:root{--bg:#F6FAFC;--white:#fff;--pale:#EAF6FA;--light:#EDF4F8;--cyan:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--navy:#174B78;--heading:#183A56;--text:#31485D;--muted:#687D8E;--line:#DCE9F0;--footer:#123653;--font:Arial,"PingFang SC","Microsoft YaHei",sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:135px}body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);font-size:16px;line-height:1.8;overflow-wrap:break-word}a{color:var(--navy);text-underline-offset:3px}a:hover{color:var(--blue)}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--blue);outline-offset:4px}button{font:inherit;cursor:pointer}.container{width:min(1180px,calc(100% - 56px));margin-inline:auto}.reading{max-width:780px}.skip-link{position:absolute;z-index:100;top:-80px;left:16px;background:#fff;padding:8px 18px}.skip-link:focus{top:8px}.site-header{position:relative;z-index:30;background:#fff}.brand-bar{border-bottom:1px solid var(--line)}.brand-inner{height:72px;display:flex;align-items:center;gap:26px}.brand{display:flex;align-items:center;min-width:130px;max-width:230px;text-decoration:none}.brand img{max-height:38px;max-width:100%;height:auto;width:auto;object-fit:contain}.brand-word{font-size:22px;color:var(--navy);font-weight:800;white-space:nowrap}.brand-word small{display:block;font-size:9px;letter-spacing:2px;line-height:1.2}.brand-tag{font-size:13px;color:var(--muted);letter-spacing:1px}.entry-btn{margin-left:auto;display:inline-flex;align-items:center;justify-content:center;gap:10px;background:var(--navy);color:white;text-decoration:none;border-radius:8px;font-size:14px;font-weight:700;min-height:44px;padding:0 22px;white-space:nowrap}.entry-btn:hover{color:#fff;background:#1268a2}.desktop-nav{background:var(--footer)}.nav-inner{height:49px;display:flex;align-items:stretch;justify-content:space-between;gap:10px}.nav-inner a{padding:0 12px;display:flex;align-items:center;color:#dfedf6;text-decoration:none;font-size:14px;white-space:nowrap;border-bottom:3px solid transparent}.nav-inner a:hover,.nav-inner a[aria-current=page]{color:white;border-bottom-color:var(--cyan)}.menu-toggle{display:none;width:40px;height:40px;align-items:center;justify-content:center;flex-direction:column;gap:5px;border:0;background:transparent;border-radius:6px}.menu-toggle span{display:block;background:var(--navy);width:23px;height:2px}.drawer-overlay{position:fixed;inset:0;z-index:40;background:rgba(10,31,47,.5);visibility:hidden;pointer-events:none;opacity:0;transition:opacity .2s,visibility .2s}.site-drawer{position:fixed;inset:0 auto 0 0;z-index:41;width:min(86vw,344px);max-height:100dvh;overflow-y:auto;background:#fff;visibility:hidden;transform:translateX(-102%);transition:transform .24s,visibility .24s;padding:22px}.drawer-open .site-drawer{visibility:visible;transform:none}.drawer-open .drawer-overlay{visibility:visible;opacity:1;pointer-events:auto}.drawer-top{display:flex;align-items:center;justify-content:space-between;color:var(--heading);font-size:20px;border-bottom:1px solid var(--line);padding-bottom:14px}.drawer-close{background:var(--light);border:0;border-radius:8px;width:40px;height:40px;font-size:28px;line-height:1}.drawer-group{padding:10px 0 12px;border-bottom:1px solid var(--line)}.drawer-group p{color:var(--muted);font-size:12px;font-weight:700;letter-spacing:2px}.drawer-group a{display:block;padding:7px 6px;text-decoration:none;font-weight:700}.eyebrow{font-size:12px!important;letter-spacing:2.5px;color:var(--blue);font-weight:800;text-transform:uppercase;margin:0 0 12px!important}.section{margin-block:54px}.section-heading{margin-bottom:25px}.section-heading h2,.content h2{font-size:26px;color:var(--heading);line-height:1.4;margin:0 0 16px}.section-heading p{margin-top:0}.content h3{font-size:20px;line-height:1.45;color:var(--heading);margin:27px 0 12px}.content p{margin:0 0 17px}.content ul,.content ol{padding-left:24px}.content li{margin:8px 0}.page-intro{padding:42px 0 12px}.page-intro h1{font-size:35px;line-height:1.35;letter-spacing:-.5px;color:var(--heading);max-width:920px;margin:0 0 19px}.page-intro p{max-width:800px;margin:0;font-size:17px}.rule-line{border-top:1px solid var(--line);margin-top:28px}.hero{display:grid;grid-template-columns:56fr 44fr;gap:40px;align-items:center;padding:43px 0 20px}.hero h1{font-size:41px;line-height:1.31;color:var(--heading);margin:0 0 20px;max-width:650px}.hero p{font-size:16px;margin:0 0 15px;max-width:620px}.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:25px}.btn{display:inline-block;text-decoration:none;border-radius:8px;background:var(--navy);color:#fff;padding:10px 20px;font-weight:700;font-size:14px}.btn:hover{background:var(--blue);color:#fff}.btn-secondary{background:#e0f2f8;color:var(--navy)}.btn-secondary:hover{background:#cde9f5;color:var(--navy)}.media{margin:0;background:var(--pale);border:1px solid var(--line);border-radius:14px;display:flex;align-items:center;justify-content:center;min-width:0;overflow:hidden;padding:10px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media-placeholder{width:100%;height:100%;min-height:50px;display:grid;place-items:center;background:linear-gradient(135deg,#edf7fb,#deeff5);border-radius:7px}.media-placeholder span{width:55px;height:55px;opacity:.25;border:2px solid var(--navy);border-radius:12px;transform:rotate(-12deg)}.media--hero{height:clamp(250px,26vw,330px)}.media--feature{height:250px}.media--card{height:170px}.media--banner{height:220px}.media--mobile{height:350px;max-width:320px}.media--feature.is-wide,.media--banner.is-wide{height:200px}.media--mobile.is-tall{max-width:290px}.quickbar{background:#e8f3f8;border-block:1px solid var(--line);padding:12px 0}.quickbar-inner{display:flex;flex-wrap:wrap;gap:12px 32px}.quickbar-group{display:flex;gap:12px;align-items:center;flex-wrap:wrap;font-size:13px}.quickbar-group strong{color:var(--heading)}.quickbar-group a{color:var(--navy);text-decoration:none;border-bottom:1px solid #9fcddd}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.topic-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:21px;min-width:0;text-decoration:none;transition:border-color .15s,transform .15s}.topic-card:hover{border-color:var(--sky);transform:translateY(-2px)}.topic-card .index{color:var(--blue);font-size:12px;font-weight:800}.topic-card h3{font-size:19px;line-height:1.45;margin:9px 0;color:var(--heading)}.topic-card p{font-size:14px;line-height:1.75;color:var(--muted);margin:0}.editor-grid{display:grid;grid-template-columns:2fr 1fr;gap:18px}.feature-story,.small-story,.soft-panel{background:#fff;border:1px solid var(--line);border-radius:13px;padding:27px}.feature-story{background:#e6f3f9}.feature-story h3,.small-story h3{color:var(--heading);font-size:23px;line-height:1.4;margin:0 0 15px}.small-story h3{font-size:19px}.story-stack{display:grid;gap:18px}.story-link{font-weight:700;text-decoration:none;color:var(--blue)}.split-feature{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center}.split-feature.reverse .media{order:-1}.split-feature h2{color:var(--heading);font-size:27px;line-height:1.4;margin:0 0 18px}.text-block p{margin:0 0 15px}.simple-grid,.triple-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.simple-card{border-top:3px solid var(--cyan);padding:20px 0}.simple-card h3{color:var(--heading);margin:5px 0;font-size:19px}.simple-card p{font-size:15px;color:var(--muted);margin:0}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;counter-reset:step}.step{padding:20px;background:#fff;border:1px solid var(--line);border-radius:11px}.step:before{counter-increment:step;content:counter(step,decimal-leading-zero);display:block;color:var(--blue);font-size:13px;font-weight:800;letter-spacing:1px;margin-bottom:10px}.step h3{font-size:17px;color:var(--heading);margin:0 0 9px}.step p{margin:0;font-size:14px;color:var(--muted)}.content-shell{display:grid;grid-template-columns:minmax(0,780px) minmax(205px,1fr);gap:44px;align-items:start}.content-section{margin:34px 0 42px}.content-section>h2{padding-bottom:12px;border-bottom:1px solid var(--line)}.side-note{background:var(--pale);border-radius:12px;padding:23px;position:sticky;top:18px}.side-note h2{font-size:19px;color:var(--heading);margin:0 0 12px}.side-note ul{padding-left:18px;margin:0}.side-note li{font-size:14px;margin-bottom:10px}.table-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--line);border-radius:10px;margin:20px 0 24px;background:#fff}.comparison{width:100%;border-collapse:collapse;min-width:540px;font-size:15px}.comparison th,.comparison td{border-bottom:1px solid var(--line);padding:13px 17px;text-align:left;vertical-align:top}.comparison th{background:#e8f4f8;color:var(--heading);font-weight:700}.comparison tr:last-child td{border-bottom:0}.timeline{display:grid;gap:15px;margin:20px 0}.timeline-item{display:grid;grid-template-columns:130px 1fr;gap:20px;padding:18px 0;border-bottom:1px solid var(--line)}.timeline-item strong{color:var(--blue)}.timeline-item p{margin:0}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.matrix-item{background:white;border:1px solid var(--line);border-radius:12px;padding:24px}.matrix-item h3{color:var(--heading);font-size:21px;margin:0 0 14px}.matrix-item p{font-size:15px}.gallery-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}.gallery-item{border:1px solid var(--line);background:white;border-radius:12px;padding:16px}.gallery-item h3{color:var(--heading);margin:18px 0 8px;font-size:19px}.gallery-item p{font-size:14px;margin:0 0 5px}.anchors{display:flex;flex-wrap:wrap;gap:10px;margin:22px 0}.anchors a{padding:7px 13px;text-decoration:none;background:#e5f2f8;border-radius:6px;font-size:14px;font-weight:700}.faq details{background:#fff;border:1px solid var(--line);border-radius:9px;margin-bottom:10px;padding:13px 18px}.faq summary{color:var(--heading);font-weight:700;cursor:pointer}.faq details p{margin:12px 0 2px;font-size:15px}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.related-link{display:flex;flex-direction:column;position:relative;gap:6px;padding:20px 42px 20px 20px;background:#fff;border:1px solid var(--line);border-radius:9px;text-decoration:none}.related-link strong{font-size:18px;color:var(--heading)}.related-link span:nth-child(2){font-size:14px;color:var(--muted)}.related-link span:last-child{position:absolute;top:19px;right:19px;color:var(--blue)}.notice{border-left:4px solid var(--cyan);background:var(--pale);padding:16px 21px;border-radius:0 8px 8px 0}.notice p{margin:0}.site-footer{background:var(--footer);color:#d6e7f1;padding:48px 0 22px;margin-top:70px;font-size:14px}.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:48px}.footer-grid h2{font-size:16px;color:#fff;margin:0 0 15px}.footer-brand{font-size:23px;font-weight:800;color:white;margin:0 0 10px}.footer-brand span{display:block;font-size:10px;letter-spacing:2px;color:#8ed4ea}.footer-grid a{color:#c4f1fb}.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:8px}.footer-grid .fine{color:#a9c8d9;font-size:13px}.footer-bottom{border-top:1px solid rgba(255,255,255,.16);display:flex;justify-content:space-between;gap:10px;padding-top:18px;margin-top:34px;color:#a9c8d9;font-size:12px}.back-top{position:fixed;right:20px;bottom:23px;background:var(--navy);color:#fff;border:0;border-radius:8px;width:42px;height:42px;visibility:hidden;opacity:0;pointer-events:none;z-index:20}.back-top.is-visible{opacity:1;visibility:visible;pointer-events:auto}.mobile-bottom{display:none}.divider{height:1px;background:var(--line);border:0;margin:38px 0}.muted{color:var(--muted)}@media(max-width:980px){.container{width:calc(100% - 44px)}.brand-inner{height:63px;gap:13px;justify-content:space-between}.menu-toggle{display:flex;flex:0 0 40px}.brand{max-width:180px;min-width:0;justify-content:center}.brand img{max-height:30px}.brand-word{font-size:19px}.brand-tag,.desktop-nav{display:none}.entry-btn{margin-left:0;padding:0 15px;min-height:40px;font-size:12px}.hero{gap:24px}.hero h1{font-size:36px}.topic-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.content-shell{grid-template-columns:minmax(0,1fr) 210px;gap:24px}}@media(max-width:760px){.hero,.split-feature,.editor-grid,.content-shell{grid-template-columns:1fr}.hero{padding-top:28px}.hero .media{order:-1}.split-feature.reverse .media{order:0}.topic-grid,.matrix,.simple-grid,.triple-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.steps{grid-template-columns:repeat(2,minmax(0,1fr))}.side-note{position:static}.footer-grid{grid-template-columns:1fr 1fr;gap:28px}.footer-grid>div:first-child{grid-column:1/-1}.related-grid{grid-template-columns:1fr 1fr}.page-intro{padding-top:27px}}@media(max-width:640px){html{scroll-padding-top:75px}.container{width:calc(100% - 32px)}body{font-size:15px;line-height:1.78}.hero h1{font-size:30px}.page-intro h1{font-size:27px}.page-intro p{font-size:15px}.section{margin-block:36px}.section-heading h2,.content h2,.split-feature h2{font-size:22px}.content h3{font-size:18px}.hero{gap:22px}.hero p{font-size:15px}.media--hero{height:200px}.media--feature{height:180px}.media--card{height:145px}.media--banner{height:150px}.media--mobile{height:290px;max-width:250px}.media--feature.is-wide{height:140px}.topic-grid,.simple-grid,.triple-grid,.matrix,.gallery-grid,.related-grid{grid-template-columns:1fr}.topic-card{padding:18px}.topic-card h3{font-size:17px}.feature-story,.small-story,.soft-panel,.matrix-item{padding:20px}.split-feature{gap:17px}.steps{gap:10px}.step{padding:15px}.timeline-item{grid-template-columns:1fr;gap:3px}.quickbar-inner{gap:10px}.quickbar-group{gap:10px}.footer-grid{grid-template-columns:1fr;gap:25px}.footer-grid>div:first-child{grid-column:auto}.footer-bottom{flex-direction:column}.site-footer{padding-bottom:108px}.mobile-bottom{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;bottom:0;left:0;right:0;z-index:25;background:#fff;box-shadow:0 -2px 14px rgba(15,61,85,.1);padding:7px 3px calc(7px + env(safe-area-inset-bottom));border-top:1px solid var(--line)}.mobile-bottom a{display:flex;flex-direction:column;align-items:center;justify-content:center;line-height:1.45;text-decoration:none;font-size:12px;min-height:42px;color:var(--muted)}.mobile-bottom a span{font-size:19px;line-height:1.1}.mobile-bottom a[aria-current=page]{color:var(--blue);font-weight:700}.back-top{bottom:91px;right:14px}.brand-inner{gap:7px}.brand{max-width:145px}.entry-btn{padding:0 10px;font-size:12px}.entry-btn span{display:none}}@media(max-height:470px) and (max-width:640px){.mobile-bottom{position:static}.site-footer{padding-bottom:25px}.back-top{bottom:20px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}
