:root{
    --navy:#0D1526;
    --navy-2:#121d33;
    --teal:#0E7C86;
    --teal-bright:#14A3B0;
    --amber:#E8A23D;
    --off-white:#F5F7F8;
    --slate:#8B98A5;
    --line: rgba(245,247,248,0.14);
    --line-dark: rgba(13,21,38,0.12);
    --ink:#0D1526;
    --font-display:'Space Grotesk', sans-serif;
    --font-body:'Inter', sans-serif;
    --font-mono:'IBM Plex Mono', monospace;
  }
  :root:not([data-theme="light"]){ }
  @media (prefers-color-scheme: dark){
    :root:not([data-theme="light"]){ --page-bg: var(--navy); }
  }
  :root[data-theme="dark"]{ --page-bg: var(--navy); }

  *{box-sizing:border-box; margin:0; padding:0;}
  html{scroll-behavior:smooth;}
  body{
    font-family:var(--font-body);
    background:var(--off-white);
    color:var(--ink);
    -webkit-font-smoothing:antialiased;
    overflow-x:hidden;
  }
  img{max-width:100%; display:block;}
  a{color:inherit; text-decoration:none;}
  .wrap{max-width:1120px; margin:0 auto; padding:0 24px;}
  .scrollx{overflow-x:auto;}

  h1,h2,h3{font-family:var(--font-display); font-weight:600; letter-spacing:-0.01em; line-height:1.08;}
  p{line-height:1.6; color:var(--slate);}

  /* ===== Header ===== */
  header{
    position:sticky; top:0; z-index:50;
    background:rgba(13,21,38,0.96);
    backdrop-filter:blur(6px);
    border-bottom:1px solid var(--line);
  }
  .nav{
    display:flex; align-items:center; justify-content:space-between;
    height:68px; max-width:1120px; margin:0 auto; padding:0 24px;
  }
  .brand{display:flex; align-items:center; gap:10px; font-family:var(--font-display); font-weight:700; font-size:1.1rem; color:var(--off-white);}
  .brand .mark{
    width:30px; height:30px; border:1.5px solid var(--teal-bright); border-radius:4px;
    display:flex; align-items:center; justify-content:center; position:relative;
  }
  .brand .mark::before{
    content:""; width:10px; height:10px; background:var(--amber); border-radius:1px;
  }
  .navlinks{display:flex; gap:30px; font-size:0.92rem;}
  .navlinks a{color:#C7D0D8; transition:color .15s;}
  .navlinks a:hover{color:var(--off-white);}
  .navcta{
    background:var(--teal); color:var(--off-white); font-size:0.88rem; font-weight:600;
    padding:9px 18px; border-radius:3px; border:1px solid var(--teal);
    white-space:nowrap;
  }
  .navcta:hover{background:var(--teal-bright); border-color:var(--teal-bright);}
  .navmob{display:none;}

  /* ===== Hero: IC pinout concept ===== */
  .hero{
    background:var(--navy);
    color:var(--off-white);
    padding:76px 0 0;
    position:relative;
  }
  .hero-top{display:grid; grid-template-columns:1.1fr 0.9fr; gap:56px; align-items:center;}
  .eyebrow-line{
    display:flex; align-items:center; gap:10px; margin-bottom:22px;
  }
  .eyebrow-line .dash{width:28px; height:1.5px; background:var(--amber);}
  .eyebrow-line span{font-family:var(--font-mono); font-size:0.78rem; color:var(--amber); letter-spacing:0.02em;}
  .hero h1{font-size:clamp(2.1rem, 4vw, 3.05rem); color:var(--off-white); max-width:12ch;}
  .hero h1 em{font-style:normal; color:var(--teal-bright);}
  .hero p.lead{margin-top:20px; color:#B7C2CC; font-size:1.05rem; max-width:46ch;}
  .hero-ctas{display:flex; gap:14px; margin-top:32px; flex-wrap:wrap;}
  .btn{
    display:inline-block; padding:13px 24px; border-radius:3px; font-weight:600; font-size:0.95rem;
    transition: transform .12s ease, background .15s;
  }
  .btn:hover{transform:translateY(-1px);}
  .btn-primary{background:var(--teal); color:var(--off-white);}
  .btn-primary:hover{background:var(--teal-bright);}
  .btn-outline{border:1px solid rgba(245,247,248,0.3); color:var(--off-white);}
  .btn-outline:hover{border-color:var(--off-white);}
  .btn-amber{background:var(--amber); color:var(--navy);}
  .btn-amber:hover{background:#f0b25c;}

  /* IC chip diagram */
  .chip-wrap{display:flex; align-items:center; justify-content:center; padding:20px 0;}
  .chip{
    position:relative; width:220px; height:220px; background:var(--navy-2);
    border:1.5px solid var(--teal); border-radius:6px;
    display:flex; align-items:center; justify-content:center;
    box-shadow: 0 0 0 1px rgba(14,124,134,0.15), 0 30px 60px -20px rgba(0,0,0,0.5);
  }
  .chip-notch{
    position:absolute; top:-1px; left:50%; transform:translateX(-50%);
    width:28px; height:10px; background:var(--navy); border:1.5px solid var(--teal); border-top:none;
    border-radius:0 0 10px 10px;
  }
  .chip-label{font-family:var(--font-mono); font-size:0.72rem; color:var(--teal-bright); text-align:center; line-height:1.5; letter-spacing:0.02em;}
  .chip-label b{display:block; font-family:var(--font-display); font-size:0.95rem; color:var(--off-white); font-weight:600; margin-bottom:4px;}
  .pin{position:absolute; display:flex; align-items:center; gap:8px;}
  .pin .leg{background:var(--teal); }
  .pin .lbl{font-family:var(--font-mono); font-size:0.68rem; color:#C7D0D8; white-space:nowrap;}
  .pin.top{top:-46px; flex-direction:column-reverse;}
  .pin.top .leg{width:1.5px; height:36px;}
  .pin.bottom{bottom:-46px; flex-direction:column;}
  .pin.bottom .leg{width:1.5px; height:36px;}
  .pin.left{left:-118px; flex-direction:row;}
  .pin.left .leg{width:36px; height:1.5px;}
  .pin.right{right:-118px; flex-direction:row-reverse;}
  .pin.right .leg{width:36px; height:1.5px;}
  .p1{top:-46px; left:38px;} .p2{top:-46px; left:112px;} .p3{top:-46px; left:186px;}
  .p4{bottom:-46px; left:38px;} .p5{bottom:-46px; left:112px;} .p6{bottom:-46px; left:186px;}
  .p7{left:-118px; top:70px;} .p8{left:-118px; top:150px;}
  .p9{right:-118px; top:70px;} .p10{right:-118px; top:150px;}

  .hero-stats{
    border-top:1px solid var(--line); margin-top:60px;
    display:grid; grid-template-columns:repeat(4,1fr);
  }
  .hero-stats div{padding:20px 0; border-right:1px solid var(--line);}
  .hero-stats div:last-child{border-right:none;}
  .hero-stats .num{font-family:var(--font-display); font-size:1.5rem; font-weight:700; color:var(--off-white);}
  .hero-stats .lbl{font-family:var(--font-mono); font-size:0.72rem; color:var(--slate); margin-top:4px;}

  /* ===== Section shell ===== */
  section{padding:88px 0;}
  .section-head{display:flex; justify-content:space-between; align-items:flex-end; gap:24px; margin-bottom:44px; flex-wrap:wrap;}
  .section-head .tag{font-family:var(--font-mono); font-size:0.78rem; color:var(--teal); margin-bottom:10px; display:block;}
  .section-head h2{font-size:clamp(1.5rem,2.6vw,2rem); color:var(--ink);}
  .section-head p{max-width:44ch; margin-top:10px;}

  /* ===== Three doors ===== */
  .doors{background:var(--off-white);}
  .door-grid{display:grid; grid-template-columns:repeat(3,1fr); border:1px solid var(--line-dark);}
  .door{
    padding:36px 30px; border-right:1px solid var(--line-dark); position:relative;
  }
  .door:last-child{border-right:none;}
  .door .idx{font-family:var(--font-mono); font-size:0.78rem; color:var(--teal); margin-bottom:16px; display:block;}
  .door h3{font-size:1.2rem; margin-bottom:10px;}
  .door p{font-size:0.92rem; margin-bottom:20px;}
  .door a.link{font-size:0.88rem; font-weight:600; color:var(--teal); border-bottom:1.5px solid var(--teal); padding-bottom:2px;}
  .door a.link:hover{color:var(--navy); border-color:var(--navy);}

  /* ===== Learn hub ===== */
  .learn{background:var(--navy); color:var(--off-white);}
  .learn .section-head p{color:#B7C2CC;}
  .learn .section-head .tag{color:var(--amber);}
  .topic-grid{display:grid; grid-template-columns:repeat(4,1fr); gap:1px; background:var(--line);}
  .topic{
    background:var(--navy); padding:26px 22px; min-height:150px;
    display:flex; flex-direction:column; justify-content:space-between;
    transition:background .15s;
  }
  .topic:hover{background:var(--navy-2);}
  .topic .code{font-family:var(--font-mono); font-size:0.7rem; color:var(--slate);}
  .topic h4{font-family:var(--font-display); font-size:1.02rem; font-weight:600; margin-top:16px; color:var(--off-white);}
  .topic .count{font-family:var(--font-mono); font-size:0.76rem; color:var(--teal-bright); margin-top:10px;}

  /* ===== Mentors ===== */
  .mentors{background:var(--off-white);}
  .mentor-grid{display:grid; grid-template-columns:repeat(3,1fr); gap:0; border-top:1px solid var(--line-dark);}
  .mentor{padding:30px 0 0; border-right:1px solid var(--line-dark);}
  .mentor:last-child{border-right:none;}
  .mentor .avatar{
    width:52px; height:52px; border-radius:50%; background:var(--teal); color:#fff;
    display:flex; align-items:center; justify-content:center; font-family:var(--font-display); font-weight:600;
    margin-bottom:16px;
  }
  .mentor h4{font-size:1.05rem; margin-bottom:4px;}
  .mentor .role{font-size:0.82rem; color:var(--teal); font-weight:600; margin-bottom:12px;}
  .mentor p{font-size:0.88rem;}
  .mentor .tags{display:flex; gap:8px; margin-top:14px; flex-wrap:wrap;}
  .mentor .tags span{font-family:var(--font-mono); font-size:0.68rem; color:var(--slate); border:1px solid var(--line-dark); padding:4px 8px; border-radius:3px;}

  /* ===== Sample question strip ===== */
  .sample{background:var(--navy-2); color:var(--off-white); border-top:1px solid var(--line); border-bottom:1px solid var(--line);}
  .sample-grid{display:grid; grid-template-columns:0.9fr 1.1fr; gap:50px; align-items:center;}
  .sample .tag{font-family:var(--font-mono); font-size:0.78rem; color:var(--amber); display:block; margin-bottom:14px;}
  .sample h2{font-size:clamp(1.4rem,2.4vw,1.9rem); margin-bottom:16px;}
  .sample p{color:#B7C2CC; margin-bottom:24px;}
  .code-card{
    background:var(--navy); border:1px solid var(--line); border-radius:4px; overflow:hidden;
  }
  .code-card .bar{display:flex; gap:6px; padding:12px 16px; border-bottom:1px solid var(--line);}
  .code-card .bar span{width:8px; height:8px; border-radius:50%; background:#3a4658;}
  .code-card pre{
    font-family:var(--font-mono); font-size:0.82rem; color:#CFEAEC; padding:20px; overflow-x:auto; line-height:1.7;
  }
  .code-card pre .q{color:var(--amber);}
  .code-card pre .c{color:#6d7d8f;}

  /* ===== Workshops/Mock CTA ===== */
  .cta-band{background:var(--teal); color:#fff;}
  .cta-band .wrap{display:flex; justify-content:space-between; align-items:center; gap:30px; flex-wrap:wrap;}
  .cta-band h2{font-size:clamp(1.4rem,2.4vw,1.85rem); color:#fff; max-width:20ch;}
  .cta-band p{color:rgba(255,255,255,0.85); margin-top:10px; max-width:40ch;}
  .cta-band .btn-amber{flex-shrink:0;}

  /* ===== Footer ===== */
  footer{background:var(--navy); color:#B7C2CC; padding:64px 0 28px;}
  .foot-grid{display:grid; grid-template-columns:1.4fr 1fr 1fr 1fr; gap:40px; padding-bottom:44px; border-bottom:1px solid var(--line);}
  .foot-brand .brand{margin-bottom:14px;}
  .foot-grid p{font-size:0.88rem; max-width:32ch;}
  .foot-col h5{font-family:var(--font-mono); font-size:0.74rem; color:var(--slate); margin-bottom:16px; letter-spacing:0.02em;}
  .foot-col a{display:block; font-size:0.88rem; color:#C7D0D8; margin-bottom:11px;}
  .foot-col a:hover{color:var(--off-white);}
  .foot-bottom{display:flex; justify-content:space-between; align-items:center; padding-top:24px; font-size:0.8rem; color:var(--slate); flex-wrap:wrap; gap:12px;}

  /* ===== Responsive ===== */
  @media (max-width:880px){
    .navlinks{display:none;}
    .hero-top{grid-template-columns:1fr;}
    .chip-wrap{order:-1; padding:50px 0 20px;}
    .pin.left, .pin.right{display:none;}
    .hero-stats{grid-template-columns:repeat(2,1fr);}
    .door-grid{grid-template-columns:1fr;}
    .door{border-right:none; border-bottom:1px solid var(--line-dark);}
    .topic-grid{grid-template-columns:repeat(2,1fr);}
    .mentor-grid{grid-template-columns:1fr; gap:30px;}
    .mentor{border-right:none; padding-top:0;}
    .sample-grid{grid-template-columns:1fr;}
    .foot-grid{grid-template-columns:1fr 1fr; row-gap:36px;}
    .cta-band .wrap{flex-direction:column; align-items:flex-start;}
  }
  @media (max-width:520px){
    .topic-grid{grid-template-columns:1fr;}
    .foot-grid{grid-template-columns:1fr;}
    .hero-stats{grid-template-columns:1fr 1fr;}
  }

  /* content protection: soft deterrent, not real security */
  body{ -webkit-user-select:none; -moz-user-select:none; user-select:none; }
  input, textarea, select{ -webkit-user-select:text; user-select:text; }

  /* More on this site — footer internal-linking section */
  .more-onsite{border-top:1px solid var(--line); padding-top:26px; margin-top:32px;}
  .more-onsite .label{font-family:var(--font-mono); font-size:0.7rem; color:var(--slate); text-align:center; letter-spacing:0.04em; margin-bottom:18px; display:block;}
  .more-onsite .links{display:flex; flex-wrap:wrap; justify-content:center; row-gap:8px;}
  .more-onsite .links a{color:#9aa7b3; font-size:0.82rem; padding:0 12px; border-right:1px solid var(--line); line-height:1.4;}
  .more-onsite .links a:last-child{border-right:none;}
  .more-onsite .links a:hover{color:var(--off-white);}
  @media (max-width:600px){ .more-onsite .links a{padding:0 8px;} }