:root{color-scheme:light;--bg:#f7f8fa;--surface:#fff;--surface-alt:#eef1f6;--ink:#202d43;--muted:#5f6c80;--line:#d6dce7;--accent:#285bbd;--area-a:#2864c3;--area-b:#7952b5;--area-c:#217d62;--area-d:#b85c1c;--planet:#5f6c80;--good:#217653;--bad:#b83e4d;--grid:#dce2eb;--chart-1:#2864c3;--chart-2:#b85c1c;--chart-3:#7952b5;--shadow:0 12px 40px #273c5c08;--radius:20px}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]){color-scheme:dark;--bg:#101722;--surface:#192332;--surface-alt:#222e40;--ink:#e4ecf8;--muted:#a7b5cb;--line:#36455c;--accent:#91b9ff;--area-a:#8bb7ff;--area-b:#c0a2f5;--area-c:#77d7b5;--area-d:#ffb579;--planet:#c9d3e3;--good:#83dfb1;--bad:#ffa1ae;--grid:#344256;--chart-1:#8bb7ff;--chart-2:#ffb579;--chart-3:#c0a2f5;--shadow:none}}
:root[data-theme=dark]{color-scheme:dark;--bg:#101722;--surface:#192332;--surface-alt:#222e40;--ink:#e4ecf8;--muted:#a7b5cb;--line:#36455c;--accent:#91b9ff;--area-a:#8bb7ff;--area-b:#c0a2f5;--area-c:#77d7b5;--area-d:#ffb579;--planet:#c9d3e3;--good:#83dfb1;--bad:#ffa1ae;--grid:#344256;--chart-1:#8bb7ff;--chart-2:#ffb579;--chart-3:#c0a2f5;--shadow:none}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.8 -apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",system-ui,sans-serif}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}button,input{font:inherit}button,a,input{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default;opacity:.5}button,.button{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:9px 18px;border:1px solid var(--line);border-radius:11px;background:var(--surface);color:var(--ink);font-size:.9rem;font-weight:600;line-height:1.5}button:hover:not(:disabled),.button:hover{border-color:var(--accent);text-decoration:none}button.primary,.button.primary{color:var(--surface);background:var(--accent);border-color:var(--accent)}:focus-visible{outline:3px solid var(--accent);outline-offset:4px}.skip-link{position:fixed;top:-100px;left:12px;z-index:100;background:var(--surface);padding:10px}.skip-link:focus{top:10px}.site-header{max-width:1360px;margin:auto;padding:24px 40px;display:flex;align-items:center;gap:35px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:12px;color:var(--ink);font-size:19px;font-weight:750;line-height:1.4;white-space:nowrap}.brand:hover{text-decoration:none}.brand small{display:block;font-size:11px;letter-spacing:.1em;color:var(--muted);font-weight:500;margin-top:4px}.brand-symbol{font:italic 36px/1 Georgia,serif;color:var(--area-a)}.brand-symbol span{color:var(--area-d)}nav{display:flex;gap:6px;margin-left:auto}nav a{color:var(--muted);font-size:14px;padding:8px 15px;border-radius:9px;white-space:nowrap}nav a[aria-current=page]{background:var(--surface-alt);color:var(--ink);font-weight:700}.theme-button{font-size:12px;padding:8px 12px;min-height:40px}#app{min-height:70vh;outline:none}.page{max-width:1280px;padding:48px 40px 72px;margin:auto}.eyebrow{font-size:12px;font-weight:750;letter-spacing:.15em;color:var(--area-a);text-transform:uppercase}.hero{max-width:760px;margin-bottom:36px}h1,h2,h3,p{margin-top:0}h1{font-size:clamp(30px,4vw,46px);letter-spacing:-.04em;line-height:1.3;margin-bottom:18px}h2{font-size:23px;line-height:1.5;margin-bottom:18px}h3{font-size:17px;line-height:1.6}.hero p{color:var(--muted);font-size:17px;max-width:640px}.hero em{font-style:normal;color:var(--ink)}.hero-meta{display:flex;gap:20px;flex-wrap:wrap;font-size:12px;color:var(--muted);margin:24px 0}.pill{display:inline-block;padding:3px 10px;border:1px solid var(--line);border-radius:99px;color:var(--muted);font-size:12px}.hero-actions{display:flex;gap:12px;margin-top:24px}.map-card,.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}.map-card{padding:16px 12px}.map-legend{display:flex;flex-wrap:wrap;gap:18px;padding:8px 18px;font-size:12px;color:var(--muted)}.legend-dot{display:inline-block;width:8px;height:8px;border-radius:50%;background:var(--area-a);margin-right:6px}.legend-dot.pending{background:var(--muted)}.map-svg{display:block;width:100%;height:auto}.map-svg .region-label{font-size:20px;font-weight:700}.map-svg .region-sub{font-size:12px;fill:var(--muted)}.map-svg .node-title{font-size:13px;fill:var(--ink);font-weight:600}.map-svg .node-id{font-size:11px;fill:var(--muted)}.map-svg .node-body{fill:var(--surface);stroke:var(--line)}.map-svg .ready .node-body{fill:var(--surface);stroke:var(--area-a);stroke-width:1.8}.map-svg .pending .node-title{fill:var(--muted)}.map-svg [role=button],.map-svg a{cursor:pointer}.map-svg [role=button]:hover .node-body,.map-svg a:hover .node-body{stroke:var(--accent);stroke-width:2}.map-svg .edge{stroke:var(--line);stroke-width:1.4;fill:none}.map-status{min-height:30px;margin:10px 20px;color:var(--area-a);font-size:14px}.map-foot{display:flex;justify-content:space-between;gap:18px;color:var(--muted);font-size:13px;margin:18px 4px}.lesson{max-width:1000px;margin:auto;padding:38px 24px 72px;--lesson-color:var(--area-a)}.lesson-header,.lesson-section{max-width:760px;margin:0 auto 28px}.lesson-header{padding:15px 0 8px}.lesson-header h1{font-size:clamp(30px,4vw,40px)}.breadcrumb{font-size:13px;margin-bottom:24px;color:var(--muted)}.lesson-one-liner{font-size:21px;line-height:1.65;color:var(--lesson-color);font-weight:600}.lesson-section{padding:28px 30px}.section-label{font-size:11px;color:var(--muted);letter-spacing:.12em;margin-bottom:10px}.lesson-section h2{font-size:21px}.lesson-section p:last-child{margin-bottom:0}.interactive-section{max-width:940px}.interaction-top{display:flex;justify-content:space-between;gap:16px;align-items:center;flex-wrap:wrap}.segmented{display:flex;gap:5px;flex-wrap:wrap;background:var(--surface-alt);border-radius:12px;padding:4px;width:fit-content}.segmented button{border-color:transparent;background:transparent}.segmented button[aria-pressed=true]{background:var(--surface);border-color:var(--line);color:var(--accent)}.controls{display:flex;gap:10px;flex-wrap:wrap;margin:20px 0}.guess fieldset,.quiz fieldset{margin:0 0 14px;padding:0;border:0;min-width:0}.guess legend,.quiz legend{font-weight:600;margin-bottom:14px}.option{display:flex;align-items:center;gap:12px;min-height:48px;padding:10px 14px;margin:8px 0;border:1px solid var(--line);border-radius:10px;cursor:pointer}.option:has(input:checked){border-color:var(--accent);background:var(--surface-alt)}input[type=radio]{width:18px;height:18px;accent-color:var(--accent);flex-shrink:0}.feedback{border-left:3px solid var(--accent);padding:12px 16px;background:var(--surface-alt);margin-top:16px;border-radius:0 10px 10px 0}.feedback.correct{border-color:var(--good)}.feedback.incorrect{border-color:var(--bad)}.callout{border-left:3px solid var(--accent)}.callout-ai{border-left-color:var(--area-d)}.callout-albert{border-left-color:var(--area-c)}.callout-cross{border-left-color:var(--area-b)}.callout-pitfall{border-left-color:var(--bad)}.pitfall+.pitfall{margin-top:18px}.pitfall strong{color:var(--bad)}.cross-item+.cross-item{margin-top:16px}.slider{display:block;margin:20px 0}.slider-caption{display:flex;justify-content:space-between;gap:20px;font-weight:600}.slider input{width:100%;min-height:44px;accent-color:var(--accent)}.sim-stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:24px 0}.stat{padding:18px;background:var(--surface-alt);border-radius:12px}.stat span{display:block;font-size:12px;color:var(--muted)}.stat strong{font-size:clamp(20px,3vw,28px);font-variant-numeric:tabular-nums;color:var(--area-a)}.chart-wrap{position:relative;width:100%;min-width:0}.chart-wrap canvas{display:block;width:100%;height:270px}.chart-caption{font-size:12px;color:var(--muted);margin:8px 0}.recent{display:flex;gap:5px;flex-wrap:wrap;min-height:30px;margin:12px 0}.result-dot{width:26px;height:26px;border-radius:50%;background:var(--surface-alt);border:1px solid var(--line);display:inline-flex;align-items:center;justify-content:center;font-size:11px}.result-dot.hit{color:var(--surface);background:var(--area-a);border-color:var(--area-a)}.muted{color:var(--muted)}.small{font-size:13px}.locked-message{background:var(--surface-alt);padding:14px 18px;border-radius:10px;margin-top:20px}.formula{font-family:Georgia,"PingFang SC",serif;font-size:21px;padding:18px;background:var(--surface-alt);border-radius:10px;overflow-wrap:anywhere}.lesson-pager{max-width:760px;margin:36px auto 0;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}.cheat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,320px),1fr));gap:22px}.cheat-grid .card{padding:28px}.empty-state{padding:40px;max-width:760px}.glossary-list{max-width:900px;display:grid;grid-template-columns:1fr 1fr;gap:14px}.term{padding:22px}.term h2{font-size:17px;margin:0}.term .en{font-size:12px;color:var(--area-a)}.term p{font-size:14px;margin:8px 0 0}.search{display:block;width:min(100%,520px);padding:12px 16px;border:1px solid var(--line);border-radius:12px;background:var(--surface);color:var(--ink);margin:20px 0 30px}.galaxy-shell{position:relative;height:620px;border:1px solid var(--line);border-radius:20px;overflow:hidden;background:var(--surface)}.galaxy-canvas{width:100%;height:100%;display:block;touch-action:none}.galaxy-labels{position:absolute;inset:0;pointer-events:none;overflow:hidden}.galaxy-label{position:absolute;pointer-events:auto;min-height:28px;padding:3px 7px;font-size:10px;line-height:1.5;white-space:nowrap;border-color:transparent;background:var(--surface);opacity:.9;transform:translate(-50%,-50%)}.galaxy-label.planet{font-size:12px;font-weight:750}.galaxy-label.active{border-color:var(--accent);z-index:2}.galaxy-hint{font-size:12px;color:var(--muted);margin-top:12px}.galaxy-panel{padding:24px;margin-top:20px;max-width:760px}.galaxy-panel h2{margin-bottom:8px}.galaxy-panel .controls{margin-bottom:0}.fallback-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,280px),1fr));gap:18px}.fallback-grid section{padding:24px}.fallback-grid button{width:100%;justify-content:start;margin-top:8px;text-align:left}.site-footer{max-width:1200px;margin:auto;padding:28px 40px;display:flex;justify-content:space-between;gap:20px;border-top:1px solid var(--line);font-size:12px;color:var(--muted)}.selftest-panel{margin:30px auto;max-width:1100px;padding:20px;overflow-wrap:anywhere}.selftest-panel table{border-collapse:collapse;width:100%;font-size:12px}.selftest-panel td,.selftest-panel th{padding:7px;border:1px solid var(--line);text-align:left}.selftest-panel pre{white-space:pre-wrap;overflow-wrap:anywhere;font-size:11px}.selftest-pass{color:var(--good)}.selftest-fail{color:var(--bad)}
@media(max-width:760px){.site-header{padding:18px 20px;gap:15px;flex-wrap:wrap}.brand{font-size:17px}.theme-button{margin-left:auto}nav{order:3;width:100%;margin-left:0;justify-content:space-between}nav a{padding:8px 12px}.page{padding:32px 20px 48px}.hero{margin-bottom:26px}h1{font-size:32px}.map-card{padding:10px 6px}.map-foot{display:block}.lesson{padding:24px 16px 48px}.lesson-section{padding:24px 20px}.sim-stats{gap:7px}.stat{padding:12px 8px}.stat strong{font-size:22px}.sim-stats .stat span{font-size:11px}.controls{gap:8px}.controls button{padding:9px 12px}.glossary-list{grid-template-columns:1fr}.site-footer{padding:24px 20px;flex-direction:column;gap:3px}.galaxy-shell{height:560px}.galaxy-label{font-size:9px;padding:3px}.galaxy-label.planet{font-size:10px}.map-legend{padding:8px 12px;gap:12px}.hero-meta{gap:12px}.hero-actions{flex-wrap:wrap}.chart-wrap canvas{height:240px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;animation:none!important;transition:none!important}}

.formula{display:block;line-height:1.6;margin:14px 0}.galaxy-layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:20px;align-items:start}.galaxy-host{min-width:0}.galaxy-layout .galaxy-panel{margin:0;max-width:none}.galaxy-panel .controls{flex-direction:column;align-items:stretch}.galaxy-panel h2{font-size:19px}.galaxy-panel p{font-size:14px}@media(max-width:1000px){.galaxy-layout{grid-template-columns:1fr}.galaxy-layout .galaxy-panel{max-width:760px}.galaxy-panel .controls{flex-direction:row;flex-wrap:wrap}}

.galaxy-label{font-size:11px;min-height:32px}@media(max-width:760px){.galaxy-label,.galaxy-label.planet{font-size:11px}}@media(pointer:coarse){.galaxy-label{min-height:44px;min-width:44px}}

.galaxy-leaders{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}.galaxy-leaders line{stroke:var(--muted);stroke-width:1;opacity:.35}

.surface{width:100%;height:380px;touch-action:none}@media(max-width:760px){.surface{height:300px}}