:root{
  --primary:#d92121;--primary-dark:#a91515;--primary-soft:#fdeaea;--primary-pale:#fff7f7;
  --ink:#24262b;--text:#34373d;--muted:#69707a;--muted-2:#949aa3;--line:#e7e9ed;
  --surface:#ffffff;--surface-2:#f7f8fa;--surface-3:#f1f3f6;--black:#151515;
  --shadow-sm:0 4px 16px rgba(30,34,40,.055);--shadow:0 16px 38px rgba(30,34,40,.09);
  --radius:16px;--max:1200px
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;color:var(--text);background:#fff;line-height:1.72}
a{color:inherit;text-decoration:none;transition:.22s ease}
a:hover{color:var(--primary)}
main{overflow:hidden}.container{width:100%;max-width:var(--max);margin:auto;padding:0 24px}
section{padding:74px 0}.section-alt{background:var(--surface-2)}.section-dark{background:#171719;color:#fff}
.breadcrumb{padding:15px 0;border-bottom:1px solid var(--line);background:#fff;font-size:14px;color:var(--muted-2)}
.breadcrumb span{margin:0 8px;color:#c3c6cc}.breadcrumb a:hover{color:var(--primary)}
.section-head{max-width:850px;margin:0 auto 42px;text-align:center}
.section-kicker{display:block;margin-bottom:8px;color:var(--primary);font-size:13px;font-weight:800;letter-spacing:.12em;text-transform:uppercase}
.section-head h2{font-size:31px;line-height:1.4;color:var(--ink);margin-bottom:12px}
.section-dark .section-head h2{color:#fff}.section-head p{color:var(--muted);font-size:16px;line-height:1.9}.section-dark .section-head p{color:rgba(255,255,255,.68)}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:0 23px;border-radius:9px;border:1px solid transparent;font-weight:700}
.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark);color:#fff;transform:translateY(-2px);box-shadow:0 9px 24px rgba(217,33,33,.22)}
.btn-outline{background:#fff;color:var(--primary);border-color:#e7bebe}.btn-outline:hover{background:var(--primary-soft)}
.hero{padding:78px 0 76px;background:radial-gradient(circle at 84% 16%,rgba(217,33,33,.12),transparent 30%),linear-gradient(135deg,#fff1f1 0%,#fff 66%)}
.hero-grid{display:grid;grid-template-columns:minmax(0,1.02fr) minmax(420px,.98fr);gap:62px;align-items:center}
.eyebrow{display:inline-flex;align-items:center;gap:9px;color:var(--primary);font-size:16px;font-weight:800;margin-bottom:14px}.eyebrow:before{content:"";width:28px;height:2px;background:var(--primary)}
.hero h1{font-size:44px;line-height:1.2;color:var(--ink);letter-spacing:-.7px;margin-bottom:19px}.hero-desc{font-size:18px;line-height:1.92;color:var(--muted);max-width:700px}
.hero-tags{display:flex;flex-wrap:wrap;gap:10px;margin:25px 0 30px}.hero-tags span{padding:7px 13px;border-radius:999px;border:1px solid #efd3d3;background:rgba(255,255,255,.9);color:#9c2929;font-size:14px}
.hero-actions{display:flex;gap:13px;flex-wrap:wrap}
.hero-art{position:relative;min-height:420px;border:1px solid #ececef;border-radius:25px;background:rgba(255,255,255,.93);box-shadow:0 26px 64px rgba(119,30,30,.12);overflow:hidden;padding:28px}
.art-label{font-size:12px;text-transform:uppercase;letter-spacing:.11em;color:var(--muted-2);font-weight:700}
.art-title{font-size:20px;color:var(--ink);font-weight:800;margin-top:4px}.art-note{font-size:13px;color:var(--muted);margin-top:5px}
.icon-svg{width:25px;height:25px;display:block}.small-icon{width:20px;height:20px}.mini-icon{width:17px;height:17px}
/* hero visual variants */
.dual-engine{display:grid;grid-template-columns:1fr 72px 1fr;gap:10px;align-items:center;margin-top:34px}
.engine-card{min-height:212px;border-radius:19px;padding:23px 18px;background:var(--surface-2);border:1px solid #e8eaee;text-align:center;display:flex;flex-direction:column;align-items:center;justify-content:center}
.engine-icon{width:58px;height:58px;border-radius:17px;background:#fff;color:var(--primary);display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow-sm);margin-bottom:15px}
.engine-card h3{font-size:18px;color:var(--ink);margin-bottom:8px}.engine-card p{font-size:13px;color:var(--muted);line-height:1.7}
.engine-multiply{font-size:38px;color:var(--primary);font-weight:300;text-align:center}.engine-result{grid-column:1/-1;margin-top:8px;border-radius:14px;background:linear-gradient(135deg,var(--primary),#8b1212);color:#fff;padding:15px;text-align:center;font-weight:800}
.flow-map{position:relative;height:322px;margin-top:22px}.flow-map:before{content:"";position:absolute;left:8%;right:8%;top:49%;height:2px;background:linear-gradient(90deg,rgba(217,33,33,.08),rgba(217,33,33,.45),rgba(217,33,33,.08))}
.flow-core{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:124px;height:124px;border-radius:30px;background:linear-gradient(135deg,var(--primary),#911414);color:#fff;display:flex;align-items:center;justify-content:center;text-align:center;font-size:20px;font-weight:800;box-shadow:0 18px 38px rgba(154,22,22,.25)}
.flow-node{position:absolute;width:103px;min-height:62px;border-radius:14px;background:#fff;border:1px solid #edd7d7;color:#922323;font-size:14px;font-weight:700;display:flex;align-items:center;justify-content:center;text-align:center;padding:9px;box-shadow:var(--shadow-sm)}
.flow-node.f1{left:2%;top:38%}.flow-node.f2{left:23%;top:5%}.flow-node.f3{right:22%;top:5%}.flow-node.f4{right:2%;top:38%}.flow-node.f5{left:21%;bottom:3%}.flow-node.f6{right:20%;bottom:3%}
.data-stack{margin-top:28px;display:grid;gap:11px}.data-layer{display:grid;grid-template-columns:52px 1fr;align-items:center;gap:14px;border:1px solid #e9eaed;border-radius:14px;padding:14px;background:#fff}.data-layer strong{display:block;color:var(--ink);font-size:15px}.data-layer span{font-size:12px;color:var(--muted)}.layer-icon{width:46px;height:46px;border-radius:13px;background:var(--primary-soft);color:var(--primary);display:flex;align-items:center;justify-content:center}.data-arrow{text-align:center;color:#c74b4b;height:13px;line-height:13px}
.ui-mock{margin-top:26px;border:1px solid #dfe2e7;border-radius:15px;background:#f8f9fb;overflow:hidden;box-shadow:var(--shadow-sm)}.mock-top{height:31px;background:#fff;border-bottom:1px solid #e1e3e7;display:flex;align-items:center;gap:6px;padding:0 11px}.mock-dot{width:7px;height:7px;border-radius:50%;background:#d5d8dd}.mock-body{display:grid;grid-template-columns:88px 1fr;min-height:260px}.mock-side{background:#f1f3f7;border-right:1px solid #e1e4e8;padding:13px 9px}.mock-menu{height:8px;background:#d7dbe2;border-radius:999px;margin-bottom:12px}.mock-menu.active{background:#d92121;width:78%}.mock-main{padding:17px}.mock-toolbar{display:flex;gap:7px;margin-bottom:15px}.mock-btn{height:24px;width:66px;background:#fff;border:1px solid #dde0e5;border-radius:5px}.mock-btn.primary{background:#1e80ff;border-color:#1e80ff}.mock-panel{background:#fff;border:1px solid #e2e4e8;border-radius:8px;padding:14px}.mock-row{display:grid;grid-template-columns:90px 1fr;gap:9px;margin-bottom:10px}.mock-field{height:23px;border:1px solid #e0e2e6;border-radius:4px;background:#fafbfc}.mock-label{height:7px;background:#d8dbe0;border-radius:999px;margin-top:8px}.mock-flow{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-top:18px}.mock-node{width:55px;height:31px;border-radius:5px;background:#fff;border:1px solid #bcd0e5}.mock-line{height:1px;background:#b9c4d0;flex:1}
/* common content */
.summary-box{max-width:1000px;margin:auto;padding:34px 38px;text-align:center;background:#fff;border:1px solid #e8eaee;border-radius:19px;box-shadow:var(--shadow-sm)}.summary-box h2{font-size:27px;color:var(--ink);margin-bottom:13px}.summary-box p{color:var(--muted);line-height:1.95}.summary-tags{display:flex;justify-content:center;gap:9px;flex-wrap:wrap;margin-top:20px}.summary-tags span{padding:6px 12px;background:var(--primary-pale);border:1px solid #efdada;border-radius:999px;color:var(--primary);font-size:13px}
.problem-grid,.card-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px}.card-grid.cols-3{grid-template-columns:repeat(3,minmax(0,1fr))}.card-grid.cols-5{grid-template-columns:repeat(5,minmax(0,1fr))}
.problem-card,.info-card{background:#fff;border:1px solid #e7e9ed;border-radius:16px;padding:24px 22px;box-shadow:var(--shadow-sm);transition:.22s ease}.problem-card:hover,.info-card:hover{transform:translateY(-4px);border-color:#e5c4c4;box-shadow:var(--shadow)}
.card-icon{width:48px;height:48px;border-radius:14px;background:var(--primary-soft);color:var(--primary);display:flex;align-items:center;justify-content:center;margin-bottom:16px}.problem-card h3,.info-card h3{font-size:18px;color:var(--ink);line-height:1.5;margin-bottom:9px}.problem-card p,.info-card p{font-size:15px;color:var(--muted);line-height:1.82}
.feature-split{display:grid;grid-template-columns:1fr 1fr;gap:24px}.feature-column{border:1px solid #e7e9ed;border-radius:18px;background:#fff;padding:28px;box-shadow:var(--shadow-sm)}.feature-column.red{background:linear-gradient(145deg,#fff7f7,#fff)}.feature-title{display:flex;gap:14px;align-items:center;margin-bottom:20px}.feature-title .card-icon{margin:0}.feature-title h3{font-size:22px;color:var(--ink)}.feature-list{display:grid;gap:10px}.feature-item{display:flex;gap:10px;align-items:flex-start;padding:12px 13px;background:#f8f9fb;border-radius:10px;color:var(--muted);font-size:14px;line-height:1.7}.feature-item:before{content:"";width:6px;height:6px;border-radius:50%;background:var(--primary);margin-top:9px;flex:0 0 6px}
.formula-bar{display:grid;grid-template-columns:1fr 90px 1fr 90px 1.15fr;align-items:center;gap:12px}.formula-box{min-height:156px;padding:24px 20px;border-radius:18px;border:1px solid #e6e8ec;background:#fff;text-align:center;box-shadow:var(--shadow-sm);display:flex;flex-direction:column;justify-content:center}.formula-box strong{font-size:21px;color:var(--ink);margin-bottom:7px}.formula-box span{font-size:14px;color:var(--muted);line-height:1.7}.formula-symbol{text-align:center;font-size:36px;color:var(--primary);font-weight:300}.formula-box.result{background:linear-gradient(135deg,var(--primary),#921313);border:none}.formula-box.result strong,.formula-box.result span{color:#fff}.formula-box.result span{opacity:.82}
.chain{display:grid;grid-template-columns:repeat(5,1fr);gap:0;align-items:stretch}.chain-step{position:relative;text-align:center;padding:0 14px}.chain-step:not(:last-child):after{content:"";position:absolute;right:-5px;top:35px;width:11px;height:11px;border-top:2px solid #d7a5a5;border-right:2px solid #d7a5a5;transform:rotate(45deg)}.chain-no{width:66px;height:66px;margin:0 auto 14px;border-radius:20px;background:#fff;border:1px solid #efcccc;color:var(--primary);display:flex;align-items:center;justify-content:center;font-size:18px;font-weight:800;box-shadow:var(--shadow-sm)}.chain-step h3{font-size:17px;color:var(--ink);margin-bottom:7px}.chain-step p{font-size:14px;color:var(--muted);line-height:1.7}
.role-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.role-card{position:relative;padding:28px;border-radius:18px;border:1px solid #e5e7eb;background:#fff;box-shadow:var(--shadow-sm);overflow:hidden}.role-card:before{content:"";position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--primary)}.role-card h3{font-size:20px;color:var(--ink);margin-bottom:6px}.role-card .role-name{color:var(--primary);font-size:13px;font-weight:800;margin-bottom:14px}.role-card ul{list-style:none;display:grid;gap:9px}.role-card li{font-size:14px;color:var(--muted);padding-left:16px;position:relative}.role-card li:before{content:"";position:absolute;left:0;top:9px;width:5px;height:5px;border-radius:50%;background:var(--primary)}
.evidence-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.evidence-card{background:#fff;border:1px solid #e5e7eb;border-radius:18px;overflow:hidden;box-shadow:var(--shadow-sm)}.evidence-top{padding:25px;background:linear-gradient(140deg,#fff1f1,#fff);border-bottom:1px solid #eee}.evidence-number{display:block;color:var(--primary);font-size:34px;font-weight:900;line-height:1.1}.evidence-top h3{font-size:18px;color:var(--ink);margin-top:9px}.evidence-body{padding:21px 24px;color:var(--muted);font-size:14px;line-height:1.82}
.capability-hub{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.hub-card{display:flex;gap:13px;padding:19px;border:1px solid #e5e7eb;border-radius:15px;background:#fff;box-shadow:var(--shadow-sm);min-height:112px}.hub-card:hover,.hub-card.active{background:var(--primary-pale);border-color:#e6bebe;transform:translateY(-3px)}.hub-icon{width:42px;height:42px;flex:0 0 42px;border-radius:12px;background:var(--primary-soft);color:var(--primary);display:flex;align-items:center;justify-content:center}.hub-card h3{font-size:16px;color:var(--ink);margin-bottom:5px}.hub-card p{font-size:13px;color:var(--muted);line-height:1.55}
.table-wrap{overflow-x:auto;background:#fff;border:1px solid #e5e7eb;border-radius:16px;box-shadow:var(--shadow-sm)}table{width:100%;border-collapse:collapse;min-width:760px}th{padding:17px 20px;background:#fff0f0;color:#912323;text-align:left;font-size:15px}td{padding:17px 20px;border-top:1px solid #eceef1;color:var(--muted);font-size:15px;line-height:1.72}td:first-child{font-weight:700;color:var(--ink);white-space:nowrap}
.checklist{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.check-item{display:flex;gap:13px;padding:17px 19px;border-radius:13px;border:1px solid #e6e8ec;background:#fff}.check-mark{width:27px;height:27px;flex:0 0 27px;border-radius:50%;background:var(--primary-soft);color:var(--primary);font-weight:900;display:flex;align-items:center;justify-content:center}.check-item strong{display:block;color:var(--ink);margin-bottom:4px}.check-item p{font-size:14px;color:var(--muted);line-height:1.7}
.note{max-width:1050px;margin:24px auto 0;padding:18px 22px;background:#fff5f5;border-left:4px solid var(--primary);border-radius:10px;color:var(--muted);font-size:15px;line-height:1.85}.note strong{color:var(--primary)}
.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.related-card{padding:24px;border:1px solid #e5e7eb;border-radius:16px;background:#fff;box-shadow:var(--shadow-sm)}.related-card:hover{transform:translateY(-4px);border-color:#e3bcbc}.related-type{display:inline-block;color:var(--primary);font-size:13px;font-weight:800;margin-bottom:10px}.related-card h3{font-size:18px;color:var(--ink);line-height:1.55;margin-bottom:8px}.related-card p{font-size:14px;color:var(--muted);line-height:1.75}
.faq-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:17px 20px;max-width:1100px;margin:auto}.faq-item{background:#fff;border:1px solid #e5e7eb;border-radius:14px;overflow:hidden;box-shadow:var(--shadow-sm)}.faq-question{list-style:none;cursor:pointer;padding:18px 54px 18px 21px;font-weight:700;color:var(--ink);position:relative}.faq-question::-webkit-details-marker{display:none}.faq-question:after{content:"+";position:absolute;right:20px;top:16px;color:var(--primary);font-size:25px;line-height:1}.faq-item[open] .faq-question:after{content:"−"}.faq-answer{padding:0 21px 20px;color:var(--muted);font-size:15px;line-height:1.82}
.cta{padding:80px 0;background-color:#151515;background-image:url("https://www.oa8000.com/statics/new/img/content_5_bg.png");background-size:cover;background-position:center;color:#fff;text-align:center}.cta h2{font-size:31px;margin-bottom:14px}.cta p{max-width:820px;margin:0 auto 29px;color:rgba(255,255,255,.8);line-height:1.92}.cta .btn-primary{background:#fff;color:#111}.cta .btn-primary:hover{background:#f5f5f5;color:var(--primary)}
@media(max-width:1080px){.hero-grid{grid-template-columns:1fr;gap:44px}.hero-art{max-width:760px;width:100%;margin:auto}.problem-grid,.capability-hub{grid-template-columns:repeat(2,1fr)}.card-grid.cols-5{grid-template-columns:repeat(3,1fr)}.formula-bar{grid-template-columns:1fr 55px 1fr}.formula-box.result{grid-column:1/-1}.formula-symbol:nth-of-type(4){display:none}}
@media(max-width:860px){section{padding:57px 0}.hero h1{font-size:36px}.card-grid,.card-grid.cols-3,.evidence-grid,.role-grid,.related-grid{grid-template-columns:repeat(2,1fr)}.feature-split{grid-template-columns:1fr}.chain{grid-template-columns:1fr;gap:20px;max-width:680px;margin:auto}.chain-step{display:grid;grid-template-columns:70px 1fr;text-align:left;column-gap:16px}.chain-no{grid-row:1/3;margin:0}.chain-step:not(:last-child):after{display:none}.faq-grid{grid-template-columns:1fr}}
@media(max-width:620px){.container{padding:0 18px}.breadcrumb{font-size:13px}.hero{padding:54px 0}.hero h1{font-size:30px}.hero-desc{font-size:16px}.hero-actions{flex-direction:column}.btn{width:100%}.hero-art{min-height:auto;padding:22px 17px}.dual-engine{grid-template-columns:1fr;gap:10px}.engine-card{min-height:145px}.engine-multiply{font-size:28px}.engine-result{grid-column:auto}.flow-map{height:auto;display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-top:20px}.flow-map:before{display:none}.flow-core,.flow-node{position:static;transform:none;width:auto;min-height:52px}.flow-core{grid-column:1/-1;height:auto;border-radius:16px}.data-stack{margin-top:19px}.mock-body{grid-template-columns:62px 1fr}.mock-main{padding:12px}.mock-row{grid-template-columns:65px 1fr}.section-head h2,.summary-box h2{font-size:24px}.summary-box{padding:26px 20px}.problem-grid,.card-grid,.card-grid.cols-3,.card-grid.cols-5,.role-grid,.evidence-grid,.capability-hub,.related-grid,.checklist{grid-template-columns:1fr}.formula-bar{grid-template-columns:1fr}.formula-symbol{font-size:28px}.formula-box.result{grid-column:auto}.cta h2{font-size:25px}}