@charset "UTF-8";
:root{--ink:#233b45;--blue:#28617b;--soft:#eef4f5;--muted:#74828a;--line:#e0e6e7;--paper:#fffefa}*{box-sizing:border-box}body{margin:0;color:var(--ink);background:#f4f5f1;font:15px/1.75 "Microsoft YaHei",sans-serif}button,input,textarea,select{font:inherit}button,a,input,textarea{ -webkit-tap-highlight-color:transparent}button{cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #cb963b;outline-offset:3px}header{max-width:1380px;margin:auto;padding:26px 42px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center}.brand{text-decoration:none;color:var(--ink);font-weight:700;font-size:24px;letter-spacing:3px}.brand>span{color:var(--blue)}.brand small{font-size:9px;display:block;letter-spacing:2px;color:var(--muted);font-weight:400;margin-top:1px}.edition{font-size:12px;text-align:right}.edition span{color:var(--muted)}.shell{max-width:1380px;margin:auto;display:grid;grid-template-columns:290px minmax(0,1fr)}aside{padding:32px 26px 32px 42px;border-right:1px solid var(--line)}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--blue)}aside h2{font-size:19px;margin:8px 0}.muted,.tiny{color:var(--muted)}.intro{font-size:13px;line-height:1.85}.progress{margin:24px 0 12px;font-size:11px}.progress>div{display:flex;justify-content:space-between}progress{width:100%;height:5px;border:0;accent-color:var(--blue);display:block;margin-top:10px}progress::-webkit-progress-bar{background:#e1e7e5;border-radius:4px}progress::-webkit-progress-value{background:var(--blue);border-radius:4px}.primary{border:0;background:var(--blue);color:white;border-radius:7px;padding:11px 18px}#resume{width:100%;font-size:13px}nav{display:grid;gap:4px;margin:24px 0}nav button{display:flex;justify-content:space-between;text-align:left;border:0;background:transparent;padding:10px 12px;border-radius:6px;color:var(--ink);font-size:13px}nav button.active{background:#e3ecee;color:#1c536b;font-weight:700}nav span{opacity:.5}.search label{font-size:11px;color:var(--muted)}input[type=search]{width:100%;min-width:0;background:#fffefa;border:1px solid var(--line);padding:9px 11px;border-radius:6px;font-size:12px;margin-top:5px}#outline{margin:18px 0}#outline h3{font-size:11px;color:var(--muted);font-weight:400;margin:18px 0 6px}#outline button{width:100%;border:0;background:transparent;text-align:left;padding:7px 4px;color:#62747c;font-size:12px;display:flex;align-items:center;gap:8px;border-radius:4px}#outline button.current{color:var(--blue);font-weight:700;background:#e9eff0}.dot{width:7px;height:7px;flex-shrink:0;border-radius:100%;border:1px solid #b7c5c8}.dot.done{background:#39705d;border-color:#39705d}.dot.weak{background:#c29144;border-color:#c29144}.backup{display:flex;gap:8px;flex-wrap:wrap;margin-top:26px}.backup button{border:1px solid var(--line);background:transparent;border-radius:5px;font-size:11px;padding:5px 8px}.tiny{font-size:10px;line-height:1.8}main{min-width:0;padding:36px 46px 60px}.breadcrumb{font-size:11px;color:var(--muted);margin-bottom:12px}.hero{border-bottom:1px solid var(--line);padding-bottom:24px;margin-bottom:25px}.hero h1{font-size:31px;font-weight:500;letter-spacing:1px;margin:9px 0 10px;line-height:1.4}.hero p{color:#6d7d85;margin:0;font-size:13px}.label{font-size:10px;letter-spacing:1px;color:var(--blue);display:inline-block;border:1px solid #c7d9dd;padding:2px 8px;border-radius:20px}.meta{font-size:11px;color:var(--muted);display:flex;gap:16px;margin-top:15px;flex-wrap:wrap}.card{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:23px 27px;margin:18px 0}.card h2{font-size:15px;margin:0 0 14px;font-weight:600}.points{padding-left:19px;margin:0;font-size:14px}.points li{padding-left:3px;margin:10px 0}.formula{background:#edf3f5;border-left:3px solid #6893a6;border-radius:0 6px 6px 0;padding:17px 21px;margin-top:20px}.formula div{font:18px/1.9 Cambria,"Microsoft YaHei",serif;overflow-wrap:anywhere}.callout{border-left:2px solid #cba35f;padding:3px 0 3px 17px;margin:20px 0;color:#7f6947;font-size:12px}.callout b{display:block;font-size:11px;letter-spacing:1px;margin-bottom:4px}.sectionlabel{font-size:11px;color:var(--muted);margin:20px 0 10px}.sourcepiece{border:1px solid var(--line);border-radius:6px;background:white;padding:8px;margin:12px 0}.sourcepiece img{width:100%;display:block}.sourcemeta{display:flex;justify-content:space-between;align-items:center;font-size:10px;color:var(--muted);padding:6px 4px}.linkbtn{background:none;border:0;color:var(--blue);font-size:11px;padding:2px}.sourcehint{font-size:11px;color:var(--muted);margin:0 0 12px}summary{cursor:pointer;color:var(--blue);font-size:12px}details>p{font-size:13px}.worked{background:#f2f6f3;border-radius:6px;padding:12px 15px;font-size:13px}.statebar{display:flex;gap:8px;flex-wrap:wrap}.statebar button,.star{border:1px solid var(--line);border-radius:5px;background:white;padding:7px 13px;font-size:12px;color:var(--ink)}.statebar button.chosen{border-color:var(--blue);color:var(--blue);background:#e8f1f4}.star[aria-pressed=true]{background:#fcf3e4;color:#99713b;border-color:#d4b788}.note-label{font-size:12px;display:block;margin:18px 0 7px}textarea{display:block;width:100%;min-height:95px;border:1px solid var(--line);border-radius:6px;padding:12px;background:white;resize:vertical;font-size:13px;color:var(--ink)}.nextrow{display:flex;justify-content:space-between;gap:14px;margin-top:27px}.nextrow button{border:1px solid var(--line);background:white;border-radius:6px;padding:10px 14px;color:var(--ink);font-size:12px}button:disabled{opacity:.35;cursor:default}.listcard{display:block;width:100%;text-align:left;border:1px solid var(--line);border-radius:7px;padding:17px 20px;background:var(--paper);margin:10px 0;color:var(--ink)}.listcard strong{font-size:14px;display:block}.listcard span{font-size:11px;color:var(--muted)}.toolbar{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}.toolbar button{padding:6px 11px;font-size:12px;border:1px solid var(--line);background:white;border-radius:20px;color:var(--ink)}.toolbar button.chosen{background:var(--blue);color:white}.maprow{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);padding:10px 0;gap:18px;font-size:13px}.maprow small{font-size:10px;white-space:nowrap;color:var(--muted)}.maprow button{background:none;border:0;padding:0;color:var(--blue);font-size:13px;text-align:left}.empty{padding:35px 20px;background:var(--paper);border:1px dashed #ccd7da;border-radius:8px;color:var(--muted);font-size:13px}.mobile-top{display:none}#toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:var(--ink);color:white;padding:8px 18px;border-radius:7px;font-size:12px;z-index:20;display:none}#toast.show{display:block}dialog{width:min(960px,95vw);height:92vh;border:0;padding:18px;border-radius:10px;background:#f3f5f2}dialog::backdrop{background:#162b36b3}.viewerbar{position:sticky;top:0;background:#f3f5f2;display:flex;justify-content:space-between;align-items:center;padding:6px 4px 15px;font-size:12px}.viewerbar button{border:1px solid var(--line);padding:6px 10px;border-radius:5px;background:white;color:var(--ink)}dialog img{width:100%;display:block} .footerhint{font-size:10px;color:var(--muted);margin-top:28px}@media(max-width:980px){.shell{grid-template-columns:240px minmax(0,1fr)}header{padding:22px 25px}aside{padding:28px 20px}main{padding:30px 25px}.hero h1{font-size:27px}}@media(max-width:700px){header{padding:18px 20px}.brand{font-size:21px}.edition{font-size:10px}.shell{display:block}aside{border-right:0;border-bottom:1px solid var(--line);padding:20px}aside h2,.intro,.eyebrow,.progress,#resume,.backup,#storage{display:none}nav{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));margin:0 0 15px;gap:2px}nav button{font-size:12px;padding:9px 5px;justify-content:center}nav span{display:none}#outline{max-height:150px;overflow:auto;margin:10px 0 0}#outline h3{margin-top:10px}main{padding:25px 20px 45px}.hero h1{font-size:26px}.card{padding:20px 18px}.formula{padding:12px 14px}.formula div{font-size:16px}.nextrow button{max-width:49%}}

.chapterpick{margin-bottom:14px}.chapterpick label{font-size:11px;color:var(--muted)}.chapterpick select{width:100%;min-width:0;border:1px solid var(--line);border-radius:6px;padding:9px 7px;background:var(--paper);font-size:11px;color:var(--ink);margin-top:5px}.intuition{background:#edf3f5;border-color:#d7e4e9}.intuition>p{font-size:15px;line-height:1.9}.symbols{border-top:1px solid #d5e1e5;padding-top:14px;margin-top:16px;font-size:12px;color:#476371}.symbols>b{font-size:11px}.symbols p{margin-bottom:0}.condition{font-size:12px;color:#687c86;line-height:1.9;margin-top:14px}.condition>b{font-size:11px;color:var(--blue);margin-right:6px}.workedsteps{padding:8px 0 0 25px;font-size:14px;line-height:1.9}.workedsteps li{padding:8px 6px;margin:5px 0;border-bottom:1px solid var(--line)}.pagechips{display:flex;flex-wrap:wrap;gap:5px;margin:8px 0 14px}.pagechips button{border:1px solid var(--line);border-radius:4px;padding:2px 8px}.viewercontrols{display:flex;justify-content:center;gap:10px;align-items:center;margin:8px 0 15px}.viewercontrols button,.viewercontrols select{font:inherit;border:1px solid var(--line);padding:5px 9px;background:white;border-radius:5px;font-size:12px;color:var(--ink)}#outline{max-height:500px;overflow:auto} .sourcepiece{margin-left:0;margin-right:0}@media(max-width:700px){.chapterpick{margin-bottom:10px}.chapterpick select{font-size:12px}#outline{max-height:145px}.viewercontrols{gap:4px}.viewercontrols select{max-width:155px}}

.formula .math-line{font-size:17px;line-height:1.6;margin:12px 0;overflow-x:auto;overflow-y:hidden;padding:4px 0}.formula .katex-display{margin:.35em 0;text-align:left}.formula .katex-display>.katex{text-align:left;white-space:nowrap}.formula .katex{font-size:1.18em}.formula .katex div{font-family:inherit;font-size:inherit;line-height:normal;overflow-wrap:normal}.formula div{overflow-wrap:normal} .katex .cjk_fallback{font-family:"Microsoft YaHei",sans-serif}@media(max-width:700px){.formula .math-line{font-size:15px}.formula .katex{font-size:1.08em}}