/* =========================================
   VARIABLES & THEME CONFIGURATION
   ========================================= */
:root {
  /* Palette de fond "Deep Space" */
  --bg-dark: #020617;
  --bg-gradient-start: #0f172a;
  --bg-gradient-end: #020617;

  /* Couleurs d'accentuation (Cyber Blue) */
  --accent-primary: #38bdf8;
  --accent-glow: rgba(56, 189, 248, 0.4);
  --accent-soft: rgba(56, 189, 248, 0.1);

  /* Surfaces vitrées (Glassmorphism) */
  --glass-surface: rgba(30, 41, 59, 0.4);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-highlight: rgba(255, 255, 255, 0.15);

  /* Typographie */
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;

  /* Dimensions */
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 8px;
}

:where([data-page="cours"]) {
  --rail-width: 80px;
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Reset de base pour garantir le rendu */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* =========================================
   LAYOUT PRINCIPAL
   ========================================= */

body[data-page="cours"] {
  background-color: var(--bg-dark);
  /* Un spot de lumière bleue en haut à droite pour l'ambiance */
  background-image:
    radial-gradient(circle at 80% 0%, rgba(56, 189, 248, 0.15), transparent 40%),
    radial-gradient(circle at 0% 100%, rgba(99, 102, 241, 0.1), transparent 40%);
  background-attachment: fixed;
  min-height: 100vh;
  color: var(--text-main);
}

body[data-page="cours"] .course-page-shell {
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  grid-template-columns: var(--rail-width) minmax(0, 1fr);
  align-items: start;
  transition: grid-template-columns 420ms var(--ease-spring);
}

body[data-page="cours"] .course-page-content {
  min-width: 0;
}

body[data-page="cours"] .course-shell {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* =========================================
   HEADER & NAVIGATION RETOUR
   ========================================= */

body[data-page="cours"] .course-shell__header {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 48px;
}

/* Bouton Retour style "Pillule de verre" */
body[data-page="cours"] .course-shell__back {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: fit-content;
  padding: 8px 24px;
  border-radius: 100px;

  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--glass-border);
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  backdrop-filter: blur(8px);
}

body[data-page="cours"] .course-shell__back:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--text-muted);
  color: #fff;
  transform: translateX(-4px); /* Petit mouvement fluide */
  box-shadow: 0 0 15px rgba(255, 255, 255, 0.05);
}

body[data-page="cours"] .course-shell__kicker {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent-primary);
  margin-bottom: 8px;
  font-weight: 700;
  text-shadow: 0 0 10px var(--accent-glow);
}

body[data-page="cours"] .course-shell__title {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 800;
  margin: 0;
  line-height: 1.1;
  letter-spacing: -0.02em;
  /* Dégradé sur le texte */
  background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* =========================================
   GRILLE ET STRUCTURE
   ========================================= */

body[data-page="cours"] .course-shell__layout {
  display: grid;
  grid-template-columns: 280px 1fr; /* Menu fixe à gauche, contenu fluide */
  gap: 40px;
  align-items: start;
}

body[data-page="cours"] .course-shell.course-shell--section-only {
  max-width: 900px;
}

body[data-page="cours"] .course-shell__layout.course-shell__layout--section-only {
  grid-template-columns: 1fr;
  gap: 0;
}

@media (max-width: 1024px) {
  body[data-page="cours"] .course-page-shell {
    grid-template-columns: minmax(0, 1fr);
  }

  body[data-page="cours"] .course-shell {
    max-width: 100%;
    padding: 24px 14px calc(56px + var(--mobile-tab-bar-h, 60px) + env(safe-area-inset-bottom));
  }

  body[data-page="cours"] .course-shell__layout {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  body[data-page="cours"] .course-nav {
    position: static;
    top: auto;
    padding: 14px;
    border-radius: 14px;
    max-height: 40dvh;
    overflow: auto;
  }
}

@media (max-width: 640px) {
  body[data-page="cours"] .course-shell {
    padding: 18px 10px calc(44px + var(--mobile-tab-bar-h, 60px) + env(safe-area-inset-bottom));
  }

  body[data-page="cours"] .course-content {
    min-width: 0;
  }

  body[data-page="cours"] .course-content h2 {
    font-size: 1.25rem;
    gap: 8px;
  }

  body[data-page="cours"] .course-content h2::before {
    width: 5px;
    height: 18px;
  }

  body[data-page="cours"] .course-content p,
  body[data-page="cours"] .course-content li {
    font-size: 0.95rem;
    line-height: 1.62;
    overflow-wrap: anywhere;
    word-break: break-word;
  }

  body[data-page="cours"] .course-card {
    margin: 16px 0;
    padding: 14px;
    border-radius: 12px;
  }

  body[data-page="cours"] .course-content mjx-container[display="true"],
  body[data-page="cours"] .course-content mjx-container.MathJax[display="true"],
  body[data-page="cours"] .course-content .mjx-container.MathJax[display="true"] {
    display: block;
    max-width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    overscroll-behavior-x: contain;
    -webkit-overflow-scrolling: touch;
    touch-action: pan-x pinch-zoom;
  }

  body[data-page="cours"] .course-content table,
  body[data-page="cours"] .course-content pre {
    display: block;
    width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    overscroll-behavior-x: contain;
    -webkit-overflow-scrolling: touch;
    touch-action: pan-x pinch-zoom;
  }
}

@media (max-width: 768px) {
  body[data-page="cours"] .course-nav {
    display: none;
  }
}

/* =========================================
   SIDEBAR / SOMMAIRE (Glass Effect)
   ========================================= */

body[data-page="cours"] .course-nav {
  position: sticky;
  top: 40px;
  padding: 24px;

  background: var(--glass-surface);
  border: 1px solid var(--glass-border);
  border-top: 1px solid var(--glass-highlight); /* Lumière zénithale */
  border-radius: var(--radius-lg);

  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 20px 40px -10px rgba(0,0,0,0.3);
}

body[data-page="cours"] .course-nav__title {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin: 0 0 16px 12px;
  opacity: 0.6;
}

body[data-page="cours"] .course-nav__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

body[data-page="cours"] .course-nav__link {
  display: block;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: all 0.2s ease;
  border-left: 2px solid transparent;
}

body[data-page="cours"] .course-nav__link:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
}

/* État Actif */
body[data-page="cours"] .course-nav__link.is-active {
  background: linear-gradient(90deg, var(--accent-soft) 0%, transparent 100%);
  color: var(--accent-primary);
  border-left-color: var(--accent-primary);
  font-weight: 500;
  box-shadow: inset 0 0 20px rgba(56, 189, 248, 0.05);
}

/* =========================================
   CONTENU DU COURS
   ========================================= */

body[data-page="cours"] .course-content {
  /* On enlève le background global du content pour laisser respirer les sections */
  background: transparent;
}

body[data-page="cours"] .course-content.course-content--section-only {
  background: rgba(15, 23, 42, 0.65);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 100%;
}

body[data-page="cours"] .course-focus-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: 0 0 18px;
  padding: 12px 14px;
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-md);
  background: rgba(56, 189, 248, 0.12);
}

body[data-page="cours"] .course-focus-banner__text {
  margin: 0;
  color: #e2e8f0;
  font-size: 0.95rem;
}

body[data-page="cours"] .course-focus-banner__link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 6px 12px;
  border-radius: 999px;
  text-decoration: none;
  color: #dbeafe;
  border: 1px solid rgba(147, 197, 253, 0.5);
  background: rgba(59, 130, 246, 0.18);
  font-weight: 600;
  font-size: 0.85rem;
}

body[data-page="cours"] .course-focus-banner__link:hover {
  background: rgba(59, 130, 246, 0.28);
}

body[data-page="cours"] .course-section {
  margin-bottom: 60px;
  scroll-margin-top: 40px;
  position: relative;
}

/* Titres H2 avec petite décoration */
body[data-page="cours"] .course-content h2 {
  font-size: 1.8rem;
  color: #fff;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

body[data-page="cours"] .course-content h2::before {
  content: '';
  display: block;
  width: 6px;
  height: 24px;
  background: var(--accent-primary);
  border-radius: 4px;
  box-shadow: 0 0 15px var(--accent-glow);
}

body[data-page="cours"] .course-content p,
body[data-page="cours"] .course-content li {
  color: #cbd5e1;
  line-height: 1.75;
  font-size: 1.05rem;
  margin-bottom: 16px;
}

/* ==========================================================================
   FIX MATHJAX INLINE (cours)
   ========================================================================== */
body[data-page="cours"] .course-content mjx-container.MathJax:not([display="true"]),
body[data-page="cours"] .course-content .mjx-container.MathJax:not([display="true"]) {
  display: inline-block !important;
  vertical-align: middle !important;
  margin: 0 !important;
}

body[data-page="cours"] .course-content p:has(mjx-container.MathJax:not([display="true"])) {
  display: block !important;
}

/* =========================================
   LES CARTES MATHEMATIQUES (Le Highlight)
   ========================================= */

body[data-page="cours"] .course-card {
  margin: 24px 0;
  padding: 24px;
  border-radius: var(--radius-md);

  /* Effet Profondeur */
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--glass-border);

  /* Une lueur subtile en bas de carte */
  box-shadow:
    0 4px 6px -1px rgba(0, 0, 0, 0.3),
    inset 0 0 0 1px rgba(255, 255, 255, 0.05);

  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

body[data-page="cours"] .course-card:hover {
  transform: translateY(-2px);
  border-color: rgba(56, 189, 248, 0.3);
  box-shadow:
    0 20px 25px -5px rgba(0, 0, 0, 0.4),
    0 0 20px rgba(56, 189, 248, 0.1); /* Glow bleu au survol */
}

/* Centrage des formules MathJax */
body[data-page="cours"] .course-card .mjx-chtml {
  margin: 10px 0 !important;
  color: #fff !important;
  font-size: 1.1em !important;
}

/* =========================================
   FIGURES & GRAPHIQUES (Style HUD)
   ========================================= */

body[data-page="cours"] .course-figure {
  margin: 32px 0;
  padding: 20px;
  border-radius: var(--radius-md);

  background: rgba(2, 6, 23, 0.8); /* Très sombre pour le contraste */
  border: 1px solid rgba(56, 189, 248, 0.1);
  box-shadow: inset 0 0 30px rgba(0,0,0,0.8);

  text-align: center;
}

body[data-page="cours"] .course-figure svg {
  max-width: 100%;
  height: auto;
  overflow: visible; /* Permet aux ombres de dépasser */
}

body[data-page="cours"] .course-figure img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
}

body[data-page="cours"] .course-figure.course-figure--paper {
  background:
    linear-gradient(180deg, rgba(15, 23, 42, 0.78), rgba(2, 6, 23, 0.92));
  border: 1px solid rgba(56, 189, 248, 0.2);
  box-shadow:
    inset 0 0 26px rgba(2, 6, 23, 0.78),
    0 16px 28px -16px rgba(56, 189, 248, 0.28);
}

body[data-page="cours"] .course-figure.course-figure--paper img {
  filter: drop-shadow(0 0 10px rgba(56, 189, 248, 0.16));
}

/* Les axes */
body[data-page="cours"] .course-figure .axis,
body[data-page="cours"] .course-figure .axis-dashed {
  stroke: #475569;
  stroke-width: 2;
}

body[data-page="cours"] .course-figure .axis-dashed {
  stroke-dasharray: 4 4;
  opacity: 0.5;
}

/* LA COURBE NÉON */
body[data-page="cours"] .course-figure .curve {
  stroke: var(--accent-primary);
  stroke-width: 4;
  fill: none;
  stroke-linecap: round;

  /* L'effet Néon magique */
  filter: drop-shadow(0 0 8px var(--accent-primary));
}

/* Le point sur la courbe */
body[data-page="cours"] .course-figure .point {
  fill: #fff;
  stroke: var(--accent-primary);
  stroke-width: 2;
  r: 6; /* Un peu plus gros */
  filter: drop-shadow(0 0 5px #fff);
}

body[data-page="cours"] .course-figure text {
  fill: var(--text-muted);
  font-family: monospace;
  font-size: 12px;
}

/* =========================================
   RESPONSIVE (MOBILE)
   ========================================= */

@media (max-width: 900px) {
  body[data-page="cours"] .course-page-shell {
    display: block;
  }

  body[data-page="cours"] .course-shell__layout {
    grid-template-columns: 1fr; /* Une seule colonne */
    gap: 32px;
  }

  body[data-page="cours"] .course-nav {
    position: relative;
    top: 0;
    margin-bottom: 20px;
    /* On change le style pour mobile : un bloc horizontal si besoin, ou juste vertical */
    border-top: 1px solid var(--glass-border);
  }

  body[data-page="cours"] .course-shell__title {
    font-size: 2rem;
  }
}