:root{color-scheme:dark;--bg:#0d1318;--surface:#131c23;--line:#29353e;--muted:#94a5b2;--ink:#e6edf2;--accent:#63ddc8}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:14px 'Segoe UI',system-ui,sans-serif}button,input,select{font:inherit}button{border:1px solid var(--line);background:#18242c;color:var(--ink);padding:7px 12px;border-radius:5px;cursor:pointer;transition:background .15s,border-color .15s}button:hover{background:#233640;border-color:#6f918e}button:focus-visible,input:focus-visible{outline:2px solid var(--accent);outline-offset:3px}button.active{background:#1c3c39;color:#bafcef;border-color:#458e83}button:disabled{opacity:.4;cursor:default}header{height:68px;display:flex;align-items:center;justify-content:space-between;padding:0 28px;border-bottom:1px solid var(--line)}.brand{font-size:22px;letter-spacing:2px;font-weight:750}.brand>span:first-child{font-weight:350;color:var(--accent)}.brand .divider{color:#546670;margin:0 17px;font-weight:300}.brand small{font-size:11px;letter-spacing:2px;font-weight:500}.header-right{display:flex;align-items:center;gap:18px}.status{font-size:12px;color:var(--accent)}.status::before{content:'●';margin-right:7px;font-size:9px}main{padding:0 24px}.windows{display:flex;gap:8px;align-items:center;padding:16px 0;flex-wrap:wrap}.eyebrow{font-size:10px;letter-spacing:1.5px;color:var(--muted);font-weight:650}.windows>.eyebrow{margin-right:10px}.guide{margin-left:auto;font-size:11px;color:var(--muted)}.workspace{display:grid;grid-template-columns:1fr 1fr 1.25fr;min-height:385px;height:43vh;max-height:590px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.view{min-width:0;display:flex;flex-direction:column;position:relative}.view+.view{border-left:1px solid var(--line)}.view-heading{display:flex;align-items:center;justify-content:space-between;padding:12px 13px;height:48px;font-size:12px;gap:6px}.view-heading b{font-weight:400;color:var(--accent);font-size:10px;margin-right:8px}.view-heading button{font-size:11px;padding:4px 7px;background:none}.viewport{position:relative;flex:1;min-height:0;overflow:hidden;background:#0a1016}.viewport>canvas{display:block;width:100%;height:100%;touch-action:none}.patient .viewport{cursor:crosshair}.anatomy .viewport{cursor:grab}.view-foot{font-size:10px;color:var(--muted);padding:10px 12px;min-height:34px}.axis-label{position:absolute;top:45%;font-size:11px;color:#738592;z-index:1;pointer-events:none}.axis-label.right{left:12px}.axis-label.left{right:12px}.surface-note{position:absolute;bottom:6px;left:12px;font-size:9px;color:#75848f;pointer-events:none}.check{font-size:11px;color:var(--muted);display:flex;align-items:center;gap:4px}input[type=checkbox]{accent-color:var(--accent)}.scan-modes{display:flex;gap:4px;padding:0 12px 7px;height:34px;align-items:center}.scan-modes button{font-size:11px;padding:4px 8px}.scan-modes span{margin-left:auto;font:11px Consolas,monospace;color:var(--muted)}#scan-view{background:#05080b}#latency{font:10px Consolas,monospace;color:var(--muted)}.empty-scan{position:absolute;inset:45% 10% auto;text-align:center;color:#aab8c1;font-size:12px;pointer-events:none}.inspector{display:grid;grid-template-columns:1.65fr 1fr;border-bottom:1px solid var(--line)}.probe-controls,.image-controls{padding:17px 0}.probe-controls{padding-right:25px}.image-controls{padding-left:25px;border-left:1px solid var(--line)}.section-heading{display:flex;align-items:center;justify-content:space-between;height:26px}.section-heading button{font-size:10px;padding:4px 7px;background:none}.sliders{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px 22px;margin-top:13px}.slider label{display:flex;justify-content:space-between;gap:4px;font-size:11px;color:#b8c6ce;margin-bottom:4px}.slider label span{white-space:nowrap}.slider input[type=number]{width:65px;padding:2px 4px;border:1px solid #2f414b;background:#0d171e;color:var(--ink);border-radius:3px;font:11px Consolas,monospace}.slider input[type=range]{width:100%;height:14px;accent-color:var(--accent);cursor:ew-resize}.slider small{color:#6f8693;font-size:9px;display:block}.actions{display:flex;gap:6px;flex-wrap:wrap;margin:15px 0 10px}.actions button{font-size:11px}.micro{font-size:11px;color:var(--muted);line-height:1.55}.learning{display:grid;grid-template-columns:.85fr 1.6fr;gap:36px;padding:19px 0}.learning p{font-size:12px;line-height:1.5;margin:7px 0}.learning .micro{font-size:10px}.structures{display:flex;flex-wrap:wrap;gap:5px;margin-top:9px}.structures button{font-size:10px;padding:4px 7px;background:transparent;border-color:#30404c}.structures button::before{content:'●';color:var(--structure-color);margin-right:5px}#selection{color:var(--accent);font-size:11px;min-height:16px}footer{padding:13px 0 17px;display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--line);font-size:10px;color:#7c909d}footer button{font-size:10px;background:none;padding:5px 8px}dialog{background:#15212a;color:var(--ink);border:1px solid #4c6671;border-radius:10px;padding:22px;max-width:670px;width:90vw;line-height:1.65}dialog::backdrop{background:#000a}.dialog-top{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:12px}dialog a{color:var(--accent)}dialog p,dialog li{font-size:13px}dialog ul,dialog ol{padding-left:22px}.error{color:#ffbb9e!important}@media(min-width:1700px){main{padding:0 40px}.workspace{height:48vh}}@media(max-width:1100px){.guide{display:none}.workspace{grid-template-columns:1fr 1fr;height:auto;max-height:none}.scan{grid-column:1/-1;height:400px;border-top:1px solid var(--line);border-left:0!important}.patient,.anatomy{height:340px}.inspector{grid-template-columns:1fr}.image-controls{border-left:0;padding-left:0;border-top:1px solid var(--line)}.probe-controls{padding-right:0}}@media(max-width:650px){header{padding:0 14px}.brand{font-size:18px}.brand small{display:none}.header-right{gap:7px}.status{font-size:10px}main{padding:0 12px}.windows button{font-size:11px}.windows>.eyebrow{width:100%;margin-bottom:3px}.workspace{grid-template-columns:1fr}.patient,.anatomy{height:330px}.view+.view{border-left:0;border-top:1px solid var(--line)}.scan{grid-column:auto;height:360px}.sliders{grid-template-columns:repeat(2,minmax(0,1fr))}.learning{grid-template-columns:1fr;gap:12px}footer{flex-wrap:wrap}.view-foot{font-size:9px}.header-right #help{font-size:10px;padding:5px 7px}}@media(prefers-reduced-motion:reduce){button{transition:none}}
/* The tutor sits beside the working anatomy; no overlay hides the probe or plane. */
.course-bar{display:flex;justify-content:space-between;align-items:center;gap:14px;padding:12px 0 17px;border-top:1px solid var(--line)}.course-bar>div{display:flex;align-items:center;gap:14px}.course-context{font-size:12px;color:var(--muted)}#course-toggle{}.course-progress{font-size:11px;color:var(--muted)}.course-progress progress{width:85px;height:5px;accent-color:var(--accent)}a{color:var(--accent)}.practice-shell{display:block}.practice-shell.with-tutor{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:24px}.practice-main{min-width:0}.display-setting{display:flex;align-items:center;gap:12px;padding:4px 0 12px;font-size:11px;color:var(--muted)}select{max-width:100%;border:1px solid var(--line);border-radius:4px;background:#15222b;color:var(--ink);padding:6px}.display-setting span{margin-left:auto;font-size:10px}.tutor{border-left:1px solid var(--line);padding:4px 0 0 22px;min-width:0}.tutor[hidden]{display:none}.tutor h1{font-size:23px;font-weight:550;line-height:1.2;margin:10px 0 12px}.tutor h2{font-size:12px;font-weight:650;margin:0 0 8px}.tutor p,.tutor li{font-size:12px;line-height:1.55}.tutor ul{padding-left:17px}.tutor li+li{margin-top:7px}.tutor #lesson-picker{width:100%;margin-top:8px;font-size:12px}.tutor #lesson-source{font-size:10px;display:inline-block;margin:0 0 12px}.practice-task,.quiz,#doppler-lab,#review-exercise{padding:15px 0;border-top:1px solid var(--line)}.tutor .micro{font-size:10px}.practice-task>p:first-of-type{color:#d4e9e3}.tutor button{font-size:11px}.tutor #practice-checks{list-style:none;padding:0;color:var(--muted)}#practice-checks .done{color:var(--accent)}#quiz-options{display:flex;flex-direction:column;gap:6px}#quiz-options button{text-align:left;padding:9px 10px;line-height:1.4}#quiz-feedback{color:#dfbc96}#quiz-feedback.correct{color:var(--accent)}#lesson-complete{width:100%;border-color:#458e83}#lesson-completion{color:var(--accent);font-size:11px}.lesson-nav{display:flex;justify-content:space-between;gap:12px;margin-top:12px}.course-save{margin-top:18px;padding-top:14px;border-top:1px solid var(--line)}#doppler-lab svg{width:100%;display:block}#doppler-angle{display:block;width:100%;accent-color:var(--accent)}#doppler-lab label,#doppler-value{display:block;font-size:11px}.angle-presets{display:flex;gap:8px;margin-top:10px}#review-exercise label{display:flex;align-items:flex-start;gap:7px;font-size:12px;line-height:1.5;margin:8px 0}.with-tutor .inspector{grid-template-columns:1fr}.with-tutor .image-controls{border-left:0;border-top:1px solid var(--line);padding-left:0}.with-tutor .probe-controls{padding-right:0}.with-tutor .learning{grid-template-columns:1fr;gap:12px}.with-tutor .workspace{min-height:385px}.with-tutor .view-heading{font-size:11px;padding:10px 8px}.with-tutor .view-foot{font-size:9px}
@media(max-width:1250px){.practice-shell.with-tutor{grid-template-columns:minmax(0,1fr) 290px;gap:16px}.with-tutor .workspace{grid-template-columns:1fr 1fr;height:auto;max-height:none}.with-tutor .patient,.with-tutor .anatomy{height:310px}.with-tutor .scan{grid-column:1/-1;height:350px;border-left:0}.course-context{display:none}.tutor{padding-left:14px}}
@media(max-width:850px){.practice-shell.with-tutor{display:flex;flex-direction:column}.tutor{order:-1;border-left:0;border-bottom:1px solid var(--line);padding:0 0 18px}.tutor h1{font-size:22px}.course-bar{align-items:flex-start}.course-bar>div{flex-wrap:wrap;gap:8px}.course-progress{justify-content:flex-end}.course-progress progress{display:none}.display-setting{flex-wrap:wrap;gap:8px}.display-setting span{margin-left:0;width:100%}}
@media(max-width:650px){.with-tutor .workspace{grid-template-columns:1fr}.with-tutor .scan{grid-column:auto}.course-progress a{font-size:10px}.course-bar{gap:8px}.course-bar button{font-size:12px}.course-progress{max-width:150px}.with-tutor .view-heading{font-size:12px}}

#clinical-window{padding:10px 0 14px;font-size:12px}#clinical-window summary{color:var(--accent);cursor:pointer;line-height:1.5}#clinical-window p{font-size:11px}#clinical-window[hidden]{display:none}

.recording-result{margin:12px 0;padding:12px;border-left:3px solid var(--accent);background:#152823}.recording-result[hidden]{display:none}.recording-result p{margin:0 0 9px;font-size:12px;line-height:1.5}.recording-result>div{display:flex;gap:10px;flex-wrap:wrap}.recording-result a{display:inline-block;padding:7px 10px;border:1px solid #458e83;border-radius:4px;font-size:12px;color:#bafcef}.recording-result a:hover{background:#24463d}

#reference-toggle{font-size:11px;color:var(--accent);padding:5px 8px}.view.reference[hidden]{display:none}.workspace.with-reference{grid-template-columns:1fr 1fr;height:auto;max-height:none}.workspace.with-reference>.view{height:440px}.workspace.with-reference .scan{grid-column:auto;border-left:0;border-top:1px solid var(--line)}.workspace.with-reference .reference{border-top:1px solid var(--line)}.reference .view-heading a{font-size:10px}.reference-toolbar{display:flex;align-items:center;gap:9px;padding:0 12px 8px;font-size:10px}.reference-toolbar select{flex:1;min-width:0;font-size:11px}.reference-toolbar .check{white-space:nowrap;font-size:10px}.reference-picture{min-height:90px;flex:1;background:#000;display:flex;align-items:center}.reference-picture video{display:block;width:100%;height:100%;min-height:0;object-fit:contain}.reference-playback{display:flex;align-items:center;gap:7px;padding:6px 12px}.reference-playback input{min-width:30px;flex:1;accent-color:var(--accent)}.reference-playback button,.reference-playback select{font-size:10px;padding:4px 6px}.reference-details{display:flex;justify-content:space-between;gap:10px;padding:0 12px;color:var(--muted);font:10px Consolas}.reference-context{padding:8px 12px;font-size:10px;line-height:1.45}.reference-context p{margin:3px 0}.reference-context strong{font-size:11px}.reference-context button{font-size:10px;padding:4px 6px;margin:4px 0}.reference-context span{color:var(--muted);font-size:9px}.reference-context #reference-link-note{color:#b4d3cb}.with-tutor .reference-toolbar{flex-wrap:wrap}.with-tutor .reference-toolbar .check{width:100%}.with-tutor .workspace.with-reference>.view{height:470px}
@media(max-width:850px){.workspace.with-reference>.view{height:420px}.reference-toolbar{flex-wrap:wrap}.reference-toolbar .check{width:100%}.reference-details{font-size:9px}}
@media(max-width:650px){.workspace.with-reference{grid-template-columns:1fr}.workspace.with-reference>.view,.with-tutor .workspace.with-reference>.view{height:370px}.workspace.with-reference .reference,.with-tutor .workspace.with-reference .reference{height:480px}.reference-toolbar .check{width:auto}.reference-details{flex-wrap:wrap}.display-setting #reference-toggle{margin-left:auto}}

/* The acquired image shares the scan canvas and the physical console. */
.scan-modes{flex-shrink:0;height:auto;min-height:34px;flex-wrap:wrap}.scan-modes select{font-size:10px;padding:3px;max-width:135px}.scan-modes select[hidden]{display:none}
#video-controls{padding:0 12px 6px;background:#101b22}#video-controls[hidden]{display:none}#echo-clip{width:100%;font-size:11px;padding:4px}.echo-transport{display:flex;gap:5px;margin-top:5px}.echo-transport button,.echo-transport select{font-size:10px;padding:4px 7px}.echo-transport #echo-play{margin-right:auto}.echo-timeline{display:flex;align-items:center;gap:8px;margin-top:4px}.echo-timeline input{flex:1;min-width:20px;accent-color:var(--accent)}#echo-time{font:9px Consolas;white-space:nowrap;color:var(--muted)}.scan:has(#video-controls:not([hidden])){min-height:400px}.workspace:has(#video-controls:not([hidden])){min-height:440px}.trackball[aria-disabled=true]{opacity:.4;cursor:default}

.volume-entry{font-size:11px;text-decoration:none;border:1px solid #458e83;border-radius:4px;padding:6px 9px;color:#bafcef;white-space:nowrap}.display-setting{flex-wrap:wrap}
.patient-info{font-size:11px;color:var(--muted);margin-right:10px}
.measure-kind{display:flex;align-items:center;gap:6px;margin:4px 0}
.measure-kind select{font-size:11px;max-width:150px}
.display-setting .patient-info{margin-left:0;font-size:11px}