:root{--navy:#13294d;--blue:#265dd6;--muted:#62738e;--line:#e2e9f2}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Arial,sans-serif;color:#1c2b42;background:#f8faff;line-height:1.6}a{color:inherit;text-decoration:none}.resource-wrap{width:min(1160px,92%);margin:auto}.resource-header{background:white;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}.resource-nav{height:72px;display:flex;align-items:center;justify-content:space-between;gap:20px}.resource-logo{display:flex;align-items:center;gap:10px;font-size:1.03rem;color:var(--navy);font-weight:800}.resource-logo span{background:var(--blue);color:#fff;width:36px;height:36px;display:grid;place-items:center;border-radius:10px;font-size:.83rem}.resource-nav nav{display:flex;gap:25px;font-size:.9rem;font-weight:650}.resource-nav nav a:hover{color:var(--blue)}.resource-hero{background:linear-gradient(115deg,#122c60,#2456c6);color:white;padding:72px 0 76px}.resource-hero h1{font-size:clamp(2.1rem,4.3vw,3.75rem);letter-spacing:-.05em;max-width:900px;line-height:1.13;margin:12px 0 20px}.resource-hero p{max-width:760px;color:#e4ecff;margin:0;font-size:1.05rem}.resource-hero .resource-kicker{color:#acc9ff;font-size:.76rem}.resource-kicker{color:#3d73dc;letter-spacing:.14em;font-size:.74rem;font-weight:800;margin:0 0 8px;text-transform:uppercase}.resource-section{padding:55px 0 80px}.resource-section h2{font-size:clamp(1.45rem,2.5vw,2rem);line-height:1.3;margin:27px 0 12px;letter-spacing:-.025em}.resource-section>p,.resource-section article>p{color:#4f6078}.resource-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px;margin:25px 0}.resource-grid.grades{grid-template-columns:repeat(4,minmax(0,1fr))}.resource-card{position:relative;display:flex;flex-direction:column;gap:9px;border:1px solid var(--line);border-radius:13px;background:white;padding:23px;min-height:137px;box-shadow:0 5px 17px #15305b09;transition:transform .16s,box-shadow .16s}.resource-card:hover{transform:translateY(-3px);box-shadow:0 9px 22px #15305b16;border-color:#a6bff2}.resource-card strong{font-size:1.06rem;line-height:1.4;color:#173969}.resource-card span{font-size:.85rem;color:var(--muted);line-height:1.5}.resource-card b{margin-top:auto;color:var(--blue);font-weight:800}.resource-feature{background:linear-gradient(115deg,#edf3ff,#f9fbff);border:1px solid #c9dcff;border-radius:16px;padding:34px;margin-top:25px}.resource-feature>span{font-size:.72rem;font-weight:800;letter-spacing:.12em;color:#2c61cf}.resource-feature a,.resource-side a:not(.resource-ad-space),.resource-prev-next a{display:inline-block;border-radius:9px;padding:11px 16px;background:#275bd4;color:#fff;font-weight:750;margin-top:12px}.resource-feature p{max-width:720px}.resource-note{background:#edf4ff;border-left:3px solid #4371da;color:#435979!important;padding:18px 20px;border-radius:5px;margin:30px 0}.resource-main-layout{display:grid;grid-template-columns:minmax(0,1fr) 255px;gap:34px;align-items:start}.resource-side{background:white;border:1px solid var(--line);border-radius:14px;padding:24px;position:sticky;top:90px}.resource-side h3{margin:0 0 11px}.resource-side p{color:var(--muted);font-size:.9rem}.resource-metrics{display:flex;flex-wrap:wrap;gap:12px;margin:0 0 30px}.resource-metrics span{background:white;border:1px solid var(--line);padding:12px 16px;border-radius:9px;font-size:.83rem;color:#50627b}.resource-metrics strong{color:#1a48ae;font-size:1.2rem}.resource-strands{display:flex;flex-wrap:wrap;gap:9px;margin:20px 0 30px}.resource-strands span{background:#e8f0ff;color:#2653a3;font-size:.82rem;border-radius:20px;padding:7px 12px;font-weight:650}.resource-grid.weeks{grid-template-columns:repeat(2,minmax(0,1fr))}.resource-grid.weeks .resource-card{min-height:162px}.resource-breadcrumb>a{font-size:.88rem;color:var(--blue);font-weight:700}.resource-lesson-nav{display:flex;flex-wrap:wrap;gap:9px;margin:25px 0}.resource-lesson-nav a{border:1px solid #c9d8ef;background:#fff;border-radius:8px;padding:8px 12px;font-weight:650;font-size:.82rem;color:#264f9b}.resource-lesson,.resource-example,.resource-progress{background:#fff;border:1px solid var(--line);border-radius:13px;margin:19px 0;padding:24px;scroll-margin-top:100px}.resource-lesson-head{display:flex;justify-content:space-between;align-items:center;gap:12px}.resource-lesson-head>span{color:#2357b4;font-size:.76rem;font-weight:800;letter-spacing:.07em}.resource-lesson-head label{font-size:.82rem;color:#52677e;display:flex;gap:8px;align-items:center}.resource-lesson-head input{width:18px;height:18px;accent-color:#2059c7}.resource-lesson h2{font-size:1.15rem;line-height:1.45;margin:15px 0 19px}.resource-lesson-split{display:grid;grid-template-columns:1fr 1fr;gap:14px}.resource-lesson-split>div{padding:15px;border-radius:10px;background:#f1f5ff}.resource-lesson-split>div+div{background:#eefaf5}.resource-lesson-split strong{font-size:.77rem;color:#2d57a1}.resource-lesson-split>div+div strong{color:#227352}.resource-lesson-split p{font-size:.88rem;margin:8px 0 0;color:#324459}.resource-anchor{display:inline-block;margin-top:14px;font-size:.83rem;color:#2455bc}.resource-progress{background:#edf4ff}.resource-progress p,.resource-progress small{color:#5c708e;font-size:.84rem}.resource-progress-track{height:8px;background:#d9e5fa;border-radius:100px;overflow:hidden;margin:14px 0 5px}.resource-progress-track span{height:100%;width:0;background:#2a68df;display:block;transition:width .2s}.resource-example{background:#fff9e9;border-color:#efdfb3}.resource-example strong{color:#966518}.resource-example details{margin-top:15px}.resource-example summary{color:#1649a4;cursor:pointer;font-weight:750}.resource-prev-next{display:flex;justify-content:space-between;gap:14px}.resource-ad-space{min-height:0;margin:16px 0}.resource-footer{background:#102342;color:#dbe4f4;padding:48px 0 27px}.resource-footer nav{display:flex;flex-wrap:wrap;gap:20px;margin-bottom:25px}.resource-footer p{color:#b2c1d6}.resource-footer small{color:#9aacc5}@media(max-width:900px){.resource-main-layout{grid-template-columns:1fr}.resource-side{position:static}.resource-grid.grades{grid-template-columns:repeat(3,minmax(0,1fr))}}@media(max-width:620px){.resource-nav{height:auto;min-height:66px;flex-wrap:wrap;padding:12px 0}.resource-nav nav{gap:14px;font-size:.79rem}.resource-logo{font-size:.92rem}.resource-hero{padding:48px 0 55px}.resource-section{padding:32px 0 60px}.resource-grid.grades,.resource-grid.weeks,.resource-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.resource-card{padding:15px;min-height:123px}.resource-card strong{font-size:.92rem}.resource-card span{font-size:.77rem}.resource-lesson-split{grid-template-columns:1fr}.resource-lesson{padding:17px}.resource-metrics span{padding:10px}.resource-prev-next a{font-size:.79rem}.resource-side{padding:18px}}
/* Step-by-step worked mathematics examples */
.resource-solved-steps{counter-reset:steps;list-style:none;margin:20px 0;padding:0;display:grid;gap:10px}.resource-solved-steps li{border:1px solid #dfe8f5;border-radius:10px;background:#f6f9ff;padding:13px 16px;color:#213c64;font-size:.96rem;overflow-wrap:anywhere}.resource-solved-steps li b{color:#2458ba}.resource-final-answer{margin:20px 0 2px;padding:16px 18px;background:#eaf8f0;border:1px solid #b6e5c9;border-radius:10px;color:#155b39!important;font-size:1.05rem;font-weight:700;overflow-wrap:anywhere}.resource-lesson>p{font-size:1rem;line-height:1.85}.resource-example details{background:#fffdf7;padding:10px 0}