:root{
  --primary:#597EF7;--primary2:#7580EE;--sky:#7AC4F5;--ink:#1D2B5F;--text:#222222;--muted:#5B647A;
  --page:#F6F8FF;--soft:#ECF0FF;--soft2:#EAF7FF;--white:#FFFFFF;--deep:#101827;--footer:#1F1F1F;--foottext:#D7DCE8;
  --line:rgba(89,126,247,.16);--shadow:0 16px 40px rgba(89,126,247,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;overflow-x:hidden}
body{margin:0;background:var(--page);color:var(--text);font-family:Arial,"PingFang SC","Microsoft YaHei",sans-serif;line-height:1.8;overflow-x:hidden}
img,svg,video{max-width:100%}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:none}
button,input,textarea{font:inherit}
button{cursor:pointer}
.container{width:min(1200px,calc(100% - 40px));margin:0 auto}
.reading{width:min(860px,100%);margin-left:auto;margin-right:auto}
.site-header{position:sticky;top:0;z-index:9999;width:100%;background:linear-gradient(135deg,#F7F9FF 0%,#ECF0FF 52%,#EAF7FF 100%);box-shadow:0 8px 24px rgba(89,126,247,.10);backdrop-filter:blur(12px)}
.header-inner{max-width:1200px;min-height:72px;margin:0 auto;padding:0 20px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.site-logo{display:flex;align-items:center;flex:0 0 auto;min-width:150px}
.site-logo img{display:block;height:40px;width:auto;max-width:168px;object-fit:contain}
.logo-fallback{display:flex;align-items:center;justify-content:center;min-width:142px;height:40px;padding:0 14px;border:1px solid var(--line);border-radius:12px;background:#fff;color:var(--ink);font-weight:800;letter-spacing:.05em}
.nav-core{display:flex;align-items:center;gap:8px;white-space:nowrap;flex-wrap:nowrap;min-width:0}
.nav-core a{color:#1D2B5F;padding:8px 10px;border-radius:999px;font-weight:700;text-decoration:none;font-size:15px}
.nav-core a.is-current,.nav-core a:hover{background:rgba(255,255,255,.82);color:#597EF7}
.header-actions{display:flex;align-items:center;gap:8px;flex:0 0 auto}
.login-link{display:inline-flex;align-items:center;justify-content:center;height:42px;padding:0 14px;color:var(--ink);font-weight:700;white-space:nowrap}
.main-btn{position:relative;overflow:hidden;isolation:isolate;display:inline-flex;align-items:center;justify-content:center;height:42px;min-width:96px;padding:0 20px;background:linear-gradient(135deg,#7580EE 0%,#597EF7 48%,#7AC4F5 100%);color:#FFFFFF;border-radius:999px;text-decoration:none;font-weight:700;box-shadow:0 10px 24px rgba(89,126,247,.28);white-space:nowrap}
.main-btn::before{content:"";position:absolute;inset:-2px;border-radius:inherit;background:linear-gradient(120deg,transparent 0%,rgba(255,255,255,.85) 35%,transparent 70%);transform:translateX(-120%);animation:btnShine 2.4s infinite;z-index:-1}
.main-btn::after{content:"";position:absolute;inset:-1px;border-radius:inherit;border:1px solid rgba(255,255,255,.65);box-shadow:0 0 8px rgba(122,196,245,.55),0 0 18px rgba(89,126,247,.35);pointer-events:none}
@keyframes btnShine{0%{transform:translateX(-120%)}55%{transform:translateX(120%)}100%{transform:translateX(120%)}}
.mobile-head{display:none;min-height:64px;padding:0 14px;align-items:center;justify-content:space-between;gap:10px}
.mobile-head .site-logo{min-width:0;justify-content:center;flex:1}
.mobile-head .site-logo img{height:36px;max-width:145px}
.mobile-menu-btn,.drawer-close{width:42px;height:42px;border:0;border-radius:12px;background:#fff;color:var(--ink);box-shadow:0 8px 22px rgba(29,43,95,.09);font-size:21px;line-height:1}
.mobile-head .main-btn{height:40px;min-width:86px;padding:0 14px;font-size:14px}
.channel-bar{background:#fff;border-top:1px solid rgba(89,126,247,.08);border-bottom:1px solid rgba(89,126,247,.10)}
.channel-scroll{max-width:1200px;margin:0 auto;padding:0 20px;display:flex;align-items:center;gap:20px;overflow-x:auto;overscroll-behavior-inline:contain;scrollbar-width:none;white-space:nowrap}
.channel-scroll::-webkit-scrollbar{display:none}
.channel-scroll a{display:inline-flex;align-items:center;height:44px;color:#5B647A;font-size:14px;font-weight:700;flex:0 0 auto}
.channel-scroll a:hover,.channel-scroll a.is-current{color:#597EF7}
.drawer-overlay{position:fixed;inset:0;z-index:10010;background:rgba(16,24,39,.42);opacity:0;visibility:hidden;transition:.22s}
.mobile-drawer{position:fixed;left:0;top:0;bottom:0;z-index:10020;width:min(84vw,320px);background:#fff;transform:translateX(-103%);transition:.24s;overflow-y:auto;padding:18px 18px 28px;box-shadow:18px 0 48px rgba(16,24,39,.18)}
.drawer-open .drawer-overlay{opacity:1;visibility:visible}
.drawer-open .mobile-drawer{transform:translateX(0)}
.drawer-open{overflow:hidden}
.drawer-top{display:flex;align-items:center;justify-content:space-between;gap:12px;padding-bottom:14px;border-bottom:1px solid var(--line)}
.drawer-top .site-logo{min-width:0}.drawer-top .site-logo img{height:36px;max-width:150px}
.drawer-group{padding-top:18px}.drawer-group h2{margin:0 0 8px;color:var(--muted);font-size:13px;letter-spacing:.12em}
.drawer-links{display:grid;grid-template-columns:1fr 1fr;gap:6px}
.drawer-links a{padding:9px 10px;border-radius:10px;color:var(--ink);font-size:14px;background:#F8FAFF}
.drawer-links a.is-current{background:var(--soft);color:var(--primary);font-weight:700}
.site-main{min-height:60vh;padding-bottom:40px}
.hero{padding:62px 0 26px}
.hero-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(300px,.85fr);gap:30px;align-items:center}
.eyebrow{display:inline-flex;align-items:center;gap:8px;padding:6px 11px;border-radius:999px;background:#fff;border:1px solid var(--line);color:var(--primary);font-size:13px;font-weight:800;letter-spacing:.06em}
h1,h2,h3{color:var(--ink);line-height:1.25;margin-top:0}
h1{font-size:clamp(38px,5vw,50px);margin:16px 0 18px;letter-spacing:-.02em}
h2{font-size:clamp(26px,3.5vw,34px);margin-bottom:14px}h3{font-size:20px;margin-bottom:8px}
.lead{font-size:18px;color:#384461;line-height:1.9;margin:0 0 22px}
.meta-note{font-size:14px;color:var(--muted)}
.section{padding:64px 0}.section.tight{padding:42px 0}.section.alt{background:linear-gradient(180deg,rgba(236,240,255,.75),rgba(234,247,255,.35))}
.section-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:24px}.section-head p{max-width:620px;margin:0;color:var(--muted)}
.media{position:relative;width:100%;max-width:100%;overflow:hidden;border-radius:16px;background:#ECF0FF;aspect-ratio:16/9}
.media>img{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;object-position:center center;display:block}
.media.placeholder::after{content:"";position:absolute;inset:22%;border:1px solid rgba(89,126,247,.18);border-radius:18px;background:linear-gradient(135deg,rgba(255,255,255,.75),rgba(255,255,255,.25))}
.media.card-media{height:172px;aspect-ratio:auto}.media.feature-media{height:242px;aspect-ratio:auto}
.surface{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow)}
.info-card{padding:24px}.info-card p{margin:0;color:#4D5871}.info-card .text-link{display:inline-block;margin-top:14px;font-weight:800}
.grid-2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}.grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.grid-4{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:18px}
.topic-card{display:flex;flex-direction:column;min-height:150px;padding:22px;background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 10px 28px rgba(89,126,247,.07)}
.topic-card h3{font-size:18px}.topic-card p{margin:0 0 12px;color:var(--muted);font-size:14px;line-height:1.7}.topic-card a{margin-top:auto;font-weight:800}
.pill-row{display:flex;gap:10px;overflow-x:auto;scrollbar-width:none;padding:4px 0 6px}.pill-row::-webkit-scrollbar{display:none}.pill{flex:0 0 auto;display:inline-flex;align-items:center;height:40px;padding:0 16px;border-radius:999px;background:#fff;border:1px solid var(--line);color:var(--ink);font-weight:700}
.observation{padding:20px 24px;border-radius:16px;background:#fff;border-left:4px solid var(--primary);box-shadow:0 10px 26px rgba(89,126,247,.08);color:#44506B}
.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(340px,.9fr);gap:30px;align-items:center}.split.reverse .media-wrap{order:-1}.split .copy p{color:#46516A}
.list-clean{margin:0;padding:0;list-style:none}.list-clean li{padding:12px 0;border-bottom:1px solid rgba(89,126,247,.12)}.list-clean li:last-child{border-bottom:0}
.number-list{counter-reset:item;list-style:none;padding:0;margin:0;display:grid;gap:14px}.number-list li{position:relative;padding:18px 18px 18px 58px;background:#fff;border:1px solid var(--line);border-radius:16px}.number-list li::before{counter-increment:item;content:counter(item);position:absolute;left:16px;top:16px;width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:var(--soft);color:var(--primary);font-weight:900}
.path-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.path-box{padding:22px;background:#fff;border-radius:18px;border:1px solid var(--line)}
.notice{padding:22px 24px;border:1px solid var(--line);background:linear-gradient(135deg,#fff,#F5F8FF);border-radius:18px}.notice strong{color:var(--ink)}
.qa-list{display:grid;gap:14px}.qa-item{padding:20px 22px;background:#fff;border:1px solid var(--line);border-radius:16px}.qa-item h3{font-size:18px}.qa-item p{margin:0;color:#4A556D}
.article{background:#fff;border:1px solid var(--line);border-radius:18px;padding:32px;box-shadow:var(--shadow)}.article p{font-size:17px;line-height:1.9;color:#343C50}.article h2{margin-top:32px;font-size:27px}.article h3{margin-top:24px}
.toc{padding:22px;background:var(--soft);border-radius:16px}.toc a{display:block;padding:7px 0;color:var(--ink);font-weight:700}
.banner{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:30px;border-radius:18px;background:linear-gradient(135deg,#EEF2FF,#EAF7FF);border:1px solid var(--line)}.banner p{margin:6px 0 0;color:var(--muted)}
.slider{position:relative;height:360px;border-radius:18px;background:#101827;overflow:hidden;box-shadow:0 22px 50px rgba(16,24,39,.18)}
.slide{position:absolute;inset:0;opacity:0;visibility:hidden;transition:opacity .45s ease;display:grid;place-items:center}.slide.is-active{opacity:1;visibility:visible}.slide .media{height:100%;aspect-ratio:auto;border-radius:0;background:#101827}.slide .media>img{object-fit:contain}
.slider-arrow{position:absolute;top:50%;transform:translateY(-50%);z-index:5;width:42px;height:42px;border:1px solid rgba(255,255,255,.28);border-radius:50%;background:rgba(255,255,255,.12);color:#fff;font-size:24px}.slider-arrow.prev{left:16px}.slider-arrow.next{right:16px}
.slider-dots{position:absolute;left:50%;bottom:15px;transform:translateX(-50%);display:flex;gap:8px;z-index:5}.slider-dot{width:9px;height:9px;border:0;border-radius:50%;background:rgba(255,255,255,.4);padding:0}.slider-dot.is-active{background:#fff;transform:scale(1.18)}
.floating-tools{position:fixed;right:14px;top:50%;transform:translateY(-50%);z-index:6000;display:grid;gap:8px;width:58px}.floating-tools a,.floating-tools button{display:flex;align-items:center;justify-content:center;min-height:52px;padding:6px;border:1px solid var(--line);border-radius:14px;background:#fff;color:var(--primary);font-size:12px;font-weight:800;text-align:center;box-shadow:0 10px 24px rgba(89,126,247,.11)}.floating-tools .main-btn{height:auto;min-width:0;color:#fff;border:0;padding:8px 4px}.floating-tools button{width:100%}
.site-footer{background:#1F1F1F;color:#D7DCE8;padding:54px 0 22px}.footer-grid{display:grid;grid-template-columns:1.25fr 1fr 1fr 1fr;gap:28px}.footer-brand .site-logo{min-width:0;margin-bottom:14px}.footer-brand .site-logo img{height:40px;max-width:168px}.footer-brand .logo-fallback{background:#2A2A2A;color:#fff;border-color:#3A3A3A}.footer-brand p{margin:0;max-width:280px;color:#BFC6D4;font-size:14px}.site-footer h2{font-size:15px;color:#fff;margin:0 0 12px}.footer-links{display:grid;gap:7px}.footer-links a{color:#D7DCE8;font-size:14px}.footer-links a:hover{color:#fff}.footer-bottom{border-top:1px solid rgba(255,255,255,.11);margin-top:30px;padding-top:20px;display:flex;justify-content:space-between;gap:20px;font-size:13px;color:#B8C0CE}.footer-bottom p{margin:0;max-width:850px}
.mobile-bottom{display:none;position:fixed;left:0;right:0;bottom:0;z-index:8000;height:62px;background:#fff;border-top:1px solid var(--line);grid-template-columns:repeat(4,1fr);box-shadow:0 -8px 24px rgba(89,126,247,.10)}.mobile-bottom a{display:flex;align-items:center;justify-content:center;color:var(--muted);font-size:13px;font-weight:800}.mobile-bottom a.is-current{color:var(--primary);background:#F7F9FF}
.chip{display:inline-flex;padding:5px 10px;border-radius:999px;background:var(--soft);color:var(--primary);font-size:12px;font-weight:800}.mini-links{display:flex;flex-wrap:wrap;gap:10px}.mini-links a{padding:8px 12px;border-radius:10px;background:#fff;border:1px solid var(--line);color:var(--ink);font-weight:700;font-size:14px}
.compare{display:grid;grid-template-columns:1fr 1fr;gap:20px}.compare>div{padding:24px;background:#fff;border:1px solid var(--line);border-radius:18px}.quote-note{font-size:18px;line-height:1.8;color:var(--ink);padding:24px 28px;border-radius:18px;background:linear-gradient(135deg,#EDF2FF,#F8FBFF);border:1px solid var(--line)}
@media (min-width:1250px){.site-main{padding-right:68px}}
@media (max-width:1080px){.nav-core{gap:2px}.nav-core a{padding:7px 7px;font-size:14px}.header-actions .login-link{display:none}.grid-4{grid-template-columns:repeat(3,minmax(0,1fr))}.footer-grid{grid-template-columns:repeat(2,1fr)}}
@media (max-width:820px){.desktop-head,.channel-bar,.floating-tools{display:none}.mobile-head{display:flex}.site-main{padding-right:0;padding-bottom:82px}.container{width:min(100% - 28px,1200px)}.hero{padding:42px 0 18px}.hero-grid,.split,.grid-3,.path-grid{grid-template-columns:1fr}.split.reverse .media-wrap{order:0}.grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}.slider{height:280px}.section{padding:50px 0}.footer-grid{grid-template-columns:1fr 1fr}.mobile-bottom{display:grid}.footer-bottom{flex-direction:column}.banner{align-items:flex-start;flex-direction:column}.media.feature-media{height:230px}}
@media (max-width:520px){h1{font-size:31px}.lead{font-size:16px}.grid-2,.compare{grid-template-columns:1fr}.grid-4{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.topic-card{padding:17px;min-height:150px}.topic-card h3{font-size:16px}.topic-card p{font-size:13px}.slider{height:210px}.slider-arrow{width:36px;height:36px}.section{padding:44px 0}.article{padding:22px 18px}.article p{font-size:16px}.footer-grid{grid-template-columns:1fr}.footer-bottom{padding-bottom:64px}.media.card-media{height:160px}.media.feature-media{height:220px}.mobile-head{gap:6px}.mobile-menu-btn{width:40px;height:40px}.mobile-head .main-btn{min-width:84px;padding:0 12px}.mobile-head .site-logo img{max-width:126px}.mobile-head .logo-fallback{min-width:118px;padding:0 9px;font-size:14px}}

.media>.media.placeholder{position:absolute;inset:0;display:block;width:100%;height:100%;aspect-ratio:auto;border-radius:0;background:#ECF0FF}
.media>.media.placeholder::after{content:"";position:absolute;inset:22%;border:1px solid rgba(89,126,247,.18);border-radius:18px;background:linear-gradient(135deg,rgba(255,255,255,.75),rgba(255,255,255,.25))}