:root{
    --bg: #0D1210;
    --bg-alt: #10160F;
    --panel: #171F1B;
    --panel-line: #2A342E;
    --amber: #FFB020;
    --amber-dim: #8a6a2c;
    --green: #5B8C6E;
    --text: #E8E6DD;
    --text-dim: #8B948B;
    --mono: 'JetBrains Mono', monospace;
    --sans: 'Inter', sans-serif;
  }

  *{ box-sizing: border-box; margin:0; padding:0; }

  body{
    background: var(--bg);
    color: var(--text);
    font-family: var(--sans);
    line-height: 1.6;
    overflow-x: hidden;
  }

  a{ color: inherit; }

  ::selection{ background: var(--amber); color: #0D1210; }

  :focus-visible{
    outline: 2px solid var(--amber);
    outline-offset: 3px;
  }

  /* background grid texture */
  .grid-bg{
    position: fixed;
    inset: 0;
    z-index: 0;
    background-image:
      linear-gradient(rgba(91,140,110,0.06) 1px, transparent 1px),
      linear-gradient(90deg, rgba(91,140,110,0.06) 1px, transparent 1px);
    background-size: 42px 42px;
    pointer-events: none;
  }

  /* signature trace line */
  .trace-svg{
    position: fixed;
    top: 0;
    left: 24px;
    height: 100vh;
    width: 40px;
    z-index: 1;
    pointer-events: none;
  }
  .trace-path{
    fill: none;
    stroke: var(--green);
    stroke-width: 1.5;
    opacity: 0.35;
    stroke-dasharray: 6 6;
  }
  .trace-node{
    fill: var(--amber);
    opacity: 0.8;
  }

  @media (max-width: 900px){
    .trace-svg{ display: none; }
  }

  .wrap{
    position: relative;
    z-index: 2;
    max-width: 980px;
    margin: 0 auto;
    padding: 0 32px;
  }

  header.top{
    padding: 28px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--panel-line);
  }
  .logo{
    font-family: var(--mono);
    font-weight: 700;
    letter-spacing: 0.5px;
    font-size: 15px;
    color: var(--amber);
  }
  .logo span{ color: var(--text-dim); }
  nav a{
    font-family: var(--mono);
    font-size: 13px;
    color: var(--text-dim);
    text-decoration: none;
    margin-left: 28px;
  }
  nav a:hover{ color: var(--amber); }

  /* HERO */
  .hero{
    padding: 100px 0 90px;
  }
  .status-line{
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--mono);
    font-size: 12px;
    color: var(--green);
    border: 1px solid var(--panel-line);
    background: var(--panel);
    padding: 6px 12px;
    border-radius: 3px;
    margin-bottom: 32px;
  }
  .dot{
    width: 7px; height: 7px;
    border-radius: 50%;
    background: var(--green);
    box-shadow: 0 0 8px var(--green);
    animation: blink 2.4s infinite;
  }
  @keyframes blink{
    0%, 100%{ opacity: 1; }
    50%{ opacity: 0.3; }
  }
  @media (prefers-reduced-motion: reduce){
    .dot{ animation: none; }
  }

  h1{
    font-family: var(--mono);
    font-weight: 800;
    font-size: clamp(32px, 5vw, 52px);
    line-height: 1.15;
    letter-spacing: -0.5px;
    max-width: 760px;
  }
  h1 .accent{ color: var(--amber); }

  .hero-sub{
    margin-top: 24px;
    max-width: 560px;
    color: var(--text-dim);
    font-size: 17px;
  }

  .hero-cta{
    margin-top: 40px;
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
  }
  .btn{
    font-family: var(--mono);
    font-size: 13px;
    padding: 12px 20px;
    border-radius: 3px;
    text-decoration: none;
    display: inline-block;
    border: 1px solid var(--panel-line);
    transition: border-color 0.15s ease, background 0.15s ease;
  }
  .btn-primary{
    background: var(--amber);
    color: #10160F;
    border-color: var(--amber);
    font-weight: 700;
  }
  .btn-primary:hover{ background: #ffc451; }
  .btn-ghost{ color: var(--text); }
  .btn-ghost:hover{ border-color: var(--amber); color: var(--amber); }

  /* SECTION LABEL */
  .sec-label{
    font-family: var(--mono);
    font-size: 12px;
    color: var(--amber-dim);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 14px;
  }
  section{ padding: 70px 0; border-top: 1px solid var(--panel-line); }

  .about p{
    max-width: 640px;
    font-size: 16px;
    color: var(--text-dim);
  }
  .about strong{ color: var(--text); font-weight: 600; }

  /* TIMELINE */
  .tl-item{
    padding: 18px 0;
    border-bottom: 1px solid var(--panel-line);
  }
  .tl-item:last-of-type{ border-bottom: none; }
  .tl-head{
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 8px;
  }
  .tl-role{
    font-family: var(--mono);
    font-weight: 700;
    font-size: 15px;
  }
  .tl-date{
    font-family: var(--mono);
    font-size: 12px;
    color: var(--amber-dim);
  }
  .tl-desc{
    margin-top: 6px;
    color: var(--text-dim);
    font-size: 14px;
    max-width: 620px;
  }

  /* PROJECT SUBGROUPS */
  .proj-subhead{
    font-family: var(--mono);
    font-size: 13px;
    color: var(--text-dim);
    margin: 36px 0 14px;
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .proj-subhead::after{
    content: '';
    flex: 1;
    height: 1px;
    background: var(--panel-line);
  }
  .cad-grid{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 14px;
  }
  .cad-card{
    background: var(--panel);
    border: 1px solid var(--panel-line);
    border-radius: 4px;
    overflow: hidden;
  }
  .cad-thumb{
    aspect-ratio: 4/3;
    background:
      repeating-linear-gradient(45deg, var(--panel-line) 0, var(--panel-line) 1px, transparent 1px, transparent 12px),
      var(--bg-alt);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--mono);
    font-size: 11px;
    color: var(--text-dim);
  }
  .cad-label{
    padding: 12px 14px;
    font-family: var(--mono);
    font-size: 13px;
  }

  /* PROJECTS */
  .proj-grid{
    display: grid;
    grid-template-columns: 1fr;
    gap: 18px;
    margin-top: 24px;
  }
  .card{
    background: var(--panel);
    border: 1px solid var(--panel-line);
    border-radius: 4px;
    padding: 26px;
    transition: border-color 0.2s ease;
  }
  .card:hover{ border-color: var(--green); }
  .card-top{
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 16px;
    flex-wrap: wrap;
  }
  .card h3{
    font-family: var(--mono);
    font-size: 19px;
    font-weight: 700;
  }
  .card-result{
    font-family: var(--mono);
    font-size: 12px;
    color: var(--green);
    white-space: nowrap;
  }
  .card p.desc{
    margin-top: 10px;
    color: var(--text-dim);
    font-size: 14.5px;
    max-width: 620px;
  }
  .tags{
    margin-top: 16px;
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
  }
  .tag{
    font-family: var(--mono);
    font-size: 11px;
    color: var(--text-dim);
    border: 1px solid var(--panel-line);
    padding: 3px 8px;
    border-radius: 2px;
  }
  .card-link{
    margin-top: 18px;
    display: inline-block;
    font-family: var(--mono);
    font-size: 12.5px;
    color: var(--amber);
    text-decoration: none;
  }
  .card-link:hover{ text-decoration: underline; }

  /* STACK LAYERS */
  .layer{
    margin-bottom: 28px;
  }
  .layer-title{
    font-family: var(--mono);
    font-size: 13px;
    color: var(--text);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .layer-title::after{
    content: '';
    flex: 1;
    height: 1px;
    background: var(--panel-line);
  }
  .chip-row{ display: flex; flex-wrap: wrap; gap: 10px; }
  .chip{
    font-family: var(--mono);
    font-size: 13px;
    padding: 7px 14px;
    border-radius: 3px;
    border: 1px solid var(--panel-line);
  }
  .chip.core{ color: var(--amber); border-color: var(--amber-dim); background: rgba(255,176,32,0.06); }
  .chip.support{ color: var(--text-dim); }

  /* CV */
  .cv-row{
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
    margin-top: 20px;
  }

  footer{
    padding: 50px 0 70px;
    border-top: 1px solid var(--panel-line);
    color: var(--text-dim);
    font-size: 13px;
    font-family: var(--mono);
  }
  footer .infra-note{
    margin-top: 10px;
    color: var(--green);
  }

  @media (min-width: 640px){
    .proj-grid{ grid-template-columns: 1fr; }
  }