* {
    box-sizing: border-box;
}

body {
    font-family: Georgia, 'Times New Roman', Times, serif;
    background: #081229;
    margin: 0;
    padding: 0;
}

.header {
    position: sticky;
    display: flex;
    height: 60px;
    justify-content: space-between;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    align-items: center;
    padding: 1rem 2rem;
    top: 0;
    z-index: 10;
    background: #081229;
    backdrop-filter: blur(4px);
}

.logo {
    font-weight: 600;
    color: #f0f0f0;
}

/* Bouton hamburger caché en PC */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 22px;
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    height: 4px;
    background-color: #fff;
    border-radius: 2px;
}

.nav ul {
    display: flex;
    list-style-type: none;
    color: #f0f0f0;
    font-size: 1em;
    gap: 1rem;
    transition: all 0.25s ease;
}

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

.nav ul li a {
    position: relative;
    text-decoration: none;
    color: #f0f0f0;
    border-radius: 5px;
    padding: 0.5rem 1rem;
}

.nav ul li a::after {
    content: "";
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: #00CCCC;
    transition: width 0.3s;
}

.nav ul li a:hover { /* tous liens lors du survol dans la balise nav */
    color: #f19c65; /* couleur de fond */
}

.nav ul li a:hover::after {
    width: 100%;
}

.container {
    background: white;
    max-width: 1000px;
    margin: 3rem auto;
    padding: 3rem 4rem;
}

.container p {
    text-align: justify;
    margin-bottom: 1.3rem;
    font-size: 1.05rem;
    line-height: 1.9;
}

.title h1 {
    text-align: left;
    font-size: 2rem;
    line-height: 1.3;
    font-weight: 600;
    color: #003366;
    border-bottom: 2px solid #003366;
    padding: 2rem 3rem;
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
}
/* Titres */

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #002e5b;
    margin-top: 2.5rem;
    /*border-left: 4px solid #0088aa;*/
}

h2::after {
    content: "";
    display: block;
    margin-top: 6px;
    width: 50px;
    height: 3px;
    background-color: #0088aa;
    border-radius: 2px;
}

h3 {
    font-size: 1.2rem;
    color: #1e3a8a;
}

h4 {
    font-style: italic;
    color: #555;
}

.crypto-header {
    background: linear-gradient(135deg, #081229, #1e1b4b);
    color: #ffffff;
}

.crypto-theory {
    border-left: 5px solid #06b6d4;
    background: #f0fdff;
}

.alice-box {
    border-left: 4px solid #3b82f6;
}

.bob-box {
    border-left: 4px solid #10b981;
}

.eve-box {
    border-left: 4px solid #ef4444;
}




.footer {
    height: 100%;
    margin: 0;
    display: flex;
    background: #081229;
    color: white;
    padding: 2rem 1rem;
    margin-top: 4rem;
}

.footer-container {
    margin: 0 auto;
    text-align: center;
}

.footer a {
    color: white;
}

.footer a:hover {
    color: #ffcc70;
}

.footer-links {
    margin-top: 1rem;
}

.footer-links a {
    margin: 0 10px;
    color: white;
    text-decoration: none;
}

.footer-links a:hover{
    text-decoration: underline;
}