:root{
  --paper:#faf7f1; --card:#fffdf8; --ink:#1d1a16; --muted:#6f675c;
  --line:#e7ddcc; --accent:#a34d1c; --accent-soft:#f3e7d3; --dark:#26221c;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);
  font-family:"Noto Serif SC","Songti SC","STSong","SimSun",serif;
  line-height:1.9;font-size:17px;-webkit-font-smoothing:antialiased}
html[lang="en"] body{font-family:Georgia,"Source Serif 4","Times New Roman",serif;line-height:1.75}
.wrap{max-width:1080px;margin:0 auto;padding:0 22px}
a{color:var(--accent)}
img{max-width:100%}

/* top bar */
.topbar{position:sticky;top:0;z-index:50;background:rgba(250,247,241,.88);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.bar-in{display:flex;align-items:center;justify-content:space-between;height:58px}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-weight:900;font-size:19px;letter-spacing:2px}
.brand span{font-weight:400;font-size:14px;letter-spacing:3px;color:var(--muted);margin-left:8px}
.brand-logo{width:36px;height:36px;border-radius:50%;object-fit:cover;box-shadow:0 2px 8px rgba(60,40,20,.28);flex:none}
.hero-logo{width:104px;height:104px;border-radius:50%;object-fit:cover;display:block;margin:0 auto 24px;box-shadow:0 12px 32px rgba(60,40,20,.30);border:1px solid var(--line)}
.foot-logo{width:44px;height:44px;border-radius:50%;object-fit:cover;display:block;margin:0 auto 12px;box-shadow:0 4px 14px rgba(60,40,20,.22)}
.lang{font-size:14px;text-decoration:none;color:var(--ink);border:1px solid var(--line);
  border-radius:999px;padding:5px 16px;background:var(--card)}
.lang:hover{border-color:var(--accent);color:var(--accent)}

/* hero */
.hero{text-align:center;padding:84px 0 60px;border-bottom:1px solid var(--line);
  background:radial-gradient(ellipse 70% 60% at 50% 0%,#f5ecdb 0%,var(--paper) 70%)}
.hero-kicker{letter-spacing:6px;font-size:13px;color:var(--accent);margin:0 0 18px}
.hero-title{font-size:64px;font-weight:900;margin:0;letter-spacing:10px;line-height:1.25}
.hero-title .hero-en{display:block;font-size:30px;font-weight:400;letter-spacing:12px;color:var(--muted);margin-top:10px}
.hero-tag{font-size:19px;color:var(--muted);margin:26px 0 0;letter-spacing:3px}
html[lang="en"] .hero-title{letter-spacing:6px}

/* sections */
.sec-t{font-size:15px;letter-spacing:5px;color:var(--muted);font-weight:600;
  margin:64px 0 26px;display:flex;align-items:center;gap:14px}
.sec-t::after{content:"";flex:1;height:1px;background:var(--line)}

/* cards */
.cards{display:grid;grid-template-columns:1fr 1fr;gap:26px}
.card{display:flex;flex-direction:column;background:var(--card);border:1px solid var(--line);
  border-radius:14px;overflow:hidden;text-decoration:none;color:var(--ink);
  transition:transform .25s ease,box-shadow .25s ease}
.card:hover{transform:translateY(-4px);box-shadow:0 14px 34px rgba(60,40,20,.12)}
.card-img{display:block;aspect-ratio:16/9;overflow:hidden;background:#eee4d2}
.card-img img{width:100%;height:100%;object-fit:cover;display:block}
.card-body{padding:22px 24px 24px;display:flex;flex-direction:column;gap:10px;flex:1}
.card-kicker{font-size:12px;letter-spacing:3px;color:var(--accent);font-weight:700}
.card-title{font-size:22px;font-weight:900;line-height:1.5;margin:0}
.card-ex{font-size:15px;color:var(--muted);line-height:1.8;margin:0;flex:1}
.card-meta{font-size:13px;color:var(--muted);border-top:1px dashed var(--line);padding-top:12px}

/* about */
.about p{font-size:16.5px;max-width:46rem}
.about{padding-bottom:70px}

/* article */
.article{max-width:760px;padding-top:56px}
.kicker{font-size:13px;letter-spacing:4px;color:var(--accent);font-weight:700;margin:0 0 16px}
.atitle{font-size:38px;font-weight:900;line-height:1.45;margin:0 0 14px}
.asub{font-size:18px;color:var(--muted);margin:0 0 18px}
.ameta{font-size:13.5px;color:var(--muted);border-top:1px solid var(--line);
  border-bottom:1px solid var(--line);padding:10px 0;margin:0 0 30px}
.article h2{font-size:24px;font-weight:900;margin:52px 0 16px;padding-bottom:10px;
  border-bottom:2px solid var(--accent);scroll-margin-top:76px;line-height:1.6}
.article h3{font-size:19px;font-weight:700;margin:36px 0 10px;color:#3a342b}
.article p{margin:14px 0;text-align:justify}
.toc{background:var(--accent-soft);border:1px solid var(--line);border-radius:12px;
  padding:20px 26px;margin:0 0 10px}
.toc-t{font-weight:900;letter-spacing:4px;font-size:14px;margin:0 0 10px;color:var(--accent)}
.toc ol{margin:0;padding-left:22px}
.toc li{margin:7px 0;font-size:15.5px}
.toc a{color:var(--ink);text-decoration:none}
.toc a:hover{color:var(--accent);text-decoration:underline}
.fig{margin:30px 0}
.fig img{width:100%;border-radius:10px;border:1px solid var(--line);display:block}
.fig.hero img{border-radius:14px}
.fig figcaption{text-align:center;font-size:13.5px;color:var(--muted);margin-top:10px;line-height:1.7}
.svg-wrap{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:18px 8px}
.chain-svg{width:100%;height:auto;display:block}
.quote{border-left:4px solid var(--accent);background:#f7efe0;border-radius:0 10px 10px 0;
  padding:16px 22px;margin:26px 0;font-size:16.5px}
.method,.warn{border-radius:10px;padding:16px 20px;margin:24px 0;font-size:15px;line-height:1.8}
.method{background:#eef2ec;border:1px solid #cfdccf;color:#3d5548}
.warn{background:#fdf4e0;border:1px solid #e3c878;color:#6b5312}
.datacards{display:flex;gap:14px;margin:26px 0;flex-wrap:wrap}
.datacard{background:var(--dark);color:#f5efe2;border-radius:12px;padding:18px 22px;flex:1;min-width:150px}
.datacard .num{font-size:30px;font-weight:900;color:#d9904f;line-height:1.3}
.datacard .label{font-size:13.5px;color:#cbbfa9;margin-top:6px;line-height:1.6}
.sign{background:#f8f1e2;border:1.5px dashed var(--accent);border-radius:10px;
  padding:18px 22px;margin:28px 0;font-size:15.5px;color:#5a4a2e}
.sign .who{text-align:right;font-weight:700;color:var(--accent);margin-top:10px;letter-spacing:1px}
.endmark{text-align:center;color:var(--accent);font-size:20px;margin:40px 0 0}
.refs h2{margin-top:56px}
.refs ol{font-size:14px;color:var(--muted);line-height:1.8;padding-left:22px}
.refs li{margin-bottom:8px}
.dl{text-align:center;margin:44px 0 10px}
.btn{display:inline-block;background:var(--accent);color:#fff;text-decoration:none;
  font-size:16px;font-weight:700;letter-spacing:2px;padding:13px 38px;border-radius:999px}
.btn:hover{background:#8c3f14}
.prevnext{display:flex;justify-content:space-between;gap:16px;margin:50px 0 8px;
  border-top:1px solid var(--line);padding-top:26px}
.prevnext a{text-decoration:none;color:var(--ink);font-size:15px;max-width:46%}
.prevnext a span{display:block;font-size:12px;letter-spacing:2px;color:var(--muted);margin-bottom:6px}
.prevnext a:hover .pn-t{color:var(--accent)}
.prevnext .next{text-align:right}
.back{text-align:center;margin:34px 0 70px}
.back a{color:var(--muted);text-decoration:none;font-size:15px}
.back a:hover{color:var(--accent)}

/* placeholder */
.soon{background:var(--card);border:1px dashed var(--accent);border-radius:14px;
  padding:60px 30px;text-align:center;margin:40px 0}
.soon p{font-size:18px;color:var(--muted);margin:8px 0}
.soon .big{font-size:24px;color:var(--ink);font-weight:700}

/* footer */
footer{border-top:1px solid var(--line);margin-top:20px}
.foot-in{padding:34px 22px 44px;text-align:center}
.foot-in p{margin:6px 0;font-size:14px}
.foot-in .dim{color:var(--muted);font-size:13px}

@media (max-width:720px){
  body{font-size:16px}
  .hero{padding:60px 0 44px}
  .hero-title{font-size:44px;letter-spacing:6px}
  .hero-title .hero-en{font-size:22px;letter-spacing:8px}
  .cards{grid-template-columns:1fr}
  .atitle{font-size:29px}
  .article{padding-top:38px}
  .datacards{flex-direction:column}
  .prevnext a{max-width:48%;font-size:14px}
}

/* ---------- reading experience upgrades ---------- */
.progress{position:fixed;top:0;left:0;height:3px;width:0;background:var(--accent);z-index:120}
.fig img{cursor:zoom-in}
.lightbox{position:fixed;inset:0;background:rgba(15,12,8,.93);display:flex;align-items:center;justify-content:center;z-index:300;opacity:0;visibility:hidden;transition:opacity .25s ease}
.lightbox.open{opacity:1;visibility:visible}
.lightbox img{max-width:94vw;max-height:90vh;border-radius:6px;box-shadow:0 24px 70px rgba(0,0,0,.55);cursor:zoom-out}
.dropcap::first-letter{font-size:3.3em;float:left;line-height:.92;padding:8px 12px 0 0;font-weight:900;color:var(--accent)}
.quote{border:none;background:none;text-align:center;font-size:21px;line-height:1.85;margin:40px auto;max-width:36rem;padding:0 18px;color:var(--ink)}
.quote::before{content:"\201C";display:block;font-family:Georgia,"Times New Roman",serif;font-size:64px;line-height:1;color:var(--accent);margin-bottom:2px}
.totop{position:fixed;right:16px;bottom:24px;width:48px;height:48px;border-radius:50%;border:1px solid var(--line);background:var(--card);color:var(--ink);font-size:20px;line-height:1;cursor:pointer;opacity:0;visibility:hidden;transform:translateY(12px);transition:all .25s ease;z-index:110;box-shadow:0 8px 22px rgba(60,40,20,.18)}
/* Netlify Drop 会在页面右下角注入 "Powered by Netlify" 角标（iframe#nl-badge-frame），用自己的样式把它藏起来 */
iframe#nl-badge-frame{display:none!important}
.totop.show{opacity:1;visibility:visible;transform:none}
.btn.ghost{background:transparent;color:var(--accent);border:1.5px solid var(--accent)}
.btn.ghost:hover{background:var(--accent-soft)}
.dl .btn{margin:6px}
.theme-toggle{background:none;border:1px solid var(--line);border-radius:999px;width:38px;height:38px;display:inline-flex;align-items:center;justify-content:center;cursor:pointer;color:var(--ink);padding:0}
.theme-toggle:hover{border-color:var(--accent);color:var(--accent)}
.theme-toggle svg{width:18px;height:18px}
.theme-toggle .moon{display:none}
html[data-theme="dark"] .theme-toggle .sun{display:none}
html[data-theme="dark"] .theme-toggle .moon{display:block}
.bar-right{display:flex;align-items:center;gap:10px}
.toast{position:fixed;left:50%;bottom:80px;transform:translateX(-50%) translateY(10px);background:var(--dark);color:#f5efe2;font-size:14px;padding:10px 22px;border-radius:999px;opacity:0;visibility:hidden;transition:all .25s;z-index:320;white-space:nowrap}
.toast.show{opacity:1;visibility:visible;transform:translateX(-50%)}

/* hero image */
.hero{background:linear-gradient(rgba(250,247,241,.80),rgba(250,247,241,.94)),url('../img/hero-gleanings.jpg') center 35%/cover}

/* dark mode */
html[data-theme="dark"]{--paper:#1a1611;--card:#231e16;--ink:#ece1c9;--muted:#a89a80;--line:#3a332a;--accent:#d08a48;--accent-soft:#2b2417;--dark:#0e0b07}
html[data-theme="dark"] .topbar{background:rgba(26,22,17,.88)}
html[data-theme="dark"] .hero{background:linear-gradient(rgba(26,22,17,.86),rgba(26,22,17,.95)),url('../img/hero-gleanings.jpg') center 35%/cover}
html[data-theme="dark"] .method{background:#1c2620;border-color:#31463a;color:#b7cdc0}
html[data-theme="dark"] .warn{background:#2b2313;border-color:#6b5a2e;color:#d9c48f}
html[data-theme="dark"] .sign{background:#251f13;color:#cdbb96}
html[data-theme="dark"] .card-img{background:#2b251b}
html[data-theme="dark"] .lightbox{background:rgba(0,0,0,.94)}

@media (max-width:720px){
  .quote{font-size:18.5px;margin:32px auto}
  .hero{background:linear-gradient(rgba(250,247,241,.84),rgba(250,247,241,.96)),url('../img/hero-gleanings.jpg') center 35%/cover}
  html[data-theme="dark"] .hero{background:linear-gradient(rgba(26,22,17,.88),rgba(26,22,17,.96)),url('../img/hero-gleanings.jpg') center 35%/cover}
  .totop{right:12px;bottom:20px;width:44px;height:44px}
}