/* System fonts, local assets, and no runtime dependencies. */
:root{color-scheme:light dark;--bg:#f0eee6;--surface:#faf9f5;--ink:#141413;--muted:#5e5d59;--line:#d8d3c4;--accent:#a8502e;--soft:#e6dfcd;--focus:#2f6f9f;--serif:"Iowan Old Style","Palatino Linotype",Palatino,"Book Antiqua",Georgia,"Songti SC","Noto Serif CJK SC",serif}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:1rem}
body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:17px;line-height:1.65}
a{color:var(--accent);text-underline-offset:.22em;text-decoration-thickness:1px}
a:hover{text-decoration-thickness:2px}
a:focus-visible,summary:focus-visible{outline:3px solid var(--focus);outline-offset:5px;border-radius:2px}
.wrap{width:min(1120px,calc(100% - 64px));margin-inline:auto}
.skip{position:absolute;top:-100px;left:1rem;padding:.65rem 1rem;background:var(--surface);z-index:10}
.skip:focus{top:1rem}
.site-header{padding-block:25px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;gap:1rem;flex-wrap:wrap}
.brand{display:inline-flex;align-items:center;gap:10px;font-size:17px;font-weight:750;letter-spacing:-.04em;color:var(--ink);text-decoration:none}
.brand-mark{display:inline-grid;place-items:center;width:28px;height:28px;border:1px solid var(--accent);color:var(--accent);font:700 17px ui-monospace,monospace}
nav{display:flex;align-items:center;gap:24px;flex-wrap:wrap;font-size:14px}
nav a{color:var(--muted);text-decoration:none;min-height:28px;display:inline-flex;align-items:center}
nav a[aria-current]{color:var(--accent);font-weight:700;text-decoration:underline}
.hero{padding-block:76px 72px;display:grid;grid-template-columns:1.15fr 1fr;gap:56px;align-items:center}
.eyebrow,.kicker,.section-no{font:600 12px/1.5 ui-monospace,SFMono-Regular,Consolas,monospace;letter-spacing:.1em;text-transform:uppercase;color:var(--accent)}
.eyebrow{display:flex;gap:12px;align-items:center;margin:0 0 22px}
.eyebrow::before{content:"";width:7px;height:7px;background:var(--accent)}
h1,h2,h3,p{margin-top:0}
h1{font-family:var(--serif);font-size:clamp(2.6rem,4.6vw,4.25rem);font-weight:500;letter-spacing:-.02em;line-height:1.08;margin-bottom:25px;text-wrap:balance}
h1 span{color:var(--accent)}
h2{font-family:var(--serif);font-size:clamp(1.7rem,3vw,2.35rem);line-height:1.2;letter-spacing:-.01em;font-weight:500;margin-bottom:20px;text-wrap:balance}
h3{font-size:1.05rem;line-height:1.4;margin-bottom:9px;font-weight:650}
p{margin-bottom:1rem}
.intro{color:var(--muted);font-size:18px;max-width:38rem}
.button{display:inline-flex;align-items:center;justify-content:center;background:var(--accent);color:var(--bg);padding:12px 22px;border-radius:4px;text-decoration:none;font-size:15px;font-weight:650;min-height:48px}
.button:hover{filter:brightness(1.12);text-decoration:underline}
.hero-links{display:flex;gap:22px;align-items:center;flex-wrap:wrap;margin-top:25px;font-size:15px}
code,pre{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}
code{font-size:.9em;overflow-wrap:anywhere}
.requirements{margin:22px 0 0;font-size:12px;color:var(--muted);line-height:1.6}
.section{padding-block:60px;border-top:1px solid var(--line)}
.section-heading{display:grid;grid-template-columns:60px 1fr;align-items:baseline;margin-bottom:24px}
.section-heading h2{margin:0}
.steps{list-style:none;display:grid;grid-template-columns:repeat(5,1fr);padding:0;margin:0;gap:22px}
.steps li{border-top:2px solid var(--accent);padding-top:18px;min-width:0}
.steps p{font-size:14px;color:var(--muted);margin:0}
.two-col{display:grid;grid-template-columns:1fr 1.3fr;gap:70px}
.safety{background:var(--soft);border:1px solid var(--line);border-radius:6px;padding:30px}
.safety ul{padding-left:20px;margin:0}
.safety li{margin-bottom:12px;font-size:15px}
.safety li:last-child{margin-bottom:0}
.note{font-size:14px;color:var(--muted)}
.note:last-child{margin-bottom:0}
.evidence{border-left:3px solid var(--accent);padding-left:26px;max-width:900px}
.evidence .results{font-size:clamp(1.1rem,2.2vw,1.45rem);line-height:1.65;letter-spacing:-.02em}
.evidence strong{color:var(--accent);font-weight:700}
.source{font:12px/1.6 ui-monospace,monospace;color:var(--muted);margin-top:24px}
.flow-layout{display:grid;grid-template-columns:1.15fr 1fr;gap:56px;align-items:center}
.flow{display:block;width:100%;height:auto;color:var(--ink)}
.flow .node{fill:var(--surface);stroke:var(--line);stroke-width:2}
.flow .lead,.flow .review{fill:var(--soft);stroke:var(--accent)}
.flow .edge{fill:none;stroke:var(--accent);stroke-width:2}
.flow .arrow{fill:var(--accent)}
.flow text{fill:var(--ink);font-family:var(--serif);font-size:18px;text-anchor:middle}
.flow .sub{fill:var(--muted);font-size:14px}
.explain{margin:0}
.explain dt{font-weight:650;margin-top:20px}
.explain dt:first-child{margin-top:0}
.explain dd{margin:5px 0 0;font-size:15px;color:var(--muted)}
.update{display:grid;grid-template-columns:1fr 1.3fr;gap:70px}
.version{display:inline-block;padding:5px 12px;border:1px solid var(--accent);border-radius:3px;font:14px/1.5 ui-monospace,monospace;color:var(--accent);margin-bottom:18px}
.faq{max-width:870px;margin-left:60px}
details{border-bottom:1px solid var(--line);padding:18px 0}
summary{cursor:pointer;font-weight:600;line-height:1.5;min-height:30px;padding-right:8px}
details p{font-size:15px;color:var(--muted);margin:13px 0 3px;max-width:760px}
.site-footer{border-top:1px solid var(--line);padding-block:30px 40px;display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;font-size:13px;color:var(--muted)}
.site-footer p{margin:0}
.site-footer nav{font-size:13px;gap:20px}
.error{max-width:700px;padding-block:90px}
html[lang="zh-CN"] h1{letter-spacing:-.035em;line-height:1.2}
html[lang="zh-CN"] h2{letter-spacing:-.025em}
@media(prefers-color-scheme:dark){:root{--bg:#1f1e1d;--surface:#262624;--ink:#f0eee6;--muted:#b7b3a8;--line:#3d3b37;--accent:#e08a64;--soft:#33302b;--focus:#f0b98c}}
@media(max-width:850px){.hero{gap:32px;grid-template-columns:1fr;padding-block:48px}.hero-copy{max-width:650px}.quickstart{max-width:650px;width:100%}.steps{grid-template-columns:repeat(2,1fr);gap:28px}.two-col,.update{grid-template-columns:1fr;gap:22px}.flow-layout{gap:28px}.section{padding-block:42px}}
@media(max-width:560px){.wrap{width:calc(100% - 36px)}.site-header{padding-block:18px}nav{gap:18px}.hero{padding-block:38px 45px}h1{font-size:2.65rem}.intro{font-size:17px}.section-heading{grid-template-columns:36px 1fr}.steps{grid-template-columns:1fr}.steps li{display:grid;grid-template-columns:110px 1fr;gap:16px;padding-top:15px}.steps h3{margin:0}.safety{padding:22px}.evidence{padding-left:18px}.flow-layout{grid-template-columns:1fr}.faq{margin-left:0}.site-footer{flex-direction:column}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* A selectable installation sentence; controls appear only when JS is ready. */
.hero>*{min-width:0}
.install-card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:25px;box-shadow:8px 8px 0 var(--soft);min-width:0}
.install-label{font-size:12px;font-weight:650;color:var(--accent);letter-spacing:.06em;margin-bottom:14px}
.install-instruction{font-size:14px;color:var(--muted)}
.install-prompt{padding:18px;background:var(--bg);border:1px solid var(--line);border-radius:8px;font-size:16px;line-height:1.75;overflow-wrap:anywhere;user-select:text;cursor:grab;margin-bottom:16px}
.install-prompt:active{cursor:grabbing}
.copy-row{display:flex;align-items:center;gap:14px;min-height:42px}
.copy-install{font:600 14px/1.4 system-ui,sans-serif;background:var(--accent);color:var(--bg);border:0;border-radius:6px;padding:11px 20px;cursor:pointer;flex:none}
.copy-install[hidden]{display:none}
.copy-install:focus-visible,.install-prompt:focus-visible{outline:3px solid var(--focus);outline-offset:4px}
.copy-status{font-size:12px;color:var(--muted)}
.manual-install{font-size:12px;margin:18px 0 0}
@media(max-width:560px){.install-card{padding:20px}.install-prompt{font-size:15px;padding:14px}}