:root{--bg:#f8fafc;--surface:#fff;--text:#0f172a;--muted:#64748b;--border:#e2e8f0;--accent:#0284c7;--accent-text:#fff;--good:#16a34a;--bad:#dc2626;--highlight:#f59e0b;--wire:#0f172a;--signal:#7c3aed;--comm:#0d9488;--radius:12px;--tabbar-h:60px;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5}@media (prefers-color-scheme:dark){:root{--lightningcss-light: ;--lightningcss-dark:initial;--bg:#0b1120;--surface:#131c2e;--text:#e2e8f0;--muted:#94a3b8;--border:#23304a;--accent:#38bdf8;--accent-text:#0b1120;--wire:#e2e8f0;--signal:#c4b5fd;--comm:#5eead4}}*{box-sizing:border-box}html,body{background:var(--bg);color:var(--text);margin:0}a{color:var(--accent)}.app{min-height:100dvh}.main{max-width:760px;padding:16px 16px calc(var(--tabbar-h) + 24px + env(safe-area-inset-bottom));margin:0 auto}.page h1{margin:8px 0 4px;font-size:1.5rem}.page h2{margin:0 0 8px;font-size:1.1rem}.lead{color:var(--muted);margin-top:0;font-size:1.05rem}.muted{color:var(--muted)}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);margin:16px 0;padding:16px}.btn{border:1px solid var(--border);background:var(--surface);min-height:44px;color:var(--text);font:inherit;cursor:pointer;border-radius:10px;justify-content:center;align-items:center;padding:0 20px;font-weight:600;text-decoration:none;display:inline-flex}.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-text)}.tabbar{height:calc(var(--tabbar-h) + env(safe-area-inset-bottom));padding-bottom:env(safe-area-inset-bottom);background:var(--surface);border-top:1px solid var(--border);justify-content:center;display:flex;position:fixed;bottom:0;left:0;right:0}.tab{max-width:160px;color:var(--muted);flex-direction:column;flex:1;justify-content:center;align-items:center;font-size:.75rem;text-decoration:none;display:flex}.tab-icon{font-size:1.25rem;line-height:1.2}.tab.active{color:var(--accent);font-weight:600}.small{color:var(--muted);font-size:.85rem}.eyebrow{text-transform:uppercase;letter-spacing:.06em;color:var(--accent);margin:0;font-size:.75rem;font-weight:700}.btn.block{width:100%;margin-top:12px}.section-title{color:var(--muted);margin:20px 0 8px;font-size:.95rem}.good-text{color:var(--good);font-weight:600}.bad-text{color:var(--bad);font-weight:600}.big-score{margin:0;font-size:2.5rem;font-weight:700}.glyph{color:var(--wire);max-width:100%;height:auto;overflow:visible}.glyph-stage{justify-content:center;padding:12px 0;display:flex}.segmented{background:var(--border);border-radius:12px;gap:4px;margin:12px 0;padding:4px;display:flex}.segmented button{min-height:40px;font:inherit;color:var(--muted);cursor:pointer;background:0 0;border:0;border-radius:9px;flex:1;font-weight:600}.segmented button.active{background:var(--surface);color:var(--text);box-shadow:0 1px 2px #0000001a}.symbol-list{flex-direction:column;gap:8px;display:flex}.symbol-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius)}.symbol-head{width:100%;min-height:56px;font:inherit;color:inherit;text-align:left;cursor:pointer;background:0 0;border:0;align-items:center;gap:12px;padding:6px 12px;display:flex}.symbol-head .glyph{flex:none;width:64px}.symbol-name{flex:1;font-weight:600}.symbol-body{padding:0 16px 16px}.symbol-body p{margin:8px 0}.badge{white-space:nowrap;border-radius:99px;padding:2px 8px;font-size:.7rem;font-weight:700}.badge.new{background:var(--border);color:var(--muted)}.badge.learning{background:color-mix(in srgb, var(--highlight) 25%, transparent);color:var(--text)}.badge.mastered{background:color-mix(in srgb, var(--good) 25%, transparent);color:var(--text)}.confused-row{flex-wrap:wrap;gap:6px;margin-top:6px;display:flex}.chip{border:1px solid var(--border);background:var(--bg);min-height:40px;color:inherit;font:inherit;cursor:pointer;border-radius:99px;align-items:center;gap:6px;padding:2px 10px;font-size:.85rem;display:inline-flex}.progress-row{align-items:center;gap:10px;margin-bottom:8px;display:flex}.bar{background:var(--border);border-radius:99px;flex:1;height:6px;overflow:hidden}.bar>div{background:var(--accent);height:100%;transition:width .3s}.prompt{margin:8px 0;font-size:1.1rem;font-weight:600}.options{gap:8px;display:grid}.options.grid{grid-template-columns:1fr 1fr}.option{border:2px solid var(--border);background:var(--surface);min-height:52px;color:var(--text);font:inherit;text-align:left;cursor:pointer;border-radius:10px;padding:10px 12px}.options.grid .option{justify-content:center;align-items:center;min-height:96px;display:flex}.option:disabled{cursor:default}.option.right{border-color:var(--good);background:color-mix(in srgb, var(--good) 12%, var(--surface))}.option.wrong{border-color:var(--bad);background:color-mix(in srgb, var(--bad) 12%, var(--surface))}.feedback{background:var(--bg);border-left:4px solid;border-radius:10px;margin-top:12px;padding:12px}.feedback.good{border-color:var(--good)}.feedback.bad{border-color:var(--bad)}.feedback p{margin:6px 0}.canvas-wrap{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}.circuit-canvas{touch-action:none;-webkit-user-select:none;user-select:none;width:100%;height:auto;max-height:60dvh;color:var(--wire);display:block}.circuit-canvas 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3}.block-title{fill:var(--accent);font-size:calc(9px * var(--ts,1));font-weight:700}.block.selected rect{stroke-width:2px;stroke-dasharray:none;fill:color-mix(in srgb, var(--accent) 12%, transparent)}.mode-blocks .block{cursor:pointer}.mode-blocks .block rect{fill:color-mix(in srgb, var(--accent) 16%, var(--surface));fill-opacity:.85;stroke-dasharray:none;stroke-width:1.5px}.mode-blocks .block-title{font-size:calc(14px * var(--ts,1))}.mode-blocks .block.selected rect{fill:color-mix(in srgb, var(--accent) 30%, var(--surface));stroke-width:2.5px}.mode-blocks .schematic{opacity:.18;pointer-events:none}.mode-blocks .block{pointer-events:all}.mode-trace .block{pointer-events:none;opacity:.35}.dim{opacity:.2;transition:opacity .25s}.wire.lit{stroke:color-mix(in srgb, var(--highlight) 55%, var(--wire));stroke-width:2.5px}.part.lit{color:color-mix(in srgb, var(--highlight) 55%, var(--wire))}.junction.lit{fill:color-mix(in srgb, var(--highlight) 55%, var(--wire))}.wire.focus{stroke:var(--highlight);stroke-width:4px}.junction.focus{fill:var(--highlight)}.part.focus{color:var(--highlight)}.part.focus .hit{fill:color-mix(in srgb, var(--highlight) 18%, transparent)}.part.hint .hit{stroke:var(--highlight);stroke-width:1.5px;animation:1.6s ease-in-out infinite pulse}.part.flash{color:var(--bad)}.part.flash .hit{fill:color-mix(in srgb, var(--bad) 20%, transparent)}@keyframes pulse{50%{stroke-opacity:.2}}@media (prefers-reduced-motion:reduce){.part.hint .hit{animation:none}}.canvas-tools{border-top:1px solid var(--border);justify-content:flex-end;gap:6px;padding:6px 8px;display:flex}.canvas-tools button{border:1px solid var(--border);background:var(--surface);width:36px;height:36px;color:var(--text);cursor:pointer;border-radius:8px;font-size:1.1rem}.info-panel{left:0;right:0;bottom:calc(var(--tabbar-h) + env(safe-area-inset-bottom));background:var(--surface);border:1px solid var(--border);z-index:10;border-bottom:0;border-radius:16px 16px 0 0;max-width:760px;max-height:52dvh;margin:0 auto;padding:0 16px 16px;position:fixed;overflow-y:auto;box-shadow:0 -6px 24px #0000002e}.info-panel header{background:var(--surface);z-index:1;align-items:center;gap:10px;padding:14px 0 6px;display:flex;position:sticky;top:0}.info-panel header h2{flex:1;margin:0;font-size:1.05rem}.icon-btn{background:var(--bg);width:40px;height:40px;color:var(--text);cursor:pointer;border:0;border-radius:10px;font-size:1rem}.explain h3{text-transform:uppercase;letter-spacing:.05em;color:var(--muted);margin:14px 0 2px;font-size:.75rem}.explain p{margin:0}.mistake{border-left:4px solid var(--highlight);background:var(--bg);border-radius:8px;margin-top:14px;padding:10px 12px}.mistake h3{margin-top:0}.mistake p+p{margin-top:6px}.chip-row{flex-wrap:wrap;gap:6px;margin-top:6px;display:flex}a.chip{text-decoration:none}.related-detail{background:var(--bg);border-radius:8px;padding:10px 12px;font-size:.95rem;margin-top:8px!important}.predict .prompt{margin-top:4px}.circuit-card{color:inherit;text-decoration:none;display:block}.circuit-card h3{margin:0 0 4px}.circuit-card p{margin:0 0 10px}.back-link{padding:8px 0;font-weight:600;text-decoration:none;display:inline-block}.circuit-page h1{margin-top:0}.circuit-page.has-panel{padding-bottom:60dvh}.canvas-anchor{scroll-margin-top:8px}.waveform{background:var(--bg);border-radius:10px;margin:6px 0 0;padding:10px}.waveform figcaption{margin-bottom:4px;font-size:.9rem;font-weight:600}.waveform svg{width:100%;height:auto;display:block}.waveform p{margin:6px 0 0;font-size:.95rem}.wf-line{fill:none;stroke:var(--accent);stroke-width:2.2px;stroke-linejoin:round}.wf-axis{stroke:var(--muted);stroke-width:1px}.wf-grid{stroke:var(--border);stroke-width:1px;stroke-dasharray:3 3}.wf-period{stroke:var(--border);stroke-width:1px}.wf-label{fill:var(--muted);font-size:10px}.wf-marker{stroke:var(--highlight);stroke-width:1px;stroke-dasharray:3 2}.wf-badge{fill:var(--highlight)}.wf-badge-text{fill:#111;font-size:9px;font-weight:700}.wf-markers{color:var(--muted);margin:6px 0 0;padding-left:22px;font-size:.85rem}.stepper{flex-wrap:wrap;gap:6px;margin:12px 0 4px;padding:0;list-style:none;display:flex}.stepper button{white-space:nowrap;border:1px solid var(--border);background:var(--surface);min-height:40px;color:var(--muted);font:inherit;cursor:pointer;border-radius:99px;align-items:center;gap:6px;padding:0 12px 0 6px;font-size:.85rem;font-weight:600;display:inline-flex}.stepper button.active{border-color:var(--accent);color:var(--text)}.step-num{background:var(--border);width:26px;height:26px;color:var(--text);border-radius:50%;place-items:center;font-size:.8rem;display:inline-grid}.stepper button.active .step-num{background:var(--accent);color:var(--accent-text)}.stepper button.done .step-num{background:var(--good);color:#fff}.trace-card{margin-top:12px}.trace-card h2{margin-bottom:4px}.trace-text{min-height:3em;margin:6px 0;font-size:1.05rem}.trace-buttons{gap:8px;margin-top:8px;display:flex}.trace-buttons .btn{flex:1}.btn:disabled{opacity:.4;cursor:default}.next-step{margin-top:16px}.hidden-part rect{fill:color-mix(in srgb, var(--accent) 12%, var(--surface));stroke:var(--accent);stroke-width:2px;stroke-dasharray:4 3}.hidden-part text{fill:var(--accent);font-size:20px;font-weight:800}.fault-mark path{stroke:var(--bad);stroke-width:3.5px;stroke-linecap:round;fill:none}.fault-mark text{fill:var(--bad);font-size:calc(10px * var(--ts,1));stroke:var(--surface);stroke-width:3px;paint-order:stroke;font-weight:800}.button-row{flex-wrap:wrap;gap:8px;margin-top:8px;display:flex}.stack-bar{background:var(--border);border-radius:99px;height:10px;display:flex;overflow:hidden}.stack-bar .seg.mastered{background:var(--good)}.stack-bar .seg.learning{background:var(--highlight)}.stack-bar .seg.unseen{background:var(--border)}.progress-item{border-top:1px solid var(--border);min-height:44px;color:inherit;flex-direction:column;gap:2px;padding:10px 0;text-decoration:none;display:flex}.progress-item:first-of-type{border-top:0}.progress-item-title{font-weight:600}.toggle{cursor:pointer;align-items:flex-start;gap:12px;padding:8px 0;display:flex}.toggle input{width:22px;height:22px;accent-color:var(--accent);margin-top:2px}.btn.danger{color:var(--bad);border-color:color-mix(in srgb, var(--bad) 40%, var(--border))}.circuit-card.locked{opacity:.55}.track-title{margin:24px 0 0;font-size:1.15rem}.zoom-btn{margin-top:14px}.panel-bay{margin:-2px 0 4px}