@font-face{font-family:"Newsreader";src:url(fonts/newsreader-latin.woff2) format("woff2");font-weight:300 700;font-display:swap;unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215}
@font-face{font-family:"Newsreader";src:url(fonts/newsreader-latin-ext.woff2) format("woff2");font-weight:300 700;font-display:swap;unicode-range:U+0100-024F,U+0259,U+1E00-1EFF,U+2020,U+20A0-20AB,U+20AD-20CF,U+2113,U+2C60-2C7F,U+A720-A7FF}
@font-face{font-family:"Newsreader";font-style:italic;src:url(fonts/newsreader-italic-400-latin.woff2) format("woff2");font-weight:400;font-display:swap;unicode-range:U+0000-00FF,U+2000-206F}
@font-face{font-family:"Newsreader";font-style:italic;src:url(fonts/newsreader-italic-400-latin-ext.woff2) format("woff2");font-weight:400;font-display:swap;unicode-range:U+0100-024F,U+1E00-1EFF}
@font-face{font-family:"Plex";src:url(fonts/IBMPlexSans-latin.woff2) format("woff2");font-weight:300 700;font-display:swap;unicode-range:U+0000-00FF,U+2000-206F,U+2190-21FF,U+2212,U+27F2-27F3}
@font-face{font-family:"Plex";src:url(fonts/IBMPlexSans-latin-ext.woff2) format("woff2");font-weight:300 700;font-display:swap;unicode-range:U+0100-024F,U+1E00-1EFF}

:root{
  --top:52px;
  --serif:"Newsreader",Georgia,"Times New Roman",serif;--sans:"Plex",system-ui,-apple-system,"Segoe UI",sans-serif;
  /* light: warm paper */
  --bg:#f3eee6;--card:#fbf8f2;--fg:#1b1714;--mut:#463d35;--line:#cdc2b2;--soft:#e4dbcd;
  --accent:#7d4f00;--accent-bg:#e0b34a;--portal:#b3264a;--hepatic:#24539e;--tumour:#9a6500;--icg:#1d7a3c;--bad:#a1261b;
  --stage-bg:#0b0908;--monitor:#050505;--monitor-fg:#e9e4da;--monitor-mut:#b9b1a3;
  color-scheme:light;
}
:root[data-theme="dark"]{
  --bg:#0f0d0c;--card:#181412;--fg:#efe8de;--mut:#c4b8a8;--line:#3a322c;--soft:#241e1b;
  --accent:#e9c169;--accent-bg:#e0b34a;--portal:#ff8aa3;--hepatic:#8fb4ff;--tumour:#f2c14e;--icg:#6ff19a;--bad:#ff9183;
  color-scheme:dark;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0f0d0c;--card:#181412;--fg:#efe8de;--mut:#c4b8a8;--line:#3a322c;--soft:#241e1b;
  --accent:#e9c169;--accent-bg:#e0b34a;--portal:#ff8aa3;--hepatic:#8fb4ff;--tumour:#f2c14e;--icg:#6ff19a;--bad:#ff9183;color-scheme:dark;}}

*{box-sizing:border-box}
[hidden]{display:none!important}
svg[hidden]{display:none}
html{-webkit-text-size-adjust:100%;scroll-padding-top:calc(var(--top) + 8px)}
body{margin:0;background:var(--bg);color:var(--fg);font:400 1.125rem/1.6 var(--serif);font-optical-sizing:auto}
a{color:inherit;text-decoration-color:color-mix(in srgb,currentColor 45%,transparent);text-underline-offset:.18em}
a:hover{text-decoration-color:currentColor}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.skip-link{position:absolute;left:-999px;top:0;background:var(--card);color:var(--fg);padding:.5em 1em;z-index:50}
.skip-link:focus{left:8px;top:8px}

/* topbar */
.topbar{position:sticky;top:0;z-index:30;height:calc(var(--top) + var(--browser-safe-top,env(safe-area-inset-top)));padding:var(--browser-safe-top,env(safe-area-inset-top)) 14px 0;display:flex;align-items:center;gap:10px;
  background:color-mix(in srgb,var(--bg) 92%,transparent);border-bottom:1px solid var(--line);font:500 .86rem/1 var(--sans)}
.brand{display:flex;align-items:center;gap:8px;text-decoration:none;font-weight:600;white-space:nowrap}
.brand svg{width:22px;height:22px}
.topnav{display:flex;gap:14px;overflow-x:auto;scrollbar-width:none;margin-left:10px;min-width:0}
.topnav::-webkit-scrollbar{display:none}
.topnav a{text-decoration:none;color:var(--mut);white-space:nowrap}
.topnav a:hover{color:var(--fg)}
.spacer{flex:1}
.chip{text-decoration:none;color:var(--mut);padding:5px 7px;border-radius:6px}
.chip[aria-current="page"]{color:var(--fg);background:var(--soft)}
.icon-btn{background:none;border:1px solid var(--line);color:var(--fg);border-radius:8px;width:32px;height:32px;display:grid;place-items:center;cursor:pointer}
:root[data-theme="dark"] .i-moon,:root:not([data-theme="dark"]) .i-sun{display:none}

/* story: steps on the left, sticky stage on the right */
.story{display:grid;grid-template-columns:minmax(330px,40%) 1fr;align-items:start}
.stage-col{grid-column:2;grid-row:1;position:sticky;top:var(--top);height:calc(100vh - var(--top));height:calc(100svh - var(--top));padding:0}
.steps{grid-column:1;grid-row:1;padding:0 clamp(18px,3vw,44px) 30vh;max-width:640px;justify-self:end;width:100%}
.step{min-height:88vh;padding:30vh 0 6vh}
.step.hero{padding-top:9vh;min-height:92vh}
.step:last-child{min-height:70vh}
.kicker{font:600 .8rem/1.3 var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--accent);margin:0 0 14px}
h1{font:600 clamp(2rem,3.4vw,3.05rem)/1.08 var(--serif);letter-spacing:-.01em;margin:0 0 22px}
.deck{font-size:1.22rem;line-height:1.55;color:var(--fg)}
.cta{font:500 .95rem/1.4 var(--sans);color:var(--accent);margin-top:26px}
h2{font:600 clamp(1.5rem,2.3vw,2rem)/1.15 var(--serif);margin:0 0 16px}
h3{font:600 1.15rem/1.3 var(--sans);margin:36px 0 10px}
.step p{margin:0 0 1em}
.ref{font:600 .68em/1 var(--sans);vertical-align:super;text-decoration:none;color:var(--accent);margin-left:1px}
.legend{list-style:none;padding:0;margin:18px 0 0;display:flex;flex-wrap:wrap;gap:8px 18px;font:500 .9rem/1.3 var(--sans);color:var(--mut)}
.legend li{display:flex;align-items:center;gap:7px}
.sw{width:12px;height:12px;border-radius:50%;display:inline-block}
.sw-portal{background:var(--portal)}.sw-hepatic{background:var(--hepatic)}.sw-tumour{background:var(--tumour)}

/* step tools */
.tools{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0 6px;align-items:center}
.tools button,.ctrl button{font:500 .88rem/1 var(--sans);color:var(--fg);background:var(--card);border:1px solid var(--line);border-radius:999px;padding:9px 14px;cursor:pointer;min-height:38px}
.tools button:hover{border-color:var(--mut)}
.tools button[aria-pressed="true"]{background:var(--fg);color:var(--bg);border-color:var(--fg)}
.tools button.primary{background:var(--accent-bg);color:#1b1306;border-color:var(--accent-bg);font-weight:600}
.tools button:disabled{opacity:.45;cursor:not-allowed}
.tools label{font:500 .85rem/1.2 var(--sans);color:var(--mut);display:flex;flex-direction:column;gap:4px;min-width:150px}
.tools.needle{gap:10px 14px}
input[type=range]{accent-color:var(--accent-bg);width:100%}
.out{font:400 .98rem/1.5 var(--sans);color:var(--fg);background:var(--card);border:1px solid var(--line);border-left:3px solid var(--accent-bg);border-radius:8px;padding:10px 13px;margin:10px 0}
.out:empty{display:none}
.readout{display:grid;grid-template-columns:auto 1fr;gap:4px 14px;margin:0;font:400 .92rem/1.4 var(--sans)}
.readout dt{color:var(--mut)}.readout dd{margin:0}
.bad{color:var(--bad)}

/* the stage: a monitor, dark in both themes */
.stage{position:absolute;inset:0;background:var(--stage-bg);overflow:hidden;touch-action:none;user-select:none;-webkit-user-select:none;outline:none}
.stage:focus-visible{box-shadow:inset 0 0 0 2px var(--accent-bg)}
#gl{position:absolute;inset:0;width:100%;height:100%;display:block}
.lapbox{position:absolute;inset:0;pointer-events:none}
.usbox{position:absolute;right:16px;top:16px;width:clamp(210px,34%,380px);background:transparent;border:1px solid #2b2724;border-radius:6px;padding:0 8px 8px;box-shadow:0 10px 40px rgba(0,0,0,.55);color:var(--monitor-fg)}
.ushead{font:500 .75rem/1 ui-monospace,Menlo,monospace;letter-spacing:.04em;color:var(--monitor-mut);padding:8px 2px 7px;display:flex;justify-content:space-between}
.stage.noprobe .usbox,.stage.noprobe .ctrl{display:none}
.usimg{position:relative;aspect-ratio:40/72;width:100%;cursor:crosshair}
.mark-dot{position:absolute;left:3px;top:3px;width:6px;height:6px;border-radius:50%;background:#e0b34a}
.ruler{position:absolute;right:-1px;top:0;bottom:0;width:6px;pointer-events:none}.ruler i{position:absolute;right:0;width:6px;height:1px;background:#bdb5a8}
.uslabels{position:absolute;inset:0;pointer-events:none;z-index:2}
.lab{position:absolute;transform:translate(-50%,-50%);font:600 .68rem/1 var(--sans);padding:3px 5px;border-radius:4px;background:rgba(0,0,0,.62);white-space:nowrap;border:1px solid rgba(255,255,255,.18)}
.lab-tumour{color:#ffd36b}.lab-hepatic,.lab-ivc{color:#a9c6ff}.lab-portal{color:#ffb0c0}
.gate{position:absolute;z-index:1;width:12px;height:6px;border-top:1.5px solid #f0d27a;border-bottom:1.5px solid #f0d27a;transform:translate(-50%,-50%);pointer-events:none}
.specwrap{height:0;overflow:hidden;transition:height .3s}
.specwrap.on{height:72px;margin-top:6px}
.spec{width:100%;height:72px;display:block;background:#000;border-radius:3px}
.ctrl{position:absolute;right:112px;bottom:22px}
.ctrl-probe{display:flex;align-items:center;gap:10px;padding:7px 12px 7px 12px;border-radius:14px;background:rgba(14,12,11,.62);border:1px solid rgba(255,255,255,.12)}
.ctrl-cap{font:600 .62rem/1 var(--sans);letter-spacing:.12em;text-transform:uppercase;color:#a99f91}
.ctrl-row{display:flex;gap:4px}
.ctrl button{width:30px;height:30px;padding:0;border-radius:50%;background:transparent;border:1px solid rgba(255,255,255,.14);color:#e9e2d6;font:400 1rem/1 var(--sans);cursor:pointer;transition:background .15s,border-color .15s}
.ctrl button:hover{background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.3)}
.ctrl .tilt{display:flex;flex-direction:column;gap:4px;font:500 .66rem/1 var(--sans);color:#a99f91;width:118px}
.ctrl .tilt input{height:14px}
/* orbit pad: four fine chevrons around a dot */
.orbit{position:absolute;right:20px;bottom:20px;width:78px;height:78px;border-radius:50%;background:rgba(14,12,11,.5);border:1px solid rgba(255,255,255,.12);opacity:.78;transition:opacity .2s}
.orbit:hover,.orbit:focus-within{opacity:1}
.stage:not(.ready) .orbit{display:none}
/* what the reader has changed, removable from the stage */
.mods{position:absolute;left:14px;top:14px;display:flex;flex-wrap:wrap;gap:6px;max-width:calc(100% - 420px);z-index:3}
.mods:empty{display:none}
.mod{display:inline-flex;align-items:center;gap:2px;padding:0 3px 0 10px;height:28px;border-radius:999px;background:rgba(14,12,11,.66);border:1px solid rgba(255,255,255,.14);color:#e9e2d6;font:500 .74rem/1 var(--sans)}
.mod button{width:22px;height:22px;padding:0;border:0;border-radius:50%;background:transparent;color:#cfc5b6;cursor:pointer;font:400 .95rem/1 var(--sans);display:grid;place-items:center}
.mod button:hover{background:rgba(255,255,255,.12);color:#fff}
.mod .x{font-size:1.05rem}
.mod-icg{border-color:rgba(111,241,154,.35)}.mod-marks{border-color:rgba(240,210,122,.35)}.mod-cover{border-color:rgba(120,200,230,.35)}
.ob{position:absolute;width:28px;height:28px;padding:0;margin:0;border:0;border-radius:50%;background:transparent;cursor:pointer;display:grid;place-items:center;transition:background .15s}
.ob svg{width:16px;height:16px;fill:none;stroke:#e9e2d6;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round;opacity:.75;transition:opacity .15s,transform .15s}
.ob:hover{background:rgba(255,255,255,.07)}.ob:hover svg,.ob.on svg{opacity:1}
.ob.on{background:rgba(224,179,74,.18)}
.ob-u{left:25px;top:2px}.ob-d{left:25px;bottom:2px}.ob-l{left:2px;top:25px}.ob-r{right:2px;top:25px}
.ob-u:active svg{transform:translateY(-1px)}.ob-d:active svg{transform:translateY(1px)}.ob-l:active svg{transform:translateX(-1px)}.ob-r:active svg{transform:translateX(1px)}
.ob-reset{position:absolute;left:31px;top:31px;width:16px;height:16px;padding:0;border-radius:50%;border:1.5px solid rgba(233,226,214,.6);background:transparent;cursor:pointer}
.ob-reset:hover{background:#e0b34a;border-color:#e0b34a}
/* the monitor moves by its bar and resizes from its corner (desktop) */
.ushead{cursor:grab;user-select:none;touch-action:none}
.usbox.dragging .ushead{cursor:grabbing}
.usbox.dragging{box-shadow:0 18px 60px rgba(0,0,0,.7)}
.grip{position:absolute;right:2px;bottom:2px;width:14px;height:14px;cursor:nwse-resize;touch-action:none;background:linear-gradient(135deg,transparent 0 55%,rgba(233,226,214,.45) 55% 62%,transparent 62% 72%,rgba(233,226,214,.45) 72% 79%,transparent 79%)}
.hint{position:absolute;left:14px;bottom:12px;margin:0;font:400 .76rem/1.2 var(--sans);color:#a59b8d;pointer-events:none}
.stage.touched .hint{opacity:0;transition:opacity .6s}
.loading{position:absolute;inset:0;display:grid;place-content:center;gap:10px;color:#d6cdbf;font:500 .9rem/1.4 var(--sans);text-align:center;background:var(--stage-bg)}
.loading .bar{width:200px;height:3px;background:#2a2420;border-radius:2px;overflow:hidden;margin:auto}
.loading .bar span{display:block;height:100%;width:0;background:#e0b34a;transition:width .3s}
.stage.nogl .loading{place-content:center;padding:24px}

/* atlas */
.wrap{max-width:1160px;margin:0 auto;padding:0 clamp(18px,4vw,40px)}
.atlas-sec{padding:14vh 0 8vh;border-top:1px solid var(--line)}
.atlas-sec p,.method p{max-width:42em}
.atlas-box{position:relative;margin-top:28px}
#atlas{width:100%;display:block;color:var(--fg);--accent:#e0b34a;touch-action:manipulation}
.atlas-tip{position:absolute;transform:translateX(-50%);background:var(--card);border:1px solid var(--line);border-radius:8px;padding:8px 11px;font:400 .84rem/1.4 var(--sans);pointer-events:none;white-space:nowrap;box-shadow:0 6px 24px rgba(0,0,0,.25)}
.method{padding:8vh 0 12vh}
.method p{font-size:1.02rem}
.sources{font:400 .86rem/1.5 var(--sans);color:var(--mut);padding-left:1.4em}
.sources li{margin:0 0 6px}
.sources a{word-break:break-all}
.site-footer{display:flex;flex-wrap:wrap;gap:8px 22px;justify-content:center;padding:26px 16px 40px;border-top:1px solid var(--line);font:400 .85rem/1.4 var(--sans);color:var(--mut)}

/* phone: stage on top (sticky, 44% of the screen), text below */
@media (max-width: 860px){
  .story{display:block}
  .stage-col{position:sticky;top:var(--top);height:44vh;height:44svh;z-index:5}
  .steps{padding:0 18px 30vh;max-width:none}
  .step{min-height:78vh;padding:18px 0 4vh}
  .step.hero{padding-top:22px;min-height:70vh}
  h1{font-size:1.8rem}
  .deck{font-size:1.08rem}
  body{font-size:1.06rem}
  .lapbox{right:41%}
  .usbox{top:0;right:0;bottom:0;width:41%;border-radius:0;border-width:0 0 0 1px;padding:0 4px 4px;display:flex;flex-direction:column;box-shadow:none}
  .ushead{padding:5px 2px 4px;font-size:.62rem}
  .usimg{aspect-ratio:40/72;flex:1 1 auto;min-height:0;height:0;width:auto;max-width:100%;margin:0 auto}
  .specwrap.on{height:44px;margin-top:3px}.spec{height:44px}
  .ctrl{left:8px;right:auto;bottom:8px}
  .ctrl-probe{padding:5px 8px;gap:6px}.ctrl-cap{display:none}
  .ctrl button{width:30px;height:30px}
  .ctrl .tilt{width:84px}
  .orbit{right:auto;left:8px;top:8px;bottom:auto;width:62px;height:62px}
  .ob{width:22px;height:22px}.ob svg{width:13px;height:13px}
  .ob-u{left:20px;top:2px}.ob-d{left:20px;bottom:2px}.ob-l{left:2px;top:20px}.ob-r{right:2px;top:20px}
  .ob-reset{left:24px;top:24px;width:14px;height:14px}
  .ushead{cursor:default}.grip{display:none}
  .mods{left:76px;top:8px;max-width:calc(59% - 84px)}
  .mod{height:26px;font-size:.68rem}
  .hint{display:none}
  .topnav{display:none}
}
@media (prefers-reduced-motion: reduce){*{scroll-behavior:auto!important;transition:none!important}}