255,0.03)"/></svg>');
    opacity: 0.5;
}

.hero-content {
    position: relative;
    text-align: center;
    color: var(--white);
    max-width: 900px;
    padding: var(--spacing-xl) 0;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    font-weight: 300;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 1rem;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: var(--primary-gold);
    color: var(--white);
}

.btn-primary:hover {
    background: #e69815;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-blue);
}

.btn-outline {
    background: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-outline:hover {
    background: var(--primary-blue);
    color: var(--white);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.1rem;
}

/* ========================================
   SECTIONS
   ======================================== */
.section {
    padding: var(--spacing-xxl) 0;
}

.section-alt {
    background: var(--light-gray);
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    color: var(--primary-blue);
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.section-intro {
    max-width: 800px;
    margin: 0 auto var(--spacing-xl);
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    line-height: 1.8;
}

/* ========================================
   CARDS GRID
   ======================================== */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.card {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
}

.card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ========================================
   RECHERCHE - RESEARCH AREAS
   ======================================== */
.research-areas {
    display: grid;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.research-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 6px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-blue), var(--primary-gold));
}

.research-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-gold);
    opacity: 0.2;
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-lg);
}

.research-card h3 {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-md);
}

.research-card > p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.research-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.research-list li {
    background: var(--light-gray);
    color: var(--primary-blue);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 500;
}

/* Publications */
.publications-section {
    margin-top: var(--spacing-xxl);
    padding-top: var(--spacing-xxl);
    border-top: 2px solid var(--medium-gray);
}

.publications-section h3 {
    font-size: 1.8rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-lg);
}

.publications-grid {
    display: grid;
    gap: var(--spacing-md);
}

.publication-item {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: var(--spacing-md);
    align-items: center;
    transition: var(--transition);
}

.publication-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(8px);
}

.publication-year {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-gold);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--light-gray);
    border-radius: var(--radius-md);
}

.publication-title {
    font-weight: 500;
    color: var(--text-dark);
}

.publication-type {
    font-size: 0.85rem;
    color: var(--text-light);
    font-style: italic;
}

/* ========================================
   COLLABORATION
   ======================================== */
.collaboration-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.collab-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    transition: var(--transition);
}

.collab-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.collab-card h3 {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-md);
}

.collab-card > p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.collab-list {
    margin-bottom: var(--spacing-lg);
    flex-grow: 1;
}

.collab-list li {
    padding: var(--spacing-xs) 0 var(--spacing-xs) var(--spacing-lg);
    position: relative;
    color: var(--text-light);
}

.collab-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-gold);
    font-weight: 700;
}

/* ========================================
   ÉVÉNEMENTS
   ======================================== */
.events-container {
    display: grid;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.event-card {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: var(--spacing-lg);
    transition: var(--transition);
}

.event-card:hover {
    box-shadow: var(--shadow-lg);
}

.event-date {
    background: var(--primary-blue);
    color: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.event-day {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1;
}

.event-month {
    font-size: 0.9rem;
    font-weight: 600;
    margin-top: 4px;
}

.event-year {
    font-size: 0.8rem;
    opacity: 0.8;
    margin-top: 2px;
}

.event-content h3 {
    font-size: 1.3rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
}

.event-content p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.event-badge {
    display: inline-block;
    background: var(--primary-gold);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.event-badge-past {
    background: var(--dark-gray);
}

.event-meta {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    font-size: 0.9rem;
    color: var(--text-light);
}

.event-past {
    opacity: 0.7;
}

/* Newsletter */
.newsletter-section {
    margin-top: var(--spacing-xxl);
}

.newsletter-card {
    background: linear-gradient(135deg, var(--primary-blue), #0a3557);
    color: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    text-align: center;
}

.newsletter-card h3 {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-sm);
}

.newsletter-card p {
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.newsletter-form {
    display: flex;
    gap: var(--spacing-sm);
    max-width: 500px;
    margin: 0 auto;
    flex-wrap: wrap;
    justify-content: center;
}

.newsletter-form input {
    flex: 1;
    min-width: 250px;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    font-size: 1rem;
}

.newsletter-form input::placeholder {
    color: rgba(255, 255, 255, 0.7);
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--primary-gold);
    background: rgba(255, 255, 255, 0.15);
}

/* ========================================
   CONTACT
   ======================================== */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.contact-form-section {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.contact-form .form-group {
    margin-bottom: var(--spacing-lg);
}

.contact-form label {
    display: block;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: var(--spacing-xs);
}

.contact-form input,
.contact-form select,
.contact-form textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--medium-gray);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-blue);
}

.contact-form textarea {
    resize: vertical;
    min-height: 120px;
}

.error-message {
    display: block;
    color: #e74c3c;
    font-size: 0.85rem;
    margin-top: var(--spacing-xs);
}

.contact-info-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.contact-info-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.contact-info-card h3 {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-lg);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.contact-item:last-child {
    margin-bottom: 0;
}

.contact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item strong {
    display: block;
    color: var(--primary-blue);
    margin-bottom: 4px;
}

.contact-item p {
    color: var(--text-light);
    line-height: 1.6;
}

.contact-item a {
    color: var(--primary-blue);
}

.contact-item a:hover {
    color: var(--primary-gold);
}

/* Map placeholder */
.map-placeholder {
    background: linear-gradient(135deg, var(--light-gray), var(--medium-gray));
    border-radius: var(--radius-xl);
    height: 250px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-sm);
}

.map-content {
    text-align: center;
    color: var(--dark-gray);
}

.map-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.map-content p {
    font-weight: 600;
    margin-bottom: 4px;
}

.map-content small {
    font-size: 0.85rem;
}

/* Alert messages */
.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-icon {
    font-size: 1.5rem;
    font-weight: 700;
}

/* Button loader */
.btn-loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: var(--white);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.btn.loading .btn-text {
    display: none;
}

.btn.loading .btn-loader {
    display: inline-block;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
    background: var(--primary-blue);
    color: var(--white);
    padding: var(--spacing-xxl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary-gold);
}

.footer-section p {
    opacity: 0.9;
    line-height: 1.7;
}

.footer-tagline {
    margin-top: var(--spacing-sm);
    font-size: 0.9rem;
}

.footer-links li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a {
    opacity: 0.9;
    transition: var(--transition);
}

.footer-links a:hover {
    opacity: 1;
    color: var(--primary-gold);
    padding-left: 5px;
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    transition: var(--transition);
}

.social-link:hover {
    background: var(--primary-gold);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    opacity: 0.8;
    font-size: 0.9rem;
    margin-bottom: var(--spacing-xs);
}

.footer-legal {
    font-size: 0.85rem;
    font-style: italic;
}

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 992px) {
    .nav-desktop {
        display: none;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .nav-mobile {
        display: flex;
    }
    
    .contact-container {
        grid-template-columns: 1fr;
    }
    
    .cards-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-xxl: 3rem;
    }
    
    .hero {
        min-height: 80vh;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .event-card {
        grid-template-columns: 80px 1fr;
        gap: var(--spacing-md);
    }
    
    .event-date {
        padding: var(--spacing-sm);
    }
    
    .event-day {
        font-size: 1.5rem;
    }
    
    .research-number {
        font-size: 2rem;
        top: var(--spacing-sm);
        right: var(--spacing-sm);
    }
    
    .collaboration-grid {
        grid-template-columns: 1fr;
    }
    
    .newsletter-form {
        flex-direction: column;
    }
    
    .newsletter-form input {
        min-width: 100%;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .logo {
        height: 50px;
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
    }
    
    .publication-item {
        grid-template-columns: 1fr;
        text-align: center;
    }
}