/* Layout: a working lab bench is the hero; protocol card under it; notebook + instructor beside on wide screens */
:root{
  --bg:#edf1f0; --surface:#ffffff; --ink:#122221; --muted:#566a68; --line:#d2dddb;
  --accent:#2350c2; --accent-ink:#ffffff; --eosin:#c43a6a; --ok:#1d8656; --bad:#b8402c;
  --bench:#1c292a; --bench-2:#253536; --glass:#d6e5e3; --dev:#3a4e50; --dev-line:#9db4b1; --screen:#0b1514; --scr:#8fd3ff;
  --f-display:"Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --f-body:"IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --f-mono:"IBM Plex Mono", ui-monospace, Menlo, monospace;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0e1615; --surface:#152120; --ink:#e2ebea; --muted:#93a7a4; --line:#263a39;
  --accent:#7f9dff; --accent-ink:#0b1430; --eosin:#f07ba4; --ok:#4cc48c; --bad:#ff8a73;
  --bench:#101b1c; --bench-2:#192728; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0e1615; --surface:#152120; --ink:#e2ebea; --muted:#93a7a4; --line:#263a39;
  --accent:#7f9dff; --accent-ink:#0b1430; --eosin:#f07ba4; --ok:#4cc48c; --bad:#ff8a73;
  --bench:#101b1c; --bench-2:#192728; color-scheme:dark}
*{box-sizing:border-box}
body{background:var(--bg);color:var(--ink);font:15px/1.55 var(--f-body);margin:0}
.wrap{max-width:1160px;margin:0 auto;padding-left:max(16px, env(safe-area-inset-left, 0px));padding-right:max(16px, env(safe-area-inset-right, 0px));padding-block:20px 48px;display:grid;gap:18px}
h1,h2,h3{font-family:var(--f-display);text-wrap:balance;margin:0;line-height:1.15}
.mast{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:12px}
.mast h1{font-size:clamp(28px,5vw,40px);font-weight:750;letter-spacing:-.02em}
.mast h1 span{color:var(--accent)}
.mast p{margin:2px 0 0;color:var(--muted);max-width:56ch}
.eyebrow{font:500 11px/1 var(--f-mono);letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}

.labhead{display:grid;gap:6px}
.labhead h2{font-size:clamp(22px,3.4vw,30px);font-weight:750;letter-spacing:-.01em}
.meta{display:flex;flex-wrap:wrap;gap:6px}
.tag{font:500 11px/1 var(--f-mono);letter-spacing:.06em;text-transform:uppercase;padding:5px 8px;border-radius:6px;border:1px solid var(--line);color:var(--muted)}
.tag.bsl{border-color:var(--eosin);color:var(--eosin)}
.labhead p{margin:0;color:var(--muted);max-width:68ch}

/* bench */
.bench{position:relative;background:linear-gradient(180deg,var(--bench-2),var(--bench));border-radius:16px;padding:18px 12px 14px;overflow:hidden;box-shadow:inset 0 -18px 0 rgba(0,0,0,.18)}
.bench-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(88px,1fr));gap:6px 4px;position:relative}
.station{background:transparent;border:0;padding:4px 2px 6px;display:grid;justify-items:center;gap:2px;border-radius:12px;position:relative;color:var(--glass)}
.station .eq{width:100%;max-width:96px;position:relative;z-index:1}
.station .eq.lifted{z-index:20}
.station svg{width:100%;height:auto;display:block;overflow:visible}
.station .nm{font:500 11px/1.25 var(--f-body);color:#c7d6d4;text-align:center;max-width:100%;overflow-wrap:break-word;hyphens:auto}
.station.cue::before{content:"";position:absolute;inset:2px;border-radius:12px;border:2px solid var(--scr);animation:cue 1.4s ease-in-out infinite}
.station.picked::before{content:"";position:absolute;inset:2px;border-radius:12px;background:rgba(143,211,255,.12);border:2px solid var(--scr)}
.station.picked .eq{transform:translateY(-6px);transition:transform .2s}
.station.wrong{animation:shake .4s}
@keyframes cue{0%,100%{opacity:.25}50%{opacity:1}}
@keyframes shake{20%,60%{transform:translateX(-5px)}40%,80%{transform:translateX(5px)}}
.fx{position:absolute;inset:0;pointer-events:none;z-index:30}
.drop{position:absolute;width:7px;height:10px;border-radius:50% 50% 50% 50%/60% 60% 40% 40%}
.bub{position:absolute;width:6px;height:6px;border-radius:50%;border:1.5px solid rgba(255,255,255,.7)}
.badge{position:absolute;font:500 12px/1 var(--f-mono);background:var(--screen);color:var(--scr);padding:6px 8px;border-radius:6px;white-space:nowrap}
.bench-foot{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;margin-top:10px;font:12px/1.3 var(--f-mono);color:#9fb4b1}

/* svg parts */
.gl{fill:rgba(214,229,227,.07);stroke:var(--glass);stroke-width:2;stroke-linejoin:round;stroke-linecap:round}
.tick{stroke:var(--glass);stroke-width:1.2;opacity:.6}
.liq{transition:fill 1s ease}
.liqg{transition:transform 1.1s cubic-bezier(.3,.7,.3,1)}
.gls{fill:url(#gGlass);stroke:none}
.glw{fill:none;stroke:rgba(228,244,242,.85);stroke-width:1.2;stroke-linejoin:round}
.rim{stroke:rgba(236,248,246,.9);stroke-width:1.3}
.grad path{stroke:#fff;stroke-opacity:.75;stroke-width:.8}
.grad.dark path{stroke:#1b2423;stroke-opacity:.6}
.gradt{fill:#fff;fill-opacity:.8;font:600 4.6px var(--f-mono)}
.tint{transition:fill 1s ease}
.dev{fill:var(--dev);stroke:var(--dev-line);stroke-width:1.6;stroke-linejoin:round}
.devl{fill:none;stroke:var(--dev-line);stroke-width:5;stroke-linecap:round}
.thin{fill:none;stroke:var(--dev-line);stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round}
.screen{fill:var(--screen);stroke:var(--dev-line);stroke-width:1}
.scr{fill:var(--scr);font:600 10px var(--f-mono)}
.label{fill:#f3f1ea}
.label-t{fill:#1b2423;font:700 6.4px var(--f-mono)}
.cap{fill:#5b6f71}
.rack{fill:#6b5644}
.frost{fill:rgba(255,255,255,.35)}
.glassfill{fill:rgba(214,229,227,.18);stroke:var(--glass);stroke-width:1.2}
.flame{opacity:0;transition:opacity .3s;transform-box:fill-box;transform-origin:50% 100%}
.on .flame{opacity:1;animation:flick .18s infinite alternate}
@keyframes flick{to{transform:scaleY(1.08) scaleX(.94)}}
.skin{fill:#c99a7c}
.gown{fill:#7fa3b8}
.trace{fill:none;stroke:var(--scr);stroke-width:1.5}
.cuff{fill:#3e5f7d;stroke:#9db4b1}
.needle{stroke:#ff6a5c;stroke-width:2;stroke-linecap:round}

/* protocol card */
.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:16px}
.step-top{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap}
.progress{display:flex;gap:4px;flex:1 1 160px}
.progress i{flex:1;height:5px;border-radius:3px;background:var(--line)}
.progress i.done{background:var(--ok)}
.progress i.now{background:var(--accent)}
.step-n{font:500 12px/1 var(--f-mono);color:var(--muted);letter-spacing:.08em}
.step-text{font:600 clamp(17px,2.4vw,20px)/1.35 var(--f-body);margin:10px 0 4px}
.step-how{color:var(--muted);margin:0;font-size:14px}
.step-how b{color:var(--ink)}
.step-actions{display:flex;gap:8px;margin-top:12px;flex-wrap:wrap}
.safety{margin:10px 0 0;padding:0;list-style:none;display:grid;gap:4px;font-size:13.5px;color:var(--muted)}
.safety li::before{content:"⚠ ";color:var(--eosin)}
details summary{cursor:pointer;font-weight:600}

/* notebook */
.nb h3,.inst h3,.quiz h3{font-size:18px;font-weight:750;margin-bottom:8px}
.nb ol{list-style:none;margin:0;padding:0;display:grid;gap:10px;max-height:420px;overflow:auto}
.nb li{display:grid;grid-template-columns:62px minmax(0,1fr);gap:8px;font-size:14px;border-top:1px dashed var(--line);padding-top:8px}
.nb time{font:12px/1.5 var(--f-mono);color:var(--muted);font-variant-numeric:tabular-nums}
.nb .rd{font-family:var(--f-mono);color:var(--accent)}
.empty{color:var(--muted);font-size:14px;margin:0}
.inst textarea{width:100%;font:inherit;font-size:15px;padding:10px;border-radius:10px;border:1px solid var(--line);background:var(--bg);color:var(--ink);resize:vertical;min-height:64px}
.inst .ans{white-space:pre-wrap;font-size:14px;margin-top:10px;color:var(--ink)}
.stats{display:flex;gap:18px;flex-wrap:wrap;margin:6px 0 12px}
.stat b{display:block;font:750 26px/1 var(--f-display)}
.stat span{font:11px var(--f-mono);color:var(--muted);text-transform:uppercase;letter-spacing:.08em}
.q{border-top:1px solid var(--line);padding-top:12px;margin-top:12px}
.q p{margin:0 0 8px;font-weight:600}
.opt{display:block;width:100%;text-align:left;border:1px solid var(--line);background:var(--bg);border-radius:9px;padding:9px 11px;margin-top:6px;font-size:14px}
.opt.right{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 14%,var(--bg))}
.opt.wrongo{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 12%,var(--bg))}
.explain{font-size:13.5px;color:var(--muted);margin-top:8px}

/* modal instruments */
.modal{position:fixed;inset:0;z-index:100;display:grid;place-items:center;background:rgba(5,10,10,.72);padding:max(16px,env(safe-area-inset-top,0px)) max(16px,env(safe-area-inset-right,0px)) max(16px,env(safe-area-inset-bottom,0px)) max(16px,env(safe-area-inset-left,0px))}
.panel{background:#0f1a1a;color:#dbe7e5;border:1px solid #2c3f3f;border-radius:18px;padding:18px;width:min(380px,100%);display:grid;gap:12px;justify-items:center;text-align:center}
.panel .eyebrow{color:#8ea7a4}
.scope{width:min(280px,72vw);aspect-ratio:1;border-radius:50%;box-shadow:0 0 0 10px #050909,0 0 0 12px #2c3f3f, inset 0 0 40px rgba(0,0,0,.6);overflow:hidden;background:#000;max-width:100%}
.scope canvas{width:100%;height:100%;display:block;transition:filter .1s}
.panel input[type=range]{width:100%}
.panel .obs{font-size:14px;color:#c4d6d3;min-height:2.6em}
.big{font:500 clamp(40px,12vw,56px)/1 var(--f-mono);color:var(--scr);font-variant-numeric:tabular-nums}
.unit{font:13px var(--f-mono);color:#8ea7a4}
.wave{width:100%;height:80px;background:var(--screen);border-radius:8px;display:block}
.note{font-size:12px;color:var(--muted)}
@media (prefers-reduced-motion: reduce){*,*::before{animation-duration:.01s!important;transition-duration:.01s!important}}

/* ===================== Chat app shell ===================== */
/* Layout: chat column on the left, live lab bench on the right; on phones the two are tabs */
:root{--f-body:"IBM Plex Sans","IBM Plex Sans Arabic","Segoe UI",system-ui,sans-serif}
html,body{height:100%}
body{overflow:hidden}
.app{height:100%;display:grid;grid-template-rows:auto minmax(0,1fr);padding-top:env(safe-area-inset-top,0px)}
.topbar{display:flex;align-items:center;gap:12px;padding-block:10px;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px));border-bottom:1px solid var(--line);background:var(--surface)}
.brand{display:flex;align-items:center;gap:9px;font:750 19px/1 var(--f-display);letter-spacing:-.01em;margin-right:auto;white-space:nowrap}
.brand b{color:var(--accent);font-weight:750}
.logo{width:26px;height:26px;border-radius:7px;background:var(--accent);position:relative;flex:none}
.logo::after{content:"";position:absolute;left:8px;right:8px;bottom:6px;height:9px;border-radius:0 0 4px 4px;background:var(--scr);clip-path:polygon(25% 0,75% 0,100% 100%,0 100%)}
.tabs{display:flex;gap:2px;background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:3px}
.tabs button{border:0;background:transparent;padding:6px 12px;border-radius:7px;font-size:13.5px;font-weight:600;color:var(--muted)}
.tabs button[aria-selected="true"]{background:var(--surface);color:var(--ink);box-shadow:0 1px 2px rgba(0,0,0,.08)}
button{font:inherit;cursor:pointer;color:inherit}
.btn{border:0;border-radius:10px;padding:11px 18px;font-weight:600;background:var(--accent);color:var(--accent-ink)}
.btn:disabled{opacity:.5;cursor:default}
.btn.ghost{background:transparent;border:1px solid var(--line);color:var(--ink)}
.btn.small{padding:7px 12px;font-size:13px}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:7px 12px;font-size:13.5px;color:var(--ink);text-align:start}
.chip:hover{border-color:var(--accent);color:var(--accent)}

.panes{display:grid;min-height:0}
.chat,.labpane{min-height:0;min-width:0}
.chat{display:grid;grid-template-rows:minmax(0,1fr) auto auto;background:var(--bg)}
.thread{overflow-y:auto;padding-block:20px 12px;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px));display:flex;flex-direction:column;gap:14px}
.hello{margin:auto 0;display:grid;gap:12px;max-width:560px;padding-block:20px}
.hello h1{font-size:clamp(26px,5vw,36px);font-weight:750;letter-spacing:-.02em}
.hello p{margin:0;color:var(--muted)}
.msg{max-width:min(88%,620px);display:grid;gap:4px}
.msg.user{align-self:flex-end}
.msg.user .body{background:var(--accent);color:var(--accent-ink);border-radius:16px 16px 4px 16px;padding:10px 14px}
.msg.assistant{align-self:flex-start}
.msg.assistant .body{background:var(--surface);border:1px solid var(--line);border-radius:16px 16px 16px 4px;padding:10px 14px}
.msg.err .body{border-color:var(--bad);color:var(--bad)}
.msg .body p{margin:0}.msg .body p+p,.msg .body p+ul,.msg .body ul+p,.msg .body p+ol,.msg .body ol+p{margin-top:8px}
.msg .body ul,.msg .body ol{margin:0;padding-inline-start:20px}
.who{font:500 10.5px/1 var(--f-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.labcard{display:flex;align-items:center;gap:12px;text-align:start;background:var(--bench);color:#e1ecea;border:0;border-radius:14px;padding:12px 14px;margin-top:4px}
.labcard:hover{outline:2px solid var(--scr)}
.lc-icon{width:34px;height:34px;flex:none;border-radius:9px;background:var(--bench-2);position:relative}
.lc-icon::after{content:"";position:absolute;left:10px;right:10px;top:8px;bottom:8px;background:var(--scr);clip-path:polygon(35% 0,65% 0,65% 35%,100% 100%,0 100%,35% 35%)}
.lc-t{display:block;font-weight:600}
.lc-s{display:block;font:12px var(--f-mono);color:#9fb4b1}
.dots{display:inline-flex;gap:4px;vertical-align:middle}
.dots i{width:6px;height:6px;border-radius:50%;background:var(--muted);animation:dot 1s infinite}
.dots i:nth-child(2){animation-delay:.15s}.dots i:nth-child(3){animation-delay:.3s}
@keyframes dot{0%,100%{opacity:.25;transform:translateY(0)}50%{opacity:1;transform:translateY(-3px)}}
.tl{color:var(--muted);font-size:14px}
.composer{display:flex;gap:8px;align-items:flex-end;padding-block:10px 4px;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px));border-top:1px solid var(--line);background:var(--bg)}
.composer textarea{flex:1;min-width:0;resize:none;font:inherit;font-size:16px;line-height:1.4;padding:11px 14px;border-radius:14px;border:1px solid var(--line);background:var(--surface);color:var(--ink);max-height:160px}
.composer .send{border-radius:12px}
.fine{margin:0;padding-block:2px calc(8px + env(safe-area-inset-bottom,0px));padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px));font-size:11.5px;color:var(--muted)}

.labpane{overflow-y:auto;display:grid;gap:16px;align-content:start;padding-block:18px calc(32px + env(safe-area-inset-bottom,0px));padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}

/* phones: one pane at a time */
@media (max-width:939px){
  .panes[data-view="chat"] .labpane{display:none}
  .panes[data-view="lab"] .chat{display:none}
}
/* wide: side by side */
@media (min-width:940px){
  .tabs{display:none}
  .panes{grid-template-columns:minmax(360px,420px) minmax(0,1fr)}
  .chat{border-right:1px solid var(--line)}
  .labpane{background:var(--surface)}
  .labpane .card{background:var(--bg)}
}
@media (max-width:380px){.brand{font-size:16px}.tabs button{padding:6px 9px}}
[hidden]{display:none!important}
.tabs button,.btn.small{white-space:nowrap}
@media (max-width:480px){.topbar{gap:8px}.brand{font-size:16px;gap:7px}.logo{width:22px;height:22px}.tabs button{padding:6px 10px}.btn.small{padding:7px 10px}}

/* realism pass: bigger stations, overhead lamp light on the bench, no squashing */
.labpane{grid-auto-rows:max-content}
.bench{overflow:visible;background:radial-gradient(120% 70% at 50% -10%,rgba(255,255,255,.10),transparent 60%),linear-gradient(180deg,var(--bench-2),var(--bench))}
.bench-grid{grid-template-columns:repeat(auto-fill,minmax(98px,1fr))}
.station .eq{max-width:118px}
@media (min-width:940px){.bench-grid{grid-template-columns:repeat(auto-fill,minmax(112px,1fr))}}

.scr{font:600 7px var(--f-mono)}
.scr.big{font-size:9.5px}

/* lab pane: children never shrink, so the bench can't be squashed by long text or the quiz */
.labpane{display:flex;flex-direction:column;gap:16px;position:relative}
.labpane>*{flex:none}
.tobench{position:sticky;bottom:calc(14px + env(safe-area-inset-bottom,0px));align-self:flex-end;box-shadow:0 6px 18px rgba(0,0,0,.25);z-index:40}

/* brand logo */
img.logo{width:28px;height:28px;border-radius:7px;background:none;display:block}
img.logo::after{content:none}
.hello-logo{width:150px;height:150px;filter:drop-shadow(0 10px 24px rgba(13,58,168,.28))}
.brand b{background:linear-gradient(90deg,#27a6ff,#1650d8);-webkit-background-clip:text;background-clip:text;color:transparent}

/* download tools */
.labhead-row{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px}
.labtools{display:flex;gap:6px;flex-wrap:wrap}
.tool{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:9px;padding:6px 11px;font-size:13px;font-weight:600}
.tool:hover{border-color:var(--accent);color:var(--accent)}
.tool:disabled{opacity:.5;cursor:default}
.panel-actions{display:flex;gap:8px;flex-wrap:wrap;justify-content:center}
.btn.ghost.dark{color:#dbe7e5;border-color:#2c3f3f}
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);background:#0f1a1a;color:#e2ebea;padding:10px 16px;border-radius:10px;font-size:14px;z-index:200;box-shadow:0 8px 24px rgba(0,0,0,.3);max-width:calc(100% - 32px)}

/* physics & chemistry motion: .live = switched on and stays on; .linked = connected in a circuit */
.link{transition:opacity .4s}
.linked .link{opacity:1}
.glow,.beam{opacity:0;transition:opacity .5s}
.live .glow,.live .beam{opacity:1}
.live .fil{stroke:#ffd76a;stroke-width:1.6}
.live .swing{animation:swing 1.8s ease-in-out infinite alternate}
@keyframes swing{from{transform:rotate(24deg)}to{transform:rotate(-24deg)}}
.live .bounce{animation:bounce 1.1s ease-in-out infinite alternate}
@keyframes bounce{from{transform:scaleY(.84)}to{transform:scaleY(1.14)}}
.live .needle-g{animation:needle 2.6s cubic-bezier(.3,1.6,.5,1) forwards}
@keyframes needle{to{transform:rotate(64deg)}}
.live .roll{animation:roll 2.2s cubic-bezier(.55,0,1,.9) forwards}
@keyframes roll{to{transform:translate(58px,34.4px)}}
.live .hand{animation:spinhand 6s linear infinite}
@keyframes spinhand{to{transform:rotate(360deg)}}
.live .wave-t{stroke-dasharray:6 1;animation:dash .5s linear infinite}
@keyframes dash{to{stroke-dashoffset:-14}}
.live .beam{animation:beamflick 1.6s ease-in-out infinite}
@keyframes beamflick{50%{opacity:.75}}
.coil{transition:fill .6s}
.on .coil,.live .coil{fill:#e5512b;filter:drop-shadow(0 0 3px #ff6a3a)}

/* advanced bench effects */
.fxsvg{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;overflow:visible}
#fxs{z-index:31}
#wires{z-index:0}
.wire{filter:drop-shadow(0 2px 1px rgba(0,0,0,.35))}
.current{opacity:0;stroke-dasharray:2 10}
.current.on{opacity:.95;animation:flow .6s linear infinite}
@keyframes flow{to{stroke-dashoffset:-24}}
.station .eq.lifted{filter:drop-shadow(0 22px 12px rgba(0,0,0,.45))}
.spl{position:absolute;width:4px;height:4px;border-radius:50%}
.bloom{position:absolute;border-radius:50%;background:radial-gradient(circle,var(--c) 0%,var(--c) 35%,transparent 70%);mix-blend-mode:screen;filter:blur(2px)}
.vortex{position:absolute;border-radius:50%;border:2px solid transparent;border-top-color:rgba(255,255,255,.75);border-left-color:rgba(255,255,255,.35);
  box-shadow:inset 0 0 0 4px rgba(255,255,255,.08),inset 0 0 0 9px rgba(255,255,255,.04)}
.steam{position:absolute;width:14px;height:14px;border-radius:50%;background:radial-gradient(circle,rgba(255,255,255,.75),rgba(255,255,255,0) 70%);filter:blur(2px)}
.flash{position:absolute;width:60px;height:60px;border-radius:50%;background:radial-gradient(circle,var(--c),transparent 65%);mix-blend-mode:screen}
.spark{position:absolute;width:6px;height:6px;border-radius:2px}
.bub{background:radial-gradient(circle at 35% 35%,rgba(255,255,255,.8),rgba(255,255,255,.05) 60%)}