:root{
    /* warm-dark engineering ground, orange bias in the neutrals */
    --bg:#0E0B09;
    --bg-2:#141019;/* unused fallback */
    --surface:#171210;
    --surface-2:#1E1815;
    --line:#2C2420;
    --line-2:#3A302A;
    --text:#EFE8E1;
    --muted:#A79688;
    --faint:#6F6157;
    --accent:#FF6A1A;
    --accent-soft:#FFA45C;
    --accent-deep:#C24400;
    --good:#54C08A;
    --grid:rgba(255,106,26,.05);
    --radius:14px;
    --maxw:1120px;
    --mono:ui-monospace,"SF Mono","JetBrains Mono","Cascadia Code",Menlo,Consolas,monospace;
    --sans:system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  }
  @media (prefers-color-scheme: light){
    :root{
      --bg:#F6F3EE;
      --surface:#FFFFFF;
      --surface-2:#FBF8F3;
      --line:#E6DED3;
      --line-2:#D8CDBE;
      --text:#211A14;
      --muted:#6C5E51;
      --faint:#9A8B7C;
      --accent:#E2540A;
      --accent-soft:#B8440A;
      --accent-deep:#B8440A;
      --good:#2E8E5C;
      --grid:rgba(226,84,10,.06);
    }
  }
  :root[data-theme="dark"]{
    --bg:#0E0B09;--surface:#171210;--surface-2:#1E1815;--line:#2C2420;--line-2:#3A302A;
    --text:#EFE8E1;--muted:#A79688;--faint:#6F6157;--accent:#FF6A1A;--accent-soft:#FFA45C;
    --accent-deep:#C24400;--good:#54C08A;--grid:rgba(255,106,26,.05);
  }
  :root[data-theme="light"]{
    --bg:#F6F3EE;--surface:#FFFFFF;--surface-2:#FBF8F3;--line:#E6DED3;--line-2:#D8CDBE;
    --text:#211A14;--muted:#6C5E51;--faint:#9A8B7C;--accent:#E2540A;--accent-soft:#B8440A;
    --accent-deep:#B8440A;--good:#2E8E5C;--grid:rgba(226,84,10,.06);
  }

  *{box-sizing:border-box}
  body{
    margin:0;min-height:100vh;background:var(--bg);color:var(--text);
    font-family:var(--sans);line-height:1.6;
    -webkit-font-smoothing:antialiased;overflow-x:hidden;
  }
  .wrap{max-width:var(--maxw);margin:0 auto;padding:0 clamp(20px,5vw,44px)}
  a{color:inherit;text-decoration:none}
  h1,h2,h3{margin:0;text-wrap:balance;letter-spacing:-.02em;line-height:1.05;font-weight:750}

  .eyebrow{
    font-family:var(--mono);font-size:12px;letter-spacing:.18em;text-transform:uppercase;
    color:var(--accent);display:inline-flex;align-items:center;gap:9px;font-weight:600;
  }
  .eyebrow::before{content:"";width:22px;height:1px;background:var(--accent);opacity:.7}

  /* ---------- NAV ---------- */
  .nav{
    position:sticky;top:0;z-index:50;
    backdrop-filter:blur(14px);background:color-mix(in srgb,var(--bg) 82%,transparent);
    border-bottom:1px solid var(--line);
  }
  .nav-in{display:flex;align-items:center;gap:22px;height:64px}
  .brand{display:flex;align-items:center;gap:10px;font-family:var(--mono);font-weight:600;font-size:16px;letter-spacing:-.01em}
  .brand .by{color:var(--faint);font-size:12px;letter-spacing:.04em}
  .logo-img{height:44px;width:auto;display:block}
  footer .logo-img{height:34px}
  .nav-links{display:flex;gap:26px;margin-left:auto}
  .nav-links a{font-size:14px;color:var(--muted);transition:color .2s}
  .nav-links a:hover{color:var(--text)}
  .nav-tools{display:flex;align-items:center;gap:8px}
  .btn-ghost{
    font-family:var(--mono);font-size:12.5px;border:1px solid var(--line-2);color:var(--muted);
    background:transparent;padding:7px 11px;border-radius:8px;cursor:pointer;transition:all .2s;letter-spacing:.02em;
  }
  .btn-ghost:hover{border-color:var(--accent);color:var(--text)}
  .btn-ghost .on{color:var(--accent)}
  @media (max-width:760px){.nav-links{display:none}}

  /* ---------- HERO ---------- */
  .hero{position:relative;padding:clamp(40px,6vw,72px) 0 0}
  .hero::before{
    content:"";position:absolute;inset:0;z-index:0;pointer-events:none;
    background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
    background-size:46px 46px;
    -webkit-mask-image:radial-gradient(120% 80% at 78% 0%,#000 0%,transparent 62%);
    mask-image:radial-gradient(120% 80% at 78% 0%,#000 0%,transparent 62%);
  }
  .hero-grid{position:relative;z-index:1;display:grid;grid-template-columns:1.15fr .85fr;gap:clamp(28px,4vw,56px);align-items:center}
  @media (max-width:900px){.hero-grid{grid-template-columns:1fr;gap:34px}}
  .hero h1{font-size:clamp(34px,5.4vw,62px);margin:20px 0 0}
  .hero h1 .hl{color:var(--accent)}
  .hero p.lead{font-size:clamp(16px,1.5vw,19px);color:var(--muted);max-width:52ch;margin:22px 0 0}
  .hero-cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:32px}
  .btn{
    display:inline-flex;align-items:center;gap:9px;font-weight:600;font-size:15px;
    padding:13px 22px;border-radius:10px;cursor:pointer;transition:transform .15s,box-shadow .2s,background .2s;
  }
  .btn-primary{background:var(--accent);color:#150a02;box-shadow:0 8px 26px -10px var(--accent-deep)}
  .btn-primary:hover{transform:translateY(-2px)}
  .btn-line{border:1px solid var(--line-2);color:var(--text);background:transparent;font-family:var(--mono);font-size:13.5px}
  .btn-line:hover{border-color:var(--accent)}
  .btn .arw{transition:transform .2s}
  .btn:hover .arw{transform:translateX(3px)}

  /* router card = the thesis */
  .router{
    background:linear-gradient(180deg,var(--surface-2),var(--surface));
    border:1px solid var(--line);border-radius:var(--radius);
    box-shadow:0 30px 70px -40px rgba(0,0,0,.7);overflow:hidden;
  }
  .router-bar{display:flex;align-items:center;gap:7px;padding:12px 15px;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--surface) 60%,transparent)}
  .router-bar .dot{width:10px;height:10px;border-radius:50%;background:var(--line-2)}
  .router-bar .lbl{margin-left:8px;font-family:var(--mono);font-size:12px;color:var(--faint);letter-spacing:.04em}
  .router-body{padding:22px 20px 24px;font-family:var(--mono);font-size:14px;line-height:1.5}
  .rline{display:flex;gap:12px;align-items:baseline;opacity:0;transform:translateY(6px);animation:rin .5s ease forwards}
  .rline .k{color:var(--faint);width:34px;flex:none;font-size:12px}
  .rline .v{color:var(--text)}
  .rline .mut{color:var(--muted)}
  .rline .acc{color:var(--accent)}
  .rline .good{color:var(--good)}
  .rarrow{color:var(--line-2);margin:2px 0 2px 46px;opacity:0;animation:rin .5s ease forwards}
  .caret{display:inline-block;width:8px;height:15px;background:var(--accent);margin-left:3px;vertical-align:-2px;animation:blink 1.1s steps(1) infinite}
  @keyframes rin{to{opacity:1;transform:none}}
  @keyframes blink{50%{opacity:0}}
  .rl1{animation-delay:.15s}.rl2{animation-delay:.5s}.rl3{animation-delay:.85s}
  .rl4{animation-delay:1.2s}.rl5{animation-delay:1.65s}.rl6{animation-delay:2s}

  /* ---------- STATS ---------- */
  .stats{border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin-top:clamp(24px,3vw,36px)}
  .stats-in{display:grid;grid-template-columns:repeat(3,1fr)}
  .stat{padding:26px 4px;text-align:center;border-right:1px solid var(--line)}
  .stat:last-child{border-right:0}
  .stat .n{font-size:clamp(24px,3vw,34px);font-weight:750;letter-spacing:-.02em;font-variant-numeric:tabular-nums}
  .stat .n b{color:var(--accent);font-weight:750}
  .stat .c{font-family:var(--mono);font-size:11.5px;text-transform:uppercase;letter-spacing:.13em;color:var(--muted);margin-top:6px}
  @media (max-width:640px){.stats-in{grid-template-columns:1fr}.stat{border-right:0;border-bottom:1px solid var(--line)}.stat:last-child{border-bottom:0}}

  /* ---------- SECTION SHELL ---------- */
  section{padding:clamp(30px,3.6vw,50px) 0;position:relative}
  .sec-head{max-width:640px}
  .sec-head h2{font-size:clamp(26px,3.4vw,40px);margin:16px 0 0}
  .sec-head p{color:var(--muted);margin:16px 0 0;font-size:16.5px}
  .divider{height:1px;background:var(--line)}

  /* lifecycle */
  .flow{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:30px}
  @media (max-width:820px){.flow{grid-template-columns:1fr 1fr}}
  @media (max-width:480px){.flow{grid-template-columns:1fr}}
  .step{
    background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px 20px;position:relative;overflow:hidden;
  }
  .step .no{font-family:var(--mono);font-size:12px;color:var(--accent);letter-spacing:.1em}
  .step h3{font-size:17px;margin:14px 0 8px;letter-spacing:-.01em}
  .step p{color:var(--muted);font-size:14px;margin:0}
  .step code{font-family:var(--mono);font-size:12.5px;color:var(--accent-soft);background:color-mix(in srgb,var(--accent) 10%,transparent);padding:1px 6px;border-radius:5px;display:inline-block;margin-top:12px}

  /* architecture */
  .cards{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:30px}
  @media (max-width:860px){.cards{grid-template-columns:1fr}}
  .card{
    background:linear-gradient(180deg,var(--surface-2),var(--surface));
    border:1px solid var(--line);border-radius:var(--radius);padding:28px 26px;transition:border-color .25s,transform .25s;
  }
  .card:hover{border-color:var(--line-2);transform:translateY(-3px)}
  .card .ic{width:40px;height:40px;border-radius:10px;display:grid;place-items:center;border:1px solid var(--line-2);color:var(--accent);margin-bottom:18px}
  .card .ic svg{width:20px;height:20px}
  .card h3{font-size:19px;margin-bottom:10px}
  .card p{color:var(--muted);font-size:14.5px;margin:0}
  .card .tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:16px}
  .tag{font-family:var(--mono);font-size:11px;color:var(--muted);border:1px solid var(--line);border-radius:20px;padding:3px 9px;letter-spacing:.03em}

  /* why grid */
  .why{display:grid;grid-template-columns:repeat(2,1fr);gap:0;margin-top:30px;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
  @media (max-width:700px){.why{grid-template-columns:1fr}}
  .prop{padding:30px 28px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);background:var(--surface)}
  .prop:nth-child(2n){border-right:0}
  .prop:nth-last-child(-n+2){border-bottom:0}
  @media (max-width:700px){.prop{border-right:0}.prop:nth-last-child(2){border-bottom:1px solid var(--line)}}
  .prop .h{display:flex;align-items:center;gap:12px}
  .prop .mk{font-family:var(--mono);font-size:12px;color:var(--accent);border:1px solid var(--line-2);border-radius:6px;padding:2px 7px}
  .prop h3{font-size:18px}
  .prop p{color:var(--muted);font-size:14.5px;margin:12px 0 0}

  /* showcase */
  .grid-p{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:30px}
  @media (max-width:860px){.grid-p{grid-template-columns:1fr 1fr}}
  @media (max-width:520px){.grid-p{grid-template-columns:1fr}}
  .proj{
    background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px 22px 20px;
    display:flex;flex-direction:column;gap:8px;transition:border-color .25s,transform .25s;min-height:150px;
  }
  .proj:hover{border-color:var(--accent);transform:translateY(-3px)}
  .proj .dom{font-family:var(--mono);font-size:12px;color:var(--accent);letter-spacing:.02em}
  .proj h3{font-size:18px}
  .proj p{color:var(--muted);font-size:13.5px;margin:0}
  .proj .kind{margin-top:auto;font-family:var(--mono);font-size:11px;color:var(--faint);text-transform:uppercase;letter-spacing:.1em;padding-top:12px}

  /* CTA band */
  .cta{
    margin:0 0 0;border:1px solid var(--line);border-radius:20px;
    background:radial-gradient(120% 160% at 15% 0%,color-mix(in srgb,var(--accent) 16%,var(--surface)) 0%,var(--surface) 55%);
    padding:clamp(40px,6vw,68px) clamp(26px,5vw,60px);text-align:center;
  }
  .cta h2{font-size:clamp(26px,3.6vw,42px)}
  .cta p{color:var(--muted);margin:16px auto 0;max-width:46ch;font-size:16.5px}
  .cta .hero-cta{justify-content:center}

  /* footer */
  footer{border-top:1px solid var(--line);margin-top:clamp(28px,4vw,44px);padding:30px 0 36px}
  .foot-in{display:flex;flex-wrap:wrap;gap:18px;align-items:center;justify-content:space-between}
  .foot-in .note{font-family:var(--mono);font-size:12px;color:var(--faint);letter-spacing:.02em}
  .foot-in .note b{color:var(--muted);font-weight:600}

  /* reveal */
  .rv{opacity:0;transform:translateY(16px);transition:opacity .7s ease,transform .7s ease}
  .rv.in{opacity:1;transform:none}
  @media (prefers-reduced-motion:reduce){
    .rv{opacity:1;transform:none;transition:none}
    .rline,.rarrow{animation:none;opacity:1;transform:none}
    .caret{animation:none}
  }
  :focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px}

/* --- language switch (server-side /tr /en) --- */
.lang-switch{display:flex;align-items:center;gap:6px;font-family:var(--mono);font-size:12.5px;border:1px solid var(--line-2);border-radius:8px;padding:6px 10px}
.lang-switch a{color:var(--muted);transition:color .2s}
.lang-switch a.on{color:var(--accent)}
.lang-switch a:hover{color:var(--text)}
.lang-switch span{color:var(--line-2)}