:root{
    --bg:#F6F7F9;
    --surface:#FFFFFF;
    --surface-alpha:rgba(255,255,255,0.62);
    --ink:#151A21;
    --muted:#5B6472;
    --accent:#2F5D8A;
    --accent-ink:#FFFFFF;
    --line:rgba(21,26,33,0.09);
    --line-strong:rgba(21,26,33,0.16);
    --track-teaching:#2F5D8A;
    --track-industry:#6D5AA6;
    --track-university:#3F7D5C;
    --track-civic:#A6642F;
    --shadow:0 1px 2px rgba(21,26,33,0.04), 0 8px 24px -8px rgba(21,26,33,0.10);
  }
  @media (prefers-color-scheme: dark){
    :root:not([data-theme="light"]){
      --bg:#0E1116;
      --surface:#171B21;
      --surface-alpha:rgba(23,27,33,0.58);
      --ink:#EDEFF3;
      --muted:#9AA3AF;
      --accent:#6FA3D8;
      --accent-ink:#0E1116;
      --line:rgba(255,255,255,0.10);
      --line-strong:rgba(255,255,255,0.18);
      --track-teaching:#6FA3D8;
      --track-industry:#B0A0DD;
      --track-university:#74C49A;
      --track-civic:#DDA05F;
      --shadow:0 1px 2px rgba(0,0,0,0.3), 0 8px 28px -8px rgba(0,0,0,0.55);
    }
  }
  :root[data-theme="dark"]{
    --bg:#0E1116;
    --surface:#171B21;
    --surface-alpha:rgba(23,27,33,0.58);
    --ink:#EDEFF3;
    --muted:#9AA3AF;
    --accent:#6FA3D8;
    --accent-ink:#0E1116;
    --line:rgba(255,255,255,0.10);
    --line-strong:rgba(255,255,255,0.18);
    --track-teaching:#6FA3D8;
    --track-industry:#B0A0DD;
    --track-university:#74C49A;
    --track-civic:#DDA05F;
    --shadow:0 1px 2px rgba(0,0,0,0.3), 0 8px 28px -8px rgba(0,0,0,0.55);
  }

  *{box-sizing:border-box;}
  html{scroll-behavior:smooth;}
  @media (prefers-reduced-motion: reduce){
    html{scroll-behavior:auto;}
    *{animation-duration:0.001ms !important; animation-iteration-count:1 !important; transition-duration:0.001ms !important;}
  }
  body{
    margin:0;
    background:var(--bg);
    color:var(--ink);
    font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",system-ui,sans-serif;
    font-size:16px;
    line-height:1.6;
    -webkit-font-smoothing:antialiased;
    padding-inline:24px;
  }
  h1,h2,h3,.display{
    font-family:"Public Sans","Inter",-apple-system,system-ui,sans-serif;
    letter-spacing:-0.01em;
    text-wrap:balance;
    margin:0;
  }
  .mono{
    font-family:"JetBrains Mono","SFMono-Regular",Menlo,monospace;
  }
  a{color:inherit;}
  img{max-width:100%; display:block;}
  section{padding-block:clamp(56px,9vw,104px);}
  .wrap{max-width:1080px; margin-inline:auto;}
  .prose{max-width:640px;}
  .eyebrow{
    font-family:"JetBrains Mono",monospace;
    font-size:12px;
    letter-spacing:0.14em;
    text-transform:uppercase;
    color:var(--accent);
    font-weight:500;
  }
  .btn{
    display:inline-flex;
    align-items:center;
    gap:8px;
    padding:11px 20px;
    border-radius:100px;
    font-family:"Public Sans",sans-serif;
    font-weight:600;
    font-size:14.5px;
    text-decoration:none;
    border:1px solid transparent;
    cursor:pointer;
    transition:transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
  }
  .btn:active{transform:scale(0.97);}
  .btn-primary{background:var(--accent); color:var(--accent-ink);}
  .btn-primary:hover{opacity:0.9;}
  .btn-ghost{background:transparent; color:var(--ink); border-color:var(--line-strong);}
  .btn-ghost:hover{background:var(--line);}
  .glass{
    background:var(--surface-alpha);
    backdrop-filter:blur(20px) saturate(1.4);
    -webkit-backdrop-filter:blur(20px) saturate(1.4);
    border:1px solid var(--line);
  }
  .card{
    background:var(--surface);
    border:1px solid var(--line);
    border-radius:18px;
    box-shadow:var(--shadow);
  }

  /* ---------- Nav ---------- */
  nav.topnav{
    position:fixed; top:16px; left:0; right:0;
    z-index:50;
    display:flex; justify-content:center;
  }
  .nav-inner{
    display:flex; align-items:center; justify-content:space-between;
    gap:20px;
    width:min(920px, calc(100vw - 32px));
    padding:10px 10px 10px 18px;
    border-radius:100px;
  }
  .brand{
    font-family:"JetBrains Mono",monospace;
    font-weight:600;
    font-size:14px;
    letter-spacing:0.04em;
    white-space:nowrap;
  }
  .nav-links{display:flex; gap:22px; list-style:none; margin:0; padding:0;}
  .nav-links a{
    font-size:14px; font-weight:500; text-decoration:none; color:var(--muted);
    padding-block:6px;
    border-bottom:1px solid transparent;
    transition:color 0.15s ease, border-color 0.15s ease;
  }
  .nav-links a:hover{color:var(--ink); border-color:var(--line-strong);}
  .lang-toggle{
    display:flex; background:var(--line); border-radius:100px; padding:3px;
    font-family:"JetBrains Mono",monospace; font-size:12px; font-weight:600;
  }
  .lang-toggle button{
    border:none; background:transparent; color:var(--muted);
    padding:6px 12px; border-radius:100px; cursor:pointer;
    transition:background 0.15s ease, color 0.15s ease;
  }
  .lang-toggle button[aria-pressed="true"]{background:var(--accent); color:var(--accent-ink);}
  @media (max-width:720px){
    .nav-links{display:none;}
  }

  /* ---------- Hero ---------- */
  .hero{padding-top:clamp(120px,16vw,168px);}
  .hero-grid{
    display:grid;
    grid-template-columns:1.15fr 0.85fr;
    gap:56px;
    align-items:center;
  }
  .hero h1{font-size:clamp(34px,5.4vw,58px); font-weight:700; line-height:1.08;}
  .hero-sub{font-size:17px; color:var(--muted); max-width:520px; margin-top:18px;}
  .hero-actions{display:flex; gap:12px; margin-top:32px; flex-wrap:wrap;}
  .hero-photo-wrap{
    position:relative;
    aspect-ratio:4/5;
    border-radius:28px;
    overflow:hidden;
    box-shadow:var(--shadow);
    border:1px solid var(--line);
    max-width:340px;
    margin-inline:auto;
  }
  .hero-photo-wrap img{width:100%; height:100%; object-fit:cover;}
  @media (max-width:820px){
    .hero-grid{grid-template-columns:1fr; text-align:left;}
    .hero-photo-wrap{max-width:220px; margin:0;}
  }

  /* ---------- About ---------- */
  #about .prose p{margin:0 0 16px; color:var(--ink);}
  #about .prose p:last-child{margin-bottom:0;}

  /* ---------- Timeline ---------- */
  .filters{
    display:flex; gap:8px; overflow-x:auto; padding-bottom:4px; margin-bottom:36px;
    scrollbar-width:none;
  }
  .filters::-webkit-scrollbar{display:none;}
  .filter-pill{
    font-family:"JetBrains Mono",monospace;
    font-size:12.5px; font-weight:500;
    white-space:nowrap;
    padding:8px 16px;
    border-radius:100px;
    border:1px solid var(--line-strong);
    background:transparent;
    color:var(--muted);
    cursor:pointer;
    display:flex; align-items:center; gap:8px;
    transition:background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
  }
  .filter-pill .dot{width:7px; height:7px; border-radius:50%; flex:none;}
  .filter-pill[aria-pressed="true"]{
    background:var(--ink); color:var(--bg); border-color:var(--ink);
  }
  .timeline{position:relative; padding-left:28px; border-left:1px solid var(--line-strong);}
  .t-item{
    position:relative;
    padding-bottom:36px;
    opacity:0; transform:translateY(10px);
    transition:opacity 0.5s ease, transform 0.5s ease;
  }
  .t-item.in{opacity:1; transform:translateY(0);}
  .t-item:last-child{padding-bottom:0;}
  .t-item::before{
    content:"";
    position:absolute; left:-33.5px; top:5px;
    width:11px; height:11px; border-radius:50%;
    background:var(--dot-color, var(--accent));
    border:2px solid var(--bg);
    box-shadow:0 0 0 1px var(--line-strong);
  }
  .t-head{display:flex; flex-wrap:wrap; align-items:baseline; gap:10px 14px; margin-bottom:6px;}
  .t-title{font-family:"Public Sans",sans-serif; font-weight:600; font-size:17px;}
  .t-period{font-family:"JetBrains Mono",monospace; font-size:12.5px; color:var(--muted);}
  .t-org{font-size:14.5px; color:var(--accent); font-weight:500; margin-bottom:6px;}
  .t-desc{font-size:14.5px; color:var(--muted); max-width:600px;}

  /* ---------- Skills ---------- */
  .skills-grid{display:grid; grid-template-columns:1.1fr 0.9fr; gap:24px; align-items:start;}
  @media (max-width:820px){.skills-grid{grid-template-columns:1fr;}}
  .skill-cat{margin-bottom:22px;}
  .skill-cat:last-child{margin-bottom:0;}
  .skill-cat h3{font-size:13px; text-transform:uppercase; letter-spacing:0.08em; color:var(--muted); font-weight:600; margin-bottom:10px;}
  .tag-row{display:flex; flex-wrap:wrap; gap:8px;}
  .tag{
    font-family:"JetBrains Mono",monospace; font-size:12.5px;
    padding:6px 12px; border-radius:8px;
    background:var(--line); color:var(--ink);
  }
  .lang-row{margin-bottom:18px;}
  .lang-row:last-child{margin-bottom:0;}
  .lang-row-head{display:flex; justify-content:space-between; font-size:14.5px; margin-bottom:8px;}
  .lang-row-head b{font-weight:600;}
  .lang-row-head span{color:var(--muted); font-family:"JetBrains Mono",monospace; font-size:12.5px;}
  .bar-track{height:6px; border-radius:100px; background:var(--line); overflow:hidden;}
  .bar-fill{height:100%; border-radius:100px; background:var(--accent); width:0%; transition:width 1s ease;}

  /* ---------- Contact ---------- */
  .contact-grid{display:grid; grid-template-columns:1fr 0.85fr; gap:40px;}
  @media (max-width:820px){.contact-grid{grid-template-columns:1fr;}}
  .field{margin-bottom:16px;}
  .field label{display:block; font-size:13px; font-weight:500; color:var(--muted); margin-bottom:6px;}
  .field input, .field textarea{
    width:100%;
    padding:11px 14px;
    border-radius:10px;
    border:1px solid var(--line-strong);
    background:var(--surface);
    color:var(--ink);
    font-family:"Inter",sans-serif;
    font-size:14.5px;
    resize:vertical;
  }
  .field input:focus, .field textarea:focus{outline:2px solid var(--accent); outline-offset:1px;}
  .form-status{font-size:13.5px; margin-top:12px; min-height:18px;}
  .form-status.ok{color:var(--track-university);}
  .form-status.err{color:var(--track-civic);}
  .social-list{list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:10px;}
  .social-list a{
    display:flex; align-items:center; gap:12px;
    padding:12px 14px; border-radius:12px;
    text-decoration:none; font-size:14.5px; font-weight:500;
    transition:background 0.15s ease;
  }
  .social-list a:hover{background:var(--line);}
  .social-list svg{width:18px; height:18px; flex:none;}

  footer{
    border-top:1px solid var(--line);
    padding-block:28px;
    margin-top:20px;
  }
  .footer-row{display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:10px; font-size:13px; color:var(--muted);}
  .footer-row a{text-decoration:none; color:var(--muted);}
  .footer-row a:hover{color:var(--ink);}

  [data-i18n-html]{display:block;}
  :focus-visible{outline:2px solid var(--accent); outline-offset:2px;}