:root{--bg:#fdfdfd;--fg:#23272e;--muted:#5c626a;--border:#e3e4e6;--accent:#6c5ce7;--accent-ink:#4437a8;--surface2:#f8f9fa;}
@media(prefers-color-scheme:dark){:root{--bg:#0f1519;--fg:#e9f1f4;--muted:#9fb4bc;--border:#24343b;--accent:#a79bfa;--accent-ink:#d5cefc;--surface2:#223038;}}
* { box-sizing: border-box; }
html { color-scheme: light dark; scroll-padding-top: 7rem; }
body { margin: 0; background: var(--bg); color: var(--fg); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; font-size: 1rem; line-height: 1.85; -webkit-text-size-adjust: 100%; }
a { color: var(--accent-ink); text-underline-offset: .22em; overflow-wrap: anywhere; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, summary:focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; border-radius: 3px; }
.skip { position: absolute; left: 1rem; top: -6rem; padding: .6rem 1rem; z-index: 10; background: var(--bg); }
.skip:focus { top: 1rem; }
.header { border-bottom: 1px solid var(--border); background: var(--bg); }
.bar { max-width: 1152px; margin: auto; padding: 1rem 2rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.brand { display: inline-flex; align-items: center; gap: .75rem; font-size: 1.25rem; font-weight: 700; color: var(--fg); text-decoration: none; letter-spacing: -.03em; }
.brand img { width: 36px; height: 36px; border-radius: 9px; }
.nav { display: flex; align-items: center; gap: 1.3rem; flex-wrap: wrap; font-size: .9375rem; }
.nav a { color: var(--muted); text-decoration: none; }
.nav a[aria-current="page"] { color: var(--accent-ink); font-weight: 650; text-decoration: underline; text-decoration-thickness: 2px; text-underline-offset: .6em; }
.layout { max-width: 1152px; margin: auto; display: grid; grid-template-columns: 210px minmax(0, 1fr); gap: 4rem; padding: 3.5rem 2rem 5rem; }
.toc { align-self: start; position: sticky; top: 2rem; max-height: calc(100vh - 4rem); overflow-y: auto; font-size: .875rem; }
.toc-title { margin: 0 0 1rem; color: var(--fg); font-weight: 650; }
.toc ol { list-style: none; padding: 0; margin: 0; border-left: 1px solid var(--border); }
.toc li { margin: 0; }
.toc a { display: block; padding: .4rem 0 .4rem 1rem; line-height: 1.6; color: var(--muted); text-decoration: none; }
.toc a:hover { color: var(--accent-ink); }
.article { min-width: 0; max-width: 740px; }
.eyebrow { color: var(--accent-ink); letter-spacing: .12em; font-size: .875rem; font-weight: 650; margin: 0 0 .6rem; }
h1 { margin: 0 0 2rem; font-size: clamp(2rem, 4.5vw, 2.8rem); line-height: 1.3; font-weight: 700; letter-spacing: -.035em; }
h2 { margin: 2.8rem 0 1rem; padding-top: 1.1rem; border-top: 1px solid var(--border); font-size: 1.4rem; line-height: 1.5; letter-spacing: -.02em; }
h3 { margin: 1.8rem 0 .6rem; font-size: 1.1rem; }
p { margin: 0 0 1.2rem; overflow-wrap: anywhere; }
ul, ol { padding-left: 1.45rem; margin: .8rem 0 1.5rem; }
li { padding-left: .2rem; margin: .55rem 0; }
blockquote { margin: 1.4rem 0; padding: .6rem 0 .6rem 1.2rem; border-left: 3px solid var(--accent); color: var(--muted); }
blockquote p:last-child { margin-bottom: 0; }
code { font-size: .92em; background: var(--surface2); padding: .1rem .3rem; border-radius: 4px; overflow-wrap: anywhere; }
pre { overflow-x: auto; padding: 1rem; background: var(--surface2); border-radius: 8px; }
.contact { border: 1px solid var(--border); border-radius: 12px; padding: 1.3rem 1.5rem; margin: 0 0 2rem; }
.contact p { margin-bottom: .35rem; }
.contact p:last-child { margin: 0; }
.contact-label { font-weight: 650; }
.small { font-size: .875rem; color: var(--muted); }
.footer { border-top: 1px solid var(--border); }
.footer-inner { max-width: 1152px; margin: auto; padding: 1.6rem 2rem 2.2rem; display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; color: var(--muted); font-size: .875rem; }
.footer p { margin: 0; }
@media (max-width: 800px) { .layout { display: block; padding: 2.2rem 1.25rem 3.5rem; } .toc { position: static; max-height: none; margin-bottom: 2.5rem; } .toc ol { columns: 2; } .toc li { break-inside: avoid; } .bar { padding: 1rem 1.25rem; } .nav { gap: 1rem; } .footer-inner { padding: 1.5rem 1.25rem; } }
@media (max-width: 420px) { .toc ol { columns: 1; } .bar { align-items: flex-start; } .nav { width: 100%; font-size: .875rem; gap: 1.1rem; } }
@media print { .header, .toc, .footer, .skip { display: none; } .layout { display: block; padding: 0; } body { color: #000; background: #fff; } .article { max-width: none; } }