* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #2c3e50;
    background: #f5f6fa;
}

/* Banniere */
.banniere {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.banniere-image {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.banniere-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.banniere-image .ombre {
    position: absolute;
    inset: 0;
    background: linear-gradient(rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.6));
}

/* banniere-contenu */
.banniere-contenu {
    text-align: center;
    color: white;
    z-index: 2;
    max-width: 800px;
    padding: 2rem;
}

.banniere-contenu h1 {
    font-size: 4.5rem;
    font-weight: 300;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
    color: #fff;
}

.banniere-contenu h2 {
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 1.5rem;
    color: #bdc3c7;
}

.banniere-contenu p {
    font-size: 1.3rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

/* Introduction */
#introduction p {
    font-size: 1.2rem;
    line-height: 1.8;
    max-width: 1200px;
    margin: 0 auto;
    color: #34495e;
}

/* Navigation */
.navigation-principale {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(44, 62, 80, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0,0,0,0.3);
    transition: all 0.3s ease;
}

.contenu-nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    gap: 2rem;
}

/* Flèche retour portfolio */
.retour-portfolio {
    display: flex;
    align-items: center;
    gap: 6px;
    text-decoration: none;
    color: #ffffff;
    font-size: 0.9rem;
    font-weight: 500;
    opacity: 0.85;
    transition: opacity 0.2s ease, transform 0.2s ease;
    white-space: nowrap;
    flex-shrink: 0;
}

.retour-portfolio:hover {
    opacity: 1;
    transform: translateX(-4px);
}

.retour-portfolio svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    stroke: #ffffff;
}

.menu-liens {
    display: flex;
    list-style: none;
    justify-content: center;
    padding: 1rem 0;
    flex: 1;
}

.menu-liens li {
    margin: 0 2rem;
}

.menu-liens a {
    text-decoration: none;
    color: white;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    padding: 0.5rem 1rem;
}

.menu-liens a:hover {
    color: #bdc3c7;
}

.menu-liens a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: #bdc3c7;
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.menu-liens a:hover::after {
    width: 100%;
}

/* Contenu des Sections */
.section-contenu {
    padding: 5rem 0;
    background: white;
}

.section-contenu:nth-child(even) {
    background: #f8f9fa;
}

.contenu {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-titre {
    text-align: center;
    font-size: 3rem;
    font-weight: 300;
    margin-bottom: 3rem;
    color: #2c3e50;
    position: relative;
}

.section-titre::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(135deg, #95a5a6 0%, #7f8c8d 100%);
}

/* Frise */
.section-frise {
    background: #2c3e50;
    color: white;
    padding: 5rem 0;
}

.section-frise .section-titre {
    color: white;
}

.section-frise .section-titre::after {
    background: linear-gradient(135deg, #bdc3c7 0%, #95a5a6 100%);
}

.frise {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 0;
}

.evenement {
    position: relative;
    margin: 0 0 80px 0;
    display: flex;
    align-items: center;
}

.evenement:nth-child(even) {
    flex-direction: row-reverse;
}

.evenement:nth-child(even) .frise-contenu {
    text-align: right;
}

.frise-date {
    background: linear-gradient(135deg, #95a5a6, #7f8c8d);
    color: white;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 0.9rem;
    min-width: 120px;
    text-align: center;
    position: relative;
    z-index: 2;
    box-shadow: 0 4px 15px rgba(149, 165, 166, 0.3);
}

.frise-contenu {
    flex: 1;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 25px;
    border-radius: 15px;
    margin: 0 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.frise-contenu:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}

.frise-contenu h3 {
    color: white;
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.frise-contenu p {
    color: #bdc3c7;
    line-height: 1.6;
    margin: 0;
}

/* Articles */
.grille-article {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.article {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.article::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, #95a5a6 0%, #7f8c8d 100%);
}

.article:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

.article h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    line-height: 1.4;
}

.article-date {
    color: #7f8c8d;
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.article p {
    color: #5d6d7e;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.lien-articles {
    margin-top: 1.5rem;
}

.liens {
    display: inline-block;
    background: linear-gradient(135deg, #95a5a6 0%, #7f8c8d 100%);
    color: white;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    margin: 0.2rem;
    text-decoration: none;
    transition: all 0.3s ease;
}

.liens:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

/* Conclusion */
#conclusion p {
    font-size: 1.2rem;
    line-height: 1.8;
    max-width: 1200px;
    margin: 0 auto;
    color: #34495e;
}

/* Scroll animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.cert-card .cert-thumbnail {
    height: 220px;
}

.cert-thumbnail div i {
    font-size: 6rem !important;
}