/* Variables CSS */
:root {
    --primary-color: #2d3436;
    --secondary-color: #0984e3;
    --accent-color: #00b894;
    --text-color: #2d3436;
    --bg-color: #ffffff;
    --card-bg: #f5f6fa;
    --gradient-start: #0984e3;
    --gradient-end: #00b894;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --card-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset et styles de base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header et Navigation */
header {
    background-color: var(--primary-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

nav {
    display: flex;
    justify-content: flex-end;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    position: relative;
}

.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.hamburger-line {
    display: block;
    width: 25px;
    height: 3px;
    background-color: white;
    margin: 5px 0;
    transition: var(--transition);
}

.nav-menu {
    display: flex;
    justify-content: center;
    list-style: none;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

nav a:hover {
    background-color: var(--secondary-color);
}

/* Main Content */
main {
    flex: 1;
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.presentation {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
}

.presentation h1 {
    color: var(--primary-color);
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
}

.presentation h2 {
    color: var(--secondary-color);
    font-size: 1.8rem;
    margin: 2rem 0 1rem;
}

.presentation p {
    margin-bottom: 2rem;
    font-size: 1.1rem;
    line-height: 1.8;
}

/* Group Section */
.group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
    padding: 1.5rem;
    background-color: var(--bg-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.group h2 {
    color: var(--secondary-color);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.group ul {
    list-style: none;
    padding-left: 1rem;
}

.group li {
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.group li::before {
    content: "•";
    color: var(--accent-color);
    position: absolute;
    left: 0;
}

/* Button Styles */
.button-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 2rem;
}

.bouton-link {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background-color: var(--secondary-color);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    transition: var(--transition);
    font-weight: 500;
}

.bouton-link:hover {
    background-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

/* Image Styles */
.img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 2rem 0;
    box-shadow: var(--shadow);
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 1.5rem;
    margin-top: auto;
}

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

footer a:hover {
    color: var(--secondary-color);
}

/* Media Queries */
@media screen and (max-width: 768px) {
    .hamburger {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        height: 100vh;
        background-color: var(--primary-color);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2rem;
        transition: var(--transition);
        padding: 2rem;
        box-shadow: -2px 0 5px rgba(0, 0, 0, 0.2);
    }

    .nav-menu.active {
        right: 0;
    }

    .hamburger.active .hamburger-line:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .hamburger.active .hamburger-line:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .hamburger-line:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .presentation h1 {
        font-size: 2rem;
    }

    .presentation h2 {
        font-size: 1.5rem;
    }

    .group {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.presentation {
    animation: fadeIn 0.6s ease-out forwards;
}

/* Optimisations des performances */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}