@font-face{font-family:'Inter';font-weight:400;font-display:swap;src:url('../fonts/inter-400.woff2') format('woff2')}
@font-face{font-family:'Inter';font-weight:500;font-display:swap;src:url('../fonts/inter-500.woff2') format('woff2')}
@font-face{font-family:'Inter';font-weight:600;font-display:swap;src:url('../fonts/inter-600.woff2') format('woff2')}
@font-face{font-family:'Inter';font-weight:700;font-display:swap;src:url('../fonts/inter-700.woff2') format('woff2')}
@font-face{font-family:'Inter';font-weight:800;font-display:swap;src:url('../fonts/inter-800.woff2') format('woff2')}

:root{
  --brand:#2f6cf0;--brand-dark:#1f57cf;--brand-light:#e7effe;--navy:#0f2448;--navy-2:#16315f;
  --accent:#6366f1;--cyan:#22c5c9;--ok:#16a34a;--ok-bg:#dcfce7;--bad:#dc2626;--bad-bg:#fee2e2;--warn:#d97706;--warn-bg:#fef3c7;
  --ink:#0f172a;--muted:#64748b;--line:#e2e8f0;--bg:#f4f7fc;--card:#fff;--r:14px;
  --shadow:0 1px 2px rgba(15,36,72,.06),0 8px 24px rgba(15,36,72,.08);
}
*{box-sizing:border-box}
html,body{margin:0}
body{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--ink);background:var(--bg);line-height:1.55;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}
button{font:inherit;cursor:pointer}
img,svg{max-width:100%}
.wrap{max-width:1240px;margin:0 auto;padding:0 18px}

/* ---------- header ---------- */
.top{position:sticky;top:0;z-index:50;background:var(--navy);color:#fff;box-shadow:0 2px 12px rgba(0,0,0,.18)}
.top .wrap{display:flex;align-items:center;gap:14px;height:62px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:800;letter-spacing:-.01em;white-space:nowrap}
.brand img{width:36px;height:36px;border-radius:8px}
.brand small{display:block;font-weight:500;font-size:11px;opacity:.7;letter-spacing:.04em;text-transform:uppercase}
.nav{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none;flex:1;margin-left:10px}
.nav::-webkit-scrollbar{display:none}
.nav a{color:#cbd5e1;font-size:14px;font-weight:600;padding:8px 12px;border-radius:9px;white-space:nowrap}
.nav a:hover{color:#fff;background:rgba(255,255,255,.08)}
.nav a.on{color:#fff;background:var(--brand)}
.nav a .dot{display:inline-block;width:7px;height:7px;border-radius:50%;background:#22c55e;margin-left:6px;vertical-align:middle}
.prog-pill{font-size:12px;font-weight:700;background:rgba(255,255,255,.1);padding:6px 10px;border-radius:999px;white-space:nowrap}
@media(max-width:820px){
  .top .wrap{height:auto;flex-wrap:wrap;padding-top:8px;padding-bottom:8px;gap:8px}
  .nav{order:3;flex-basis:100%;margin:0}
  .brand small{display:none}
  .prog-pill{margin-left:auto}
}

/* ---------- generic ---------- */
main{padding:26px 0 60px;min-height:70vh}
h1,h2,h3{letter-spacing:-.02em;line-height:1.2;margin:0 0 .4em}
h1{font-size:clamp(26px,4vw,40px);font-weight:800}
h2{font-size:clamp(20px,2.6vw,26px);font-weight:800}
h3{font-size:17px;font-weight:700}
p{margin:0 0 .8em}
.muted{color:var(--muted)}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow)}
.pad{padding:18px}
.grid{display:grid;gap:16px}
.g2{grid-template-columns:repeat(auto-fill,minmax(300px,1fr))}
.g3{grid-template-columns:repeat(auto-fill,minmax(250px,1fr))}
.g4{grid-template-columns:repeat(auto-fill,minmax(170px,1fr))}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:0;border-radius:10px;padding:10px 16px;font-weight:700;font-size:14px;background:var(--brand);color:#fff;transition:.15s}
.btn:hover{background:var(--brand-dark)}
.btn.ghost{background:#fff;color:var(--navy);border:1px solid var(--line)}
.btn.ghost:hover{border-color:var(--brand);color:var(--brand)}
.btn.ok{background:var(--ok)}
.btn.sm{padding:7px 12px;font-size:13px}
.btn[disabled]{opacity:.45;pointer-events:none}
.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{border:1px solid var(--line);background:#fff;border-radius:999px;padding:6px 13px;font-size:13px;font-weight:600;color:var(--navy)}
.chip.on{background:var(--navy);color:#fff;border-color:var(--navy)}
.tag{display:inline-block;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.05em;padding:3px 8px;border-radius:6px;background:var(--brand-light);color:var(--brand-dark)}
.input{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:10px;font:inherit;background:#fff}
.input:focus{outline:2px solid var(--brand);border-color:transparent}
.head-row{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-bottom:18px}
.kbd{font-family:ui-monospace,Consolas,monospace;font-size:12px;background:#eef2f7;border:1px solid var(--line);border-radius:5px;padding:1px 6px}

/* ---------- hero ---------- */
.hero{background:linear-gradient(135deg,var(--navy) 0%,#1c3f86 60%,var(--brand) 100%);color:#fff;border-radius:22px;padding:34px;display:grid;grid-template-columns:1.2fr 1fr;gap:26px;align-items:center;overflow:hidden;position:relative}
.hero p{color:#dbe6ff;font-size:16px}
.hero .art{background:rgba(255,255,255,.06);border-radius:16px;padding:10px}
.hero .stats{display:flex;gap:22px;margin-top:18px;flex-wrap:wrap}
.hero .stats b{display:block;font-size:24px}
.hero .stats span{font-size:12px;color:#b8c8ee;text-transform:uppercase;letter-spacing:.05em}
@media(max-width:820px){.hero{grid-template-columns:1fr;padding:22px}}

.mod{display:flex;flex-direction:column;gap:8px;padding:18px;transition:.15s;color:inherit}
.mod:hover{transform:translateY(-3px);border-color:var(--brand)}
.mod .ic{width:48px;height:48px;border-radius:12px;display:grid;place-items:center;background:var(--brand-light);font-size:24px}
.mod .bar{height:6px;background:#eef2f7;border-radius:9px;overflow:hidden;margin-top:auto}
.mod .bar i{display:block;height:100%;background:linear-gradient(90deg,var(--brand),var(--cyan))}
.mod .done{color:var(--ok);font-size:12px;font-weight:700}
.safety li{margin-bottom:6px}

/* ---------- parts explorer ---------- */
.pcard{padding:12px;text-align:center;cursor:pointer;transition:.15s;position:relative;border:1px solid var(--line);background:#fff;border-radius:var(--r)}
.pcard:hover{border-color:var(--brand);transform:translateY(-2px)}
.pcard .pic{background:#f1f5fb;border-radius:10px;aspect-ratio:200/140;display:grid;place-items:center}
.pcard .pic svg{width:100%;height:100%}
.pcard b{display:block;font-size:14px;margin-top:8px}
.pcard small{color:var(--muted);font-size:12px}
.pcard .seen{position:absolute;top:8px;right:8px;background:var(--ok);color:#fff;border-radius:50%;width:20px;height:20px;font-size:12px;display:grid;place-items:center}
.detail{display:grid;grid-template-columns:1fr 1.2fr;gap:22px}
.detail .pic{background:#f1f5fb;border-radius:14px;padding:10px}
.detail dl{margin:0}
.detail dt{font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.05em;color:var(--brand-dark);margin-top:12px}
.detail dd{margin:3px 0 0}
.detail ul{margin:4px 0 0;padding-left:18px}
.hinglish{background:var(--warn-bg);border-left:4px solid var(--warn);padding:10px 12px;border-radius:8px;margin-top:14px;font-size:14px}
@media(max-width:760px){.detail{grid-template-columns:1fr}}

/* ---------- modal / toast ---------- */
.modal-bg{position:fixed;inset:0;background:rgba(10,20,40,.55);z-index:100;display:grid;place-items:center;padding:16px;animation:fade .15s}
.modal{background:#fff;border-radius:18px;max-width:860px;width:100%;max-height:92vh;overflow:auto;padding:22px;position:relative;box-shadow:0 20px 60px rgba(0,0,0,.3)}
.modal .x{position:absolute;top:10px;right:12px;border:0;background:#f1f5f9;border-radius:50%;width:34px;height:34px;font-size:18px}
@keyframes fade{from{opacity:0}to{opacity:1}}
.toast{position:fixed;left:50%;bottom:22px;transform:translateX(-50%);z-index:120;padding:12px 18px;border-radius:12px;font-weight:600;font-size:14px;box-shadow:0 10px 30px rgba(0,0,0,.2);max-width:min(560px,92vw);animation:up .2s}
.toast.ok{background:#14532d;color:#fff}.toast.bad{background:#7f1d1d;color:#fff}.toast.info{background:var(--navy);color:#fff}
@keyframes up{from{transform:translate(-50%,20px);opacity:0}}

/* ---------- lab layout ---------- */
.lab{display:grid;grid-template-columns:290px 1fr;gap:16px;align-items:start}
.lab .side{position:sticky;top:78px;display:flex;flex-direction:column;gap:12px}
@media(max-width:900px){.lab{grid-template-columns:1fr}.lab .side{position:static}}
.scene{background:radial-gradient(circle at 30% 20%,#23324a,#0d1626);border-radius:16px;padding:10px;position:relative;touch-action:manipulation}
.scene svg{display:block;width:100%;height:auto;user-select:none;-webkit-user-select:none}
.scene.light{background:#e9eef6}
.steps{list-style:none;margin:0;padding:0;font-size:14px}
.steps li{display:flex;gap:10px;align-items:flex-start;padding:7px 0;border-bottom:1px dashed var(--line);color:var(--muted)}
.steps li:last-child{border:0}
.steps li .n{flex:0 0 24px;height:24px;border-radius:50%;background:#eef2f7;display:grid;place-items:center;font-size:12px;font-weight:700}
.steps li.cur{color:var(--ink);font-weight:600}
.steps li.cur .n{background:var(--brand);color:#fff}
.steps li.ok{color:var(--ok)}
.steps li.ok .n{background:var(--ok);color:#fff}
.task{background:var(--navy);color:#fff;border-radius:12px;padding:14px}
.task b{display:block;font-size:15px;margin-bottom:4px}
.task p{color:#c7d5f2;font-size:13px;margin:0}
.tray{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}
.titem{border:2px solid var(--line);border-radius:12px;background:#fff;padding:6px;text-align:center;font-size:12px;font-weight:700;color:var(--navy);touch-action:none;user-select:none;transition:.12s;position:relative}
.titem svg{width:100%;height:auto;pointer-events:none}
.titem.sel{border-color:var(--brand);box-shadow:0 0 0 3px rgba(47,108,240,.25)}
.titem.need{animation:pulse 1.4s infinite}
.titem.used{opacity:.35;pointer-events:none}
.titem .cnt{position:absolute;top:4px;right:6px;background:var(--navy);color:#fff;border-radius:8px;padding:0 6px;font-size:11px}
@keyframes pulse{0%,100%{box-shadow:0 0 0 0 rgba(47,108,240,.45)}50%{box-shadow:0 0 0 6px rgba(47,108,240,0)}}
.dragghost{position:fixed;z-index:200;pointer-events:none;width:110px;opacity:.9;transform:translate(-50%,-50%);filter:drop-shadow(0 8px 16px rgba(0,0,0,.35))}
.meter{height:10px;background:#eef2f7;border-radius:9px;overflow:hidden}
.meter i{display:block;height:100%;transition:width .4s}
.scorebox{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;text-align:center}
.scorebox div{background:#f1f5fb;border-radius:10px;padding:8px}
.scorebox b{display:block;font-size:20px}
.scorebox span{font-size:11px;color:var(--muted);text-transform:uppercase;font-weight:700}
.infobar{min-height:46px;background:#fff;border:1px solid var(--line);border-radius:12px;padding:10px 12px;font-size:14px}
.infobar b{color:var(--brand-dark)}

/* svg interaction */
[data-zone]{cursor:pointer}
.zone-hl{fill:rgba(34,197,201,.18);stroke:#22c5c9;stroke-width:2;stroke-dasharray:6 4;animation:dash 1s linear infinite}
.zone-hover{fill:rgba(250,204,21,.28)!important;stroke:#facc15!important}
.hs{fill:transparent;stroke:transparent;stroke-width:2;transition:.12s}
.hs:hover,.hs.on{fill:rgba(250,204,21,.22);stroke:#facc15}
.hs.found{fill:rgba(34,197,94,.25);stroke:#22c55e}
.hs.wrong{fill:rgba(239,68,68,.3);stroke:#ef4444}
@keyframes dash{to{stroke-dashoffset:-20}}
.flash-ok{animation:fok .6s}
@keyframes fok{0%{filter:drop-shadow(0 0 0 #22c55e)}50%{filter:drop-shadow(0 0 12px #22c55e)}100%{filter:none}}
.cable{fill:none;stroke-linecap:round;stroke-linejoin:round}
.cable.behind{stroke-dasharray:3 5;opacity:.45}
.cable.draw{stroke-dasharray:1400;stroke-dashoffset:1400;animation:draw .9s forwards}
@keyframes draw{to{stroke-dashoffset:0}}
.blink{animation:blink 1s steps(2) infinite}
@keyframes blink{50%{opacity:0}}
.spin{transform-box:fill-box;transform-origin:center;animation:spin 1s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

/* quiz */
.qopts{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:14px}
.qopt{border:2px solid var(--line);background:#fff;border-radius:12px;padding:12px 14px;text-align:left;font-weight:600;font-size:15px;color:var(--ink)}
.qopt:hover{border-color:var(--brand)}
.qopt.right{border-color:var(--ok);background:var(--ok-bg)}
.qopt.wrongp{border-color:var(--bad);background:var(--bad-bg)}
.qopt[disabled]{cursor:default}
.explain{margin-top:12px;padding:12px;border-radius:10px;background:#f1f5fb;font-size:14px}
@media(max-width:600px){.qopts{grid-template-columns:1fr}}
.qpic{background:#f1f5fb;border-radius:14px;max-width:420px;margin:0 auto}

/* choice cards (in modals) */
.choices{display:grid;grid-template-columns:repeat(auto-fill,minmax(125px,1fr));gap:10px;margin-top:12px}
.choice{border:2px solid var(--line);background:#fff;border-radius:12px;padding:10px;text-align:center;font-weight:600;font-size:13px}
.choice:hover{border-color:var(--brand)}
.choice svg{width:100%;height:auto}
.choice.pick{border-color:var(--brand);background:var(--brand-light)}
.checklist label{display:flex;gap:10px;align-items:center;padding:9px 12px;border:1px solid var(--line);border-radius:10px;margin-bottom:8px;cursor:pointer}
.checklist input{width:18px;height:18px}

/* front panel mini-game */
.fp-wrap{display:grid;grid-template-columns:1fr 220px;gap:16px}
@media(max-width:640px){.fp-wrap{grid-template-columns:1fr}}

/* certificate */
.cert{background:#fff;border:10px solid var(--navy);outline:3px solid var(--brand);outline-offset:-22px;padding:54px 50px;text-align:center;border-radius:6px;position:relative;aspect-ratio:1.414/1;display:flex;flex-direction:column;justify-content:center}
.cert .t1{font-size:14px;letter-spacing:.3em;text-transform:uppercase;color:var(--brand-dark);font-weight:700}
.cert h1{font-size:clamp(24px,4vw,44px);color:var(--navy);margin:.2em 0}
.cert .nm{font-size:clamp(24px,4vw,40px);font-weight:800;color:var(--brand);border-bottom:2px solid var(--line);display:inline-block;padding:0 30px 6px;margin:10px auto}
.cert .meta{display:flex;justify-content:space-between;margin-top:34px;font-size:13px;color:var(--muted);gap:12px}
.cert .meta b{display:block;color:var(--ink);font-size:15px}
.cert .logo{width:70px;margin:0 auto 6px}
@media print{
  @page{size:A4 landscape;margin:8mm}
  body{background:#fff}
  .top,.noprint,footer{display:none!important}
  main{padding:0}
  .cert{box-shadow:none;width:100%;height:calc(100vh - 16mm);aspect-ratio:auto}
}
footer{border-top:1px solid var(--line);padding:20px 0;color:var(--muted);font-size:13px;text-align:center}
.scene.tall svg{max-height:calc(100vh - 120px);width:auto;max-width:100%;margin:0 auto}
@media(max-width:900px){.scene.tall svg{max-height:none;width:100%}}

@media(max-width:900px){
  .lab{display:flex;flex-direction:column}
  .lab .side{display:contents}
  .lab>:not(.side){order:4}
  .lab .side>*{order:5}
  .lab .side>.o1{order:1}.lab .side>.o2{order:2}.lab .side>.o3{order:3}
  .hide-m{display:none!important}
  .tray{grid-template-columns:repeat(4,1fr);gap:6px}
  .titem{font-size:10px;padding:4px;border-radius:9px}
  .hlist{flex-direction:row!important;overflow-x:auto;flex-wrap:nowrap;padding-bottom:4px}
  .hlist>*{flex:0 0 auto;white-space:nowrap}
  .scorebox b{font-size:16px}
}