:root{--bb-blue:#0b3d91;--bb-blue-dark:#082a66;--bb-orange:#ff6a13;--bb-racing-red:#d73931;--bb-bg:#f6f8fb;--bb-text:#1c2530;--bb-muted:#5b6472;--bb-border:#e2e6ed;--bb-white:#fff;--bb-radius:10px;--bb-maxw:1120px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bb-bg);color:var(--bb-text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",Arial,sans-serif;line-height:1.75;overflow-x:hidden}img{display:block;max-width:100%;height:auto}a{color:var(--bb-blue);text-decoration:none}a:hover{color:var(--bb-orange)}.site-header{position:sticky;top:0;z-index:50;background:#fff;border-bottom:1px solid var(--bb-border)}.nav-wrap{max-width:var(--bb-maxw);min-height:72px;margin:auto;padding:0 20px;display:flex;align-items:center;gap:22px}.brand{display:flex;align-items:center;gap:10px;color:var(--bb-blue-dark);font-size:22px;font-weight:800;white-space:nowrap}.brand img{width:48px;height:48px}.site-nav{margin-left:auto;display:flex;align-items:center;gap:6px}.site-nav a{color:#354052;font-size:15px;padding:9px 8px;border-radius:6px;white-space:nowrap}.site-nav a:hover,.site-nav a.active{color:var(--bb-orange);background:#fff5ed}.menu-toggle{display:none;margin-left:auto;border:1px solid var(--bb-border);background:#fff;padding:9px 13px;border-radius:7px;color:var(--bb-blue-dark);font-weight:700}.hero{background:linear-gradient(135deg,#061d46 0%,#0b3d91 56%,#1355a4 100%);color:#fff}.hero-inner{max-width:var(--bb-maxw);margin:auto;padding:52px 20px;display:grid;grid-template-columns:1.1fr .9fr;gap:44px;align-items:center}.hero-copy h1{font-size:clamp(34px,4vw,52px);line-height:1.16;margin:14px 0 18px;letter-spacing:-.03em}.hero-copy p{color:#d8e7ff;font-size:17px;max-width:660px}.eyebrow,.section-kicker{display:inline-flex;color:#ffd8bf;font-size:13px;font-weight:800;letter-spacing:.08em}.eyebrow.dark{color:var(--bb-orange)}.hero-art img{border-radius:12px;box-shadow:0 18px 50px rgba(0,0,0,.2)}.section-wrap{max-width:var(--bb-maxw);margin:auto;padding:54px 20px}.alt-section{max-width:none;background:#edf2f8;padding-left:max(20px,calc((100% - var(--bb-maxw))/2 + 20px));padding-right:max(20px,calc((100% - var(--bb-maxw))/2 + 20px))}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:30px;margin-bottom:24px}.section-heading h2{font-size:28px;line-height:1.25;margin:4px 0}.section-heading p{max-width:520px;margin:0;color:var(--bb-muted)}.trust-strip{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:-28px;position:relative}.trust-card{background:#fff;border:1px solid var(--bb-border);padding:21px 24px;border-radius:var(--bb-radius);box-shadow:0 10px 30px rgba(12,38,75,.08)}.trust-card span{font-weight:800;color:var(--bb-blue)}.trust-card.simulation{border-left:4px solid var(--bb-orange)}.trust-card.simulation span{color:#b44700}.topic-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.topic-card{background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);padding:22px;color:var(--bb-text);transition:transform .18s,border-color .18s}.topic-card:hover{transform:translateY(-3px);border-color:#9eb7df}.topic-card>span{font-size:12px;font-weight:800;color:var(--bb-orange)}.topic-card h3{margin:6px 0 8px;font-size:18px}.topic-card p{color:var(--bb-muted);margin:0;font-size:14px}.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.content-card{overflow:hidden;background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);display:flex;flex-direction:column}.content-card.real{border-top:4px solid var(--bb-blue)}.content-card.simulation{border-left:4px solid var(--bb-orange)}.content-card img{aspect-ratio:16/9;object-fit:cover;background:#dfe8f7}.card-body{padding:18px;display:flex;flex-direction:column;flex:1}.card-body h3{font-size:17px;line-height:1.45;margin:9px 0}.card-body h3 a{color:var(--bb-text)}.card-body h3 a:hover{color:var(--bb-orange)}.card-body p{font-size:14px;color:var(--bb-muted);margin:0 0 12px}.badge{display:inline-flex;align-self:flex-start;border-radius:4px;padding:3px 8px;font-size:12px;font-weight:800}.badge.knowledge{color:#0b3d91;background:#e8f0ff}.badge.racing{color:#a02020;background:#fdebea}.badge.real{color:#0754b8;background:#e4f0ff}.badge.simulation{color:#a33e00;background:#fff0e6}.card-body .meta{font-size:12px;margin-top:auto}.read-link{font-size:14px;font-weight:700}.mini-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.mini-grid>div,.mini-grid>article{background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);padding:20px}.mini-grid h2,.mini-grid h3{font-size:18px;margin-top:0}.entry-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.entry-grid a{background:var(--bb-blue-dark);color:#fff;border-radius:var(--bb-radius);padding:22px;display:flex;flex-direction:column}.entry-grid a:hover{background:var(--bb-blue)}.entry-grid span{font-size:13px;color:#bcd3f6}.entry-grid strong{font-size:17px;margin-top:5px}.learning-path,.editorial-note,.prose-page{background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);margin-top:30px;margin-bottom:30px}.learning-path ol{display:grid;grid-template-columns:1fr 1fr;gap:16px;padding-left:22px}.prose-columns,.split-content{display:grid;grid-template-columns:1fr 1fr;gap:34px}.real-notice,.simulation-notice,.safety-notice{padding:20px 22px;border-radius:var(--bb-radius);margin-bottom:24px}.real-notice{background:#eaf3ff;border:1px solid #bcd6fa}.simulation-notice{background:#fff1e8;border:1px solid #ffc9a6;border-left:5px solid var(--bb-orange)}.safety-notice{background:#fff9db;border:1px solid #ecd87c}.real-notice p,.simulation-notice p,.safety-notice p{margin:6px 0 0}.page-intro{background:linear-gradient(180deg,#eef4fc,#f6f8fb);border-bottom:1px solid var(--bb-border)}.page-intro .section-wrap{padding-top:40px;padding-bottom:40px}.page-intro h1{font-size:36px;line-height:1.25;margin:10px 0}.page-intro p{max-width:760px;color:var(--bb-muted)}.breadcrumbs{display:flex;flex-wrap:wrap;gap:8px;font-size:13px;color:var(--bb-muted);margin-bottom:20px}.breadcrumbs a{font-weight:700}.table-wrap{overflow-x:auto;margin:28px 0}table{width:100%;border-collapse:collapse;background:#fff;font-size:14px}caption{text-align:left;font-size:18px;font-weight:800;margin-bottom:10px}th,td{padding:12px 14px;border:1px solid var(--bb-border);text-align:left;vertical-align:top}th{background:#eaf1fb;color:var(--bb-blue-dark)}.check-list{padding-left:22px}.check-list li{margin-bottom:8px}.article-layout{max-width:var(--bb-maxw);margin:auto;padding:34px 20px 60px}.article-main{max-width:780px;margin:auto;background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);padding:clamp(22px,4vw,44px)}.article-main h1{font-size:clamp(28px,4vw,34px);line-height:1.25;margin:12px 0}.article-main h2{font-size:21px;line-height:1.4;margin:34px 0 12px;color:#132c55}.article-main h3{font-size:17px}.article-main p{font-size:16px;line-height:1.82;margin:0 0 16px}.article-meta{display:flex;flex-wrap:wrap;gap:8px 18px;color:var(--bb-muted);font-size:13px;margin:16px 0 22px}.article-cover{width:100%;border-radius:8px;margin:0 0 26px}.key-answer,.summary-box,.source-box{background:#f0f5fc;border-left:4px solid var(--bb-blue);padding:18px 20px;margin:24px 0}.real-answer{background:#eaf3ff}.summary-box h2,.source-box h2{margin-top:0}.news-disclaimer{font-size:14px!important;color:var(--bb-muted);border-top:1px solid var(--bb-border);padding-top:18px}.related{border-top:1px solid var(--bb-border);margin-top:34px}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-grid a{border:1px solid var(--bb-border);padding:14px;border-radius:8px;display:flex;flex-direction:column}.related-grid span{font-size:11px;color:var(--bb-orange)}.related-grid strong{font-size:14px;color:var(--bb-text)}.article-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:24px}.article-actions a,.button{border:0;background:var(--bb-blue);color:#fff;padding:10px 15px;border-radius:7px;font-weight:700;cursor:pointer}.article-actions a:hover,.button:hover{background:var(--bb-orange);color:#fff}.form-wrap{display:grid;grid-template-columns:2fr 1fr;gap:30px}.form-wrap form,.form-wrap aside{background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);padding:24px}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.form-wrap label{display:flex;flex-direction:column;gap:6px;font-weight:700;margin-bottom:16px}.form-wrap input,.form-wrap select,.form-wrap textarea{width:100%;border:1px solid #bfc7d4;border-radius:6px;padding:11px;font:inherit}.form-message{color:var(--bb-muted)}.faq-list{display:grid;grid-template-columns:1fr 1fr;gap:16px}.faq-list article{background:#fff;border:1px solid var(--bb-border);border-radius:var(--bb-radius);padding:20px}.faq-list h2{font-size:18px;margin:0 0 10px;display:flex;gap:10px}.faq-list h2 span{color:var(--bb-orange)}.faq-list p{margin:0}.site-footer{background:#06172e;color:#cbd7e8;margin-top:40px}.footer-grid{max-width:var(--bb-maxw);margin:auto;padding:44px 20px;display:grid;grid-template-columns:repeat(3,1fr);gap:40px}.footer-grid h2{color:#fff;font-size:17px}.footer-grid a{display:block;color:#cbd7e8;margin:7px 0}.footer-grid a:hover{color:#ffb27d}.footer-bottom{border-top:1px solid #21324b;padding:18px 20px;text-align:center;font-size:13px}.meta{color:var(--bb-muted)}@media(max-width:900px){.site-nav{gap:1px}.site-nav a{font-size:13px;padding:8px 5px}.card-grid{grid-template-columns:repeat(2,1fr)}.topic-grid{grid-template-columns:repeat(2,1fr)}.mini-grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:760px){.nav-wrap{min-height:64px}.brand img{width:42px;height:42px}.menu-toggle{display:block}.site-nav{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;border-bottom:1px solid var(--bb-border);padding:10px 16px;flex-direction:column;align-items:stretch}.site-nav.open{display:flex}.site-nav a{font-size:15px;padding:10px}.hero-inner{grid-template-columns:1fr;padding-top:40px;padding-bottom:40px}.hero-copy h1{font-size:27px}.trust-strip{grid-template-columns:1fr;margin-top:0}.section-heading{display:block}.section-heading p{margin-top:8px}.card-grid,.topic-grid,.entry-grid,.mini-grid,.faq-list,.form-grid,.form-wrap,.prose-columns,.split-content,.learning-path ol{grid-template-columns:1fr}.section-wrap{padding:38px 16px}.alt-section{padding-left:16px;padding-right:16px}.article-layout{padding:24px 12px}.article-main{padding:22px 17px}.related-grid{grid-template-columns:1fr}.footer-grid{grid-template-columns:1fr;gap:18px}.article-actions{flex-direction:column}.article-actions a{text-align:center}.page-intro h1{font-size:28px}}