.vp{--ink:#123f39;--muted:#66837e;--green:#078574;--soft:#eaf8f5;--line:#d4e6e2;--accent:#078574;--accent-soft:#e8f7f3;margin:-12px -22px 0;padding:.75rem 0 4rem;background:#f4fbfa;color:var(--ink);font-family:Inter,system-ui,-apple-system,"Segoe UI",sans-serif}.vp *{box-sizing:border-box}.vp--purple{--accent:#6850da;--accent-soft:#f0edff}.vp--pink{--accent:#d94e7b;--accent-soft:#fff0f5}.vp--orange{--accent:#cf6819;--accent-soft:#fff3e8}.vp-shell{width:min(960px,calc(100% - 40px));margin:auto}.vp-crumb{display:flex;flex-wrap:wrap;gap:.55rem;margin-bottom:1.3rem;color:#68857f;font-size:.72rem}.vp-crumb a{color:inherit;text-decoration:none}.vp-header{display:flex;align-items:flex-end;justify-content:space-between;gap:2rem}.vp-header>div:first-child>span{color:var(--accent);font-size:.67rem;font-weight:900;letter-spacing:.14em;text-transform:uppercase}.vp-header h1{max-width:680px;margin:.55rem 0 1.3rem;color:var(--ink);font:700 clamp(2.25rem,5vw,3.55rem)/.98 Georgia,serif;letter-spacing:-.035em}.vp-progress{display:grid;width:160px;gap:.4rem;margin-bottom:1.5rem;color:var(--muted);font-size:.68rem;font-weight:900;text-align:right}.vp-progress i{height:7px;overflow:hidden;border-radius:99px;background:#dcece8}.vp-progress i b{display:block;height:100%;border-radius:inherit;background:var(--accent)}.vp-question{display:grid;grid-template-columns:1.05fr .95fr;overflow:hidden;border:1px solid var(--line);border-radius:25px;background:#fff;box-shadow:0 18px 42px rgba(19,78,69,.07)}.vp-prompt{align-self:center;padding:2rem}.vp-prompt>span{color:var(--accent);font-size:.65rem;font-weight:900;letter-spacing:.13em;text-transform:uppercase}.vp-prompt h2{margin:.75rem 0;color:var(--ink);font:700 clamp(1.5rem,3vw,2.15rem)/1.17 Georgia,serif}.vp-visual{display:grid;min-height:300px;place-items:center;padding:1rem;background:var(--accent-soft)}.vp-visual svg{width:100%;height:auto}.vp-visual svg .axis{fill:none;stroke:#9ebbb5;stroke-width:2}.vp-visual svg .purple{fill:none;stroke:#7057e8;stroke-width:5}.vp-visual svg .pink{fill:none;stroke:#e75683;stroke-width:5}.vp-visual svg .green{fill:none;stroke:#079e89;stroke-width:5}.vp-visual svg .guide{fill:none;stroke:#92aaa6;stroke-width:2;stroke-dasharray:7 5}.vp-visual svg .dashed{stroke-dasharray:7 5}.vp-visual svg .plane{fill:rgba(112,87,232,.12);stroke:#7057e8;stroke-width:3}.vp-visual svg marker path{fill:context-stroke}.vp-visual svg text{fill:var(--ink);font:800 13px Inter,sans-serif}.vp-visual svg circle{fill:#fff;stroke:var(--accent);stroke-width:3}.vp-symbols{display:flex;flex-wrap:wrap;gap:1rem;justify-content:center}.vp-symbols span{display:grid;width:72px;height:72px;place-items:center;border-radius:20px;background:#fff;color:#cf6819;font:700 2rem Georgia,serif}.vp-symbols .vector{background:#e7f6f2;color:var(--green)}.vp-answer-area{margin-top:1rem;padding:1.25rem;border:1px solid var(--line);border-radius:21px;background:#fff}.vp-options{display:grid;grid-template-columns:1fr 1fr;gap:.75rem}.vp-options button{display:grid;grid-template-columns:38px 1fr;align-items:center;gap:.75rem;min-height:70px;padding:.75rem;border:1px solid var(--line);border-radius:14px;background:#fff;color:var(--ink);cursor:pointer;font:inherit;text-align:left}.vp-options button:hover,.vp-options button:focus-visible,.vp-options button.is-selected{border-color:var(--accent);outline:none;background:var(--accent-soft)}.vp-options button.is-correct{border-color:#079e89;background:#e5f8f3}.vp-options button.is-wrong{border-color:#e75683;background:#fff0f5}.vp-options button b{display:grid;width:34px;height:34px;place-items:center;border-radius:10px;background:var(--accent-soft);color:var(--accent)}.vp-options button span{font-size:.8rem;line-height:1.4}.vp-numeric{display:grid;grid-template-columns:repeat(4,1fr);gap:.7rem}.vp-numeric label{display:grid;gap:.4rem;color:var(--muted);font-size:.7rem;font-weight:900}.vp-numeric input{width:100%;min-height:45px;padding:.6rem;border:1px solid var(--line);border-radius:10px;color:var(--ink);font:800 .9rem Inter,sans-serif}.vp-actions{display:flex;justify-content:flex-end;gap:.65rem;margin-top:1rem}.vp-actions button{min-height:42px;padding:.65rem 1rem;border:0;border-radius:10px;background:var(--accent);color:#fff;font-weight:900;cursor:pointer}.vp-actions .secondary{border:1px solid var(--line);background:#fff;color:var(--accent)}.vp-hint,.vp-feedback{margin:.85rem 0 0;padding:.85rem 1rem;border-radius:11px;background:#fff5e8;color:#775b3f;font-size:.78rem;line-height:1.5}.vp-hint{display:flex;gap:.75rem}.vp-hint strong{color:#bd651d}.vp-feedback.correct{background:#e6f8f3;color:#08695c}.vp-feedback.wrong{background:#fff0f5;color:#a73e60}.vp-explanation{margin-top:1rem;border:1px solid var(--line);border-radius:20px;background:#fff;overflow:hidden}.vp-explanation>summary{display:grid;grid-template-columns:1fr auto 34px;align-items:center;gap:1rem;padding:1.1rem 1.25rem;cursor:pointer;list-style:none}.vp-explanation>summary::-webkit-details-marker{display:none}.vp-explanation>summary span{color:var(--accent);font-size:.65rem;font-weight:900;letter-spacing:.12em;text-transform:uppercase}.vp-explanation>summary strong{font:700 1.05rem Georgia,serif}.vp-explanation>summary b{display:grid;width:32px;height:32px;place-items:center;border-radius:50%;background:var(--accent-soft);color:var(--accent)}.vp-explanation[open]>summary b{transform:rotate(180deg)}.vp-explanation>div{display:grid;grid-template-columns:.8fr 1.2fr;gap:1rem;padding:1.2rem;border-top:1px solid var(--line)}.vp-explanation-diagram{display:grid;min-height:115px;place-items:center;padding:1rem;border-radius:14px;background:var(--accent-soft)}.mini-path{color:var(--accent);font:800 1rem/1.45 Georgia,serif;text-align:center}.vp-explanation p{align-self:center;margin:0;color:var(--muted);font-size:.84rem;line-height:1.65}.vp-pagination{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:1rem;margin-top:1.2rem;padding-top:1.1rem;border-top:1px solid var(--line)}.vp-pagination a{color:var(--accent);font-size:.75rem;font-weight:900;text-decoration:none}.vp-pagination a:last-child{text-align:right}.vp-pagination span{color:var(--muted);font-size:.64rem;font-weight:800;text-transform:uppercase}
@media(max-width:720px){.vp{margin:-12px -14px 0;padding-top:.5rem}.vp-shell{width:min(100% - 24px,560px)}.vp-header{align-items:stretch;flex-direction:column;gap:0}.vp-header h1{font-size:2.3rem}.vp-progress{width:100%;margin-bottom:1rem;text-align:left}.vp-question{grid-template-columns:1fr}.vp-prompt{padding:1.35rem}.vp-visual{min-height:230px}.vp-options,.vp-numeric{grid-template-columns:1fr}.vp-actions{position:sticky;bottom:0;z-index:2;padding:.65rem 0;background:#fff}.vp-actions button{flex:1}.vp-explanation>summary{grid-template-columns:1fr 32px}.vp-explanation>summary strong{display:none}.vp-explanation>div{grid-template-columns:1fr}.vp-pagination{grid-template-columns:1fr 1fr}.vp-pagination span{display:none}}
@media(max-width:420px){.vp-header h1{font-size:2rem}.vp-visual{min-height:200px}.vp-options button{min-height:64px}.vp-actions{flex-direction:column-reverse}}
.vp-header>div:first-child>span,.vp-progress,.vp-prompt>span,.vp-numeric label,.vp-explanation>summary span,.vp-pagination span{font-size:.72rem}