:root{--ink:#252d29;--muted:#707970;--green:#285c48;--paper:#fbfaf6;--border:#dddcd2;--math-size:18px}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:SimSun,"Noto Serif CJK SC","Songti SC",serif}button,input,select{font:14px system-ui,sans-serif;color:inherit}button,select{cursor:pointer}button,a,select,input{outline-offset:4px}a{color:var(--green);text-decoration:none}button{border:1px solid var(--border);background:#fff;border-radius:6px;padding:8px 12px}button:hover{border-color:var(--green);background:#f1f5ed}button:disabled{opacity:.4;cursor:default}.skip{position:absolute;left:12px;top:-80px;background:white;padding:15px;z-index:20}.skip:focus{top:5px}.topbar{height:68px;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:48px;padding:0 36px;background:#fffefb}.brand{font-size:29px;display:flex;gap:12px;align-items:center}.brand span{font:22px KaiTi,STKaiti,serif;font-weight:bold}.topbar nav{display:flex;gap:30px;font:14px system-ui,sans-serif}.topbar nav a[aria-current]{color:var(--ink);border-bottom:2px solid var(--green);padding:24px 0}.top-note{margin-left:auto;font-size:14px;color:var(--muted)}.layout{display:grid;grid-template-columns:280px minmax(0,1fr);max-width:1580px;margin:auto}aside{border-right:1px solid var(--border);padding:30px 22px;position:sticky;top:0;height:100vh;overflow:auto;background:#f5f5ee;scrollbar-width:thin}.eyebrow{font:10px system-ui,sans-serif;font-weight:650;letter-spacing:2px;color:var(--green)}h1,h2,h3,.chapter-label{font-family:KaiTi,STKaiti,"楷体",serif}h1{font-size:29px;margin:10px 0}aside p{font-size:13px;color:var(--muted);margin:0 0 26px}.search-label{font-size:12px}.search-wrap{display:flex;margin:8px 0 16px;border:1px solid var(--border);border-radius:6px;background:white}.search-wrap input{min-width:0;width:100%;border:0;background:transparent;padding:11px 4px 11px 9px;font-size:12px}.search-wrap button{border:0;padding:5px 8px;background:transparent}.subject-tabs{display:grid;grid-template-columns:repeat(4,1fr);gap:4px}.subject-tabs button{padding:7px 0;border-color:transparent;background:transparent;font-size:13px}.subject-tabs button[aria-pressed=true],.view-tabs button[aria-pressed=true]{background:var(--green);border-color:var(--green);color:white}.review-select{display:flex;flex-direction:column;gap:7px;margin-top:20px;font-size:12px}.review-select select{padding:8px 4px;background:#fffefb;border:1px solid var(--border);border-radius:5px;font-size:12px}.checkline{display:flex;align-items:center;gap:6px;font-size:12px;margin:13px 0 23px}.checkline input{accent-color:var(--green)}.nav-summary{color:var(--muted);font:11px system-ui,sans-serif;margin:12px 0}#chapters{display:flex;flex-direction:column;gap:2px}#chapters a{display:flex;align-items:baseline;gap:10px;font-size:13px;line-height:1.6;color:#525a52;padding:9px 8px;border-radius:5px}#chapters a span{font:10px system-ui;color:#92988f}#chapters 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button{font-size:12px;padding:8px 12px}.tools{display:flex;align-items:center;gap:8px;font:12px system-ui}.tools select{border:1px solid var(--border);border-radius:5px;padding:7px;font-size:12px}.tools button{font-size:12px}#result-count{font-size:12px;color:var(--muted);margin:19px 0}.formula-card{background:#fffefb;border:1px solid var(--border);border-radius:8px;margin:0 0 20px;padding:24px 28px;scroll-margin-top:90px}.card-head{display:flex;align-items:start;justify-content:space-between;gap:16px;margin-bottom:18px}.card-id{font:10px system-ui;letter-spacing:1px;color:#90978c;display:block;margin-bottom:9px}.card-head h3{font-size:24px;line-height:1.45;margin:0;font-weight:600}.card-actions{display:flex;gap:5px;flex-shrink:0}.card-actions button{font-size:12px;padding:5px 7px;border:0;background:transparent;color:var(--muted)}.card-actions button[aria-pressed=true]{color:#a85b24;background:#fff1d9}.scope{display:inline-block;font:10px system-ui;background:#eeeae1;color:#7a6d56;padding:3px 6px;border-radius:4px;margin-top:8px}.conditions{padding:10px 13px;border-left:2px solid #6b93ba;background:#f1f5f8;font-size:14px;line-height:1.9;margin-bottom:18px}.formula{overflow-x:auto;overflow-y:hidden;padding:6px 4px 9px;scrollbar-width:thin;font-size:var(--math-size);margin:3px 0}.katex-display{margin:.3em 0;text-align:left}.katex-display>.katex{text-align:left}.katex{font-size:1.08em}.conditions .katex,.note .katex{font-size:1.1em}.formula-main{padding:3px 0 12px}.formula-main .formula:first-child{border-left:3px solid #c4d3b8;padding-left:14px}.derivation{border-top:1px dashed var(--border);margin-top:8px;padding-top:13px}.derivation summary{font:13px KaiTi,STKaiti,serif;color:var(--green);cursor:pointer;padding:3px 0;list-style-position:inside}.derivation summary:hover{text-decoration:underline}.steps{margin-top:17px;padding:4px 15px;border-left:2px solid #b5cbbb;background:#f8faf5}.steps .formula{margin:8px 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@media(min-width:1450px){main{padding-left:65px;padding-right:65px}}@media(max-width:1000px){.layout{grid-template-columns:235px minmax(0,1fr)}main{padding:30px 25px}aside{padding:24px 15px}.intro{display:block}.legend{margin-top:15px}.toolbar{flex-wrap:wrap}.formula-card{padding:21px 20px}.intro h2{font-size:29px}}@media(max-width:700px){.topbar{padding:0 17px;gap:20px;height:58px}.brand span{font-size:20px}.topbar nav{font-size:12px;gap:16px}.topbar nav a[aria-current]{padding:20px 0}.top-note{display:none}.layout{display:block}aside{position:static;height:auto;border-right:0;border-bottom:1px solid var(--border);padding:20px}.sidebar-head h1{font-size:27px}.sidebar-head p{margin-bottom:17px}.sidebar-head .eyebrow{display:none}.subject-tabs{max-width:360px}.review-select{margin-top:14px}.checkline{margin-bottom:8px}#chapters{max-height:210px;overflow:auto;border-top:1px solid var(--border)}#chapters a{padding:7px}#chapters .chapter-group{padding-top:12px}.about-link{margin:14px 8px 0}main{padding:25px 15px}.intro h2{font-size:27px}.intro p{font-size:13px}.toolbar{padding:13px 0 12px;gap:10px}.tools{margin-left:auto}.tools button{padding:7px}.formula-card{padding:18px 14px;margin-bottom:16px}.card-head h3{font-size:22px}.card-head{gap:8px}.card-actions{flex-direction:column}.conditions{font-size:13px}.formula{font-size:var(--math-size)}.steps{padding-left:8px;padding-right:5px}footer{display:block}footer a{display:block;margin-top:8px}}
@media print{@page{size:A4;margin:14mm}body{background:white}.topbar,aside,.toolbar,.pager,.card-actions,.reveal,.legend,#result-count,#toast,footer,.skip{display:none!important}.layout{display:block}main{max-width:none;padding:0}.intro{margin-bottom:20px}.formula-card{border:0;border-bottom:1px solid #ccc;border-radius:0;padding:10px 0;break-inside:avoid;margin-bottom:14px}.formula{font-size:14px;overflow:visible}.formula-main .formula:first-child{border:0;padding-left:4px}.formula-card .formula-main{display:block!important}.steps{background:none}.conditions{background:none}.card-head h3{font-size:20px}.derivation{break-inside:auto}details:not([open]){display:none}.card-id{font-size:9px}.note{font-size:11px}}
.topbar nav{align-items:center}#toggle-nav{display:none}@media(max-width:700px){#toggle-nav{display:block;width:100%;text-align:left;color:var(--green)}#sidebar-controls{display:none;margin-top:20px}.nav-open #sidebar-controls{display:block}.sidebar-head{display:none}aside{padding:13px 15px}}@media print{#toggle-nav{display:none!important}}