@import url('https://fonts.googleapis.com/css2?family=Baloo+2:wght@400;500;600;700&family=Comic+Neue:wght@300;400;700&display=swap');

:root{
--paper:#fdfbf7;
--wash:#f5f5f5;
--ink:#1a1a1a;
--muted:#6f6b63;
--line:#e3ded4;
--card:#ffffff;
--soft:0 1px 0 rgba(26,26,26,.05),0 16px 32px rgba(26,26,26,.06);
--rail:238px;
--read:"Comic Neue","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
--head:"Baloo 2","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
}

*{box-sizing:border-box}

html{
scroll-behavior:smooth;
-webkit-text-size-adjust:100%;
background:var(--paper);
}

body{
margin:0;
background:var(--paper);
color:var(--ink);
font-family:var(--read);
font-size:17px;
line-height:1.78;
font-weight:400;
letter-spacing:.01em;
}

body::before{
content:"";
position:fixed;
inset:0;
z-index:70;
pointer-events:none;
opacity:.35;
background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
}

[id]{scroll-margin-top:20px}

a{color:var(--ink)}

:focus-visible{outline:2px solid var(--ink);outline-offset:3px}

hr{
border:0;
border-top:1px solid var(--line);
margin:.55rem 0 1.15rem;
}

img{max-width:100%}

/* ---- 左侧固定竖排栏 ---- */
.rail{
position:fixed;
top:0;
left:0;
bottom:0;
width:var(--rail);
z-index:50;
display:flex;
flex-direction:column;
gap:16px;
padding:22px 18px 28px;
background:var(--paper);
border-right:1px solid var(--line);
overflow-y:auto;
}

.mark{
width:52px;
height:52px;
min-height:52px;
display:grid;
place-items:center;
border:1px solid var(--ink);
border-radius:16px;
background:var(--card);
text-decoration:none;
font-family:var(--head);
font-size:24px;
font-weight:700;
line-height:1;
}

.mark img{width:34px;height:34px;display:block;border-radius:8px}

.find{display:flex;flex-direction:column;gap:6px}

.find-label{
font-size:16px;
letter-spacing:.14em;
color:var(--muted);
padding-left:2px;
}

.find-input{
width:100%;
min-height:44px;
padding:10px 13px;
font-family:var(--read);
font-size:16px;
color:var(--ink);
background:var(--card);
border:1px solid var(--line);
border-radius:14px;
appearance:none;
}

.find-input::placeholder{color:#a9a49a}

.rail-nav{display:flex;flex-direction:column;gap:4px}

.rail-link{
display:flex;
align-items:center;
min-height:44px;
padding:10px 12px;
border:1px solid transparent;
border-radius:14px;
font-size:16px;
text-decoration:none;
line-height:1.4;
}

.rail-link:hover,.rail-link:focus-visible{
background:var(--card);
border-color:var(--line);
}

.rail-group{border-radius:14px}

.rail-group summary{
display:flex;
align-items:center;
justify-content:space-between;
min-height:44px;
padding:10px 12px;
font-size:16px;
letter-spacing:.06em;
color:var(--muted);
list-style:none;
cursor:pointer;
border:1px solid transparent;
border-radius:14px;
}

.rail-group summary::-webkit-details-marker{display:none}

.rail-group summary::after{content:"+";font-family:var(--head);font-size:18px}

.rail-group[open] summary{
background:var(--card);
border-color:var(--line);
color:var(--ink);
}

.rail-group[open] summary::after{content:"–"}

.rail-group a{margin-left:10px}

/* ---- 主区 ---- */
.paper{
margin-left:var(--rail);
padding:0 clamp(16px,4vw,54px);
}

.hero,.read,.turn{max-width:1120px;margin:0 auto}

.hero{
position:relative;
isolation:isolate;
display:grid;
grid-template-columns:1fr 1fr;
align-items:center;
gap:clamp(20px,4vw,56px);
min-height:70vh;
padding:clamp(28px,6vh,64px) 0;
}

.hero::before{
content:"";
position:absolute;
inset:0;
z-index:-1;
background:var(--wash);
clip-path:polygon(54% 0,100% 0,100% 100%,42% 100%);
}

.hero-figure{
position:relative;
z-index:1;
margin:0;
border:1px solid var(--line);
border-radius:28px;
overflow:hidden;
background:var(--card);
box-shadow:var(--soft);
}

.hero-img{display:block;width:100%;height:auto}

.hero-blank{
display:grid;
place-items:center;
min-height:300px;
font-family:var(--head);
font-size:clamp(72px,12vw,132px);
line-height:1;
color:#d7d1c6;
}

.hero-figure figcaption{
padding:11px 16px;
border-top:1px solid var(--line);
font-size:16px;
letter-spacing:.1em;
color:var(--muted);
}

.hero-copy{text-align:right}

.hero-h1{
margin:0 0 16px;
font-family:var(--head);
font-size:clamp(28px,4.4vw,52px);
line-height:1.24;
font-weight:700;
letter-spacing:.01em;
}

.hero-lead{
margin:0 0 24px auto;
max-width:32em;
font-size:17px;
color:var(--muted);
}

.hero-jump{
display:inline-flex;
align-items:center;
justify-content:center;
min-height:46px;
padding:12px 26px;
border-radius:999px;
background:var(--ink);
color:var(--paper);
font-weight:700;
text-decoration:none;
}

/* ---- 正文 + 右侧栏 ---- */
.read{
display:grid;
grid-template-columns:minmax(0,1fr) 258px;
gap:clamp(20px,3vw,44px);
align-items:start;
padding:38px 0 8px;
}

.read-h2,.side-h2{
margin:0;
font-family:var(--head);
font-size:20px;
font-weight:700;
letter-spacing:.1em;
}

.prose{min-width:0}

.prose > section{
background:var(--card);
border:1px solid var(--line);
border-radius:28px;
padding:clamp(20px,3vw,34px);
box-shadow:var(--soft);
margin:0 0 26px;
}

.prose > section:last-child{margin-bottom:0}

.prose h2{
margin:0 0 .35rem;
font-family:var(--head);
font-size:clamp(22px,2.6vw,30px);
line-height:1.34;
font-weight:700;
}

.prose h3{
margin:1.5rem 0 .4rem;
font-family:var(--head);
font-size:clamp(19px,2vw,23px);
line-height:1.4;
font-weight:700;
}

.prose h4{
margin:1.2rem 0 .3rem;
font-size:17px;
font-weight:700;
}

.prose p{margin:0 0 1rem}

.prose ul,.prose ol{margin:0 0 1rem;padding-left:1.35em}

.prose li{margin:0 0 .45rem}

.prose a{text-decoration:underline;text-underline-offset:3px}

.prose blockquote{
margin:1rem 0;
padding:.7rem 1.1rem;
border-left:3px solid var(--ink);
background:var(--wash);
border-radius:0 18px 18px 0;
}

.prose blockquote p:last-child{margin:0}

.prose figure{margin:1rem 0}

.prose figure img{border-radius:20px;display:block}

.prose figcaption{font-size:16px;color:var(--muted);padding-top:6px}

.prose table{
width:100%;
border-collapse:collapse;
font-size:16px;
margin:0 0 1rem;
}

.prose th,.prose td{
border:1px solid var(--line);
padding:9px 11px;
text-align:left;
vertical-align:top;
}

.prose th{background:var(--wash)}

.prose code{
font-size:16px;
background:var(--wash);
border-radius:6px;
padding:1px 5px;
}

.side{
position:sticky;
top:22px;
align-self:start;
border:1px solid var(--line);
border-radius:28px;
background:var(--card);
box-shadow:var(--soft);
padding:20px 18px 16px;
}

.toc{list-style:none;margin:0;padding:0;counter-reset:toc}

.toc li{counter-increment:toc;margin:0}

.toc a{
display:block;
padding:9px 9px;
min-height:44px;
border-radius:12px;
font-size:16px;
line-height:1.45;
text-decoration:none;
}

.toc a::before{
content:counter(toc,decimal-leading-zero) " ";
font-family:var(--head);
color:var(--muted);
}

.toc a:hover{background:var(--wash)}

/* ---- 结尾条 ---- */
.turn{
display:flex;
align-items:baseline;
justify-content:space-between;
gap:20px;
margin-top:34px;
padding:26px 0 58px;
border-top:1px solid var(--ink);
}

.turn-k{
margin:0;
font-size:16px;
letter-spacing:.16em;
color:var(--muted);
}

.turn-link{
font-family:var(--head);
font-size:clamp(22px,3.2vw,36px);
line-height:1.3;
font-weight:700;
text-decoration:none;
text-align:right;
}

/* ---- 页脚 ---- */
.colophon{
margin-left:var(--rail);
display:flex;
align-items:center;
justify-content:space-between;
flex-wrap:wrap;
gap:18px;
padding:20px clamp(16px,4vw,54px);
border-top:1px solid var(--ink);
background:var(--paper);
}

.foot-mark a{
display:inline-flex;
align-items:center;
gap:10px;
min-height:44px;
text-decoration:none;
}

.foot-mark img{width:34px;height:34px;border-radius:8px;display:block}

.foot-mark span:not(.foot-brand){
display:grid;
place-items:center;
width:34px;
height:34px;
border:1px solid var(--ink);
border-radius:10px;
font-family:var(--head);
font-size:18px;
font-weight:700;
line-height:1;
}

.foot-brand{font-family:var(--head);font-size:17px;font-weight:700}

.foot-nav dl{
display:flex;
flex-wrap:wrap;
align-items:center;
gap:2px 14px;
margin:0;
}

.foot-nav dt{
font-size:16px;
letter-spacing:.1em;
color:var(--muted);
}

.foot-nav dd{margin:0}

.foot-nav a{
display:inline-flex;
align-items:center;
min-height:40px;
padding:2px 1px;
font-size:16px;
text-decoration:none;
border-bottom:1px solid transparent;
}

.foot-nav a:hover{border-bottom-color:var(--ink)}

.foot-legal{
display:flex;
align-items:center;
gap:18px;
}

.foot-legal p{margin:0;font-size:16px;color:var(--muted)}

.foot-legal .up{
display:inline-flex;
align-items:center;
min-height:40px;
font-size:16px;
text-decoration:none;
border-bottom:1px solid var(--line);
}

@media (prefers-reduced-motion:no-preference){
.prose > section{animation:rise .34s steps(4) both}
.prose > section:nth-child(2){animation-delay:.04s}
.prose > section:nth-child(3){animation-delay:.08s}
.prose > section:nth-child(4){animation-delay:.12s}
@keyframes rise{
from{transform:translateY(9px);opacity:.001}
to{transform:none;opacity:1}
}
}

/* ---- 窄屏：栏变顶栏，正文先于配图 ---- */
@media (max-width:980px){
.rail{
position:static;
width:auto;
border-right:0;
border-bottom:1px solid var(--line);
display:grid;
grid-template-columns:auto minmax(0,1fr);
align-items:center;
gap:8px 10px;
padding:10px 14px 12px;
overflow:visible;
}

.mark{
width:44px;
height:44px;
min-height:44px;
border-radius:12px;
font-size:20px;
}

.mark img{width:28px;height:28px;border-radius:7px}

.find{flex-direction:row;align-items:center;gap:8px}

.find-label{flex:0 0 auto;font-size:15px;letter-spacing:.08em;padding-left:0}

.find-input{min-height:44px;padding:8px 12px}

.rail-nav{
grid-column:1 / -1;
display:flex;
flex-wrap:nowrap;
gap:6px;
overflow-x:auto;
overscroll-behavior-x:contain;
padding-bottom:2px;
scrollbar-width:thin;
}

.rail-link,.rail-group{flex:0 0 auto}

.rail-link,.rail-group summary{
min-height:44px;
padding:9px 13px;
white-space:nowrap;
font-size:16px;
}

.rail-group a{margin-left:8px;white-space:normal}

.paper{margin-left:0}
.colophon{margin-left:0}

.read{grid-template-columns:minmax(0,1fr);padding-top:26px}
.side{position:static;order:2}

.hero{
grid-template-columns:minmax(0,1fr);
min-height:0;
padding:14px 0 30px;
gap:18px;
}

.hero::before{clip-path:none}

.hero-copy{order:1;text-align:left}

.hero-figure{order:2}

.hero-lead{margin-left:0;margin-bottom:20px}

.hero-h1{font-size:clamp(26px,7vw,38px);margin-bottom:12px}

.hero-blank{min-height:170px;font-size:clamp(64px,18vw,110px)}
}

@media (max-width:620px){
.turn{flex-direction:column;align-items:flex-start;gap:8px;padding-bottom:44px}
.turn-link{text-align:left}
.colophon{flex-direction:column;align-items:flex-start;gap:14px}
.foot-legal{width:100%}
.foot-legal .up{margin-left:auto}
.prose > section{padding:18px 16px;border-radius:22px}
.hero{padding-top:10px}
.hero-blank{min-height:140px}
}

button[aria-expanded]{min-width:44px;min-height:44px}