:root{--bg-color:#F5F7FB;--bg-deep:#E8EEF6;--card-bg:#FFFFFF;--text-main:#0B1220;--text-muted:#3D4B63;--text-soft:#64748B;--primary:#155EEF;--primary-hover:#1249C8;--primary-soft:#E8EFFF;--accent:#F97316;--accent-hover:#EA580C;--accent-soft:#FFF1E7;--info:#0284C7;--info-soft:#E0F2FE;--success:#0F766E;--success-soft:#CCFBF1;--warning:#C2410C;--border-color:#D7E0EC;--border-strong:#A8B8CC;--focus-ring:3px solid #155EEF;--shadow-sm:0 1px 2px rgba(15, 23, 42, 0.05);--shadow-md:0 10px 30px -12px rgba(15, 23, 42, 0.14);--shadow-lg:0 24px 48px -20px rgba(15, 23, 42, 0.2);--radius-sm:10px;--radius-md:16px;--radius-lg:24px;--font-display:"Sora","Plus Jakarta Sans","PingFang SC",sans-serif;--font-body:"Plus Jakarta Sans","PingFang SC","Microsoft YaHei",sans-serif;--font-num:"Plus Jakarta Sans","Sora",ui-sans-serif,sans-serif;--header-h:68px;--max-w:1120px;--surface-glass:rgba(255, 255, 255, 0.78)}*,::after,::before{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth}body{font-family:var(--font-body);background-color:var(--bg-color);background-image:radial-gradient(ellipse 70% 45% at 0 0,rgba(21,94,239,.1),transparent 55%),radial-gradient(ellipse 55% 40% at 100% 5%,rgba(249,115,22,.08),transparent 50%),linear-gradient(180deg,#fafbfe 0,var(--bg-color) 45%,var(--bg-deep) 100%);background-attachment:fixed;color:var(--text-main);line-height:1.65;font-size:16px;padding-bottom:96px;min-height:100vh;-webkit-font-smoothing:antialiased}img,svg{display:block;max-width:100%}a{color:var(--primary)}.skip-link{position:absolute;top:-48px;left:12px;background:var(--primary);color:#fff;padding:10px 18px;z-index:9999;text-decoration:none;border-radius:var(--radius-sm);font-weight:700;transition:top .2s}.skip-link:focus{top:12px;outline:var(--focus-ring);outline-offset:2px}:focus-visible{outline:var(--focus-ring);outline-offset:3px}.container{max-width:var(--max-w);margin:0 auto;padding:0 22px}.site-header{background:var(--surface-glass);backdrop-filter:blur(16px) saturate(1.2);border-bottom:1px solid var(--border-color);position:sticky;top:0;z-index:100}.header-inner{display:flex;justify-content:space-between;align-items:center;min-height:var(--header-h);gap:12px}.logo-area{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--text-main)}.logo-mark{width:40px;height:40px;border-radius:12px;background:linear-gradient(145deg,#3b82f6 0,#155eef 55%,#1d4ed8 100%);color:#fff;display:grid;place-items:center;flex-shrink:0}.logo-mark svg{width:22px;height:22px}.logo-text-wrap{display:flex;flex-direction:column;line-height:1.15}.logo-text{font-family:var(--font-display);font-size:1.22rem;font-weight:800;letter-spacing:-.03em}.logo-sub{font-size:.7rem;color:var(--text-soft);font-weight:650;letter-spacing:.06em;text-transform:uppercase}.main-nav{display:flex;gap:4px;list-style:none;align-items:center}.nav-btn{background:0 0;border:none;color:var(--text-muted);font-size:.9rem;font-weight:650;padding:8px 13px;cursor:pointer;border-radius:10px;text-decoration:none;display:inline-flex;align-items:center;transition:background .2s,color .2s;font-family:var(--font-body)}.nav-btn:hover{color:var(--primary);background:var(--primary-soft)}.nav-btn.active{color:#fff;background:var(--primary)}.nav-cta{background:var(--accent)!important;color:#fff!important;margin-left:4px}.nav-cta:hover{background:var(--accent-hover)!important;color:#fff!important}.page-main{padding:28px 0 20px;animation:pageIn .4s ease}.section-lead{display:none}@keyframes pageIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.hero-visual,.milestone-card,.page-main,.quiz-card{animation:none!important}}.section-block{margin:15px auto;max-width:98%}.section-kicker{display:inline-block;font-size:.75rem;font-weight:800;letter-spacing:.1em;text-transform:uppercase;color:var(--primary);margin-bottom:10px}.section-title{font-family:var(--font-display);font-size:clamp(1.55rem, 2.6vw, 1.2rem);line-height:1.2;letter-spacing:-.03em;margin-bottom:12px;color:var(--text-main)}.section-lead{color:var(--text-muted);font-size:1.02rem;margin-bottom:24px}.cta-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--primary);color:#fff;font-size:1.02rem;font-weight:750;padding:13px 26px;border-radius:12px;text-decoration:none;border:none;cursor:pointer;box-shadow:0 8px 20px rgba(21,94,239,.25);transition:transform .2s,background .2s,box-shadow .2s;font-family:var(--font-body)}.cta-btn:hover{background:var(--primary-hover);transform:translateY(-2px);box-shadow:0 12px 28px rgba(21,94,239,.3)}.cta-btn--accent{background:#155eef;box-shadow:0 8px 20px rgba(249,115,22,.28)}.cta-btn--accent:hover{background:var(--accent-hover);box-shadow:0 12px 28px rgba(249,115,22,.34)}.cta-btn--ghost{background:0 0;color:var(--text-main);border:1.5px solid var(--border-strong);box-shadow:none}.cta-btn--ghost:hover{background:var(--card-bg);border-color:var(--primary);color:var(--primary);box-shadow:none}.cta-btn--dark{background:var(--text-main);box-shadow:0 8px 20px rgba(11,18,32,.2)}.cta-btn--dark:hover{background:#1e293b}.ad-banner-placeholder{background:0 0;border:none;border-radius:0;padding:0;margin:12px 0;position:relative;min-height:280px;display:flex;flex-direction:column;align-items:stretch;text-align:left;box-shadow:none}.ad-banner-placeholder>*{width:100%}.ad-tag{position:static;display:inline-flex;align-items:center;gap:10px;width:auto;max-width:none;margin:0 0 8px;font-size:13px;color:#888;font-style:italic;font-weight:400;letter-spacing:normal;text-transform:none;background:0 0;padding:0;border-radius:0;text-align:left}.ad-tag::after,.ad-tag::before{content:"";display:block;width:28px;border-bottom:1px dashed #888;flex:0 0 28px}.sticky-bottom-ad{position:fixed;bottom:0;left:0;right:0;height:72px;background:rgba(255,255,255,.96);border-top:1px solid var(--border-color);box-shadow:0 -6px 20px rgba(15,23,42,.05);z-index:900;display:flex;align-items:center;justify-content:center}.sticky-ad-box{width:728px;max-width:100%;height:90px;background:#f1f5f9;border:1px dashed var(--border-color);display:flex;align-items:center;justify-content:center;font-size:13px;color:var(--text-soft);position:relative}.answer-box{background:var(--card-bg);border:1px solid var(--border-color);border-left:4px solid var(--primary);border-radius:var(--radius-md);padding:22px 24px;box-shadow:var(--shadow-sm)}.answer-box .answer-label,.answer-box h2{font-family:var(--font-display);font-size:1.15rem;margin-bottom:10px;letter-spacing:-.02em}.answer-box p{color:var(--text-muted);margin-bottom:10px}.answer-box p:last-child{margin-bottom:0}.prose-panel{background:var(--card-bg);border:1px solid var(--border-color);border-radius:var(--radius-lg);padding:clamp(22px,3vw,36px);box-shadow:var(--shadow-sm)}.prose-panel h2{font-family:var(--font-display);font-size:1.45rem;margin-bottom:14px;letter-spacing:-.03em}.prose-panel h3{font-size:1.08rem;margin:22px 0 8px;color:var(--text-main)}.prose-panel p{color:var(--text-muted);margin-bottom:12px;font-size:.98rem}.prose-panel ol,.prose-panel ul{margin:0 0 14px 1.2em;color:var(--text-muted)}.prose-panel li{margin-bottom:6px}.cite-note{font-size:.85rem;color:var(--text-soft);border-top:1px solid var(--border-color);padding-top:12px;margin-top:16px}.faq-list{display:grid;gap:10px}.faq-item{background:var(--card-bg);border:1px solid var(--border-color);border-radius:var(--radius-md);overflow:hidden}.faq-item summary{cursor:pointer;list-style:none;padding:16px 18px;font-weight:700;color:var(--text-main);display:flex;justify-content:space-between;align-items:center;gap:12px}.faq-item summary::-webkit-details-marker{display:none}.faq-item summary::after{content:"+";font-size:1.25rem;color:var(--primary);font-weight:500}.faq-item[open] summary::after{content:"−"}.faq-item .faq-a{padding:0 18px 16px;color:var(--text-muted);font-size:.95rem}.breadcrumb{display:flex;flex-wrap:wrap;gap:6px;align-items:center;font-size:.85rem;color:var(--text-soft);margin-bottom:3px;max-width:98%;margin:0 auto}.breadcrumb a{color:var(--text-muted);text-decoration:none;font-weight:600}.breadcrumb a:hover{color:var(--primary)}.breadcrumb span[aria-hidden]{opacity:.45}.site-footer{background:linear-gradient(180deg,#0f172a 0,#0b1220 100%);color:#94a3b8;padding:48px 0 36px;margin-top:64px;font-size:.92rem}.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:32px;margin-bottom:28px}.footer-brand{font-family:var(--font-display);font-size:1.4rem;color:#f8fafc;margin-bottom:10px;letter-spacing:-.03em}.footer-col h3{color:#f8fafc;font-size:.95rem;margin-bottom:12px}.footer-col ul{list-style:none}.footer-col li{margin-bottom:8px}.footer-col a{color:#94a3b8;text-decoration:none}.footer-col a:hover{color:#f8fafc}.footer-bottom{border-top:1px solid rgba(148,163,184,.2);padding-top:18px;font-size:.82rem;color:#64748b}.footer-bottom p+p{margin-top:6px}.trust-strip{display:flex;flex-wrap:wrap;gap:10px 14px;margin-top:20px}.trust-chip{display:inline-flex;align-items:center;gap:8px;font-size:.8rem;font-weight:700;color:var(--text-muted);background:rgba(255,255,255,.7);border:1px solid var(--border-color);padding:7px 12px;border-radius:10px}.trust-chip i{width:8px;height:8px;border-radius:50%;background:var(--primary);display:inline-block}kbd{background:#e8eef6;border:1px solid var(--border-color);border-radius:5px;padding:1px 6px;font-size:.85em;font-family:var(--font-body);font-weight:700}@media (max-width:860px){.footer-grid{grid-template-columns:1fr;gap:22px}.main-nav .nav-hide-sm{display:none}}@media (max-width:640px){:root{--radius-sm:8px;--radius-md:8px;--radius-lg:8px}.main-nav{gap:2px}.nav-btn{padding:8px 9px;font-size:.8rem}.logo-sub{display:none}.sticky-ad-box{width:320px;height:50px}}