:root{--ink:#15231f;--muted:#63706b;--paper:#fbfaf6;--cream:#f1eddf;--line:#d9ded7;--green:#15735e;--deep:#0d3d34;--yellow:#f4c950;--serif:"Fraunces",Georgia,serif;--sans:"DM Sans",Arial,sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:var(--paper);font:16px/1.6 var(--sans)}a{color:inherit;text-decoration:none}.site-header{height:76px;border-bottom:1px solid var(--line);background:rgba(251,250,246,.94);position:sticky;top:0;z-index:5;backdrop-filter:blur(12px)}.nav-shell{max-width:1200px;height:100%;display:flex;align-items:center;justify-content:space-between;margin:auto;padding:0 28px}.brand{font-weight:700;font-size:1.08rem;letter-spacing:-.03em}.brand span{display:inline-grid;place-items:center;width:27px;height:27px;border-radius:8px;margin-right:6px;background:var(--green);color:#fff}.main-nav{display:flex;gap:29px;font-size:.93rem;font-weight:600}.main-nav a{color:#43534d}.main-nav a:hover{color:var(--green)}.menu-button{display:none;border:0;background:transparent;font:inherit;font-weight:700;cursor:pointer;padding:10px 14px;border-radius:6px;background:var(--cream)}.hero{min-height:535px;text-align:center;padding:106px 25px 80px;position:relative;overflow:hidden;background:linear-gradient(121deg,#edf4e9 0%,#fbfaf6 48%,#f7edcf 100%)}.hero>*:not(.hero-orbit){position:relative}.hero h1,.page-hero h1,.chapter-header h1{font:700 clamp(3.2rem,8vw,6.3rem)/.98 var(--serif);letter-spacing:-.07em;margin:13px 0 8px}.eyebrow{text-transform:uppercase;letter-spacing:.16em;font-size:.7rem;font-weight:700;color:var(--green);margin:0}.hero-copy{font-size:1.18rem;font-weight:600;margin:0}.hero-intro{max-width:510px;margin:22px auto 29px;color:var(--muted)}.hero-orbit{position:absolute;border:1px solid rgba(21,115,94,.18);border-radius:50%}.orbit-one{width:540px;height:540px;top:-220px;left:-180px}.orbit-two{width:420px;height:420px;right:-150px;bottom:-260px}.button{display:inline-flex;gap:15px;align-items:center;padding:13px 20px;border-radius:7px;font-weight:700;font-size:.91rem;transition:transform .15s,background .15s}.button:hover{transform:translateY(-2px)}.button:active{transform:scale(0.98)}.button-primary{background:var(--green);color:#fff}.button-primary span{font-size:1.25rem;line-height:.8}.grades-section,.topics-section{max-width:1200px;margin:0 auto;padding:90px 28px}.section-heading h2,.info-strip h2,.resource-section h2,.contact-section h2{font:700 clamp(2rem,4vw,3.35rem)/1.08 var(--serif);letter-spacing:-.05em;margin:9px 0 35px}.grade-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.grade-card{min-height:164px;padding:22px;border:1px solid var(--line);border-radius:10px;background:#fff;display:flex;flex-direction:column;justify-content:space-between;transition:transform .2s,box-shadow .2s}.grade-card.featured{background:var(--deep);color:#fff;border-color:var(--deep)}.grade-card.featured:hover,.topic-card:hover{transform:translateY(-3px);box-shadow:0 13px 30px rgba(13,61,52,.13)}.card-number{font:600 2.4rem/1 var(--serif);color:var(--green)}.featured .card-number{color:var(--yellow)}.card-title{font-weight:700;font-size:1.08rem}.coming-soon{color:#8a9690;font-size:.77rem}.card-arrow{font-size:1.4rem;align-self:flex-end}.info-strip{background:var(--cream);padding:74px max(28px,calc((100vw - 1144px)/2));display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:end}.info-strip h2{margin-bottom:0}.info-strip>p{max-width:440px;color:#4f5c56}.resource-section{padding:100px max(28px,calc((100vw - 1144px)/2))}.resource-list{display:grid;grid-template-columns:repeat(3,1fr);gap:35px}.resource-list div{border-top:1px solid var(--line);padding-top:18px}.resource-list b{color:var(--green);font-size:.82rem}.resource-list h3{margin:15px 0 5px;font-family:var(--serif);font-size:1.35rem}.resource-list p{color:var(--muted);margin:0}.contact-section{background:var(--deep);color:#fff;text-align:center;padding:90px 25px}.contact-section .eyebrow{color:var(--yellow)}.contact-section h2{margin-bottom:25px}.button-light{background:var(--yellow);color:var(--ink)}.site-footer{background:#102c26;color:#d5e0d8;padding:38px max(28px,calc((100vw - 1144px)/2));display:flex;justify-content:space-between;align-items:end;font-size:.82rem}.site-footer p{margin:10px 0 0}.site-footer .brand span{background:var(--yellow);color:var(--ink)}
.page-hero{max-width:1200px;margin:auto;padding:86px 28px 67px;display:flex;justify-content:space-between;gap:35px;align-items:end;background:linear-gradient(to right,#f4f3e8,transparent)}.page-hero h1{font-size:clamp(3rem,6vw,5rem);max-width:720px}.page-hero>div>p:last-child{max-width:620px;color:var(--muted);margin-bottom:0}.progress-card{padding:23px 25px;background:var(--deep);color:#fff;border-radius:10px;min-width:190px;display:grid;gap:3px}.progress-card span{font-size:.75rem;color:#c9dfd5}.progress-card b{font:600 2rem var(--serif);color:var(--yellow)}.progress-card small{font-size:.76rem}.topics-section{padding-top:25px}.topic-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.topic-card{background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden;transition:transform .2s,box-shadow .2s}.topic-header{padding:22px 21px 17px;display:flex;gap:13px;align-items:baseline}.topic-header span{font-size:.73rem;color:var(--green);font-weight:700}.topic-header h3{font:600 1.34rem var(--serif);margin:0}.topic-card ul{list-style:none;padding:0 21px 12px;margin:0}.topic-card li{border-top:1px solid #e8ece7}.topic-card li a{padding:12px 0;display:flex;justify-content:space-between;font-size:.87rem;font-weight:600}.topic-card li a span{color:var(--green)}
.chapter-layout{max-width:1080px;margin:auto;padding:36px 28px 100px}.breadcrumbs{font-size:.8rem;color:var(--muted);display:flex;gap:9px}.breadcrumbs a:hover{color:var(--green)}.chapter-header{max-width:780px;padding:66px 0 52px;border-bottom:1px solid var(--line)}.chapter-header h1{font-size:clamp(3rem,6vw,5.2rem)}.chapter-header>p:last-child{color:var(--muted);font-size:1.08rem;max-width:670px;margin:21px 0 0}.lesson-content{display:grid;grid-template-columns:175px minmax(0,680px);gap:68px;padding-top:47px}.lesson-nav{position:sticky;top:105px;height:max-content;border-left:2px solid #d5dfd8;padding-left:16px;font-size:.82rem;display:grid;gap:10px}.lesson-nav p{font-weight:700;margin:0 0 3px}.lesson-nav a{color:var(--muted);padding:4px 8px;border-radius:4px;transition:all 0.15s ease}.lesson-nav a:hover,.lesson-nav a.active{color:var(--green);font-weight:700;background:rgba(21,115,94,0.08)}.content-section{margin-bottom:56px}.content-section h2{font:600 2rem/1.15 var(--serif);letter-spacing:-.04em;margin:0 0 18px}.content-section>p{color:#4f5b56}.objective-list{list-style:none;margin:0;padding:0;display:grid;gap:12px}.objective-list li{padding:13px 16px 13px 44px;border-radius:7px;background:#f0f5f1;position:relative}.objective-list li:before{content:"✓";position:absolute;left:17px;color:var(--green);font-weight:700}.math-callout{border-left:4px solid var(--yellow);background:#fffae9;padding:18px 20px;margin-top:25px}.math-callout span,.example-label{font-weight:700;color:var(--green);font-size:.78rem;text-transform:uppercase;letter-spacing:.08em}.math-callout p{margin:4px 0 0}.example{padding:24px;margin-top:15px;border:1px solid var(--line);border-radius:8px}.example h3{font:600 1.2rem var(--serif);margin:9px 0 12px}.example ol{margin:0;padding-left:22px;color:#4f5b56}.example li+li{margin-top:5px}.illustration{background:#d9eee4;border-radius:10px;padding:27px;display:flex;justify-content:space-between;align-items:center;gap:20px}.illustration h2{margin:7px 0}.balance-art{width:170px;height:120px;display:flex;align-items:center;justify-content:space-between;position:relative}.balance-art:after{content:"";height:7px;background:var(--deep);width:170px;position:absolute;bottom:24px;border-radius:8px}.balance-art i{height:70px;width:4px;background:var(--deep);position:absolute;bottom:25px;left:83px}.balance-art span{display:grid;place-items:center;width:53px;height:53px;border-radius:50%;background:#fff;font:700 1.4rem var(--serif);z-index:1}.video-wrap{aspect-ratio:16/9;background:var(--ink);border-radius:8px;overflow:hidden}.video-wrap iframe{width:100%;height:100%;border:0}.practice-list{display:grid;gap:9px}.practice-list details{border:1px solid var(--line);border-radius:7px;padding:0 18px}.practice-list summary{padding:16px 2px;cursor:pointer;font-weight:600}.practice-list summary span{display:block;color:var(--green);text-transform:uppercase;font-size:.68rem;letter-spacing:.1em}.practice-list details p{color:var(--muted);font-size:.9rem;margin:0 0 16px}.summary-box{background:var(--deep);color:#fff;border-radius:10px;padding:37px}.summary-box .eyebrow{color:var(--yellow)}.summary-box h2{margin:8px 0}.summary-box p{color:#d8e6df}.summary-box .button{margin-top:12px}

.nav-pagination-bar{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin-top:40px;padding:18px 24px;background:#ffffff;border:1px solid var(--line);border-radius:12px;box-shadow:0 4px 12px rgba(0,0,0,0.03)}
.button-outline{display:inline-flex;gap:8px;align-items:center;padding:10px 18px;border-radius:7px;font-weight:600;font-size:.9rem;background:var(--paper);color:var(--ink);border:1px solid var(--line);transition:transform .15s,background .15s,border-color .15s}
.button-outline:hover{transform:translateY(-2px);background:#ffffff;border-color:var(--green);color:var(--green)}

@media(max-width:1024px){.grade-grid,.topic-grid{grid-template-columns:1fr 1fr}}
@media(max-width:760px){.nav-shell{padding:0 20px}.menu-button{display:block}.main-nav{display:none;position:absolute;top:76px;left:0;right:0;padding:20px;background:var(--paper);border-bottom:1px solid var(--line);flex-direction:column;gap:16px;z-index:99}.main-nav.is-open{display:flex}.hero{min-height:450px;padding:80px 20px 60px}.grade-grid,.topic-grid{grid-template-columns:1fr 1fr}.info-strip{grid-template-columns:1fr;gap:12px}.resource-list{grid-template-columns:1fr;gap:23px}.site-footer{align-items:start;flex-direction:column}.page-hero{padding-top:40px;display:block}.progress-card{margin-top:25px;width:max-content}.lesson-content{grid-template-columns:1fr;gap:10px}.lesson-nav{position:static;display:flex;flex-wrap:wrap;border-left:0;border-bottom:1px solid var(--line);padding:0 0 14px;margin-bottom:24px}.lesson-nav p{width:100%}.chapter-header{padding:36px 0 28px}.illustration{display:block}.balance-art{margin:22px auto 0}.nav-pagination-bar{flex-direction:column;align-items:stretch;text-align:center}.nav-pagination-bar>div{text-align:center !important}}
@media(max-width:480px){.grade-grid,.topic-grid{grid-template-columns:1fr}.hero h1{font-size:2.8rem}.grades-section,.topics-section,.chapter-layout{padding-left:16px;padding-right:16px}.summary-box{padding:24px 18px}}