/* RC170: independent palette keeps the same contrast in all three modes. */
.sk170-path,.sk170-guide{--sk170-bg:#edf5fc;--sk170-card:#fff;--sk170-text:#162f4b;--sk170-muted:#45617c;--sk170-edge:#b9d1e6;--sk170-accent:#21618e;--sk170-soft:#dbeefa;color:var(--sk170-text);background:var(--sk170-bg);border:1px solid var(--sk170-edge);border-radius:19px;margin:22px 0;padding:19px;overflow-wrap:anywhere}
.sk170-head{margin:0 0 16px}.sk170-head>span{font-size:11px;font-weight:800;letter-spacing:.09em;color:var(--sk170-accent)}.sk170-head h3{margin:6px 0 4px;font-size:clamp(18px,2vw,23px);color:var(--sk170-text);line-height:1.3}.sk170-head p{color:var(--sk170-muted);font-size:14px;margin:0;line-height:1.65}
.sk170-path-grid{counter-reset:none;list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.sk170-path-item{list-style:none;min-width:0;position:relative;display:flex;align-items:flex-start;gap:12px;border:1px solid var(--sk170-edge);border-radius:13px;background:var(--sk170-card);padding:14px}.sk170-path-item:not(:last-child):after{content:'›';position:absolute;right:-11px;top:36px;border-radius:50%;width:20px;height:20px;display:grid;place-items:center;background:var(--sk170-accent);color:#fff;font-weight:900;z-index:1}.sk170-path-index{display:grid;place-items:center;flex:none;width:29px;height:29px;border-radius:9px;background:var(--sk170-soft);color:var(--sk170-text);font-weight:900}.sk170-path-item h4{font-size:14px;line-height:1.5;margin:0 0 8px;color:var(--sk170-text)}.sk170-path-item p{font-size:13px;line-height:1.7;margin:0;color:var(--sk170-muted)}
.sk170-guide{display:grid;gap:14px}.sk170-problem,.sk170-result,.sk170-warning,.sk170-selfcheck{background:var(--sk170-card);color:var(--sk170-text);border:1px solid var(--sk170-edge);border-radius:13px;padding:15px}.sk170-problem p{margin:7px 0 0;line-height:1.75}.sk170-solution{display:grid;gap:9px;margin:0;padding:0;list-style:none}.sk170-solution li{display:flex;gap:12px;padding:11px 14px;border-radius:12px;background:var(--sk170-card);border:1px solid var(--sk170-edge)}.sk170-solution li span{font-weight:900;color:var(--sk170-accent)}.sk170-solution p{margin:0;color:var(--sk170-text);line-height:1.65}.sk170-result{background:var(--sk170-soft);margin:0;line-height:1.65}.sk170-warning{margin:0;line-height:1.65}.sk170-selfcheck>p{line-height:1.65;margin:10px 0}.sk170-selfcheck fieldset{border:0;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;min-width:0}.sk170-selfcheck legend{padding:0 0 7px;color:var(--sk170-muted);font-size:13px}.sk170-selfcheck fieldset label{display:flex;align-items:center;gap:9px;border-radius:10px;border:1px solid var(--sk170-edge);padding:10px;background:var(--sk170-bg);cursor:pointer;min-width:0;color:var(--sk170-text)}.sk170-selfcheck input{flex:none;accent-color:#2781be}.sk170-selfcheck input:focus-visible,.sk170-selfcheck button:focus-visible{outline:3px solid #70b7ec;outline-offset:2px}.sk170-selfcheck button{margin:14px 0 0;border:0;background:#245f94;color:#fff;font-weight:800;min-height:44px;padding:9px 17px;border-radius:11px;cursor:pointer}.sk170-feedback{min-height:24px;color:var(--sk170-muted)}.sk170-feedback[data-result=correct]{color:#116b52;font-weight:700}.sk170-feedback[data-result=review]{color:#8b5114;font-weight:700}
:is(html.lessonsky-dark body,body.lessonsky-dark) :is(.sk170-path,.sk170-guide){--sk170-bg:#142840;--sk170-card:#1e3956;--sk170-text:#f3f8ff;--sk170-muted:#c3d5e9;--sk170-edge:#4d6e91;--sk170-accent:#a6d5ff;--sk170-soft:#294969}
:is(html.lessonsky-dim body,body.lessonsky-dim) :is(.sk170-path,.sk170-guide){--sk170-bg:#23384d;--sk170-card:#304d63;--sk170-text:#f4f8ff;--sk170-muted:#d0e1ef;--sk170-edge:#66839b;--sk170-accent:#b7dfff;--sk170-soft:#3c607b}
:is(html.lessonsky-dark body,body.lessonsky-dark,html.lessonsky-dim body,body.lessonsky-dim) .sk170-selfcheck :is(.sk170-feedback[data-result=correct],.sk170-feedback[data-result=review]){color:#c5ffdd}
@media(max-width:760px){.sk170-path-grid{grid-template-columns:1fr}.sk170-path-item:not(:last-child):after{top:auto;right:50%;bottom:-11px;transform:rotate(90deg)}.sk170-selfcheck fieldset{grid-template-columns:1fr}.sk170-path,.sk170-guide{padding:14px}.sk170-path-item{padding:12px}}
@media(forced-colors:active){.sk170-path,.sk170-guide,.sk170-path-item,.sk170-problem,.sk170-result,.sk170-warning,.sk170-selfcheck{forced-color-adjust:auto;background:Canvas;color:CanvasText;border:1px solid CanvasText}.sk170-selfcheck button{background:ButtonFace;color:ButtonText}}

/* Topic-matched additions to the local science SVG laboratory. */
.sk167-stage svg .sk170-water{fill:#8acde9;fill-opacity:.47;stroke:#5ba5c9;stroke-width:2}.sk167-stage svg .sk170-float{fill:#e3aa62;stroke:#b07939;stroke-width:3}.sk167-stage svg .sk170-heat{fill:#ec835f;stroke:#b75541;stroke-width:3}.sk167-stage svg .sk170-flow{fill:#edd280;stroke:#c89c43;stroke-width:2}.sk167-stage svg .sk170-alveolus{fill:#eac2d3;stroke:#ad6485;stroke-width:3}.sk167-stage svg .sk170-capillary{fill:#aed9ee;stroke:#578aac;stroke-width:3}.sk167-stage svg .sk170-cell{fill:#adcbeb;stroke:#668bb7;stroke-width:3}