:root{--bg:#F6FAFC;--paper:#fff;--pale:#EAF6FA;--pale2:#EDF4F8;--cyan:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--navy:#174B78;--title:#183A56;--text:#31485D;--muted:#687D8E;--line:#DCE9F0;--foot:#123653}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:25px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;overflow-x:hidden}a{color:var(--navy);text-decoration-thickness:1px;text-underline-offset:4px}a:hover{color:var(--blue)}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--sky);outline-offset:3px}button{font:inherit;cursor:pointer}.wrap{width:min(100% - 56px,1180px);margin-inline:auto}.site-header{background:#fff;border-bottom:1px solid var(--line);position:relative;z-index:10}.topbar{height:72px;display:flex;align-items:center;gap:20px}.brand{display:flex;align-items:center;text-decoration:none;color:var(--title);font-size:22px;font-weight:800;flex-shrink:0}.brand 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