/* ════════════════════════════════════════════
   DESIGN TOKENS — identical to fonctions_physique
   ════════════════════════════════════════════ */
:root {
  --ink:  #080a12;
  --ink2: #0e1120;
  --ink3: #141828;
  --ink4: #1c2235;
  --paper:  #edeef5;
  --paper2: #c8cad8;
  --rule:   #252a3e;
  --accent:  #e05a20;
  --accent2: #4a9edd;
  --accent3: #3dba62;
  --gold:    #e0a832;
  --purple:  #9b6fe0;
  --teal:    #2ec4c4;
  --text:  #edeef5;
  --text2: #a8abbe;
  --text3: #60688a;
  --card:        #111525;
  --card-border: #222840;
}

*,*::before,*::after { box-sizing:border-box; margin:0; padding:0; }
html { scroll-behavior:smooth; }

body {
  background: var(--ink);
  color: var(--text);
  font-family: 'Lora', Georgia, serif;
  overflow-x: hidden;
}

/* noise */
body::before {
  content:''; position:fixed; inset:0; z-index:0; pointer-events:none;
  opacity:0.03;
  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)'/%3E%3C/svg%3E");
}

/* scrollbar */
::-webkit-scrollbar { width:6px; }
::-webkit-scrollbar-track { background:var(--ink); }
::-webkit-scrollbar-thumb { background:var(--rule); border-radius:3px; }
::-webkit-scrollbar-thumb:hover { background:var(--accent); }

/* ════════════════════════════════════════════
   HERO
   ════════════════════════════════════════════ */
.hero {
  position:relative; z-index:1;
  min-height:100vh;
  display:flex; flex-direction:column;
  align-items:center; justify-content:center;
  padding:4rem 2rem 3rem;
  overflow:hidden;
}

/* animated grid */
.hero-grid {
  position:absolute; inset:0; pointer-events:none;
  background-image:
    linear-gradient(rgba(74,158,221,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(74,158,221,0.05) 1px, transparent 1px);
  background-size:70px 70px;
  animation: gridDrift 40s linear infinite;
}
@keyframes gridDrift {
  from { background-position:0 0; }
  to   { background-position:70px 70px; }
}

/* dual glow */
.hero-glow-a {
  position:absolute; pointer-events:none;
  width:700px; height:700px; border-radius:50%;
  background:radial-gradient(circle, rgba(74,158,221,0.10) 0%, transparent 65%);
  top:50%; left:30%; transform:translate(-50%,-50%);
}
.hero-glow-b {
  position:absolute; pointer-events:none;
  width:500px; height:500px; border-radius:50%;
  background:radial-gradient(circle, rgba(224,90,32,0.09) 0%, transparent 65%);
  top:55%; left:70%; transform:translate(-50%,-50%);
}

/* ── LOGO ZONE (Epic Background Variant) ── */
.hero-logo-zone {
  position: absolute;
  /* Centering it perfectly in the middle of the hero view */
  top: 20%; 
  left: 50%; 
  transform: translate(-50%, -50%);
  
  /* Pushes it behind the text (which usually has z-index: 1 or 2) */
  z-index: 0; 
  
  /* Crucial: prevents the logo from blocking clicks on text or buttons in front of it */
  pointer-events: none; 
  
  animation: fadeUp 1.2s ease both;
}

/* ── Styled to look like a giant faded background watermark ── */
.logo-placeholder {
  display: flex; 
  align-items: center; 
  gap: 1.5rem;
  padding: 2rem 4rem;
  
  /* Very subtle, highly transparent border and background */
  border: 1px solid rgba(224, 90, 32, 0.1);
  border-radius: 16px;
  background: rgba(224, 90, 32, 0.02);
  
  /* Slight blur to make it feel deeply integrated into the background space */
  backdrop-filter: blur(2px);
  
  /* Fading out the entire element so it doesn't distract from readability */
  opacity: 0.25; 
  
  /* Scaled up significantly to fill the space behind the text */
  transform: scale(1.5); 
  cursor: default;
}

/* ── NEW: Targets your actual logo image if you put it inside this div ── */
.logo-placeholder img {
  filter: invert(1); /* Flips your black logo to pure white */
  opacity: 0.25; /* Softens the pure white into a sleek light grey */
}


/* Turning off hover states since it's just a background watermark now */
.logo-placeholder:hover {
  border-color: rgba(224, 90, 32, 0.1);
  background: rgba(224, 90, 32, 0.02);
}

.logo-placeholder-icon {
  font-size: 2.5rem; /* Bigger icon */
  color: rgba(255, 255, 255, 0.6); /* Soft grey */
}

.logo-placeholder-text {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.1rem; /* Bigger text */
  letter-spacing: 0.4em; /* Sweeping space for an elegant look */
  color: rgba(255, 255, 255, 0.3); /* Deeply faded grey */ 
  text-transform: uppercase;
}

/* hero canvas — particle field */
#hero-canvas {
  position:absolute; inset:0; width:100%; height:100%;
  pointer-events:none; z-index:0;
}

.hero-content {
  position:relative; z-index:2;
  text-align:center; max-width:860px;
  margin-top:3rem;
}

.hero-eyebrow {
  font-family:'JetBrains Mono',monospace;
  font-size:0.7rem; letter-spacing:0.28em; text-transform:uppercase;
  color:var(--accent2); margin-bottom:1.4rem;
  animation:fadeUp 0.8s ease both;
}
.hero-title {
  font-family:'Syne',sans-serif; font-weight:800;
  font-size:clamp(3rem,8vw,6.5rem); line-height:0.9;
  color:var(--paper); margin-bottom:1rem;
  animation:fadeUp 0.8s 0.12s ease both;
}
.hero-title em { color:var(--accent2); font-style:normal; }
.hero-title .accent-o { color:var(--accent); }

.hero-sub {
  font-size:1.05rem; color:var(--text2);
  line-height:1.75; max-width:540px; margin:0 auto 2.5rem;
  animation:fadeUp 0.8s 0.24s ease both;
}

/* stats row */
.hero-stats {
  display:flex; gap:2.5rem; justify-content:center; flex-wrap:wrap;
  margin-bottom:3rem;
  animation:fadeUp 0.8s 0.36s ease both;
}
.stat-item { text-align:center; }
.stat-num {
  font-family:'Syne',sans-serif; font-weight:800;
  font-size:2rem; color:var(--paper); line-height:1;
}
.stat-num span { color:var(--accent2); }
.stat-label {
  font-family:'JetBrains Mono',monospace;
  font-size:0.6rem; letter-spacing:0.15em; text-transform:uppercase;
  color:var(--text3); margin-top:0.25rem;
}
.stat-sep {
  width:1px; background:var(--rule); align-self:stretch; margin:0.2rem 0;
}

.scroll-hint {
  font-family:'JetBrains Mono',monospace; font-size:0.65rem;
  color:rgba(237,238,245,0.25); letter-spacing:0.18em;
  animation:fadeUp 0.8s 0.5s ease both, pulse 2.5s 1.5s infinite;
}

@keyframes fadeUp {
  from { opacity:0; transform:translateY(22px); }
  to   { opacity:1; transform:translateY(0); }
}
@keyframes pulse {
  0%,100% { opacity:0.25; } 50% { opacity:0.6; }
}

/* ════════════════════════════════════════════
   FILTER BAR
   ════════════════════════════════════════════ */
.filter-bar {
  position:relative; z-index:1;
  background:var(--ink2);
  border-bottom:1px solid var(--rule);
  padding:1rem 2rem;
}
.filter-inner {
  max-width:1280px; margin:0 auto;
  display:flex; align-items:center; gap:0.75rem; flex-wrap:wrap;
}
.filter-label {
  font-family:'JetBrains Mono',monospace;
  font-size:0.62rem; letter-spacing:0.18em; text-transform:uppercase;
  color:var(--text3); margin-right:0.25rem;
}
.filter-chip {
  font-family:'JetBrains Mono',monospace; font-size:0.7rem;
  color:var(--text3); background:transparent;
  border:1px solid var(--rule); border-radius:20px;
  padding:4px 14px; cursor:pointer; transition:all 0.18s;
  letter-spacing:0.06em;
}
.filter-chip:hover { color:var(--text2); border-color:var(--text3); }
.filter-chip.active {
  color:var(--ink); background:var(--accent2);
  border-color:var(--accent2);
}

/* ════════════════════════════════════════════
   GRID SECTION
   ════════════════════════════════════════════ */
.sims-section {
  position:relative; z-index:1;
  max-width:1280px; margin:0 auto;
  padding:4rem 2rem 5rem;
}

.section-header {
  display:flex; align-items:baseline; justify-content:space-between;
  margin-bottom:2.5rem; flex-wrap:wrap; gap:1rem;
}
.section-eyebrow {
  font-family:'JetBrains Mono',monospace;
  font-size:0.62rem; letter-spacing:0.22em; text-transform:uppercase;
  color:var(--text3); margin-bottom:0.4rem;
  display:flex; align-items:center; gap:0.6rem;
}
.section-eyebrow::after { content:''; display:inline-block; width:40px; height:1px; background:var(--rule); }
.section-title {
  font-family:'Syne',sans-serif; font-weight:700;
  font-size:clamp(1.6rem,3vw,2.2rem); color:var(--text); line-height:1.1;
}
.section-count {
  font-family:'JetBrains Mono',monospace; font-size:0.7rem;
  color:var(--text3);
}
.section-count span { color:var(--accent2); }

/* sims grid */
.sims-grid {
  display:grid;
  grid-template-columns:repeat(auto-fill, minmax(340px, 1fr));
  gap:1.5rem;
}

/* ════════════════════════════════════════════
   SIMULATION CARD
   ════════════════════════════════════════════ */
.sim-card {
  background:var(--card);
  border:1px solid var(--card-border);
  border-radius:16px;
  overflow:hidden;
  transition:transform 0.28s cubic-bezier(.34,1.2,.64,1), box-shadow 0.28s, border-color 0.22s;
  cursor:pointer;
  position:relative;
  display:flex; flex-direction:column;
}
.sim-card:hover {
  transform:translateY(-6px);
  box-shadow:0 24px 60px rgba(0,0,0,0.55);
  border-color:var(--card-accent, var(--accent2));
}
.sim-card::after {
  content:''; position:absolute; inset:0;
  border-radius:16px;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,0.04);
  pointer-events:none;
}

/* card preview canvas */
.sim-preview {
  width:100%; height:200px;
  position:relative; overflow:hidden;
  background:var(--ink);
}
.sim-preview canvas {
  width:100%; height:100%; display:block;
}
.sim-preview-overlay {
  position:absolute; inset:0;
  background:linear-gradient(to bottom, transparent 50%, var(--card) 100%);
  pointer-events:none;
}

/* play button over preview */
.sim-play-btn {
  position:absolute; top:50%; left:50%;
  transform:translate(-50%,-50%) scale(0.85);
  width:54px; height:54px; border-radius:50%;
  background:rgba(8,10,18,0.7); backdrop-filter:blur(8px);
  border:2px solid rgba(255,255,255,0.15);
  display:flex; align-items:center; justify-content:center;
  font-size:1.4rem; color:rgba(255,255,255,0.85);
  transition:all 0.22s; pointer-events:none;
  opacity:0;
}
.sim-card:hover .sim-play-btn {
  opacity:1; transform:translate(-50%,-50%) scale(1);
  border-color:rgba(255,255,255,0.35);
  box-shadow:0 0 30px rgba(0,0,0,0.5);
}

/* subject badge */
.sim-subject {
  position:absolute; top:1rem; left:1rem;
  font-family:'JetBrains Mono',monospace; font-size:0.6rem;
  letter-spacing:0.12em; text-transform:uppercase;
  padding:3px 10px; border-radius:20px;
  background:rgba(8,10,18,0.75); backdrop-filter:blur(4px);
  border:1px solid rgba(255,255,255,0.1);
}

/* difficulty badge */
.sim-diff {
  position:absolute; top:1rem; right:1rem;
  font-family:'JetBrains Mono',monospace; font-size:0.58rem;
  letter-spacing:0.1em; text-transform:uppercase;
  padding:3px 10px; border-radius:20px;
  background:rgba(8,10,18,0.75); backdrop-filter:blur(4px);
  border:1px solid;
}
.diff-easy   { color:#3dba62; border-color:rgba(61,186,98,0.35); }
.diff-medium { color:#e0a832; border-color:rgba(224,168,50,0.35); }
.diff-hard   { color:#e05a20; border-color:rgba(224,90,32,0.35); }

/* card body */
.sim-body {
  padding:1.4rem 1.5rem 1.5rem;
  display:flex; flex-direction:column; flex:1;
}
.sim-num {
  font-family:'JetBrains Mono',monospace; font-size:0.6rem;
  color:var(--text3); margin-bottom:0.35rem; letter-spacing:0.1em;
}
.sim-title {
  font-family:'Syne',sans-serif; font-weight:700;
  font-size:1.25rem; color:var(--text); line-height:1.15;
  margin-bottom:0.5rem;
}
.sim-desc {
  font-size:0.85rem; color:var(--text2); line-height:1.65;
  margin-bottom:1.2rem; flex:1;
}

/* concepts chips */
.sim-concepts {
  display:flex; flex-wrap:wrap; gap:0.35rem; margin-bottom:1.3rem;
}
.concept-chip {
  font-family:'JetBrains Mono',monospace; font-size:0.62rem;
  color:var(--text3); background:var(--ink4);
  border:1px solid var(--rule); border-radius:20px;
  padding:2px 9px;
}

/* card footer */
.sim-footer {
  display:flex; align-items:center; justify-content:space-between;
  padding-top:1rem;
  border-top:1px solid var(--rule);
}
.sim-meta {
  display:flex; gap:1.2rem;
}
.sim-meta-item {
  display:flex; align-items:center; gap:0.35rem;
  font-family:'JetBrains Mono',monospace; font-size:0.62rem;
  color:var(--text3);
}
.sim-meta-item .meta-icon { font-size:0.75rem; opacity:0.7; }

.sim-link {
  display:inline-flex; align-items:center; gap:0.5rem;
  font-family:'JetBrains Mono',monospace; font-size:0.72rem;
  letter-spacing:0.06em; text-transform:uppercase;
  color:var(--ink); background:var(--card-accent, var(--accent2));
  border:none; border-radius:8px; padding:0.5rem 1.1rem;
  text-decoration:none; cursor:pointer;
  transition:opacity 0.2s, transform 0.18s;
  flex-shrink:0;
}
.sim-link:hover { opacity:0.88; transform:translateX(2px); }
.sim-link .link-arrow { font-size:0.85rem; transition:transform 0.18s; }
.sim-link:hover .link-arrow { transform:translateX(3px); }

/* ════════════════════════════════════════════
   COMING SOON CARD
   ════════════════════════════════════════════ */
.sim-card-soon {
  background:transparent;
  border:1px dashed var(--rule);
  border-radius:16px;
  display:flex; flex-direction:column;
  align-items:center; justify-content:center;
  padding:3rem 2rem; min-height:340px;
  text-align:center;
  transition:border-color 0.22s, background 0.22s;
}
.sim-card-soon:hover {
  border-color:var(--text3);
  background:rgba(255,255,255,0.015);
}
.soon-icon {
  font-size:2.5rem; margin-bottom:1rem; opacity:0.3;
}
.soon-label {
  font-family:'Syne',sans-serif; font-weight:600;
  font-size:1rem; color:var(--text3); margin-bottom:0.4rem;
}
.soon-sub {
  font-family:'JetBrains Mono',monospace; font-size:0.65rem;
  color:var(--text3); letter-spacing:0.1em; text-transform:uppercase;
  opacity:0.6;
}

/* ════════════════════════════════════════════
   FEATURED BANNER (large card top)
   ════════════════════════════════════════════ */
.featured-banner {
  position:relative; z-index:1;
  background:var(--ink3);
  border-top:1px solid var(--rule);
  border-bottom:1px solid var(--rule);
  overflow:hidden;
}
.featured-inner {
  max-width:1280px; margin:0 auto;
  display:grid; grid-template-columns:1fr 1fr;
  align-items:stretch; min-height:320px;
}
@media (max-width:800px) { .featured-inner { grid-template-columns:1fr; } }

.featured-text {
  padding:3.5rem 3rem;
  display:flex; flex-direction:column; justify-content:center;
}
.featured-eyebrow {
  font-family:'JetBrains Mono',monospace;
  font-size:0.62rem; letter-spacing:0.22em; text-transform:uppercase;
  color:var(--accent); margin-bottom:0.75rem;
  display:flex; align-items:center; gap:0.5rem;
}
.featured-eyebrow::before {
  content:''; display:inline-block; width:24px; height:2px;
  background:var(--accent); border-radius:1px;
}
.featured-title {
  font-family:'Syne',sans-serif; font-weight:800;
  font-size:clamp(1.8rem,3.5vw,2.8rem); color:var(--paper);
  line-height:1.1; margin-bottom:0.9rem;
}
.featured-title em { color:var(--accent); font-style:normal; }
.featured-desc {
  font-size:0.92rem; color:var(--text2); line-height:1.7;
  margin-bottom:1.8rem; max-width:440px;
}
.featured-link {
  display:inline-flex; align-items:center; gap:0.6rem;
  font-family:'JetBrains Mono',monospace; font-size:0.75rem;
  letter-spacing:0.08em; text-transform:uppercase;
  color:var(--ink); background:var(--accent);
  border-radius:10px; padding:0.7rem 1.6rem;
  text-decoration:none; font-weight:600;
  transition:opacity 0.2s, box-shadow 0.2s;
  align-self:flex-start;
}
.featured-link:hover { opacity:0.88; box-shadow:0 0 30px rgba(224,90,32,0.3); }
.featured-canvas {
  position:relative; overflow:hidden;
}
.featured-canvas canvas {
  width:100%; height:100%; min-height:320px; display:block;
}
.featured-canvas-overlay {
  position:absolute; inset:0;
  background:linear-gradient(to right, var(--ink3) 0%, transparent 30%, transparent 70%, var(--ink3) 100%);
  pointer-events:none;
}

/* ════════════════════════════════════════════
   BOTTOM STRIP — "à venir"
   ════════════════════════════════════════════ */
.upcoming-strip {
  position:relative; z-index:1;
  background:var(--ink2);
  border-top:1px solid var(--rule);
  padding:3rem 2rem;
}
.upcoming-inner { max-width:1280px; margin:0 auto; }
.upcoming-title {
  font-family:'Syne',sans-serif; font-weight:700;
  font-size:1.3rem; color:var(--text); margin-bottom:0.4rem;
}
.upcoming-sub {
  font-size:0.85rem; color:var(--text3); margin-bottom:1.8rem;
}
.upcoming-list {
  display:flex; flex-wrap:wrap; gap:0.6rem;
}
.upcoming-item {
  font-family:'JetBrains Mono',monospace; font-size:0.72rem;
  color:var(--text3); background:var(--ink4);
  border:1px solid var(--rule); border-radius:8px;
  padding:0.5rem 1rem;
  display:flex; align-items:center; gap:0.5rem;
  transition:border-color 0.18s, color 0.18s;
}
.upcoming-item:hover { border-color:var(--text3); color:var(--text2); }
.upcoming-item .tag-dot {
  width:6px; height:6px; border-radius:50%;
  background:var(--text3); flex-shrink:0;
}

/* ════════════════════════════════════════════
   FOOTER
   ════════════════════════════════════════════ */
footer {
  background:var(--ink); border-top:1px solid var(--rule);
  padding:2rem; text-align:center;
  font-family:'JetBrains Mono',monospace; font-size:0.62rem;
  color:rgba(237,238,245,0.18); letter-spacing:0.1em;
  position:relative; z-index:1;
}
footer a {
  color:rgba(74,158,221,0.5); text-decoration:none;
  transition:color 0.18s;
}
footer a:hover { color:var(--accent2); }

/* ════════════════════════════════════════════
   ANIMATIONS / UTILS
   ════════════════════════════════════════════ */
.reveal {
  opacity:0; transform:translateY(28px);
  transition:opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible { opacity:1; transform:translateY(0); }
.reveal-d1 { transition-delay:0.08s; }
.reveal-d2 { transition-delay:0.16s; }
.reveal-d3 { transition-delay:0.24s; }
.reveal-d4 { transition-delay:0.32s; }