:root{
    --ink:#0E1116;
    --panel:#161B22;
    --panel-2:#1D242D;
    --line: rgba(245,243,238,0.08);
    --myelin:#F2B341;
    --myelin-dim: rgba(242,179,65,0.15);
    --signal:#5EEAD4;
    --signal-dim: rgba(94,234,212,0.15);
    --text:#F5F3EE;
    --muted:#94A0AF;
    --radius: 14px;
  }
  *{box-sizing:border-box; margin:0; padding:0;}
  html{scroll-behavior:smooth;}
  body{
    background:var(--ink);
    color:var(--text);
    font-family:'IBM Plex Sans', sans-serif;
    line-height:1.6;
    -webkit-font-smoothing:antialiased;
  }
  h1,h2,h3{
    font-family:'Space Grotesk', sans-serif;
    font-weight:600;
    letter-spacing:-0.01em;
  }
  .eyebrow{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.75rem;
    letter-spacing:0.14em;
    text-transform:uppercase;
    color:var(--signal);
    display:flex;
    align-items:center;
    gap:0.6rem;
  }
  .eyebrow::before{
    content:'';
    width:18px;
    height:1px;
    background:var(--signal);
    display:inline-block;
  }
  a{color:inherit; text-decoration:none;}
  .wrap{
    max-width:1180px;
    margin:0 auto;
    padding:0 32px;
  }
  @media (max-width:640px){ .wrap{padding:0 20px;} }

  /* ---------- NAV ---------- */
  nav{
    position:fixed; top:0; left:0; right:0; z-index:100;
    background:rgba(14,17,22,0.85);
    backdrop-filter:blur(10px);
    border-bottom:1px solid var(--line);
  }
  .nav-inner{
    max-width:1180px; margin:0 auto; padding:18px 32px;
    display:flex; align-items:center; justify-content:space-between;
  }
  @media (max-width:640px){ .nav-inner{padding:16px 20px;} }
  .logo{
    font-family:'Space Grotesk', sans-serif;
    font-weight:700;
    font-size:1.15rem;
    letter-spacing:-0.01em;
    display:flex; align-items:center; gap:8px;
  }
  .logo .it{color:var(--myelin);}
  .nav-links{display:flex; gap:36px; font-size:0.92rem; color:var(--muted);}
  .nav-links a:hover{color:var(--text);}
  .nav-cta{
    font-size:0.88rem; font-weight:500;
    padding:9px 18px;
    border:1px solid var(--myelin);
    border-radius:999px;
    color:var(--myelin);
    transition:all .2s ease;
    white-space:nowrap;
  }
  .nav-cta:hover{background:var(--myelin); color:var(--ink);}
  @media (max-width:820px){ .nav-links{display:none;} }

  /* ---------- HERO ---------- */
  .hero{
    padding:168px 0 100px;
    position:relative;
    overflow:hidden;
  }
  .hero-grid{
    display:grid;
    grid-template-columns:1.1fr 0.9fr;
    gap:60px;
    align-items:center;
  }
  @media (max-width:900px){ .hero-grid{grid-template-columns:1fr; gap:56px;} .hero{padding:140px 0 72px;} }

  .hero h1{
    font-size:clamp(2.4rem, 5vw, 3.6rem);
    line-height:1.08;
    margin:20px 0 22px;
  }
  .hero h1 em{
    font-style:normal;
    color:var(--myelin);
  }
  .hero p.lede{
    font-size:1.1rem;
    color:var(--muted);
    max-width:480px;
    margin-bottom:34px;
  }
  .hero-ctas{display:flex; gap:16px; flex-wrap:wrap;}
  .btn-primary{
    background:var(--myelin);
    color:var(--ink);
    font-weight:600;
    padding:14px 28px;
    border-radius:999px;
    font-size:0.95rem;
    transition:transform .2s ease, box-shadow .2s ease;
    display:inline-block;
  }
  .btn-primary:hover{transform:translateY(-2px); box-shadow:0 10px 30px -8px var(--myelin-dim);}
  .btn-ghost{
    border:1px solid var(--line);
    padding:14px 28px;
    border-radius:999px;
    font-size:0.95rem;
    color:var(--text);
    transition:border-color .2s ease;
  }
  .btn-ghost:hover{border-color:var(--signal); color:var(--signal);}

  /* signature: animated neural pathway */
  .pathway-box{
    position:relative;
    background:var(--panel);
    border:1px solid var(--line);
    border-radius:var(--radius);
    padding:28px;
    height:340px;
  }
  .pathway-box svg{width:100%; height:100%; display:block;}
  .pathway-label{
    position:absolute; top:22px; left:28px;
    font-family:'IBM Plex Mono', monospace;
    font-size:0.7rem;
    color:var(--muted);
    letter-spacing:0.08em;
    text-transform:uppercase;
  }
  .pathway-caption{
    position:absolute; bottom:22px; left:28px; right:28px;
    font-family:'IBM Plex Mono', monospace;
    font-size:0.72rem;
    color:var(--muted);
    display:flex;
    justify-content:space-between;
  }
  .pathway-caption .fast{color:var(--signal);}

  @media (prefers-reduced-motion: reduce){
    .pulse, .pulse2, .pulse3 { animation: none !important; }
  }

  /* ---------- SECTION SHARED ---------- */
  section{padding:96px 0;}
  .section-head{max-width:640px; margin-bottom:56px;}
  .section-head h2{font-size:clamp(1.7rem, 3vw, 2.3rem); margin-top:16px;}
  .section-head p{color:var(--muted); margin-top:14px; font-size:1.02rem;}

  /* ---------- METAPHOR SECTION ---------- */
  .metaphor{background:var(--panel); border-top:1px solid var(--line); border-bottom:1px solid var(--line);}
  .metaphor-grid{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:64px;
    align-items:center;
  }
  @media (max-width:900px){ .metaphor-grid{grid-template-columns:1fr; gap:40px;} }
  .metaphor-copy p{color:var(--muted); margin-bottom:18px; font-size:1.02rem;}
  .metaphor-copy strong{color:var(--text); font-weight:600;}
  .fiber-diagram{
    background:var(--ink);
    border:1px solid var(--line);
    border-radius:var(--radius);
    padding:36px 30px;
  }
  .fiber-row{display:flex; align-items:center; gap:16px; margin-bottom:28px;}
  .fiber-row:last-child{margin-bottom:0;}
  .fiber-label{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.72rem;
    color:var(--muted);
    width:96px;
    flex-shrink:0;
  }
  .fiber-track{flex:1; height:10px; background:var(--panel-2); border-radius:6px; position:relative; overflow:hidden;}
  .fiber-fill{position:absolute; top:0; left:0; height:100%; border-radius:6px;}
  .fiber-fill.f1{width:28%; background:var(--muted);}
  .fiber-fill.f2{width:62%; background:var(--myelin);}
  .fiber-fill.f3{width:94%; background:var(--signal);}

  /* ---------- TRACKS ---------- */
  .tracks-grid{
    display:grid;
    grid-template-columns:repeat(3, 1fr);
    gap:20px;
  }
  @media (max-width:900px){ .tracks-grid{grid-template-columns:repeat(2,1fr);} }
  @media (max-width:600px){ .tracks-grid{grid-template-columns:1fr;} }
  .track-card{
    background:var(--panel);
    border:1px solid var(--line);
    border-radius:var(--radius);
    padding:26px;
    transition:border-color .2s ease, transform .2s ease;
  }
  .track-card:hover{border-color:var(--myelin); transform:translateY(-3px);}
  .track-card .tag{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.68rem;
    color:var(--signal);
    letter-spacing:0.08em;
    text-transform:uppercase;
  }
  .track-card h3{font-size:1.12rem; margin:12px 0 8px;}
  .track-card p{color:var(--muted); font-size:0.92rem;}

  /* ---------- FOUNDER ---------- */
  .founder{
    background:var(--panel);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
  }
  .founder-grid{
    display:grid;
    grid-template-columns:auto 1fr;
    gap:40px;
    align-items:start;
  }
  @media (max-width:700px){ .founder-grid{grid-template-columns:1fr;} }
  .founder-mark{
    width:64px; height:64px;
    border-radius:50%;
    background:linear-gradient(135deg, var(--myelin), var(--signal));
    display:flex; align-items:center; justify-content:center;
    font-family:'Space Grotesk', sans-serif;
    font-weight:700;
    color:var(--ink);
    font-size:1.3rem;
    flex-shrink:0;
  }
  .founder-copy p{color:var(--muted); margin-bottom:14px; font-size:1.02rem; max-width:640px;}
  .founder-copy strong{color:var(--text);}

  /* ---------- CTA ---------- */
  .cta{
    text-align:center;
    padding:110px 0;
  }
  .cta h2{font-size:clamp(1.9rem, 4vw, 2.6rem); margin-bottom:18px;}
  .cta p{color:var(--muted); max-width:480px; margin:0 auto 34px;}

  /* ---------- FOOTER ---------- */
  footer{
    border-top:1px solid var(--line);
    padding:36px 0;
  }
  .footer-inner{
    display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:16px;
    font-size:0.85rem; color:var(--muted);
  }
  .footer-inner .logo{font-size:1rem;}

  /* ---------- PAGE HEADER (inner pages) ---------- */
  .page-header{
    padding:168px 0 64px;
    border-bottom:1px solid var(--line);
  }
  .page-header h1{
    font-size:clamp(2rem, 4vw, 2.8rem);
    margin-top:16px;
  }
  .page-header p{color:var(--muted); margin-top:14px; max-width:560px; font-size:1.02rem;}

  /* ---------- ABOUT PAGE ---------- */
  .about-grid{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:64px;
    align-items:start;
  }
  @media (max-width:900px){ .about-grid{grid-template-columns:1fr; gap:40px;} }
  .about-copy p{color:var(--muted); margin-bottom:18px; font-size:1.02rem;}
  .about-copy strong{color:var(--text);}
  .value-list{list-style:none;}
  .value-list li{
    padding:20px 0;
    border-bottom:1px solid var(--line);
  }
  .value-list li:first-child{padding-top:0;}
  .value-list .num{
    font-family:'IBM Plex Mono', monospace;
    color:var(--signal);
    font-size:0.8rem;
    display:block;
    margin-bottom:6px;
  }
  .value-list h3{font-size:1.05rem; margin-bottom:6px;}
  .value-list p{color:var(--muted); font-size:0.92rem;}

  /* ---------- CONTACT PAGE / FORM ---------- */
  .contact-grid{
    display:grid;
    grid-template-columns:0.9fr 1.1fr;
    gap:56px;
    align-items:start;
  }
  @media (max-width:900px){ .contact-grid{grid-template-columns:1fr; gap:40px;} }
  .contact-info p{color:var(--muted); margin-bottom:22px; font-size:1.02rem;}
  .contact-item{margin-bottom:22px;}
  .contact-item .label{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.7rem;
    color:var(--signal);
    letter-spacing:0.08em;
    text-transform:uppercase;
    display:block;
    margin-bottom:6px;
  }
  .contact-item .value{font-size:1rem;}

  form.contact-form{
    background:var(--panel);
    border:1px solid var(--line);
    border-radius:var(--radius);
    padding:32px;
  }
  .form-row{margin-bottom:20px;}
  .form-row label{
    display:block;
    font-size:0.85rem;
    color:var(--muted);
    margin-bottom:8px;
  }
  .form-row input, .form-row textarea{
    width:100%;
    background:var(--ink);
    border:1px solid var(--line);
    border-radius:8px;
    padding:12px 14px;
    color:var(--text);
    font-family:'IBM Plex Sans', sans-serif;
    font-size:0.95rem;
    outline:none;
    transition:border-color .2s ease;
  }
  .form-row input:focus, .form-row textarea:focus{border-color:var(--signal);}
  .form-row textarea{resize:vertical; min-height:120px;}
  .form-submit{
    background:var(--myelin);
    color:var(--ink);
    font-weight:600;
    padding:13px 26px;
    border-radius:999px;
    font-size:0.95rem;
    border:none;
    cursor:pointer;
    transition:transform .2s ease, box-shadow .2s ease;
  }
  .form-submit:hover{transform:translateY(-2px); box-shadow:0 10px 30px -8px var(--myelin-dim);}
  .form-note{font-size:0.8rem; color:var(--muted); margin-top:14px;}

  /* ---------- COURSE DETAIL PAGES ---------- */
  .course-hero{
    padding:168px 0 64px;
    border-bottom:1px solid var(--line);
  }
  .course-hero h1{font-size:clamp(2rem, 4vw, 2.7rem); margin:16px 0 18px;}
  .course-hero p.lede{color:var(--muted); max-width:600px; font-size:1.05rem;}
  .course-meta{display:flex; gap:28px; flex-wrap:wrap; margin-top:28px;}
  .course-meta-item{
    font-family:'IBM Plex Mono', monospace;
    font-size:0.78rem;
    color:var(--muted);
  }
  .course-meta-item span{color:var(--signal); display:block; font-size:0.68rem; text-transform:uppercase; letter-spacing:0.08em; margin-bottom:4px;}

  .curriculum-grid{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:20px;
  }
  @media (max-width:760px){ .curriculum-grid{grid-template-columns:1fr;} }
  .curriculum-item{
    background:var(--panel);
    border:1px solid var(--line);
    border-radius:var(--radius);
    padding:22px 24px;
  }
  .curriculum-item h3{font-size:1rem; margin-bottom:8px;}
  .curriculum-item p{color:var(--muted); font-size:0.9rem;}

  .approach-row{
    display:grid;
    grid-template-columns:repeat(3,1fr);
    gap:20px;
  }
  @media (max-width:760px){ .approach-row{grid-template-columns:1fr;} }
  .approach-item{padding:22px 0; border-top:1px solid var(--line);}
  .approach-item .num{font-family:'IBM Plex Mono', monospace; color:var(--myelin); font-size:0.8rem; display:block; margin-bottom:8px;}
  .approach-item h3{font-size:1rem; margin-bottom:6px;}
  .approach-item p{color:var(--muted); font-size:0.9rem;}

  .related-tracks{
    display:flex; gap:14px; flex-wrap:wrap; margin-top:20px;
  }
  .related-pill{
    border:1px solid var(--line);
    border-radius:999px;
    padding:8px 18px;
    font-size:0.85rem;
    color:var(--muted);
    transition:border-color .2s ease, color .2s ease;
  }
  .related-pill:hover{border-color:var(--signal); color:var(--signal);}