:root{
  --bg:#f5f7fa; --panel:#fff; --ink:#16202c; --muted:#5b6877; --line:#d8dee6;
  --accent:#2F5FE5; --accent-ink:#fff; --chip:#eef2f6; --err:#b3261e;
  /* workstation (always dark, like a reading room) */
  --w-bg:#0a0e13; --w-panel:#10161d; --w-panel2:#151d26; --w-line:#222c37; --w-ink:#dbe3ea; --w-muted:#8493a3;
  --w-accent:#7da0ff; --w-accent-dim:#2a4aa6; --w-warn:#ffd24a; --w-sel:#4cc9ff;
}
@media (prefers-color-scheme: dark){
  :root{ --bg:#0f151b; --panel:#171f27; --ink:#e8edf2; --muted:#98a5b3; --line:#2a3541;
    --accent:#7da0ff; --accent-ink:#0a1633; --chip:#212c37; --err:#ff8a80; }
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{background:var(--bg);color:var(--ink);font:16px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
[hidden]{display:none!important}

/* ---------- start page ---------- */
.intro-wrap{min-height:100vh;display:flex;flex-direction:column}
.top{display:flex;gap:12px;justify-content:space-between;align-items:center;flex-wrap:wrap;padding:12px 16px;border-bottom:1px solid var(--line);background:var(--panel)}
.brand{display:flex;align-items:center;gap:10px;font-weight:650}
.logo{width:22px;height:22px;border-radius:6px;background:linear-gradient(135deg,var(--accent),#8fb0ff);flex:none}
.privacy{font-size:13px;color:var(--muted)}
.intro{flex:1;width:100%;max-width:720px;margin:24px auto;padding:0 16px}
h1{font-size:clamp(26px,5vw,38px);line-height:1.15;margin:0 0 10px}
.lead{color:var(--muted);font-size:18px;margin:0 0 22px}
.drop{border:2px dashed var(--line);border-radius:16px;background:var(--panel);padding:36px 20px;text-align:center;transition:border-color .15s,background .15s}
.drop.over,.drop:focus-visible{border-color:var(--accent);outline:none;background:color-mix(in srgb,var(--accent) 8%,var(--panel))}
.drop-icon{font-size:44px;line-height:1;color:var(--accent)}
.drop-title{font-size:22px;font-weight:650;margin-top:8px}
.drop-sub{color:var(--muted);margin:2px 0 18px}
.drop-actions{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.btn{font:inherit;border:1px solid var(--line);background:var(--chip);color:var(--ink);padding:10px 16px;border-radius:10px;cursor:pointer}
.btn:hover{border-color:var(--accent)}
.btn.primary{background:var(--accent);color:var(--accent-ink);border-color:var(--accent);font-weight:600}
.linkbtn{background:none;border:0;color:var(--accent);cursor:pointer;font:inherit;text-decoration:underline;padding:0}
.status{margin-top:16px;padding:12px 14px;border-radius:10px;background:var(--panel);border:1px solid var(--line)}
.status.err{border-color:var(--err);color:var(--err)}
.bar-track{height:6px;border-radius:3px;background:var(--chip);margin-top:8px;overflow:hidden}
.bar-fill{height:100%;width:0;background:var(--accent);transition:width .1s}
.how{color:var(--muted);padding-left:20px}
.how li{margin:6px 0}
code{background:var(--chip);padding:1px 6px;border-radius:5px}
.small{font-size:14px;color:var(--muted)}
.learn{margin-top:28px;padding:22px 22px 10px;border:1px solid var(--line);border-radius:16px;background:var(--panel)}
.learn h2{margin:0 0 8px;font-size:20px}
.learn p{margin:6px 0}
.learn-actions{justify-content:flex-start;margin:14px 0 10px}
.learn .how{margin-top:8px}
footer{border-top:1px solid var(--line);padding:14px 16px;font-size:13px;color:var(--muted);text-align:center}
footer p{margin:2px 0}

/* ---------- workstation ---------- */
.ws{position:fixed;inset:0;display:grid;grid-template-columns:68px minmax(0,1fr) 300px;grid-template-rows:48px minmax(0,1fr) 28px;
  grid-template-areas:"top top top" "rail stage panel" "status status status";
  background:var(--w-bg);color:var(--w-ink);font-size:13px;line-height:1.4;user-select:none;-webkit-user-select:none}
.ws.nopanel{grid-template-columns:68px minmax(0,1fr) 0}
.ws.nopanel .panel{display:none}
.ws button{font:inherit;color:inherit}
.ws-top{grid-area:top;display:flex;align-items:center;gap:14px;padding:0 10px 0 14px;background:var(--w-panel);border-bottom:1px solid var(--w-line);min-width:0}
.ws-top .brand{font-size:14px;letter-spacing:.01em;color:var(--w-ink)}
.study{flex:1;min-width:0;color:var(--w-muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:12.5px}
.tgroup{display:flex;gap:2px;align-items:center;padding:3px;border-radius:9px;background:var(--w-panel2);border:1px solid var(--w-line)}
.tbtn{height:30px;min-width:32px;padding:0 7px;display:inline-flex;align-items:center;justify-content:center;gap:6px;border:0;background:transparent;border-radius:6px;cursor:pointer;color:var(--w-muted)}
.tbtn:hover{background:#1d2834;color:var(--w-ink)}
.tbtn.on,.tbtn[aria-pressed=true]{background:var(--w-accent-dim);color:#fff}
.tbtn.text span{font-size:12.5px}
.tbtn svg,.tool svg{width:19px;height:19px;stroke:currentColor;fill:none;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.ptabs{display:none}
.ptab{border:0;background:transparent;color:var(--w-muted);padding:5px 10px;border-radius:6px;cursor:pointer}
.ptab.on{background:var(--w-accent-dim);color:#fff}

.rail{grid-area:rail;display:flex;flex-direction:column;align-items:center;gap:3px;padding:8px 0;background:var(--w-panel);border-right:1px solid var(--w-line);overflow-y:auto}
.tool{width:56px;padding:6px 0 4px;border:1px solid transparent;background:transparent;border-radius:9px;cursor:pointer;color:var(--w-muted);display:flex;flex-direction:column;align-items:center;gap:2px}
.tool span{font-size:10.5px;letter-spacing:.01em}
.tool:hover{background:#1a2430;color:var(--w-ink)}
.tool.on{background:#12302f;border-color:var(--w-accent-dim);color:var(--w-accent)}
.tool.act[aria-pressed=true]{color:var(--w-accent)}
.sep{width:36px;height:1px;background:var(--w-line);margin:5px 0}

/* stage and panes */
.stage{grid-area:stage;display:grid;gap:4px;padding:4px;min-width:0;min-height:0;background:#050709}
.stage.l-2x2{grid-template-columns:1fr 1fr;grid-template-rows:1fr 1fr}
.stage.l-1x3{grid-template-columns:1fr 1fr 1fr;grid-template-rows:1fr}
.stage.l-1x3 .pane[data-view=three]{display:none}
.stage.l-1x1{grid-template-columns:1fr;grid-template-rows:1fr}
.stage.l-1x1 .pane:not(.active){display:none}
.stage.l-1p3{grid-template-columns:3fr 1fr;grid-template-rows:repeat(3,minmax(0,1fr))}
.stage.l-1p3 .pane.active{grid-column:1;grid-row:1/4}
.stage.l-1p3 .pane:not(.active){grid-column:2}
.pane{position:relative;min-width:0;min-height:0;background:#000;border:1px solid var(--w-line);border-radius:6px;overflow:hidden;touch-action:none}
.pane.active{border-color:var(--w-accent-dim);box-shadow:0 0 0 1px var(--w-accent-dim) inset}
.pane canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.ph{position:absolute;left:0;right:0;top:0;height:24px;display:flex;align-items:center;gap:6px;padding:0 6px 0 9px;background:linear-gradient(#000c,#0000);pointer-events:none;z-index:2}
.pt{font-weight:600;letter-spacing:.02em;color:#cfe3e1;font-size:12px}
.pane.active .pt{color:var(--w-accent)}
.pb{margin-left:auto;display:flex;gap:2px;pointer-events:auto}
.pb button{border:0;background:transparent;color:#9fb0bf;width:22px;height:20px;border-radius:4px;cursor:pointer;font-size:13px;padding:0}
.pb button:hover{background:#ffffff1c;color:#fff}
.pane[data-tool=nav] canvas{cursor:crosshair}
.pane canvas.c-zoom{cursor:zoom-in}.pane canvas.c-pan{cursor:grab}.pane canvas.c-wl{cursor:ns-resize}
.pane canvas.c-meas{cursor:crosshair}.pane canvas.c-edit{cursor:move}.pane canvas.c-grab{cursor:grabbing}

/* panel */
.panel{grid-area:panel;overflow-y:auto;background:var(--w-panel);border-left:1px solid var(--w-line);padding:4px 0}
.sec{border-bottom:1px solid var(--w-line)}
.sec>summary{cursor:pointer;list-style:none;padding:10px 14px;font-size:11px;letter-spacing:.09em;text-transform:uppercase;color:var(--w-muted);display:flex;align-items:center;gap:8px}
.sec>summary::-webkit-details-marker{display:none}
.sec>summary::before{content:"";width:6px;height:6px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(-45deg);transition:transform .15s}
.sec[open]>summary::before{transform:rotate(45deg)}
.sec>summary:hover{color:var(--w-ink)}
.secbody{padding:2px 14px 14px;display:flex;flex-direction:column;gap:9px}
.count{margin-left:auto;color:var(--w-accent);letter-spacing:0}
.chips{display:flex;flex-wrap:wrap;gap:5px}
.chip{border:1px solid var(--w-line);background:var(--w-panel2);color:var(--w-ink);padding:4px 10px;border-radius:999px;cursor:pointer;font-size:12px}
.chip:hover{border-color:var(--w-accent-dim)}
.chip.on{background:var(--w-accent-dim);border-color:var(--w-accent-dim);color:#fff}
.row{display:flex;align-items:center;justify-content:space-between;gap:8px;color:var(--w-muted)}
.row select{flex:1;max-width:170px}
select{font:inherit;font-size:12.5px;padding:4px 6px;border-radius:6px;border:1px solid var(--w-line);background:var(--w-panel2);color:var(--w-ink);min-width:0}
.sl{display:grid;grid-template-columns:1fr auto;gap:2px 8px;color:var(--w-muted)}
.sl output{color:var(--w-ink);font-variant-numeric:tabular-nums}
.sl input{grid-column:1/3;width:100%}
input[type=range]{-webkit-appearance:none;appearance:none;height:18px;background:transparent;margin:0}
input[type=range]::-webkit-slider-runnable-track{height:3px;border-radius:2px;background:#2b3744}
input[type=range]::-moz-range-track{height:3px;border-radius:2px;background:#2b3744}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:14px;height:14px;border-radius:50%;background:var(--w-accent);border:2px solid #0a0e13;margin-top:-5.5px}
input[type=range]::-moz-range-thumb{width:11px;height:11px;border-radius:50%;background:var(--w-accent);border:2px solid #0a0e13}
.chk{display:flex;align-items:center;gap:8px;color:var(--w-ink);cursor:pointer}
.chk input{accent-color:var(--w-accent)}
.cbar{height:8px;border-radius:4px;border:1px solid var(--w-line)}
.info{color:var(--w-muted);font-size:12px;line-height:1.55}
.info b{color:var(--w-ink);font-weight:600}
.info .warn{color:var(--w-warn)}
.ws .small{font-size:12px;color:var(--w-muted);margin:0}
.meas{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:3px;max-height:220px;overflow:auto}
.meas li{display:flex;align-items:center;gap:6px;padding:5px 6px;border-radius:6px;background:var(--w-panel2);border:1px solid transparent;cursor:pointer}
.meas li.sel{border-color:var(--w-sel)}
.meas li .mt{flex:1;min-width:0;font-size:12px}
.meas li .mt small{display:block;color:var(--w-muted);font-size:11px}
.meas li button{border:0;background:transparent;color:var(--w-muted);cursor:pointer;padding:2px 5px;border-radius:4px}
.meas li button:hover{color:#ff8a80;background:#ffffff14}
.meas:empty::before{content:"No measurements yet. Choose Ruler, Angle or Region and draw on an image.";color:var(--w-muted);font-size:12px;padding:2px}
.keys{color:var(--w-muted);font-size:12px;gap:6px}
kbd{font:inherit;font-size:11px;background:var(--w-panel2);border:1px solid var(--w-line);border-bottom-width:2px;border-radius:4px;padding:0 5px;color:var(--w-ink)}

.ws-status{grid-area:status;display:flex;align-items:center;gap:12px;padding:0 12px;background:var(--w-panel);border-top:1px solid var(--w-line);color:var(--w-muted);font-size:12px;border-bottom:0;text-align:left;white-space:nowrap;overflow:hidden}
.ws-status .grow{flex:1}
#hover{font-variant-numeric:tabular-nums;overflow:hidden;text-overflow:ellipsis}

/* narrow screens: tools on top, panel as a drawer, one view at a time */
@media (max-width:860px){
  .ws{grid-template-columns:minmax(0,1fr);grid-template-rows:46px 56px minmax(0,1fr) 26px;grid-template-areas:"top" "rail" "stage" "status"}
  .ws.nopanel{grid-template-columns:minmax(0,1fr)}
  .rail{flex-direction:row;overflow-x:auto;overflow-y:hidden;border-right:0;border-bottom:1px solid var(--w-line);padding:3px 6px;justify-content:flex-start}
  .tool{flex:none;width:52px;padding:3px 0}
  .tool span{font-size:10px}
  .sep{width:1px;height:34px;margin:0 4px}
  .panel{position:fixed;right:0;top:46px;bottom:26px;width:min(86vw,320px);z-index:20;box-shadow:-12px 0 30px #000a;transform:translateX(105%);transition:transform .2s;display:block}
  .ws:not(.nopanel) .panel{transform:none}
  .ws.nopanel .panel{display:block}
  .layouts,.study,.ws-top .brandName,.disc,#snapAllBtn{display:none}
  .ptabs{display:flex;margin-left:auto}
  .ws-top .tgroup.actions{margin-left:0}
  .stage .pane:not(.active){display:none}
  .stage{grid-template-columns:1fr!important;grid-template-rows:1fr!important}
  .stage .pane.active{grid-column:1!important;grid-row:1!important}
}
@media (max-width:480px){ #fsBtn,#cineBtn{display:none} .tbtn.text span{display:none} .ptab{padding:5px 7px} .ws-top{gap:6px;padding:0 6px} }

/* ---------- HiDental additions ---------- */
.topnav{display:flex;align-items:center;gap:16px}
.topnav a{color:var(--ink);text-decoration:none;font-size:14.5px}
.topnav a:hover{text-decoration:underline}
.topnav a.cta{background:var(--accent);color:var(--accent-ink);padding:7px 14px;border-radius:999px;font-weight:600}
.privacy-line{margin:0 0 14px;padding:10px 14px;border-radius:10px;background:color-mix(in srgb,var(--accent) 10%,var(--panel));border:1px solid color-mix(in srgb,var(--accent) 30%,var(--line));font-size:15px}
.intro.locked .drop{opacity:.45;pointer-events:none}
.intro-wrap footer a{color:inherit}
.agree{border:1px solid var(--line);border-radius:16px;padding:22px 24px;max-width:min(560px,92vw);background:var(--panel);color:var(--ink);box-shadow:0 20px 60px #0008}
.agree::backdrop{background:rgba(5,10,20,.7)}
.agree h2{margin:0 0 10px;font-size:22px}
.agree ul{margin:0 0 14px;padding-left:20px}
.agree li{margin:7px 0}
.chk-agree{display:flex;gap:10px;align-items:flex-start;padding:12px;border-radius:10px;background:var(--chip);cursor:pointer}
.chk-agree input{margin-top:4px;width:18px;height:18px;accent-color:var(--accent)}
.chk-agree a{color:var(--accent)}
.agree-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:16px}
.agree-actions .btn:disabled{opacity:.45;cursor:not-allowed}
.findbtn{text-decoration:none;background:var(--w-accent-dim);color:#fff!important}
.findbtn:hover{background:#3558c4!important}
.nextbtn{display:block;text-align:center;text-decoration:none;font-size:13px;padding:9px 12px;border-radius:9px;background:var(--w-accent-dim);border:0;color:#fff}
.nextbtn:hover{background:#3558c4}
@media (max-width:480px){ .findbtn span{display:none} }