/* ==========================================================================
   纵横国际 — 全站样式表（原创）
   风格：AI Food Innovation Lab · 深石墨 / 深绿 / 植物青绿 / 冷白 / 少量食品橙
   ========================================================================== */

:root{
  --ink-950:#06100c;
  --ink-900:#0a1712;
  --ink-800:#0f221a;
  --ink-700:#163326;
  --green-700:#0f3d2e;
  --green-600:#1f8f68;
  --green-500:#22c58b;
  --green-300:#7fe0bb;
  --mint-200:#bfead9;
  --mint-100:#e1f3ea;
  --mint-50:#f2faf6;
  --white:#ffffff;
  --text-900:#0d1f19;
  --text-700:#2c443a;
  --text-500:#587066;
  --text-400:#7a9088;
  --line:#d6e7de;
  --line-soft:#e7f1eb;
  --orange:#f08a3c;
  --orange-deep:#c96a1f;
  --orange-soft:#fff2e6;
  --success:#1fae74;
  --radius-lg:18px;
  --radius-md:12px;
  --radius-sm:8px;
  --shadow-card:0 4px 22px rgba(10,23,18,.07);
  --shadow-pop:0 12px 40px rgba(10,23,18,.16);
  --maxw:1240px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei","Noto Sans SC","Helvetica Neue",Arial,sans-serif;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;scroll-padding-top:128px;-webkit-text-size-adjust:100%;}
body{
  margin:0;font-family:var(--font);color:var(--text-700);background:var(--white);
  line-height:1.75;font-size:16px;-webkit-font-smoothing:antialiased;overflow-x:hidden;
}
img{max-width:100%;display:block;}
a{color:var(--green-600);text-decoration:none;}
a:hover{text-decoration:underline;}
h1,h2,h3,h4{color:var(--text-900);line-height:1.38;margin:0 0 .6em;font-weight:700;}
p{margin:0 0 1em;}
ul,ol{margin:0 0 1em;padding-left:1.4em;}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px;}
/* 网格/弹性子项允许收缩，避免内部图片、表格把整页撑出横向滚动 */
.hero-grid>*,.la>*,.article-layout>*,.about-box>*,.grid>*,.callouts>*,.dl-panel>*,.footer-grid>*,.intent-grid>*,.matrix-grid>*{min-width:0;}
.skip-link{position:absolute;left:-999px;top:0;background:var(--green-600);color:#fff;padding:10px 16px;z-index:999;border-radius:0 0 8px 0;}
.skip-link:focus{left:0;}

/* ---------- Top utility bar ---------- */
.topbar{background:var(--ink-950);color:var(--mint-200);font-size:13px;}
.topbar .wrap{display:flex;justify-content:space-between;align-items:center;min-height:36px;gap:12px;overflow:hidden;white-space:nowrap;}
.topbar span{opacity:.88;overflow:hidden;text-overflow:ellipsis;}
.topbar .topbar-tag{color:var(--green-300);letter-spacing:.05em;font-weight:600;flex:none;}
@media (max-width:640px){.topbar .wrap>span:not(.topbar-tag){display:none;}}

/* ---------- Header / Nav (两行：品牌行 + 完整导航行) ---------- */
.site-header{position:sticky;top:0;z-index:60;background:var(--ink-900);border-bottom:1px solid rgba(255,255,255,.06);}
.header-row{display:flex;align-items:center;justify-content:space-between;height:58px;gap:16px;}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:700;font-size:18px;flex:0 0 auto;}
.brand:hover{text-decoration:none;}
.brand .logo-mark{width:32px;height:32px;flex:none;}
.brand small{display:block;font-size:11px;font-weight:500;color:var(--green-300);letter-spacing:.06em;}
.header-actions{display:flex;align-items:center;gap:10px;flex:0 0 auto;}
.header-note{color:var(--mint-200);font-size:12.5px;opacity:.85;}

.nav-bar{border-top:1px solid rgba(255,255,255,.07);background:var(--ink-800);}
.main-nav{display:flex;align-items:center;gap:2px;flex-wrap:nowrap;min-width:0;}
.main-nav a{
  color:var(--mint-100);font-size:13px;font-weight:500;padding:11px 11px;border-radius:8px;white-space:nowrap;
}
.main-nav a:hover,.main-nav a:focus-visible{background:rgba(255,255,255,.08);text-decoration:none;}
.main-nav a[aria-current="page"]{color:#fff;background:rgba(34,197,139,.24);}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:6px;
  padding:9px 18px;border-radius:999px;font-size:14px;font-weight:600;
  border:1px solid transparent;cursor:pointer;white-space:nowrap;
}
.btn:hover{text-decoration:none;}
.btn-primary{background:linear-gradient(135deg,var(--green-600),var(--green-500));color:#fff;}
.btn-primary:hover{filter:brightness(1.07);}
.btn-accent{background:var(--orange);color:#fff;}
.btn-accent:hover{filter:brightness(1.06);}
.btn-ghost{background:transparent;color:var(--mint-100);border-color:rgba(255,255,255,.3);}
.btn-ghost:hover{background:rgba(255,255,255,.09);}
.btn-outline{background:transparent;color:var(--green-600);border-color:var(--green-600);}
.btn-outline:hover{background:var(--mint-50);}
.btn-lg{padding:13px 26px;font-size:15.5px;}
.btn-block{width:100%;}

.nav-toggle{
  display:none;background:transparent;border:1px solid rgba(255,255,255,.3);
  border-radius:8px;width:40px;height:40px;flex:none;cursor:pointer;position:relative;
}
.nav-toggle span,.nav-toggle::before,.nav-toggle::after{content:"";position:absolute;left:9px;right:9px;height:2px;background:#fff;border-radius:2px;}
.nav-toggle span{top:19px;}
.nav-toggle::before{top:13px;}
.nav-toggle::after{top:25px;}

.toc-inline{display:none;}
@media (max-width:1100px){
  html{scroll-padding-top:76px;}
  .nav-toggle{display:block;}
  .header-note{display:none;}
  .nav-bar{
    position:absolute;left:0;right:0;top:58px;background:var(--ink-900);
    max-height:0;overflow:hidden;transition:max-height .25s ease;border-top:1px solid rgba(255,255,255,.08);
  }
  .site-header.is-open .nav-bar{max-height:560px;}
  .main-nav{flex-direction:column;align-items:stretch;gap:0;}
  .main-nav a{padding:14px 20px;border-radius:0;border-bottom:1px solid rgba(255,255,255,.06);font-size:14.5px;}
  .nav-bar .wrap{padding:0;}
}

/* ---------- Breadcrumb ---------- */
.breadcrumb{font-size:13.5px;color:var(--text-500);padding:16px 0;}
.breadcrumb a{color:var(--text-500);}
.breadcrumb a:hover{color:var(--green-600);}
.breadcrumb .sep{margin:0 6px;color:var(--text-400);}
.breadcrumb .current{color:var(--text-700);}

/* ---------- Hero (首页) ---------- */
.hero{
  background:
    radial-gradient(1000px 520px at 84% -10%,rgba(34,197,139,.22),transparent 60%),
    radial-gradient(860px 480px at -8% 12%,rgba(31,143,104,.30),transparent 55%),
    linear-gradient(160deg,var(--ink-950),var(--ink-900) 58%,var(--ink-800));
  color:var(--mint-100);padding:54px 0 60px;
}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:36px;align-items:center;}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:12.5px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--green-300);margin-bottom:14px;}
.hero h1{color:#fff;font-size:clamp(26px,3.6vw,40px);margin-bottom:18px;line-height:1.32;}
.hero h1 em{font-style:normal;color:var(--green-300);}
.hero p.lead{font-size:16.5px;color:var(--mint-200);max-width:600px;}
.hero-actions{display:flex;gap:12px;margin-top:24px;flex-wrap:wrap;}
.hero-fig{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.14);border-radius:var(--radius-lg);padding:14px;}
.hero-fig figcaption{color:var(--mint-200);font-size:12.8px;padding:10px 6px 2px;line-height:1.6;}
.hero-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:34px;}
.hero-strip div{background:rgba(255,255,255,.045);border:1px solid rgba(255,255,255,.11);border-radius:var(--radius-md);padding:14px 16px;}
.hero-strip b{display:block;color:var(--green-300);font-size:12.5px;margin-bottom:4px;}
.hero-strip span{color:var(--mint-100);font-size:13.5px;}
@media (max-width:900px){
  .hero-grid{grid-template-columns:1fr;}
  .hero-strip{grid-template-columns:repeat(2,1fr);}
}

/* ---------- Page hero (二级页) ---------- */
.page-hero{
  background:
    radial-gradient(900px 400px at 88% -20%,rgba(34,197,139,.2),transparent 60%),
    linear-gradient(160deg,var(--ink-950),var(--ink-800));
  color:var(--mint-100);padding:40px 0 44px;
}
.page-hero h1{color:#fff;font-size:clamp(25px,3.4vw,36px);margin-bottom:14px;}
.page-hero .lead{font-size:16.5px;color:var(--mint-200);max-width:820px;margin-bottom:0;}
.page-hero .eyebrow{margin-bottom:10px;}
.page-hero .kw-row{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px;}
.page-hero .kw-row span{font-size:12.5px;padding:5px 11px;border-radius:999px;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.16);color:var(--mint-100);}

/* ---------- Section scaffolding ---------- */
.section{padding:60px 0;}
.section-tight{padding:40px 0;}
.wrap.section-tight{padding-left:20px;padding-right:20px;}
.section-alt{background:var(--mint-50);}
.section-dark{background:var(--ink-900);color:var(--mint-100);}
.section-dark h2,.section-dark h3{color:#fff;}
.section-head{max-width:800px;margin:0 0 30px;}
.section-head.center{margin-left:auto;margin-right:auto;text-align:center;}
.section-head h2{font-size:clamp(22px,3vw,30px);}
.section-head p{color:var(--text-500);font-size:15.5px;}
.section-dark .section-head p{color:var(--mint-200);}
.section-kicker{font-size:12.5px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--green-600);margin-bottom:10px;display:block;}
.section-dark .section-kicker{color:var(--green-300);}

/* ---------- Grids & Cards ---------- */
.grid{display:grid;gap:20px;}
.grid-2{grid-template-columns:repeat(2,1fr);}
.grid-3{grid-template-columns:repeat(3,1fr);}
.grid-4{grid-template-columns:repeat(4,1fr);}
@media (max-width:900px){.grid-3,.grid-4{grid-template-columns:repeat(2,1fr);}}
@media (max-width:640px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}}

.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius-md);padding:22px;box-shadow:var(--shadow-card);}
.card h3{font-size:17px;}

/* ---------- Article cards (摘要回流) ---------- */
.article-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius-md);overflow:hidden;box-shadow:var(--shadow-card);display:flex;flex-direction:column;height:100%;}
.article-card .thumb{aspect-ratio:16/9;background:var(--mint-100);overflow:hidden;display:block;}
.article-card .thumb img{width:100%;height:100%;object-fit:contain;}
.article-card .body{padding:18px 20px 20px;display:flex;flex-direction:column;flex:1;}
.meta-row{font-size:12.8px;color:var(--text-400);display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-bottom:8px;}
.meta-row .chip{color:var(--green-700);background:var(--mint-100);padding:2px 9px;border-radius:999px;font-weight:600;}
.meta-row time{color:var(--text-500);font-weight:600;}
.article-card h3{font-size:16.5px;margin-bottom:8px;}
.article-card h3 a{color:var(--text-900);}
.article-card h3 a:hover{color:var(--green-600);text-decoration:none;}
.article-card p.excerpt{font-size:14px;color:var(--text-500);flex:1;line-height:1.75;}
.tag-row{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0;}
.tag{font-size:12px;color:var(--green-700);background:var(--mint-100);padding:3px 9px;border-radius:999px;font-weight:600;}
.read-more{font-size:13.5px;font-weight:700;color:var(--green-600);display:inline-flex;align-items:center;gap:4px;margin-top:auto;}
.read-more:hover{text-decoration:none;gap:8px;transition:gap .15s;}
.article-card.wide{flex-direction:row;}
.article-card.wide .thumb{width:38%;aspect-ratio:auto;flex:none;}
.article-card.wide .body{width:62%;}
@media (max-width:760px){.article-card.wide{flex-direction:column;}.article-card.wide .thumb,.article-card.wide .body{width:100%;}.article-card.wide .thumb{aspect-ratio:16/9;}}

/* ---------- 首页长文（重点文章） ---------- */
.la{display:grid;grid-template-columns:minmax(0,.86fr) minmax(0,1.14fr);gap:38px;padding:46px 0;border-top:1px solid var(--line);}
.la:first-of-type{border-top:0;padding-top:8px;}
.la.reverse{grid-template-columns:minmax(0,1.14fr) minmax(0,.86fr);}
.la.reverse .la-fig{order:2;}
.la-fig{align-self:start;position:sticky;top:132px;}
.la-main h3{font-size:clamp(20px,2.4vw,25px);margin:4px 0 16px;line-height:1.45;}
.callouts{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:0 0 20px;}
.callout{background:var(--mint-50);border:1px solid var(--line);border-left:4px solid var(--green-500);border-radius:var(--radius-sm);padding:12px 14px;}
.callout.alt{background:var(--orange-soft);border-color:#f6d9bd;border-left-color:var(--orange);}
.callout b{display:block;font-size:12.5px;letter-spacing:.05em;color:var(--green-700);margin-bottom:4px;}
.callout.alt b{color:var(--orange-deep);}
.callout p{font-size:14px;line-height:1.7;margin:0;color:var(--text-700);}
.rel{margin-top:16px;padding:12px 14px;background:var(--mint-50);border-radius:var(--radius-sm);font-size:14px;}
.rel b{color:var(--text-900);margin-right:6px;}
.rel a{display:inline-block;margin:2px 14px 2px 0;font-weight:600;}
@media (max-width:900px){
  .la,.la.reverse{grid-template-columns:1fr;gap:20px;padding:34px 0;}
  .la.reverse .la-fig{order:0;}
  .la-fig{position:static;}
  .callouts{grid-template-columns:1fr;}
}

/* ---------- 图与图注（移动端在容器内部横向浏览） ---------- */
.fig{margin:0;}
.fig-frame{background:var(--mint-50);border:1px solid var(--line);border-radius:var(--radius-md);overflow:hidden;}
.fig-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;}
.fig-scroll img{width:100%;height:auto;}
.fig figcaption{font-size:13px;color:var(--text-500);margin-top:9px;line-height:1.65;}
.fig figcaption strong{color:var(--green-700);}
@media (max-width:640px){
  .fig-scroll img{min-width:520px;}
  .fig-frame::after{content:"左右滑动查看完整图示";display:block;font-size:11.5px;color:var(--text-400);text-align:center;padding:4px 0 6px;}
  .hero-fig .fig-scroll img{min-width:480px;}
}

/* ---------- 技术总链 ---------- */
.chain{display:flex;flex-wrap:wrap;gap:10px 8px;align-items:center;margin:8px 0 26px;}
.chain .node{background:rgba(255,255,255,.06);border:1px solid rgba(127,224,187,.35);border-radius:999px;padding:7px 14px;font-size:13.5px;color:var(--mint-100);}
.chain .node.hot{background:linear-gradient(135deg,var(--green-600),var(--green-500));border-color:transparent;color:#fff;font-weight:700;}
.chain .node.warm{border-color:var(--orange);color:#ffd9b8;}
.chain .arr{color:var(--green-300);font-size:14px;}

/* ---------- 搜索意图直达 ---------- */
.intent-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px 18px;}
.intent-grid a{display:block;padding:10px 14px;border:1px solid var(--line);border-radius:var(--radius-sm);background:#fff;color:var(--text-700);font-size:14px;line-height:1.55;}
.intent-grid a:hover{border-color:var(--green-500);color:var(--green-600);text-decoration:none;background:var(--mint-50);}
@media (max-width:900px){.intent-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:600px){.intent-grid{grid-template-columns:1fr;}}

/* ---------- Matrix (深色区块小卡片) ---------- */
.matrix-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;}
@media (max-width:980px){.matrix-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:560px){.matrix-grid{grid-template-columns:1fr;}}
.matrix-item{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.13);border-radius:var(--radius-md);padding:18px;}
.matrix-item h4{color:#fff;font-size:14.5px;margin-bottom:6px;}
.matrix-item p{color:var(--mint-200);font-size:13px;margin:0;line-height:1.7;}
.matrix-item .ic{width:34px;height:34px;border-radius:10px;background:rgba(34,197,139,.18);display:flex;align-items:center;justify-content:center;margin-bottom:10px;color:var(--green-300);font-weight:700;font-size:14px;}

/* ---------- 二级页文章布局 ---------- */
.article-layout{display:grid;grid-template-columns:minmax(0,800px) 290px;gap:44px;align-items:start;justify-content:space-between;}
@media (max-width:1000px){.article-layout{grid-template-columns:1fr;}.toc-inline{display:block;}}
.post{padding:6px 0 46px;margin-bottom:46px;border-bottom:1px solid var(--line);}
.post:last-of-type{border-bottom:0;margin-bottom:0;}
.article-cat{color:var(--green-600);font-weight:700;font-size:13px;letter-spacing:.04em;}
.post h1{font-size:clamp(24px,3.2vw,34px);margin:10px 0 14px;line-height:1.42;}
.post h2{font-size:clamp(23px,3vw,31px);margin:10px 0 14px;line-height:1.42;}
.post.single{border-bottom:0;margin-bottom:0;padding-bottom:20px;}
.post .callouts{margin:0 0 24px;}
.more-title{font-size:20px;margin:38px 0 4px;}
.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:16px;}
.related-grid .article-card h3{font-size:14.5px;}
.related-grid .article-card p.excerpt{display:none;}
@media (max-width:760px){.related-grid{grid-template-columns:1fr;}}
.col-intro{max-width:880px;}
.col-intro p{font-size:16.5px;}
.la-more{margin:6px 0 10px;}
.la-more .btn{padding:9px 20px;}
.la-main h3 a{color:var(--text-900);}
.la-main h3 a:hover{color:var(--green-600);text-decoration:none;}
.toc-list a[aria-current="page"]{color:var(--green-600);}
.article-meta{display:flex;flex-wrap:wrap;gap:8px 18px;font-size:13.5px;color:var(--text-500);padding-bottom:18px;border-bottom:1px solid var(--line);margin-bottom:24px;align-items:center;}
.article-meta .author{display:flex;align-items:center;gap:8px;color:var(--text-700);font-weight:600;}
.article-meta .avatar{width:26px;height:26px;border-radius:7px;flex:none;}
.article-meta time{font-weight:600;color:var(--text-700);}
.post .fig{margin:0 0 26px;}

/* 正文排版 */
.prose{font-size:16.5px;color:var(--text-700);line-height:1.9;}
.prose h3{font-size:20px;margin:1.7em 0 .6em;padding-left:12px;border-left:4px solid var(--green-500);}
.prose h4{font-size:17px;margin:1.4em 0 .5em;}
.prose p{margin-bottom:1.1em;}
.prose ul,.prose ol{margin-bottom:1.1em;}
.prose li{margin-bottom:.4em;}
.prose a{border-bottom:1px solid rgba(31,143,104,.4);}
.prose a:hover{text-decoration:none;border-bottom-color:var(--green-600);}
.prose blockquote{margin:1.2em 0;padding:12px 16px;background:var(--mint-50);border-left:4px solid var(--orange);border-radius:0 var(--radius-sm) var(--radius-sm) 0;color:var(--text-700);}
.prose blockquote p:last-child{margin-bottom:0;}
.table-wrap{overflow-x:auto;margin:1.3em 0;-webkit-overflow-scrolling:touch;}
.prose table{border-collapse:collapse;width:100%;min-width:480px;font-size:14.5px;line-height:1.65;}
.prose th,.prose td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top;}
.prose th{background:var(--mint-100);color:var(--text-900);font-weight:700;}
.prose tbody tr:nth-child(even) td{background:var(--mint-50);}
.article-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:26px;}

.related{margin-top:30px;padding:18px 20px;background:var(--mint-50);border:1px solid var(--line);border-radius:var(--radius-md);}
.related h3{font-size:16px;margin-bottom:10px;}
.related ul{list-style:none;padding:0;margin:0;}
.related li{margin-bottom:8px;padding-left:16px;position:relative;font-size:15px;}
.related li::before{content:"";position:absolute;left:0;top:.72em;width:6px;height:6px;border-radius:50%;background:var(--green-500);}
.related li:last-child{margin-bottom:0;}

/* 侧栏 */
aside.sidebar{position:sticky;top:130px;}
@media (max-width:1000px){aside.sidebar{position:static;}}
.sidebar-box{background:var(--mint-50);border:1px solid var(--line);border-radius:var(--radius-md);padding:18px 20px;margin-bottom:18px;}
.sidebar-box h4{font-size:14.5px;margin-bottom:12px;}
.toc-list{list-style:none;padding:0;margin:0;counter-reset:toc;}
.toc-list li{display:flex;gap:10px;margin-bottom:12px;}
.toc-list li:last-child{margin-bottom:0;}
.toc-list li::before{counter-increment:toc;content:counter(toc);flex:none;width:24px;height:24px;border-radius:50%;background:var(--green-600);color:#fff;font-size:12px;font-weight:700;display:flex;align-items:center;justify-content:center;margin-top:1px;}
.toc-list a{color:var(--text-900);font-size:13.8px;font-weight:600;line-height:1.55;}
.toc-list a:hover,.toc-list a.active{color:var(--green-600);text-decoration:none;}
.side-links{list-style:none;padding:0;margin:0;}
.side-links li{margin-bottom:8px;font-size:13.8px;}
.side-links a{color:var(--text-700);}
.side-links a:hover{color:var(--green-600);}
.side-links a[aria-current="page"]{color:var(--green-600);font-weight:700;}
.notice-box{background:var(--orange-soft);border:1px solid #f6d9bd;border-radius:var(--radius-md);padding:14px 16px;font-size:13.8px;color:var(--text-700);margin:0 0 22px;}
.notice-box strong{color:var(--orange-deep);}

/* ---------- 下载区（App 页） ---------- */
.dl-panel{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:0 0 26px;}
.dl-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius-md);padding:18px 20px;box-shadow:var(--shadow-card);}
.dl-card h3{font-size:16px;margin-bottom:6px;}
.dl-card p{font-size:13.8px;color:var(--text-500);margin-bottom:12px;}
.dl-card dl{margin:0 0 12px;font-size:13.5px;}
.dl-card dt{float:left;clear:left;width:5.5em;color:var(--text-400);}
.dl-card dd{margin:0 0 4px 5.5em;color:var(--text-700);}
@media (max-width:640px){.dl-panel{grid-template-columns:1fr;}}

/* ---------- FAQ (details/summary，无 JS 也可展开) ---------- */
.faq{border-top:1px solid var(--line);}
.faq-item{border-bottom:1px solid var(--line);}
.faq-item summary{
  list-style:none;cursor:pointer;padding:17px 4px;font-size:15.8px;font-weight:600;color:var(--text-900);
  display:flex;justify-content:space-between;align-items:center;gap:16px;
}
.faq-item summary::-webkit-details-marker{display:none;}
.faq-item summary::after{content:"+";font-size:22px;color:var(--green-600);flex:none;transition:transform .2s;}
.faq-item[open] summary::after{transform:rotate(45deg);}
.faq-item .faq-a{font-size:15px;color:var(--text-500);padding:0 4px 18px;line-height:1.85;}
.faq-item .faq-a a{border-bottom:1px solid rgba(31,143,104,.4);}

/* ---------- CTA band ---------- */
.cta-band{background:linear-gradient(120deg,var(--ink-950),var(--green-700));border-radius:var(--radius-lg);padding:42px;text-align:center;color:#fff;}
.cta-band h2{color:#fff;}
.cta-band p{color:var(--mint-200);max-width:640px;margin:0 auto 22px;}
.cta-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;}
@media (max-width:560px){.cta-band{padding:30px 20px;}}

/* ---------- 关于 ---------- */
.about-box{display:grid;grid-template-columns:1.3fr .7fr;gap:34px;align-items:start;}
@media (max-width:900px){.about-box{grid-template-columns:1fr;}}
.about-facts{background:var(--mint-50);border:1px solid var(--line);border-radius:var(--radius-md);padding:20px 22px;font-size:14.5px;}
.about-facts dl{margin:0;}
.about-facts dt{font-weight:700;color:var(--text-900);font-size:13px;letter-spacing:.03em;margin-top:12px;}
.about-facts dt:first-child{margin-top:0;}
.about-facts dd{margin:2px 0 0;color:var(--text-700);}

/* ---------- Footer ---------- */
.site-footer{background:var(--ink-950);color:var(--text-400);padding:52px 0 24px;}
.footer-grid{display:grid;grid-template-columns:1.5fr repeat(3,1fr);gap:28px;padding-bottom:32px;border-bottom:1px solid rgba(255,255,255,.08);}
.footer-brand .brand{color:#fff;margin-bottom:10px;}
.footer-brand p{font-size:13.5px;color:var(--text-400);max-width:340px;line-height:1.75;}
.footer-col h5{color:var(--mint-100);font-size:13.5px;letter-spacing:.03em;margin:0 0 14px;}
.footer-col ul{list-style:none;padding:0;margin:0;}
.footer-col li{margin-bottom:9px;}
.footer-col a{color:var(--text-400);font-size:13.8px;}
.footer-col a:hover{color:var(--green-300);text-decoration:none;}
.footer-bottom{padding-top:20px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px 24px;font-size:12.8px;line-height:1.7;}
.footer-bottom a{color:var(--mint-200);}
@media (max-width:900px){.footer-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:560px){.footer-grid{grid-template-columns:1fr;}}

/* ---------- Utilities ---------- */
.mt-0{margin-top:0;}
.text-center{text-align:center;}
.back-to-top{position:fixed;right:18px;bottom:18px;width:44px;height:44px;border-radius:50%;background:var(--green-700);color:#fff;display:none;align-items:center;justify-content:center;box-shadow:var(--shadow-pop);border:none;cursor:pointer;z-index:50;font-size:18px;}
.back-to-top.show{display:flex;}

@media (max-width:430px){
  body{font-size:15.5px;}
  .wrap{padding:0 16px;}
  .wrap.section-tight{padding-left:16px;padding-right:16px;}
  .section{padding:44px 0;}
  .prose{font-size:16px;line-height:1.85;}
  .prose h3{font-size:18.5px;}
  .hero{padding:38px 0 44px;}
  .cta-band{padding:28px 18px;}
}