:root{color-scheme:light;--ink:#172b3b;--muted:#536776;--accent:#126b72;--line:#dce5e8;--paper:#fff;--background:#f4f7f8}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:85px}
body{margin:0;background:var(--background);color:var(--ink);font:16px/1.85 "Segoe UI","Microsoft YaHei","PingFang SC",Arial,sans-serif}
.toolbar{position:sticky;top:0;z-index:3;background:#fffefef5;border-bottom:1px solid var(--line);display:flex;gap:20px;align-items:center;padding:12px 28px;backdrop-filter:blur(10px)}
.brand{font-weight:750;letter-spacing:.02em;margin-right:auto}.toolbar button{font:inherit;background:var(--accent);color:white;border:0;border-radius:7px;padding:5px 16px;cursor:pointer}.toolbar label{font-size:14px;cursor:pointer;white-space:nowrap}.toolbar input{accent-color:var(--accent)}
.layout{display:grid;grid-template-columns:250px minmax(0,960px);gap:30px;max-width:1296px;margin:30px auto;padding:0 24px}
aside{position:sticky;top:85px;align-self:start;max-height:calc(100vh - 105px);overflow:auto;padding:12px 8px 20px 0}aside h2{font-size:14px;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);margin:0 0 12px}nav a{display:block;color:var(--muted);text-decoration:none;font-size:13px;line-height:1.55;padding:8px 10px;border-left:2px solid transparent}nav a:hover,nav a:focus{color:var(--accent);background:#e8f2f2;border-left-color:var(--accent)}
main{min-width:0;background:var(--paper);padding:40px 50px 60px;border:1px solid var(--line);border-radius:12px;box-shadow:0 5px 28px #17374906}
h1,h2,h3{line-height:1.45;scroll-margin-top:85px}h1{font-size:29px;margin:12px 0 24px}h1:not(:first-child){margin-top:46px;padding-top:16px;border-top:3px solid var(--accent)}h2{font-size:23px;margin:38px 0 18px;padding-bottom:10px;border-bottom:1px solid var(--line)}h3{font-size:17px;color:var(--accent);margin:24px 0 12px}p{margin:12px 0}a{color:var(--accent);text-underline-offset:3px;overflow-wrap:anywhere}li{margin:7px 0}ul,ol{padding-left:25px}
blockquote{margin:20px 0;padding:10px 20px;border-left:4px solid var(--accent);background:#eef6f6;font-size:14px;color:var(--muted)}blockquote p{margin:0}
code{font: .92em/1.6 Consolas,"Cascadia Mono","Microsoft YaHei",monospace;background:#eef3f5;padding:2px 5px;border-radius:4px;overflow-wrap:anywhere}pre{background:#f1f5f7;border:1px solid var(--line);border-radius:7px;padding:16px;overflow:auto;line-height:1.75}pre code{padding:0;background:none;white-space:pre-wrap;word-break:normal}
.table-wrap{overflow-x:auto;margin:18px 0}table{border-collapse:collapse;width:100%;font-size:14px;line-height:1.7}th,td{border:1px solid var(--line);padding:10px 13px;text-align:left;vertical-align:top}th{background:#eaf2f3;font-weight:650}tbody tr:nth-child(even){background:#fafcfc}td:first-child{min-width:90px}hr{border:0;border-top:1px solid var(--line);margin:35px 0}.hide-answers .answer-section{display:none}.footer{font-size:12px;color:var(--muted);margin-top:45px;padding-top:15px;border-top:1px solid var(--line)}
math{font-family:"Cambria Math","STIX Two Math",serif;font-size:1.13em;margin:0 .12em}math[display="inline"]{display:inline math;vertical-align:middle}.display-formula{background:#f6f8fa;border:1px solid var(--line);border-radius:7px;padding:18px 16px;margin:18px 0;overflow-x:auto}.display-formula math{margin:8px 0;min-width:max-content}math mtext{font-family:"Microsoft YaHei",sans-serif;font-size:.85em}td math{font-size:1.12em}
@media(max-width:1000px){.layout{grid-template-columns:190px minmax(0,1fr);gap:18px}main{padding:28px}}
@media(max-width:720px){.toolbar{padding:10px 14px;gap:12px;flex-wrap:wrap}.brand{font-size:14px}.toolbar button{font-size:13px}.layout{display:block;margin:15px auto;padding:0 12px}aside{position:static;max-height:230px;margin-bottom:15px;background:white;border:1px solid var(--line);border-radius:8px;padding:14px}nav{columns:2;column-gap:10px}nav a{break-inside:avoid}main{padding:22px 18px}h1{font-size:24px}h2{font-size:21px}body{font-size:15px}}
@media print{@page{size:A4;margin:16mm 14mm}html{scroll-behavior:auto}body{background:white;font-size:10.5pt;color:#000}.toolbar,aside{display:none}.layout{display:block;max-width:none;margin:0;padding:0}main{border:0;padding:0;box-shadow:none}h1{font-size:19pt}h2{font-size:15pt}h3{font-size:12pt}h1,h2,h3{break-after:avoid}pre,blockquote,tr{break-inside:avoid}.table-wrap{overflow:visible}table{font-size:9pt}thead{display:table-header-group}a{color:#000}pre{white-space:pre-wrap}.footer{display:none}}
body{padding:16px;margin:0;max-width:100%;}img{max-width:100%;}math{max-width:100%;}table{display:block;overflow:auto;} main{padding:0;margin:0}