*,*::before,*::after{box-sizing:border-box}
:root{--bg:#F5F7F8;--surface:#fff;--soft:#EDEFF1;--blue:#E8EEF2;--warm:#F3E9DF;--navy:#183247;--navy2:#102536;--slate:#496779;--teal:#3F746F;--copper:#B9653B;--title:#1E2A32;--text:#38454D;--muted:#65727A;--hint:#758189;--border:#D6DDE1;--footer:#132A3A;--footerText:#F3F6F7}
html{background:var(--bg);scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;font-size:16px;line-height:1.82}
img{display:block;max-width:100%;height:auto;object-fit:contain}
a{color:var(--navy);text-underline-offset:3px;text-decoration-thickness:1px}a:hover{color:var(--copper);text-decoration-thickness:2px}
a:focus-visible,button:focus-visible{outline:3px solid rgba(185,101,59,.42);outline-offset:3px}button{font:inherit}
.skip-link{position:absolute;top:-80px;left:16px;z-index:100;background:#fff;padding:10px 14px}.skip-link:focus{top:10px}
h1,h2,h3{color:var(--title);margin:0 0 .65em;line-height:1.35}h1{font-size:36px;line-height:1.25}h2{font-size:26px}h3{font-size:20px}
p{margin:0 0 1.2em}ul,ol{padding-left:1.35em}main{min-height:60vh}
.container{width:100%;max-width:1200px;margin:0 auto;padding-left:34px;padding-right:34px}.content-width{max-width:1040px}.article-width{max-width:780px}.narrow-width{max-width:700px}
.section{padding-top:62px;padding-bottom:62px}.eyebrow{font-size:14px;font-weight:700;letter-spacing:.06em;color:var(--copper);margin-bottom:8px}.muted,.note{color:var(--muted)}.note{font-size:14px;line-height:1.65}
.breadcrumb{font-size:14px;color:var(--muted);margin-bottom:16px}.breadcrumb a{color:var(--slate)}.page-head{padding:42px 0 30px}.page-head .lead{max-width:780px;font-size:17px;color:var(--slate);margin-bottom:0}
.content-image{margin:24px 0;border:1px solid var(--border);border-radius:10px}.image-regular{max-width:460px;max-height:280px}.image-focus{max-width:520px;max-height:310px}.image-device{max-width:250px;max-height:390px}.image-opening{max-width:390px;max-height:280px}
.text-link-row{display:flex;flex-wrap:wrap;gap:10px 20px;margin-top:22px}.text-link-row a{font-weight:600}
.site-header{background:#fff;border-bottom:1px solid var(--border);position:relative;z-index:20}.header-inner{max-width:1200px;min-height:70px;margin:auto;padding:0 34px;display:flex;align-items:center;gap:24px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;min-width:0;margin-right:auto}.brand-logo{height:32px;width:auto;max-width:170px}.brand-copy{display:flex;flex-direction:column;line-height:1.15}.brand-copy strong{font-size:16px;color:var(--navy)}.brand-copy small{font-size:10px;color:var(--muted);letter-spacing:.04em}
.desktop-nav{display:flex;align-items:center;gap:18px;min-width:0}.desktop-nav a,.path-link{font-size:15px;text-decoration:none;white-space:nowrap}.desktop-nav .is-active,.path-link.is-active{color:var(--copper);font-weight:700}
.header-actions{display:flex;align-items:center;gap:10px}.menu-toggle,.menu-close{min-height:44px;border:1px solid var(--border);background:#fff;color:var(--navy);border-radius:8px;padding:0 14px;cursor:pointer}
.category-panel{background:var(--bg);border-bottom:1px solid var(--border)}.category-inner{max-width:1200px;margin:auto;padding:24px 34px 22px}.menu-close{float:right}.category-groups{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:34px;clear:both}.category-groups>*{min-width:0}.category-groups h2{font-size:17px;margin-bottom:10px}.category-groups a{display:block;padding:7px 0;text-decoration:none}.category-groups a span{display:block;font-size:13px;color:var(--muted)}
.service-strip{border-top:1px solid var(--border);margin-top:18px;padding-top:14px;display:flex;flex-wrap:wrap;gap:8px 18px}.service-strip a{font-size:14px}
.opening{display:grid;grid-template-columns:minmax(0,1fr) minmax(280px,390px);gap:42px;align-items:center}.opening>*{min-width:0}.opening .lead{font-size:17px;max-width:680px}
.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.button{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:9px 16px;border-radius:8px;text-decoration:none;border:1px solid var(--navy);font-size:15px;font-weight:700}.button.primary{background:var(--navy);color:#fff}.button.secondary{background:#fff}
.reading-line{border-top:1px solid var(--border);border-bottom:1px solid var(--border)}.line-items{display:grid;grid-template-columns:repeat(5,minmax(0,1fr))}.line-item{min-width:0;padding:22px 18px;border-right:1px solid var(--border)}.line-item:last-child{border-right:0}.line-item b{display:block;color:var(--copper);margin-bottom:7px}
.two-col{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:42px;align-items:start}.two-col>*{min-width:0}.asym{display:grid;grid-template-columns:minmax(220px,.68fr) minmax(0,1.45fr);gap:44px}.asym>*{min-width:0}
.trajectory{border-left:2px solid var(--border);padding-left:22px}.trajectory span{display:block;padding:9px 0;color:var(--navy);font-weight:700}.analysis-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.analysis-list>*{min-width:0;border-top:3px solid var(--copper);padding-top:12px}
.dark-band{background:var(--navy);color:#eef4f6;border-radius:14px;padding:26px}.dark-band h2,.dark-band h3,.dark-band a{color:#fff}.dark-band .two-col{align-items:center}
.steps{counter-reset:s;display:grid}.steps>div{position:relative;padding:16px 0 16px 58px;border-bottom:1px solid var(--border)}.steps>div:before{counter-increment:s;content:counter(s,decimal-leading-zero);position:absolute;left:0;color:var(--copper);font-weight:800}
.case-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:26px}.case-grid>*{min-width:0}.case-lead{grid-row:span 2;background:var(--blue);padding:24px;border-radius:12px}.case-small{border-top:1px solid var(--border);padding-top:16px}
.topic-terms{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px 24px}.topic-terms>*{min-width:0}.continue-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(180px,230px);gap:40px}.continue-grid>*{min-width:0}
.prose{max-width:780px}.prose h2{margin-top:1.7em}.prose h3{margin-top:1.35em}.index-rail{display:flex;flex-wrap:wrap;gap:8px 16px;border-bottom:1px solid var(--border);padding-bottom:16px;margin-bottom:28px}.chapter{padding:28px 0;border-top:1px solid var(--border)}.chapter:first-child{border-top:0}
.timeline{border-left:2px solid var(--border);padding-left:26px}.timeline .stage{position:relative;margin-bottom:30px}.timeline .stage:before{content:"";position:absolute;width:10px;height:10px;border-radius:50%;background:var(--copper);left:-32px;top:.65em}
.dialogue-block{padding:24px 0;border-bottom:1px solid var(--border)}.dialogue-levels{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.dialogue-levels>*{min-width:0}
.side-layout{display:grid;grid-template-columns:minmax(0,1fr) 190px;gap:36px}.side-layout>*{min-width:0}.side-note{border-left:3px solid var(--teal);padding-left:16px;color:var(--slate);font-size:14px}
.casebook article{padding:34px 0;border-top:1px solid var(--border)}.casebook article:first-child{border-top:0}.time-points{display:grid;gap:12px;border-left:2px solid var(--border);padding-left:20px}.columns article{margin-bottom:48px}.narrow-article{max-width:670px}
.collection-split{display:grid;grid-template-columns:.8fr 1.2fr;gap:34px}.collection-split>*{min-width:0}.text-index{border-top:1px solid var(--border)}.text-index a{display:grid;grid-template-columns:180px minmax(0,1fr);gap:18px;padding:14px 0;border-bottom:1px solid var(--border);text-decoration:none}.text-index a>*{min-width:0}
.path-stage{padding:28px 0;border-top:1px solid var(--border)}.path-stage .num{color:var(--copper);font-weight:800}.directory-group{padding:22px 0;border-top:1px solid var(--border)}.directory-links{display:flex;flex-wrap:wrap;gap:8px 18px}
.terms{max-width:820px}.terms section{padding:22px 0;border-top:1px solid var(--border)}.faq-list{max-width:820px}.faq-item{padding:26px 0;border-bottom:1px solid var(--border)}.faq-item h2{font-size:20px}
.site-footer{background:var(--footer);color:var(--footerText);padding:48px 0 74px}.footer-inner{max-width:1200px;margin:auto;padding:0 34px;display:grid;grid-template-columns:1.35fr repeat(3,minmax(0,1fr));gap:34px}.footer-inner>*{min-width:0}.footer-inner h2{font-size:17px;color:#fff}.footer-inner p,.footer-inner span{color:#d9e2e6}.footer-inner a{display:block;color:#f3f6f7;padding:4px 0}.mobile-bottom{display:none}
@media(max-width:1024px){.header-inner,.container,.category-inner,.footer-inner{padding-left:24px;padding-right:24px}.desktop-nav{gap:12px}.desktop-nav a{font-size:14px}.line-items{grid-template-columns:repeat(3,minmax(0,1fr))}.line-item:nth-child(3){border-right:0}.line-item:nth-child(n+4){border-top:1px solid var(--border)}}
@media(max-width:900px){.desktop-nav,.path-link{display:none}.header-inner{min-height:62px}.opening,.two-col,.asym,.continue-grid,.collection-split,.side-layout{grid-template-columns:minmax(0,1fr)}.footer-inner{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:767px){body{font-size:16px;line-height:1.8;padding-bottom:calc(58px + env(safe-area-inset-bottom))}h1{font-size:28px;line-height:1.35}h2{font-size:22px;line-height:1.4}h3{font-size:18px;line-height:1.5}.container{padding-left:16px;padding-right:16px}.section{padding-top:40px;padding-bottom:40px}.page-head{padding:30px 0 22px}.header-inner{padding:0 16px;min-height:60px}.brand-logo{height:27px}.brand-copy small{display:none}.brand-copy strong{font-size:15px}.header-actions{margin-left:auto}.category-inner{padding:16px}.category-groups{grid-template-columns:minmax(0,1fr);gap:18px}.service-strip{gap:6px 14px}
.opening,.two-col,.asym,.continue-grid,.collection-split,.side-layout,.case-grid{display:grid;grid-template-columns:minmax(0,1fr);grid-template-areas:none;gap:26px}.opening>*,.two-col>*,.asym>*,.continue-grid>*,.collection-split>*,.side-layout>*,.case-grid>*{grid-column:auto!important;grid-row:auto!important;grid-area:auto!important;min-width:0;width:auto}
.line-items,.analysis-list,.topic-terms,.dialogue-levels{grid-template-columns:minmax(0,1fr)}.line-item{border-right:0;border-top:1px solid var(--border);padding:16px 0}.line-item:first-child{border-top:0}.trajectory{border-left:0;border-top:2px solid var(--border);padding:12px 0 0;display:flex;flex-wrap:wrap;gap:6px 16px}.dark-band{padding:20px;border-radius:12px}
.image-device{max-width:190px;max-height:300px}.image-opening{max-width:100%;max-height:210px}.image-regular,.image-focus{max-width:100%;max-height:210px}.steps>div{padding-left:46px}.timeline{border-left:0;padding-left:0}.timeline .stage{border-top:1px solid var(--border);padding-top:18px}.timeline .stage:before{position:static;display:inline-block;margin-right:8px;vertical-align:middle}.case-lead{grid-row:auto}.text-index a{grid-template-columns:minmax(0,1fr);gap:4px}
.footer-inner{padding:0 16px;grid-template-columns:minmax(0,1fr);gap:26px}.site-footer{padding-bottom:92px}.mobile-bottom{position:fixed;left:0;right:0;bottom:0;z-index:30;min-height:58px;padding-bottom:env(safe-area-inset-bottom);background:#fff;border-top:1px solid var(--border);display:grid;grid-template-columns:repeat(5,minmax(0,1fr))}.mobile-bottom a{min-width:0;min-height:58px;display:flex;align-items:center;justify-content:center;font-size:12px;text-decoration:none;color:var(--navy)}}
@media(max-width:359px){.container,.header-inner,.category-inner,.footer-inner{padding-left:14px;padding-right:14px}.brand-copy strong{font-size:14px}}
@media(min-width:768px){.mobile-bottom{display:none!important}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}