@font-face{font-family:__Hanken_Grotesk_9c618b;font-style:normal;font-weight:100 900;font-display:swap;src:url(/_next/static/media/a6c19694cd327cd4-s.woff2) format("woff2");unicode-range:u+0460-052f,u+1c80-1c8a,u+20b4,u+2de0-2dff,u+a640-a69f,u+fe2e-fe2f}@font-face{font-family:__Hanken_Grotesk_9c618b;font-style:normal;font-weight:100 900;font-display:swap;src:url(/_next/static/media/851c4691abdf3def-s.woff2) format("woff2");unicode-range:u+0102-0103,u+0110-0111,u+0128-0129,u+0168-0169,u+01a0-01a1,u+01af-01b0,u+0300-0301,u+0303-0304,u+0308-0309,u+0323,u+0329,u+1ea0-1ef9,u+20ab}@font-face{font-family:__Hanken_Grotesk_9c618b;font-style:normal;font-weight:100 900;font-display:swap;src:url(/_next/static/media/a8a8dd7277bab4cf-s.woff2) format("woff2");unicode-range:u+0100-02ba,u+02bd-02c5,u+02c7-02cc,u+02ce-02d7,u+02dd-02ff,u+0304,u+0308,u+0329,u+1d00-1dbf,u+1e00-1e9f,u+1ef2-1eff,u+2020,u+20a0-20ab,u+20ad-20c0,u+2113,u+2c60-2c7f,u+a720-a7ff}@font-face{font-family:__Hanken_Grotesk_9c618b;font-style:normal;font-weight:100 900;font-display:swap;src:url(/_next/static/media/313510e2713fb214-s.p.woff2) format("woff2");unicode-range:u+00??,u+0131,u+0152-0153,u+02bb-02bc,u+02c6,u+02da,u+02dc,u+0304,u+0308,u+0329,u+2000-206f,u+20ac,u+2122,u+2191,u+2193,u+2212,u+2215,u+feff,u+fffd}@font-face{font-family:__Hanken_Grotesk_Fallback_9c618b;src:local("Arial");ascent-override:99.07%;descent-override:30.02%;line-gap-override:0.00%;size-adjust:100.94%}.__className_9c618b{font-family:__Hanken_Grotesk_9c618b,__Hanken_Grotesk_Fallback_9c618b;font-style:normal}.__variable_9c618b{--font-hanken:"__Hanken_Grotesk_9c618b","__Hanken_Grotesk_Fallback_9c618b"}.learn-root{--bg:#fbfbfd;--surface:#fff;--ink:#1c1f28;--ink-2:#4b5162;--ink-3:#697083;--line:#e7e9f0;--line-2:#d9dce7;--accent:#3557d4;--accent-text:#2e4cc0;--accent-soft:rgba(53,87,212,.07);--accent-line:rgba(53,87,212,.32);--amber:#b45309;--amber-fill:#e79009;--glow:rgba(80,110,235,.16);--shadow:0 1px 2px rgba(20,24,40,.05),0 8px 28px -12px rgba(20,24,40,.12);--code:#39415a;--accent-contrast:#fff}@media (prefers-color-scheme:dark){.learn-root{--bg:#0c0e13;--surface:#11141b;--ink:#e7eaf3;--ink-2:#a6adbf;--ink-3:#8189a0;--line:#20242f;--line-2:#2c3140;--accent:#8ea6ff;--accent-text:#a2b4ff;--accent-soft:rgba(142,166,255,.08);--accent-line:rgba(142,166,255,.38);--amber:#f5b544;--amber-fill:#f0a92e;--glow:rgba(110,140,255,.13);--shadow:0 1px 2px rgba(0,0,0,.4),0 12px 32px -14px rgba(0,0,0,.55);--code:#c3cae0;--accent-contrast:#10131c}}.learn-root[data-theme=dark]{--bg:#0c0e13;--surface:#11141b;--ink:#e7eaf3;--ink-2:#a6adbf;--ink-3:#8189a0;--line:#20242f;--line-2:#2c3140;--accent:#8ea6ff;--accent-text:#a2b4ff;--accent-soft:rgba(142,166,255,.08);--accent-line:rgba(142,166,255,.38);--amber:#f5b544;--amber-fill:#f0a92e;--glow:rgba(110,140,255,.13);--shadow:0 1px 2px rgba(0,0,0,.4),0 12px 32px -14px rgba(0,0,0,.55);--code:#c3cae0;--accent-contrast:#10131c}.learn-root[data-theme=light]{--bg:#fbfbfd;--surface:#fff;--ink:#1c1f28;--ink-2:#4b5162;--ink-3:#697083;--line:#e7e9f0;--line-2:#d9dce7;--accent:#3557d4;--accent-text:#2e4cc0;--accent-soft:rgba(53,87,212,.07);--accent-line:rgba(53,87,212,.32);--amber:#b45309;--amber-fill:#e79009;--glow:rgba(80,110,235,.16);--shadow:0 1px 2px rgba(20,24,40,.05),0 8px 28px -12px rgba(20,24,40,.12);--code:#39415a;--accent-contrast:#fff}.learn-root,.learn-root *{box-sizing:border-box;margin:0;padding:0}html:has(.learn-root){scroll-behavior:smooth}.learn-root{background:var(--bg);color:var(--ink);font-family:var(--font-hanken),system-ui,-apple-system,sans-serif;font-size:17px;line-height:1.7;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;overflow-x:hidden}.learn-root ::-moz-selection{background:var(--accent-soft);color:var(--ink)}.learn-root ::selection{background:var(--accent-soft);color:var(--ink)}.learn-root .val{font-family:ui-monospace,SF Mono,SFMono-Regular,Menlo,monospace;font-size:.9em;color:var(--code);letter-spacing:-.01em}.learn-root .tnum{font-variant-numeric:tabular-nums}.learn-root .topbar{position:static;background:color-mix(in srgb,var(--bg) 86%,transparent);border-bottom:1px solid var(--line)}.learn-root .topbar-in{max-width:1060px;margin:0 auto;padding:.7rem 1.5rem;display:flex;align-items:center;justify-content:space-between;gap:1rem}.learn-root .brand{font-weight:600;font-size:.9rem;letter-spacing:-.01em;color:var(--ink);text-decoration:none}.learn-root .brand small{font-weight:500;color:var(--ink-3);margin-left:.55rem;font-size:.82rem}.learn-root .theme-btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:1px solid var(--line-2);background:var(--surface);color:var(--ink-2);width:32px;height:32px;border-radius:8px;display:grid;place-items:center;cursor:pointer;transition:border-color .15s ease,color .15s ease,transform .15s ease}.learn-root .theme-btn:hover{border-color:var(--accent-line);color:var(--ink)}.learn-root .theme-btn:active{transform:scale(.94)}.learn-root .theme-btn svg{width:15px;height:15px}.learn-root .theme-btn .moon{display:none}.learn-root[data-theme=dark] .theme-btn .moon{display:block}.learn-root[data-theme=dark] .theme-btn .sun{display:none}@media (prefers-color-scheme:dark){.learn-root:not([data-theme=light]) .theme-btn .moon{display:block}.learn-root:not([data-theme=light]) .theme-btn .sun{display:none}}.learn-root .wrap{max-width:720px;margin:0 auto;padding:0 1.5rem}.learn-root .wrap-wide{max-width:880px;margin:0 auto;padding:0 1.5rem}.learn-root .hero{position:relative;padding:0 0 1rem}.learn-root .hero-visual{position:relative;background:#0c0e13;overflow:hidden;border-bottom:1px solid var(--line)}.learn-root .hero-img{display:block;width:100%;height:auto;min-height:440px;max-height:min(85vh,820px);-o-object-fit:cover;object-fit:cover;-o-object-position:center;object-position:center}.learn-root .hero-anim{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}.learn-root .hero-scrim{position:absolute;inset:0;pointer-events:none;background:linear-gradient(118deg,rgba(8,10,17,.74),rgba(8,10,17,.36) 34%,rgba(8,10,17,0) 58%)}.learn-root .hero-overlay{position:absolute;inset:0;padding:clamp(1.6rem,4.5vw,3.6rem) clamp(1.5rem,5vw,4rem)}.learn-root .hero-overlay .meta{color:#b8c2df}.learn-root .hero-overlay .meta .series{color:#a8b8ff}.learn-root .hero-overlay .meta .sep{color:#3a4260}.learn-root .hero-overlay h1{color:#f4f6fd;margin-top:.9rem;max-width:14ch}@keyframes hero-rise{0%{opacity:0;transform:translateY(22px)}to{opacity:1;transform:none}}@keyframes hero-fade{0%{opacity:0}to{opacity:1}}.learn-root .hero-img{animation:hero-fade 1.1s ease both}.learn-root .hero-overlay .meta{animation:hero-rise .8s cubic-bezier(.16,1,.3,1) .45s both}.learn-root .hero-overlay h1{animation:hero-rise .8s cubic-bezier(.16,1,.3,1) .6s both}.learn-root .hero .short-answer{animation:hero-rise .8s cubic-bezier(.16,1,.3,1) .85s both}@keyframes drift-a{0%{transform:translate(0);opacity:0}12%{opacity:.9}80%{opacity:.75}to{transform:translate(30px,-300px);opacity:0}}@keyframes drift-b{0%{transform:translate(0);opacity:0}15%{opacity:.85}to{transform:translate(-38px,-270px);opacity:0}}.learn-root .hero-anim .drift1{animation:drift-a 11s linear 1.4s infinite}.learn-root .hero-anim .drift2{animation:drift-b 14s linear 4s infinite}.learn-root .hero-anim .drift3{animation:drift-a 16s linear 7s infinite}.learn-root .hero-anim .drift1,.learn-root .hero-anim .drift2,.learn-root .hero-anim .drift3{opacity:0}@keyframes atom-pulse{0%{transform:scale(.55);opacity:0}12%{opacity:.45}55%{opacity:.16}to{transform:scale(1.6);opacity:0}}.learn-root .hero-anim .pulse{transform-box:fill-box;transform-origin:center;animation:atom-pulse 5.5s cubic-bezier(.2,.6,.35,1) infinite;opacity:0}.learn-root .hero-anim .pulse.p2{animation-delay:2.75s}.learn-root .meta{font-size:.86rem;font-weight:500;color:var(--ink-3);letter-spacing:.005em;display:flex;flex-wrap:wrap;-moz-column-gap:.6rem;column-gap:.6rem;row-gap:.15rem;align-items:baseline}.learn-root .meta .sep{color:var(--line-2);-webkit-user-select:none;-moz-user-select:none;user-select:none}.learn-root .meta .series{color:var(--accent-text);font-weight:600}.learn-root h1{font-size:clamp(2.3rem,5.6vw,3.35rem);font-weight:700;letter-spacing:-.032em;line-height:1.06;margin-top:1.1rem}.learn-root .short-answer{margin-top:2.1rem;background:var(--accent-soft);border:1px solid var(--accent-line);border-radius:12px;padding:1.25rem 1.4rem 1.3rem}.learn-root .short-answer .lbl{font-size:.8rem;font-weight:600;color:var(--accent-text);display:flex;align-items:center;gap:.45rem;margin-bottom:.5rem}.learn-root .short-answer .lbl svg{width:13px;height:13px;flex:none}.learn-root .short-answer p{font-size:1.06rem;line-height:1.62;color:var(--ink);max-width:62ch}.learn-root .short-answer strong{font-weight:600}.learn-root article{padding-bottom:2rem}.learn-root .section{margin-top:4.6rem}.learn-root h2{font-size:clamp(1.42rem,3vw,1.72rem);font-weight:700;letter-spacing:-.024em;line-height:1.22;margin-bottom:1.05rem}.learn-root .section p{color:var(--ink-2);max-width:66ch;margin-bottom:1.1rem}.learn-root .section p strong{color:var(--ink);font-weight:600}.learn-root .section p em{font-style:italic}.learn-root a{color:var(--accent-text);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px;text-decoration-color:var(--accent-line)}.learn-root a:hover{text-decoration-color:var(--accent-text)}.learn-root a:focus-visible,.learn-root button:focus-visible,.learn-root summary:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:4px}.learn-root figure.panel{margin:2.2rem 0 2.4rem;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);overflow:hidden}.learn-root figure.panel .panel-body{padding:1.7rem 1.7rem 1.5rem}.learn-root figure.panel figcaption{border-top:1px solid var(--line);padding:.8rem 1.7rem .85rem;font-size:.85rem;color:var(--ink-3);line-height:1.55}.learn-root figure.panel figcaption b{font-weight:600;color:var(--ink-2)}.learn-root .reveal{opacity:0;transform:translateY(18px);transition:opacity .8s cubic-bezier(.16,1,.3,1),transform .8s cubic-bezier(.16,1,.3,1)}.learn-root .reveal.in{opacity:1;transform:none}.learn-root .lanes{display:grid;gap:1.15rem}.learn-root .lane-row{display:grid;grid-template-columns:118px 1fr;gap:1.1rem;align-items:center}.learn-root .lane-key{font-size:.85rem;line-height:1.4}.learn-root .lane-key b{display:block;font-weight:600;color:var(--ink)}.learn-root .lane-key span{color:var(--ink-3)}.learn-root .lane{position:relative;height:44px;border-radius:10px;background:var(--bg);border:1px solid var(--line-2);overflow:hidden}.learn-root .dot{position:absolute;top:50%;width:8px;height:8px;margin-top:-4px;border-radius:50%;background:var(--accent);left:-12px}.learn-root .flowing .dot{animation:flow 2.6s linear infinite}.learn-root .dot.d2{animation-delay:.85s}.learn-root .dot.d3{animation-delay:1.7s}@keyframes flow{0%{transform:translateX(0)}to{transform:translateX(560px)}}@keyframes stall{0%{transform:translateX(0);opacity:1}38%{transform:translateX(198px);opacity:1}55%{transform:translateX(206px);opacity:1}78%{transform:translateX(206px);opacity:0}to{transform:translateX(206px);opacity:0}}.learn-root .blocked .dot{animation:stall 2.6s cubic-bezier(.2,.9,.3,1) infinite}.learn-root .wall{position:absolute;top:5px;bottom:5px;left:222px;width:9px;border-radius:3px;background:var(--line-2)}.learn-root .wall.solid{background:var(--ink-3);opacity:.55}.learn-root .gate{position:absolute;top:4px;left:224px;width:5px;height:36px;border-radius:3px;background:var(--accent);transform-origin:top center;transform:rotate(74deg);transition:transform .45s cubic-bezier(.16,1,.3,1),background .3s}.learn-root .lane.closed .gate{transform:rotate(0deg);background:var(--amber-fill)}.learn-root .lane.closed .dot{animation:stall 2.6s cubic-bezier(.2,.9,.3,1) infinite}.learn-root .lane-ctl{display:flex;align-items:center;gap:.7rem;margin-top:1.2rem;padding-top:1.1rem;border-top:1px solid var(--line)}.learn-root .switch-btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;cursor:pointer;border:1px solid var(--line-2);background:var(--surface);color:var(--ink);font:inherit;font-size:.85rem;font-weight:600;padding:.42rem .9rem;border-radius:8px;display:inline-flex;align-items:center;gap:.5rem;transition:border-color .15s,background .15s,transform .1s}.learn-root .switch-btn:hover{border-color:var(--accent-line)}.learn-root .switch-btn:active{transform:scale(.97)}.learn-root .switch-btn .led{width:7px;height:7px;border-radius:50%;background:var(--accent);transition:background .3s}.learn-root .switch-btn[aria-pressed=true] .led{background:var(--amber-fill)}.learn-root .lane-ctl .state{font-size:.85rem;color:var(--ink-3)}.learn-root .lane-ctl .state b{color:var(--ink-2);font-weight:600}.learn-root .si-grid{display:grid;grid-template-columns:200px 1fr;gap:2rem;align-items:center}.learn-root .si-cell svg{display:block;width:100%;height:auto}.learn-root .si-reasons{list-style:none}.learn-root .si-reasons li{padding:.85rem 0;display:grid;grid-template-columns:auto 1fr;gap:.85rem;align-items:baseline;font-size:.95rem;line-height:1.55;color:var(--ink-2)}.learn-root .si-reasons li+li{border-top:1px solid var(--line)}.learn-root .si-reasons b{color:var(--ink);font-weight:600}.learn-root .si-reasons .tick{width:18px;height:18px;flex:none;transform:translateY(2px);color:var(--accent)}.learn-root .band-fig svg{display:block;width:100%;height:auto}.learn-root .hop-e{animation:hop 4.2s cubic-bezier(.34,1.2,.4,1) infinite}@keyframes hop{0%,30%{transform:translate(0)}38%{transform:translate(4px,-30px)}46%,72%{transform:translate(9px,-52px)}80%,to{transform:translate(0)}}.learn-root .hop-ring{transform-origin:center;animation:ring 4.2s ease-out infinite;opacity:0}@keyframes ring{24%{opacity:0;transform:scale(.4)}30%{opacity:.85;transform:scale(.7)}42%{opacity:0;transform:scale(1.7)}}.learn-root .seg{display:inline-flex;background:var(--bg);border:1px solid var(--line-2);border-radius:10px;padding:3px;gap:2px;margin-bottom:1.4rem}.learn-root .seg button{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:0;background:transparent;cursor:pointer;font:inherit;font-size:.85rem;font-weight:600;color:var(--ink-3);padding:.4rem .95rem;border-radius:7px;transition:color .18s,background .18s,box-shadow .18s}.learn-root .seg button:hover{color:var(--ink)}.learn-root .seg button[aria-pressed=true]{background:var(--surface);color:var(--ink);box-shadow:0 1px 3px rgba(15,18,30,.14)}.learn-root .dope-wrap{display:grid;grid-template-columns:minmax(0,340px) 1fr;gap:2rem;align-items:center}.learn-root .dope-svg svg{display:block;width:100%;height:auto}.learn-root .dope-note{font-size:.95rem;line-height:1.6;color:var(--ink-2)}.learn-root .dope-note b{color:var(--ink);font-weight:600}.learn-root .dope-note .chip-tag{display:inline-block;font-size:.78rem;font-weight:600;padding:.1rem .5rem;border-radius:99px;margin-bottom:.6rem;background:var(--accent-soft);color:var(--accent-text);border:1px solid var(--accent-line)}.learn-root .dope-note[data-mode=p] .chip-tag{background:rgba(230,150,20,.1);color:var(--amber);border-color:rgba(230,150,20,.35)}.learn-root .dopant{display:none}.learn-root .dope-svg.mode-n .dopant-n,.learn-root .dope-svg.mode-p .dopant-p{display:block}.learn-root .dope-svg.mode-n .center-si,.learn-root .dope-svg.mode-p .center-si{display:none}.learn-root .free-e{offset-path:path("M 60 88 C 150 30, 230 30, 290 96 C 330 150, 300 250, 220 268 C 130 288, 50 240, 60 150 Z");animation:carry 7s linear infinite}.learn-root .free-h{offset-path:path("M 290 96 C 230 30, 150 30, 60 88 C 20 150, 60 250, 150 272 C 240 290, 320 230, 290 160 Z");animation:carry 8.5s linear infinite}@keyframes carry{0%{offset-distance:0}to{offset-distance:100%}}.learn-root .junction-strip{margin-top:1.6rem;padding-top:1.35rem;border-top:1px solid var(--line)}.learn-root .junction-strip svg{max-width:560px;margin:0 auto}.learn-root .chain svg,.learn-root .junction-strip svg{display:block;width:100%;height:auto}.learn-root .chain .node{opacity:0;transform:translateY(12px);transition:opacity .7s cubic-bezier(.16,1,.3,1),transform .7s cubic-bezier(.16,1,.3,1)}.learn-root .chain .link{opacity:0;transition:opacity .5s ease}.learn-root .in .chain .node{opacity:1;transform:none}.learn-root .in .chain .n1{transition-delay:.05s}.learn-root .in .chain .n2{transition-delay:.25s}.learn-root .in .chain .n3{transition-delay:.45s}.learn-root .in .chain .n4{transition-delay:.65s}.learn-root .in .chain .n5{transition-delay:.85s}.learn-root .in .chain .k1{transition-delay:.2s}.learn-root .in .chain .k2{transition-delay:.4s}.learn-root .in .chain .k3{transition-delay:.6s}.learn-root .in .chain .k4{transition-delay:.8s}.learn-root .in .chain .link{opacity:1}.learn-root .facts{display:flex;flex-wrap:wrap;margin:2.2rem 0 .4rem;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.learn-root .fact{flex:1 1 180px;padding:1.15rem 1.4rem 1.2rem}.learn-root .fact+.fact{border-left:1px solid var(--line)}.learn-root .fact .num{font-size:1.35rem;font-weight:700;letter-spacing:-.02em;color:var(--ink);font-variant-numeric:tabular-nums}.learn-root .fact .lab{font-size:.84rem;color:var(--ink-3);margin-top:.15rem;line-height:1.45}.learn-root .takeaways{margin-top:4.6rem}.learn-root .tk-list{list-style:none;margin-top:1.4rem}.learn-root .tk-list li{display:grid;grid-template-columns:auto 1fr;gap:.9rem;align-items:baseline;padding:.9rem 0;font-size:1rem;line-height:1.6;color:var(--ink-2)}.learn-root .tk-list li+li{border-top:1px solid var(--line)}.learn-root .tk-list b{color:var(--ink);font-weight:600}.learn-root .tk-mark{width:17px;height:17px;flex:none;transform:translateY(2px);color:var(--accent)}.learn-root .faq{margin-top:4.6rem}.learn-root .faq details{border-top:1px solid var(--line)}.learn-root .faq details:last-of-type{border-bottom:1px solid var(--line)}.learn-root .faq summary{cursor:pointer;list-style:none;display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:1.05rem .2rem;font-weight:600;font-size:1.02rem;letter-spacing:-.008em;transition:color .15s}.learn-root .faq summary::-webkit-details-marker{display:none}.learn-root .faq summary:hover{color:var(--accent-text)}.learn-root .faq .chev{flex:none;width:16px;height:16px;color:var(--ink-3);transition:transform .35s cubic-bezier(.16,1,.3,1)}.learn-root .faq details[open] .chev{transform:rotate(45deg)}.learn-root .faq .faq-a{padding:0 .2rem 1.25rem;color:var(--ink-2);max-width:64ch;line-height:1.65}.learn-root .faq .faq-a p+p{margin-top:.7rem}.learn-root .series-nav{margin-top:5rem;padding:2.6rem 0 4.5rem;border-top:1px solid var(--line)}.learn-root .series-nav h3{font-size:.88rem;font-weight:600;color:var(--ink-3);margin-bottom:1.5rem}.learn-root .parts{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}.learn-root .part{border:1px solid var(--line);border-radius:12px;padding:1.05rem 1.15rem 1.15rem;background:var(--surface);position:relative;transition:border-color .18s,transform .18s}.learn-root .part.here{border-color:var(--accent-line);background:var(--accent-soft)}.learn-root .part .p-no{font-size:.78rem;font-weight:600;color:var(--ink-3)}.learn-root .part.here .p-no{color:var(--accent-text)}.learn-root .part .p-t{font-weight:600;letter-spacing:-.012em;margin-top:.2rem;line-height:1.3}.learn-root .part .p-s{font-size:.83rem;color:var(--ink-3);margin-top:.3rem;line-height:1.45}.learn-root .part .badge{position:absolute;top:.95rem;right:1rem;font-size:.72rem;font-weight:600;color:var(--accent-text)}.learn-root .footnote{margin-top:2.6rem;font-size:.83rem;color:var(--ink-3);line-height:1.6}.learn-root .progress{position:fixed;top:0;left:0;right:0;height:2px;z-index:60;pointer-events:none}.learn-root .progress-fill{height:100%;width:0;background:var(--accent);transition:width .12s linear}.learn-root .qc{margin:2.6rem 0 0;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);padding:1.45rem 1.7rem 1.5rem}.learn-root .qc-head{display:flex;align-items:center;gap:.45rem;font-size:.8rem;font-weight:600;color:var(--accent-text)}.learn-root .qc-head svg{width:13px;height:13px;flex:none}.learn-root .qc-head .qc-count{margin-left:auto;font-weight:500;color:var(--ink-3)}.learn-root .qc-q{font-weight:600;font-size:1.02rem;letter-spacing:-.008em;line-height:1.5;margin:.6rem 0 1rem;max-width:62ch;color:var(--ink)}.learn-root .qc-opts{display:grid;gap:.55rem}.learn-root .qc-opt{-webkit-appearance:none;-moz-appearance:none;appearance:none;text-align:left;cursor:pointer;font:inherit;font-size:.93rem;font-weight:500;line-height:1.5;color:var(--ink-2);background:var(--bg);border:1px solid var(--line-2);border-radius:10px;padding:.62rem .95rem;transition:border-color .15s,background .15s,color .15s,transform .1s}.learn-root .qc-opt:hover:not(:disabled){border-color:var(--accent-line);color:var(--ink)}.learn-root .qc-opt:active:not(:disabled){transform:scale(.99)}.learn-root .qc-opt:disabled{cursor:default;opacity:.6}.learn-root .qc-opt.right{background:var(--accent-soft);border-color:var(--accent-line);color:var(--ink);opacity:1}.learn-root .qc-opt.wrong{background:rgba(230,150,20,.09);border-color:rgba(230,150,20,.4);color:var(--ink);opacity:1}.learn-root .qc-fb{margin-top:.95rem;padding:.7rem .95rem;border-radius:10px;font-size:.9rem;line-height:1.55;color:var(--ink-2);animation:qcfb .3s ease}@keyframes qcfb{0%{opacity:0;transform:translateY(5px)}to{opacity:1;transform:none}}.learn-root .qc-fb.ok{background:var(--accent-soft);border:1px solid var(--accent-line)}.learn-root .qc-fb.no{background:rgba(230,150,20,.09);border:1px solid rgba(230,150,20,.4)}.learn-root .qc-fb b{font-weight:600;color:var(--ink)}.learn-root .cta-panel{margin-top:4.6rem}.learn-root .cta-card{background:var(--accent-soft);border:1px solid var(--accent-line);border-radius:14px;padding:1.9rem 2rem 2rem}.learn-root .cta-card h2{font-size:clamp(1.28rem,2.8vw,1.55rem);letter-spacing:-.02em;margin-bottom:.8rem;max-width:34ch}.learn-root .cta-card p{color:var(--ink-2);max-width:58ch;line-height:1.65}.learn-root .cta-btn{display:inline-flex;align-items:center;gap:.55rem;margin-top:1.35rem;background:var(--accent);color:var(--accent-contrast);font-weight:600;font-size:.95rem;letter-spacing:-.005em;text-decoration:none;padding:.68rem 1.2rem;border-radius:10px;transition:transform .15s ease,box-shadow .15s ease,filter .15s ease}.learn-root .cta-btn:hover{transform:translateY(-1px);box-shadow:var(--shadow);filter:brightness(1.06);text-decoration:none}.learn-root .cta-btn:active{transform:translateY(0) scale(.98)}.learn-root .cta-btn svg{width:15px;height:15px;flex:none}.learn-root .cta-note{margin-top:.95rem;font-size:.83rem;color:var(--ink-3)}.learn-root .end-cta{margin-top:0;padding:1.5rem 0 4.2rem;border-top:1px solid var(--line);font-size:.93rem;color:var(--ink-3);line-height:1.6}.learn-root .series-nav{padding-bottom:2.6rem}@media (max-width:760px){.learn-root .dope-wrap,.learn-root .si-grid{grid-template-columns:1fr;gap:1.4rem}.learn-root .si-cell{max-width:210px;margin:0 auto}.learn-root .lane-row{gap:.4rem}.learn-root .lane-row,.learn-root .parts{grid-template-columns:1fr}.learn-root .fact+.fact{border-left:0;border-top:1px solid var(--line)}.learn-root .facts{flex-direction:column}@keyframes flow{0%{transform:translateX(0)}to{transform:translateX(110vw)}}}@media (max-width:560px){.learn-root{font-size:16px}.learn-root figure.panel .panel-body{padding:1.2rem 1.1rem 1.1rem}.learn-root figure.panel figcaption{padding:.75rem 1.1rem .8rem}.learn-root .qc{padding:1.15rem 1.1rem 1.2rem}.learn-root .cta-card{padding:1.5rem 1.2rem 1.6rem}}@media (prefers-reduced-motion:reduce){html:has(.learn-root){scroll-behavior:auto}.learn-root,.learn-root *,.learn-root :after,.learn-root :before{animation-duration:1ms!important;animation-iteration-count:1!important;transition-duration:1ms!important}.learn-root .chain .link,.learn-root .chain .node,.learn-root .reveal{opacity:1!important;transform:none!important}.learn-root .hero .short-answer,.learn-root .hero-img,.learn-root .hero-overlay .meta,.learn-root .hero-overlay h1{animation:none!important;opacity:1!important;transform:none!important}.learn-root .hero-anim{display:none!important}.learn-root .progress-fill{transition:none!important}.learn-root .mo-only{display:none!important}.learn-root .dot{left:40%}.learn-root .free-e,.learn-root .free-h{animation:none;offset-distance:12%}}