:root{--paper:#f7f9fc;--surface:#fff;--ink:#172033;--blue:#3157d5;--line:#d9e0ec;--muted:#667085;--green:#2f7d5a;--night:#111a2d;--shell:min(1120px,calc(100% - 48px));--shadow:0 24px 70px rgb(23 32 51 / 9%)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;font-size:16px;line-height:1.75;-webkit-font-smoothing:antialiased}a{color:inherit}a:focus-visible{outline:3px solid rgb(49 87 213 / 35%);outline-offset:4px;border-radius:3px}.shell{width:var(--shell);margin-inline:auto}.skip-link{position:fixed;z-index:20;top:12px;left:12px;transform:translateY(-160%);padding:8px 14px;background:var(--ink);color:#fff;text-decoration:none}.skip-link:focus{transform:translateY(0)}
.site-header{border-bottom:1px solid var(--line);background:rgb(247 249 252 / 88%);backdrop-filter:blur(14px)}.header-inner{min-height:78px;display:flex;align-items:center;justify-content:space-between;gap:32px}.site-mark{display:inline-flex;align-items:center;gap:11px;font-size:17px;font-weight:700;letter-spacing:.04em;text-decoration:none}.site-mark svg{width:31px;height:31px}.site-mark circle{fill:var(--blue)}.site-mark path{fill:none;stroke:var(--blue);stroke-width:1.8}nav{display:flex;align-items:center;gap:28px}nav a{color:var(--muted);font-size:14px;text-decoration:none}nav a:hover{color:var(--blue)}
.hero{min-height:650px;display:grid;grid-template-columns:minmax(0,1fr) minmax(380px,.82fr);align-items:center;gap:72px;padding-block:88px 96px}.eyebrow,.section-label,.note-topic{margin:0;color:var(--blue);font-size:12px;font-weight:700;letter-spacing:.14em;text-transform:uppercase}.hero h1{max-width:720px;margin:22px 0 28px;font-family:"STSong","Songti SC","Noto Serif CJK SC",serif;font-size:clamp(48px,6vw,78px);font-weight:700;letter-spacing:-.045em;line-height:1.16}.hero-intro{max-width:640px;margin:0 0 30px;color:var(--muted);font-size:18px}.text-link{display:inline-flex;align-items:center;gap:10px;color:var(--blue);font-weight:700;text-decoration:none}.text-link span{transition:transform 180ms ease}.text-link:hover span{transform:translateX(4px)}
.topology-card{position:relative;overflow:hidden;border:1px solid var(--line);background:var(--surface);box-shadow:var(--shadow)}.topology-card::before{position:absolute;top:0;left:0;width:52px;height:4px;background:var(--blue);content:""}.topology-card svg{display:block;width:100%;height:auto}.topology-card>p{margin:0;border-top:1px solid var(--line);padding:16px 22px;color:var(--muted);font-size:13px;letter-spacing:.08em}.grid-lines path{fill:none;stroke:#edf1f7;stroke-width:1}.route-lines path{fill:none;stroke:var(--blue);stroke-linecap:round;stroke-linejoin:round;stroke-width:2.2}.nodes circle{fill:var(--surface);stroke:var(--blue);stroke-width:3}.nodes circle:nth-child(4),.nodes circle:nth-child(6){fill:var(--blue)}.node-labels text{fill:var(--muted);font-family:"PingFang SC","Microsoft YaHei",sans-serif;font-size:13px}
.about-section{border-block:1px solid var(--line);background:var(--surface)}.split-section{display:grid;grid-template-columns:.9fr 1.1fr;gap:96px;padding-block:92px}.section-heading h2{max-width:640px;margin:13px 0 0;font-family:"STSong","Songti SC","Noto Serif CJK SC",serif;font-size:clamp(32px,4vw,46px);letter-spacing:-.025em;line-height:1.28}.section-copy{padding-top:34px}.section-copy p{margin:0;color:var(--muted);font-size:17px}.section-copy p+p{margin-top:20px}
.notes-section{padding-block:104px}.row-heading{display:flex;align-items:end;justify-content:space-between;gap:48px;margin-bottom:48px}.row-heading>p{max-width:330px;margin:0 0 5px;color:var(--muted)}.note-list{border-top:1px solid var(--ink)}.note-item{display:grid;grid-template-columns:140px 1fr 56px;gap:36px;align-items:start;border-bottom:1px solid var(--line);padding-block:32px}.note-item time{color:var(--muted);font-family:ui-monospace,"SFMono-Regular",Consolas,monospace;font-size:13px}.note-item h3{margin:8px 0 9px;font-size:21px;line-height:1.4}.note-item p:last-child{max-width:680px;margin:0;color:var(--muted)}.note-index{color:#b1bdcf;font-family:ui-monospace,"SFMono-Regular",Consolas,monospace;font-size:14px;text-align:right}
.practice-section{background:var(--night);color:#f4f7fc;padding-block:104px}.light-heading .section-label{color:#91a9ff}.light-heading>p{color:#a9b4c8}.practice-grid{display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid rgb(255 255 255 / 24%);border-left:1px solid rgb(255 255 255 / 24%)}.practice-grid article{min-height:245px;border-right:1px solid rgb(255 255 255 / 24%);border-bottom:1px solid rgb(255 255 255 / 24%);padding:28px}.practice-grid span{color:#91a9ff;font-family:ui-monospace,"SFMono-Regular",Consolas,monospace;font-size:12px}.practice-grid h3{margin:54px 0 12px;font-size:21px}.practice-grid p{margin:0;color:#a9b4c8;font-size:14px}
.statement-section{padding-block:88px}.statement-card{display:grid;grid-template-columns:150px .8fr 1.2fr;align-items:start;gap:42px;border:1px solid var(--line);background:var(--surface);padding:42px}.statement-card h2{margin:0;font-family:"STSong","Songti SC",serif;font-size:28px;line-height:1.4}.statement-card>p:last-child{margin:3px 0 0;color:var(--muted)}.site-footer{border-top:1px solid var(--line);background:var(--surface)}.footer-inner{min-height:88px;display:flex;align-items:center;justify-content:space-between;gap:24px;color:var(--muted);font-size:13px}.footer-inner p{margin:0}.filing-link{display:inline-flex;align-items:center;gap:7px;color:inherit;text-decoration:none;transition:color 180ms ease}.filing-link:hover{color:var(--blue)}.filing-mark{width:17px;height:17px;fill:none;stroke:var(--green);stroke-linecap:round;stroke-linejoin:round;stroke-width:1.6;transition:stroke 180ms ease}.filing-link:hover .filing-mark{stroke:var(--blue)}
.error-page{min-height:100vh;display:grid;place-items:center;padding:24px}.error-card{width:min(680px,100%);border:1px solid var(--line);background:var(--surface);box-shadow:var(--shadow);padding:clamp(34px,7vw,72px)}.error-card h1{margin:18px 0 12px;font-family:"STSong","Songti SC",serif;font-size:clamp(38px,7vw,58px);line-height:1.2}.error-card>p:not(.eyebrow){margin:0 0 28px;color:var(--muted)}
@media(max-width:900px){.hero{min-height:auto;grid-template-columns:1fr;gap:54px;padding-block:72px}.topology-card{max-width:620px}.split-section{grid-template-columns:1fr;gap:26px}.section-copy{padding-top:0}.practice-grid{grid-template-columns:repeat(2,1fr)}.statement-card{grid-template-columns:1fr;gap:18px}}
@media(max-width:680px){:root{--shell:min(100% - 32px,1120px)}.header-inner{min-height:68px}.site-mark span{font-size:15px}nav{display:none}.hero{padding-block:56px 64px}.hero h1{margin-block:18px 22px;font-size:clamp(40px,13vw,58px)}.hero-intro{font-size:16px}.split-section,.notes-section,.practice-section{padding-block:72px}.row-heading{display:block;margin-bottom:34px}.row-heading>p{margin-top:18px}.note-item{grid-template-columns:1fr auto;gap:12px 20px}.note-item time{grid-column:1/-1}.note-item>div{grid-column:1}.note-index{grid-column:2;grid-row:2}.practice-grid{grid-template-columns:1fr}.practice-grid article{min-height:210px}.statement-section{padding-block:56px}.statement-card{padding:28px}.footer-inner{min-height:104px;flex-direction:column;align-items:flex-start;justify-content:center;gap:7px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{scroll-behavior:auto!important;transition-duration:.01ms!important}}
@media print{.site-header,.topology-card,.text-link{display:none}body,.practice-section{background:#fff;color:#000}.practice-grid p,.light-heading>p{color:#333}}