/* Stage 4 Cancer — Design system & responsive */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=Source+Serif+4:ital,opsz,wght@0,8..60,600;0,8..60,700;1,8..60,400&display=swap');

:root {
    --primary: #0f172a;
    --primary-soft: #1e293b;
    --accent: #0d9488;
    --accent-hover: #0f766e;
    --alert: #b91c1c;
    --alert-bg: #fef2f2;
    --bg: #fafaf9;
    --bg-card: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 10px 40px -10px rgba(15, 23, 42, 0.15);
    --max-width: 1100px;
    --nav-height: 64px;
    --tap-min: 44px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: 'DM Sans', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.65;
    font-size: 1rem;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 clamp(1rem, 5vw, 2rem);
}

/* Typography */
h1, h2, h3, h4 {
    font-family: 'Source Serif 4', serif;
    color: var(--primary);
    line-height: 1.25;
}
h1 { font-size: clamp(1.75rem, 5vw, 2.75rem); margin-bottom: 1rem; font-weight: 700; }
h2 { font-size: clamp(1.35rem, 3vw, 1.75rem); margin-top: 2.5rem; margin-bottom: 0.75rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--border); font-weight: 600; }
h3 { font-size: 1.15rem; margin-top: 1.5rem; margin-bottom: 0.5rem; font-weight: 600; }
h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); margin-bottom: 0.5rem; font-family: 'DM Sans', sans-serif; font-weight: 600; }
p { margin-bottom: 1.25rem; font-size: clamp(0.9375rem, 2vw, 1.0625rem); }
.intro-lead { font-size: clamp(1rem, 2.5vw, 1.2rem); color: var(--text-muted); font-weight: 400; margin-bottom: 1.5rem; line-height: 1.6; }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

/* Nav — desktop */
nav {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
    min-height: var(--nav-height);
}
.nav-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    min-height: var(--nav-height);
    gap: 1rem;
}
.logo {
    font-family: 'Source Serif 4', serif;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
    flex-shrink: 0;
}
.logo:hover { text-decoration: none; color: var(--primary); }

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}
.nav-links a {
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    min-height: var(--tap-min);
    display: inline-flex;
    align-items: center;
}
.nav-links a:hover {
    background: var(--bg);
    color: var(--accent);
    text-decoration: none;
}

/* Hamburger button — visible only on mobile */
.nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: var(--tap-min);
    height: var(--tap-min);
    padding: 0;
    border: none;
    background: transparent;
    cursor: pointer;
    border-radius: var(--radius-sm);
    color: var(--primary);
    font-size: 1.5rem;
}
.nav-toggle:hover { background: var(--bg); }
.nav-toggle[aria-expanded="true"] { background: var(--bg); }

/* Mobile nav */
@media (max-width: 767px) {
    .nav-toggle { display: flex; }
    .nav-links {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--bg-card);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
        box-shadow: var(--shadow-lg);
        border-bottom: 1px solid var(--border);
        max-height: 0;
        overflow: hidden;
        opacity: 0;
        transition: max-height 0.3s ease, opacity 0.2s ease;
        pointer-events: none;
    }
    .nav-links.is-open {
        max-height: 80vh;
        opacity: 1;
        pointer-events: auto;
        overflow-y: auto;
    }
    .nav-links a {
        width: 100%;
        padding: 1rem 1.25rem;
        min-height: var(--tap-min);
        border-radius: var(--radius-sm);
    }
}

@media (min-width: 768px) {
    .nav-links { display: flex !important; }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: var(--tap-min);
    padding: 0 1.75rem;
    background: var(--primary);
    color: #fff;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: background 0.2s, transform 0.15s, box-shadow 0.2s;
    border: none;
    cursor: pointer;
}
.btn:hover {
    background: var(--primary-soft);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
    text-decoration: none;
    color: #fff;
}
.btn:active { transform: translateY(0); }
.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}
.btn-outline:hover { background: var(--bg); color: var(--primary); }

/* Hero */
.hero {
    padding: clamp(2rem, 6vw, 4rem) 0;
    background: var(--bg-card);
}
.hero-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: clamp(2rem, 5vw, 3rem);
    align-items: center;
}
.hero-grid .hero-img {
    width: 100%;
    max-width: 320px;
    height: auto;
    margin: 0 auto;
    display: block;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
}
.hero .btn { margin-top: 0.5rem; }

@media (min-width: 768px) {
    .hero-grid { grid-template-columns: 1.2fr 1fr; }
    .hero-grid .hero-img { max-width: 380px; margin: 0; }
}

/* Alert YMYL */
.alert-ymyl {
    background: var(--alert-bg);
    border: 1px solid #fecaca;
    border-left: 4px solid var(--alert);
    padding: clamp(1.25rem, 4vw, 1.75rem);
    margin: 2rem 0;
    border-radius: var(--radius-sm);
}
.alert-ymyl strong {
    color: var(--alert);
    font-size: 1rem;
    display: block;
    margin-bottom: 0.5rem;
}
.alert-ymyl p { margin-bottom: 0; font-size: 0.9375rem; }

/* Academic note */
.academic-note {
    background: #f0fdfa;
    border-left: 4px solid var(--accent);
    padding: clamp(1.25rem, 4vw, 1.5rem);
    margin: 1.5rem 0;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    font-size: 0.9375rem;
}

/* TOC */
.toc {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: clamp(1.25rem, 4vw, 1.75rem);
    border-radius: var(--radius);
    margin-bottom: 2rem;
}
.toc h4 { margin-bottom: 1rem; }
.toc ul {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.5rem;
}
.toc a {
    display: block;
    padding: 0.6rem 0;
    color: var(--text);
    font-size: 0.9375rem;
    text-decoration: none;
    border-bottom: 1px solid var(--border);
    min-height: var(--tap-min);
    display: flex;
    align-items: center;
}
.toc a:last-child { border-bottom: none; }
.toc a:hover { color: var(--accent); text-decoration: none; background: var(--bg); margin: 0 -0.5rem; padding-left: 0.5rem; padding-right: 0.5rem; border-radius: var(--radius-sm); }

@media (min-width: 600px) {
    .toc ul { grid-template-columns: 1fr 1fr; }
}

/* Sommaire du livre (preview) — 1 colonne, responsive */
.toc-section { margin-bottom: 2.5rem; }
.toc-section h2 { margin-top: 2rem; }
.toc-intro { font-size: 0.9375rem; color: var(--text-muted); margin-bottom: 1rem; }
.toc-book { margin-bottom: 1.5rem; }
.toc-list {
    list-style: none;
    counter-reset: toc;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0;
}
.toc-list li {
    counter-increment: toc;
    padding: 0.75rem 0;
    padding-left: 0;
    border-bottom: 1px solid var(--border);
    font-size: clamp(0.875rem, 2vw, 0.9375rem);
    line-height: 1.5;
    word-wrap: break-word;
    hyphens: auto;
    min-height: var(--tap-min);
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.35rem;
}
.toc-list li:last-child { border-bottom: none; }
.toc-num {
    flex-shrink: 0;
    font-weight: 600;
    color: var(--primary);
    font-size: 0.8125rem;
}

/* Preview teaser */
.preview-teaser { margin-bottom: 2rem; }
.preview-teaser h2 { margin-top: 2rem; }
.teaser-list {
    padding-left: 1.25rem;
    margin: 0 0 1.5rem 0;
}
.teaser-list li {
    margin-bottom: 0.75rem;
    font-size: 0.9375rem;
    line-height: 1.6;
}
.faq-section h2 { margin-top: 2rem; }
.faq-section .btn { margin-top: 1rem; }
.btn-cta { font-size: 1.0625rem; padding: 0 2rem; }

/* Table wrapper for horizontal scroll on mobile */
.table-wrap {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin: 1.5rem 0;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}
.scientific-table {
    width: 100%;
    min-width: 520px;
    border-collapse: collapse;
    font-size: 0.9375rem;
}
.scientific-table th {
    background: var(--primary);
    color: #fff;
    padding: 0.75rem 1rem;
    text-align: left;
    font-family: 'DM Sans', sans-serif;
    font-weight: 600;
}
.scientific-table td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
}
.scientific-table tr:nth-child(even) { background: var(--bg); }
.scientific-table tr:last-child td { border-bottom: none; }

/* FAQ */
.faq-grid { margin-top: 1.5rem; }
.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: clamp(1.25rem, 4vw, 1.5rem);
    margin-bottom: 1rem;
    border-radius: var(--radius);
}
.faq-item h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1rem;
    margin-top: 0;
    margin-bottom: 0.5rem;
    color: var(--primary);
}
.faq-item p { margin-bottom: 0; font-size: 0.9375rem; }

/* Footer */
footer {
    background: var(--primary);
    color: #94a3b8;
    padding: clamp(2.5rem, 6vw, 4rem) 0 clamp(1.5rem, 4vw, 2rem);
    margin-top: 3rem;
}
footer h3, footer h4 {
    color: #fff;
    margin-bottom: 0.75rem;
    font-size: 1rem;
}
footer a { color: #cbd5e1; }
footer a:hover { color: #fff; text-decoration: underline; }
.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
.footer-bottom {
    margin-top: 2.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    text-align: center;
    font-size: 0.8125rem;
    color: #64748b;
}
.footer-bottom p { margin-bottom: 0.25rem; }

@media (min-width: 640px) {
    .footer-grid { grid-template-columns: 1.5fr 1fr 1fr; }
}

/* Page content (sous-pages) */
.page-content { padding: clamp(1.5rem, 4vw, 2.5rem) 0 clamp(2rem, 5vw, 3rem); }
.breadcrumb {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent); }
.page-content .btn { margin-top: 0.5rem; }
.page-content ul { padding-left: 1.25rem; margin-bottom: 1rem; }
.page-content li { margin-bottom: 0.35rem; }
.page-content p .btn { margin-right: 0.5rem; margin-bottom: 0.5rem; }
@media (max-width: 380px) {
    .btn { width: 100%; justify-content: center; }
    .page-content p .btn { margin-right: 0; }
}
footer p a {
    display: inline-block;
    padding: 0.5rem 0;
    line-height: 1.4;
}
footer .footer-grid > div p { margin-bottom: 0.5rem; }

/* Utilitaires */
.text-muted { font-size: 0.875rem; color: var(--text-muted); margin-top: 0.75rem; }