:root{--ink:#14363c;--navy:#102f35;--muted:#5c6f72;--green:#8bc53f;--lime:#adf20a;--paper:#f7f9f6;--line:#dce5df;--soft:#edf3ec;--white:#fff;font-family:Arial,'Helvetica Neue',-apple-system,BlinkMacSystemFont,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--ink);background:var(--paper);font-synthesis:none}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:105px}body{margin:0}button,input{font:inherit;color:inherit}button,a{touch-action:manipulation;-webkit-tap-highlight-color:transparent}button{cursor:pointer}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,.table-scroll:focus-visible{outline:3px solid #608829;outline-offset:4px}button{border:0;background:none}a{text-decoration:none}::selection{background:var(--lime);color:var(--ink)}[hidden]{display:none!important}.wrap{width:min(1240px,calc(100% - 96px));margin-inline:auto}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip{position:fixed;top:-90px;left:20px;padding:15px;background:var(--lime);z-index:100}.skip:focus{top:10px}.site-header{background:rgba(255,255,255,.97);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:30}.header-inner{width:min(1344px,calc(100% - 64px));height:86px;margin:auto;display:flex;align-items:center;gap:23px}.brand{padding:5px 9px;border-radius:5px;display:flex;align-items:center;transition:background .2s}.brand img{width:73px;height:auto}.brand:hover{background:#e9f3ff;outline:1px solid 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span:last-child{font-size:20px;line-height:14px}.ask:hover,.email-button:hover{background:#bbff1d}.hero{background:var(--ink);color:white;overflow:hidden}.hero-inner{display:grid;grid-template-columns:1.6fr 1fr;gap:95px;padding-top:60px;padding-bottom:55px}.eyebrow{font-size:10px;font-weight:700;letter-spacing:.14em;line-height:1.7;text-transform:uppercase}.hero .eyebrow{display:flex;align-items:center;gap:10px;color:#c8d8d5}.live-dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--lime)}h1{font-size:clamp(52px,6.4vw,92px);letter-spacing:-.065em;line-height:.99;margin:27px 0 23px;font-weight:900}em{font-style:normal;color:var(--lime)}.hero-desc{font-size:16px;line-height:1.75;max-width:490px;color:#d8e3df;margin:0}.hero-side{border-left:1px solid 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var(--line)}.search-box{display:flex;align-items:center;gap:16px;background:white;border:1px solid #c8d6cd;border-radius:6px;padding:0 23px;height:66px;box-shadow:0 5px 15px #14363c04}.search-box:focus-within{border-color:var(--ink);box-shadow:0 0 0 2px #8bc53f55}.search-box input{background:transparent;border:0;outline:0!important;font-size:17px;min-width:0;flex:1;height:100%;width:100%}.search-box input::placeholder{color:#7b8a85}.search-box input::-webkit-search-cancel-button{display:none}.search-box svg{flex:none}.search-hint{font-size:9px;letter-spacing:.14em;color:var(--muted);border-left:1px solid var(--line);padding-left:24px}.search-box button{font-size:28px;width:34px;height:38px;line-height:1}.popular{display:flex;align-items:center;gap:10px;margin-top:16px;flex-wrap:wrap}.popular>span{font-size:9px;letter-spacing:.12em;font-weight:bold;margin-right:7px;color:var(--muted)}.popular button{padding:7px 11px;border:1px solid #d3dfd5;border-radius:4px;background:#f9fcf7;font-size:11px}.popular button:hover{border-color:var(--ink);background:white}.intro-note{display:flex;gap:13px;align-items:flex-start;padding-top:26px;padding-bottom:27px;border-bottom:1px solid var(--line)}.intro-note p{margin:0;font-size:12px;line-height:1.9;color:var(--muted)}.note-mark{flex:none;border:1px solid #a6b8af;border-radius:50%;width:17px;height:17px;text-align:center;font-size:11px;font-family:Georgia,serif;line-height:16px;margin-top:3px}.faq-layout{display:grid;grid-template-columns:249px minmax(0,1fr);gap:55px;padding-top:42px;padding-bottom:85px;align-items:start}.sidebar{position:sticky;top:116px}.sidebar-heading{font-size:10px;letter-spacing:.13em;font-weight:bold;margin-bottom:16px}.chapter-button{display:grid;grid-template-columns:25px 1fr auto;width:100%;align-items:center;gap:7px;text-align:left;padding:13px 11px;border-radius:5px;font-size:12px;line-height:1.6;margin-bottom:3px;transition:background 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@media(min-width:1350px){h1{font-size:92px}}@media(max-width:1100px){.wrap{width:calc(100% - 56px)}.hero-inner{gap:50px}.header-inner{gap:17px;width:calc(100% - 40px)}.header-actions{gap:15px}.header-label{font-size:9px}.faq-layout{gap:28px;grid-template-columns:220px minmax(0,1fr)}.answer{padding-left:23px}.hero-side{padding-left:30px}.contact-inner{gap:45px}.stats{gap:43px}.chapter-heading h2{font-size:19px}}
@media(max-width:800px){html{scroll-padding-top:145px}.header-inner{height:auto;min-height:78px;flex-wrap:wrap;padding:11px 0;gap:10px}.header-divider,.header-label{display:none}.header-actions{gap:10px}.brand{padding:2px}.brand img{width:65px}.languages button{padding:9px 8px;font-size:11px}.ask{padding:13px;font-size:9px;gap:8px}.hero-inner{grid-template-columns:1fr;gap:32px;padding-top:40px;padding-bottom:37px}.hero-side{border-left:0;border-top:1px solid #3b565a;padding:25px 0 0;display:grid;grid-template-columns:1fr 1fr;column-gap:25px}.hero-side-top{display:none}.stats{margin:0;gap:35px;grid-row:span 2}.stats strong{font-size:42px}.stats span{font-size:8px}.hero-side>p{font-size:11px;margin:0 0 10px}.hero-link{font-size:9px;padding-top:12px}.hero-desc{font-size:15px;max-width:550px}h1{font-size:66px;margin:23px 0 20px}.faq-layout{grid-template-columns:1fr;padding-top:28px;gap:24px;padding-bottom:48px}.sidebar{position:static}.sidebar-heading{margin-bottom:12px}#chapter-nav{display:flex;gap:7px;overflow-x:auto;padding-bottom:8px;scrollbar-width:thin}.chapter-button{flex-shrink:0;width:auto;grid-template-columns:auto 1fr auto;gap:8px;border:1px solid var(--line);white-space:nowrap;margin:0;padding:10px 13px;font-size:11px}.sidebar-resource{display:none}.search-section{padding:23px 0 19px}.search-box{height:60px;padding:0 17px;gap:12px}.search-box input{font-size:15px}.search-hint{display:none}.intro-note{padding-block:20px}.intro-note p{font-size:11px;line-height:1.9}.results-toolbar{margin-bottom:25px}.answer{font-size:14px;line-height:1.95}.contact-inner{grid-template-columns:1fr;gap:25px;padding-block:38px}.contact-inner h2{font-size:36px}.contact-details{gap:13px}.email-button{max-width:360px}.footer{flex-wrap:wrap;gap:8px 18px;padding-block:20px}.footer>span:first-child{width:100%}.footer a{margin-left:auto}.faq-item{scroll-margin-top:110px}}
@media(max-width:480px){.wrap{width:calc(100% - 32px)}.header-inner{width:calc(100% - 24px)}.brand img{width:53px}.ask{display:none}.header-actions{margin-left:auto}.languages{padding:3px}.languages button{padding:9px 8px;font-size:11px}h1{font-size:56px}.hero-inner{padding-top:34px}.hero .eyebrow{font-size:9px;letter-spacing:.1em}.hero-desc{font-size:14px}.stats{gap:25px}.stats strong{font-size:38px}.hero-side{gap:22px}.hero-side>p{font-size:10px}.hero-link{font-size:8px;letter-spacing:.07em}.search-box{height:56px}.search-box input{font-size:14px}.popular{gap:7px}.popular>span{font-size:8px;width:100%;margin-bottom:1px}.popular button{font-size:10px;padding:7px 9px}.results-toolbar{align-items:flex-start}.view-actions{gap:12px;margin-top:8px}.view-actions button{font-size:8px}.results-toolbar p{font-size:13px}.chapter-heading{gap:10px}.chapter-heading h2{font-size:17px;line-height:1.5}.chapter-heading .question-count{font-size:9px}.chapter-heading>span{width:27px;height:27px;font-size:10px}.faq-item summary{padding:17px 15px;gap:9px;font-size:14px}.q-num{min-width:19px;font-size:10px}.plus{width:21px;height:21px}.plus:before,.plus:after{left:6px;top:9px}.answer{padding:0 17px 20px}.answer table{font-size:12px}.scenario-grid{grid-template-columns:1fr}.scenario-grid>div{padding:12px 14px}.scenario-grid b{margin-bottom:4px}.contact-inner h2{font-size:32px}.footer{font-size:8px}#toast{max-width:90vw;width:max-content}}

/* Match the instructor handbook's reading scale: 16px navigation, 18px answers. */
.hero-inner{grid-template-columns:minmax(0,1fr);gap:0}
.hero-desc{font-size:18px;line-height:1.85;max-width:820px}
.faq-layout{grid-template-columns:280px minmax(0,1fr);gap:50px}
.sidebar{max-height:calc(100vh - 140px);max-height:calc(100dvh - 140px);overflow-y:auto;scrollbar-width:thin;scrollbar-color:#bacbbd transparent;padding-right:8px}
.sidebar-heading{font-size:14px;line-height:1.6;margin-bottom:18px}
.chapter-button{grid-template-columns:25px minmax(0,1fr) auto;font-size:16px;line-height:1.6;padding:12px;gap:10px}
.chapter-button .chapter-no,.chapter-button .chapter-count{font-size:14px}
.sidebar-resource .eyebrow{font-size:13px;line-height:1.6}
.sidebar-resource a{font-size:16px;line-height:1.65;gap:12px}
.questions-area{min-width:0}
.chapter-heading h2{font-size:24px;line-height:1.5}
.chapter-heading>span{font-size:14px;width:35px;height:35px}
.chapter-heading .question-count{font-size:13px}
.faq-item summary{font-size:20px;line-height:1.65;padding:22px 23px}
.q-num{font-size:14px;line-height:33px;min-width:25px}
.plus{margin-top:5px}
.answer{font-size:18px;line-height:1.9;padding-bottom:26px}
.answer p{margin-bottom:18px}
.answer li{margin-bottom:13px}
.answer table{font-size:16px;line-height:1.85;min-width:560px}
html[lang^=zh] .answer table{font-size:17px}
.scenario-grid>div{font-size:17px;line-height:1.85}
.related-links a{font-size:16px;line-height:1.65;padding:12px 15px}
html[lang^=zh] .related-links a{font-size:17px}
.copy-link{font-size:13px;line-height:1.7;margin-top:24px}
.search-box input{font-size:18px}
.search-hint{font-size:12px}
.popular>span{font-size:12px}
.popular button{font-size:14px;padding:9px 13px}
.intro-note p{font-size:16px;line-height:1.9}
.results-toolbar .eyebrow{font-size:12px}
.results-toolbar p{font-size:17px;line-height:1.6}
.view-actions button{font-size:13px;line-height:1.6}
#empty p{font-size:18px}
#reset{font-size:15px}
.contact-inner>div>p:last-child{font-size:16px}
.email-button{font-size:15px}
.email-address{font-size:18px}
.contact-details p{font-size:15px!important}
@media(max-width:1100px){.faq-layout{grid-template-columns:240px minmax(0,1fr);gap:28px}.chapter-button{padding:11px 10px;gap:7px}.chapter-heading h2{font-size:22px}.view-actions{gap:14px;flex-wrap:wrap;justify-content:flex-end}.scenario-grid{grid-template-columns:1fr}}
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