@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,300;0,400;0,500;0,600;1,300;1,400&family=Montserrat:wght@300;400;500;600&display=swap');

/* ============================
   VARIABLES
   ============================ */
:root {
    --rouge:        #ff5f57;
    --rouge-dim:    rgba(255, 95, 87, 0.15);
    --rouge-bord:   rgba(255, 95, 87, 0.3);
    --noir:         #0a0a0a;
    --noir-header:  #0d0d0d;
    --gris-fonce:   #121212;
    --gris-moyen:   #1e1e1e;
    --gris-clair:   #2a2a2a;
    --gris-texte:   #888;
    --blanc:        #f0ece6;
    --blanc-dim:    rgba(240, 236, 230, 0.7);
    --transition:   0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --font-display: 'Cormorant Garamond', serif;
    --font-body:    'Montserrat', sans-serif;
}

/* ============================
   RESET & BASE
   ============================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html { scroll-behavior: smooth; }

body {
    background-color: var(--gris-fonce);
    color: var(--blanc);
    font-family: var(--font-body);
    font-weight: 300;
    line-height: 1.7;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Grain overlay */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.035'/%3E%3C/svg%3E");
    pointer-events: none;
    z-index: 9999;
    opacity: 0.4;
}

/* ============================
   HEADER
   ============================ */
header {
    width: 100%;
    background-color: var(--noir-header);
    border-bottom: 1px solid rgba(255, 95, 87, 0.2);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 48px;
    height: 72px;
    max-width: 1400px;
    margin: 0 auto;
}

.nav-brand {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    color: var(--blanc);
    text-decoration: none;
}

.nav-brand span { color: var(--rouge); }

.nav-links {
    display: flex;
    gap: 36px;
    list-style: none;
}

.nav-links a {
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--gris-texte);
    text-decoration: none;
    transition: color var(--transition);
    padding-bottom: 4px;
}

.nav-links a:hover { color: var(--blanc); }

.nav-links a.active {
    color: var(--blanc);
    border-bottom: 1px solid var(--rouge);
}

/* Hamburger */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 1px;
    background: var(--blanc);
    transition: var(--transition);
}

.hamburger.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ============================
   PAGE HEADER (bannière)
   ============================ */
.page-header {
    padding: 80px 48px 60px;
    max-width: 1400px;
    margin: 0 auto;
    border-bottom: 1px solid var(--gris-clair);
}

.eyebrow {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--rouge);
    margin-bottom: 16px;
}

.page-header h1 {
    font-family: var(--font-display);
    font-size: clamp(2.8rem, 6vw, 5rem);
    font-weight: 300;
    line-height: 1.05;
    color: var(--blanc);
    margin-bottom: 12px;
}

.page-header h1 em {
    font-style: italic;
    color: var(--rouge);
}

.page-header p {
    font-size: 0.82rem;
    color: var(--gris-texte);
    letter-spacing: 0.06em;
}

/* ============================
   BANDEAU PORTFOLIO
   ============================ */
.portfolio-banner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 12px 24px;
    background: var(--rouge-dim);
    border-bottom: 1px solid var(--rouge-bord);
    text-decoration: none;
    color: var(--blanc-dim);
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    transition: background var(--transition), color var(--transition);
}

.portfolio-banner:hover {
    background: rgba(255, 95, 87, 0.22);
    color: var(--blanc);
}

.portfolio-banner-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--rouge);
    flex-shrink: 0;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50%       { opacity: 0.5; transform: scale(0.8); }
}

.portfolio-banner-text strong {
    color: var(--blanc);
    font-weight: 500;
}

.portfolio-banner-arrow {
    color: var(--rouge);
    font-size: 0.9rem;
    transition: transform var(--transition);
}

.portfolio-banner:hover .portfolio-banner-arrow {
    transform: translateX(4px);
}

/* ============================
   ONGLETS SEMESTRES + FLÈCHES
   ============================ */
.semestre-nav-wrapper {
    max-width: 1400px;
    margin: 0 auto;
    padding: 40px 48px 0;
    display: flex;
    align-items: flex-end;
    gap: 0;
    border-bottom: 1px solid var(--gris-clair);
}

.semestre-arrow {
    flex-shrink: 0;
    background: none;
    border: 1px solid var(--gris-clair);
    color: var(--gris-texte);
    width: 36px;
    height: 36px;
    cursor: pointer;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1px;
    transition: color var(--transition), border-color var(--transition);
}

.semestre-arrow:hover:not(:disabled) {
    color: var(--blanc);
    border-color: var(--rouge);
}

.semestre-arrow:disabled {
    opacity: 0.2;
    cursor: default;
}

.semestre-nav {
    flex: 1;
    display: flex;
    align-items: flex-end;
    gap: 0;
    overflow-x: auto;
    scrollbar-width: none;
}

.semestre-nav::-webkit-scrollbar { display: none; }

.semestre-tab {
    position: relative;
    font-family: var(--font-body);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--gris-texte);
    padding: 14px 28px;
    cursor: pointer;
    background: none;
    border: none;
    white-space: nowrap;
    transition: color var(--transition);
    margin-bottom: -1px;
}

.semestre-tab::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--rouge);
    transform: scaleX(0);
    transition: transform var(--transition);
}

.semestre-tab:hover { color: var(--blanc-dim); }

.semestre-tab.actif {
    color: var(--blanc);
}

.semestre-tab.actif::after {
    transform: scaleX(1);
}

/* ============================
   CONTENU PRINCIPAL
   ============================ */
.main-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 56px 48px 100px;
}

/* Panneau semestre */
.semestre-panel {
    display: none;
    animation: fadeIn 0.4s ease;
}

.semestre-panel.actif { display: block; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ============================
   TITRE DE MATIÈRE
   ============================ */
.matiere-titre {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    color: var(--blanc);
    margin-bottom: 20px;
    margin-top: 52px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.matiere-titre:first-child { margin-top: 0; }

.matiere-titre::after {
    content: '';
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, var(--gris-clair), transparent);
}

.matiere-code {
    font-family: var(--font-body);
    font-size: 0.65rem;
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--rouge);
    background: var(--rouge-dim);
    padding: 3px 10px;
    border: 1px solid var(--rouge-bord);
    flex-shrink: 0;
}

/* ============================
   GRILLE DE CARTES
   ============================ */
/* Pour ajouter une carte : copiez un bloc <a class="carte"> dans la bonne .cours-grille */
.cours-grille {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 16px;
    margin-bottom: 8px;
}

/* ============================
   CARTE
   ============================ */
/*
   STRUCTURE D'UNE CARTE :
   ─────────────────────────────────────────────────────────
   <a class="carte" href="CHEMIN/index.html">
       <span class="carte-label">TP 1</span>
       <span class="carte-titre">Titre du cours</span>
       <span class="carte-desc">Description courte.</span>
   </a>
   ─────────────────────────────────────────────────────────
   - carte-label : numéro / type (TP 1, Séquence 2…)
   - carte-titre  : intitulé principal (affiché en grand)
   - carte-desc   : une ligne d'explication (optionnel)
*/
.carte {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 24px 28px;
    background: var(--gris-moyen);
    border: 1px solid var(--gris-clair);
    text-decoration: none;
    color: inherit;
    position: relative;
    overflow: hidden;
    transition: border-color var(--transition), background var(--transition);
}

.carte::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 3px;
    height: 100%;
    background: var(--rouge);
    transform: scaleY(0);
    transform-origin: bottom;
    transition: transform var(--transition);
}

.carte:hover {
    border-color: rgba(255, 95, 87, 0.4);
    background: #222;
}

.carte:hover::before { transform: scaleY(1); }

.carte-label {
    font-size: 0.65rem;
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--rouge);
}

.carte-titre {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--blanc);
    line-height: 1.3;
}

.carte-desc {
    font-size: 0.75rem;
    color: var(--gris-texte);
    line-height: 1.6;
}

.carte-arrow {
    margin-top: auto;
    padding-top: 12px;
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    color: var(--rouge);
    opacity: 0;
    transform: translateX(-6px);
    transition: opacity var(--transition), transform var(--transition);
}

.carte:hover .carte-arrow {
    opacity: 1;
    transform: translateX(0);
}

/* Carte désactivée / placeholder */
.carte.disabled {
    opacity: 0.35;
    pointer-events: none;
}

/* ============================
   FOOTER
   ============================ */
footer {
    border-top: 1px solid rgba(255, 95, 87, 0.15);
    padding: 32px 48px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
}

footer p {
    font-size: 0.7rem;
    color: var(--gris-texte);
    letter-spacing: 0.08em;
}

.btn-top {
    font-family: var(--font-body);
    font-size: 0.68rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--gris-texte);
    background: none;
    border: 1px solid var(--gris-clair);
    padding: 8px 18px;
    cursor: pointer;
    transition: color var(--transition), border-color var(--transition);
}

.btn-top:hover {
    color: var(--blanc);
    border-color: var(--rouge);
}

/* ============================
   RESPONSIVE
   ============================ */
@media (max-width: 768px) {
    nav { padding: 0 24px; }
    .hamburger { display: flex; }

    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        flex-direction: column;
        gap: 0;
        background: var(--noir-header);
        border-bottom: 1px solid var(--gris-clair);
        padding: 16px 0;
    }

    .nav-links.open { display: flex; }

    .nav-links li a {
        display: block;
        padding: 12px 24px;
    }

    .page-header,
    .semestre-nav-wrapper,
    .main-content,
    footer {
        padding-left: 24px;
        padding-right: 24px;
    }

    .semestre-nav-wrapper { padding-top: 24px; }

    .page-header { padding-top: 48px; padding-bottom: 40px; }

    .semestre-tab { padding: 12px 16px; font-size: 0.65rem; }

    .cours-grille { grid-template-columns: 1fr; }

    footer { flex-direction: column; gap: 16px; text-align: center; }
}