/* --- CONTENU : LE CHAPITRE --- */
.chapter {
    max-width: 750px;
    margin: 0 auto;
    padding: 0px 20px;
}

.chapter h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 60px;
    /* text-align: left; */
    background: linear-gradient(180deg, #1d1d1f 0%, #6e6e73 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

body.dark .chapter h1 {
    background: linear-gradient(180deg, #ffffff 0%, #86868b 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.chapter h2 {
    font-size: 2rem;
    margin: 80px 0 30px;
    border-left: 4px solid #0066cc;
    padding-left: 20px;
}

.chapter p {
    font-size: 1.25rem;
    color: #424245;
    margin-bottom: 30px;
    transition: color 0.3s ease;
}

body.dark .chapter p { color: #a1a1a6; }

/* Focus Interactif pour garder le lecteur */
.chapter p:hover {
    color: #000;
}
body.dark .chapter p:hover {
    color: #b1b1b1;
}

/* --- ANIMATIONS --- */
h1, h2, h3, p, .item {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

h1 { animation-delay: 0.1s; }
h2 { animation-delay: 0.3s; }
p { animation-delay: 0.4s; }
.item:nth-child(n) { animation-delay: 0.5s; }

@keyframes fadeInUp {
    to { opacity: 1; transform: translateY(0); }
}