:root{--ink:#172033;--muted:#667085;--line:#e8ebf2;--soft:#f6f8fc;--brand:#5b5cf0;--brand2:#816bff;--good:#16a36a;--shadow:0 20px 60px rgba(27,35,63,.09)}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:#fff;line-height:1.55}a{color:inherit;text-decoration:none}.site-header{height:74px;display:flex;align-items:center;gap:28px;padding:0 max(24px,calc((100vw - 1180px)/2));border-bottom:1px solid var(--line);position:sticky;top:0;background:rgba(255,255,255,.96);backdrop-filter:blur(14px);z-index:30}.logo{display:flex;align-items:center;font-weight:900;font-size:20px;letter-spacing:-.5px;white-space:nowrap}.logo>span{display:grid;place-items:center;width:34px;height:34px;border-radius:11px;background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;margin-right:9px}.logo 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.topic-nav{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:-20px 0 38px}.topic-nav a{display:grid;gap:2px;border:1px solid var(--line);border-radius:16px;padding:15px;background:#fff}.topic-nav a.next{text-align:right}.topic-nav small{color:var(--muted);font-size:11px}.topic-nav b{font-size:14px}.related-subjects{margin:0 0 45px}.related-subjects h2{font-size:23px;letter-spacing:-.5px}.related-subjects>div{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.related-subjects a{display:flex;gap:8px;align-items:center;border:1px solid var(--line);border-radius:14px;padding:12px;font-size:13px}.related-subjects a span{width:28px;height:28px;border-radius:8px;background:#f0f1ff;display:grid;place-items:center;color:#4d4ed7;font-weight:900}.related-subjects a b{flex:1}@media(max-width:600px){.topic-nav{grid-template-columns:1fr;margin-top:-10px}.topic-nav a.next{text-align:left}.related-subjects>div{grid-template-columns:1fr 1fr}}
.grade-grid.compact{grid-template-columns:repeat(6,1fr)}.topic-chips{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0 28px}.topic-chips span{border:1px solid var(--line);background:var(--soft);border-radius:999px;padding:8px 12px;font-size:13px;color:#475467}@media(max-width:600px){.grade-grid.compact{grid-template-columns:repeat(4,1fr)}}
/* v1.1 SEO curriculum */
.page-stats{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}.page-stats span{display:flex;align-items:baseline;gap:5px;border:1px solid var(--line);border-radius:999px;padding:8px 12px;color:var(--muted);font-size:12px}.page-stats b{color:var(--ink);font-size:15px}.section-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:22px 0 38px}.section-card{display:grid;grid-template-columns:44px 1fr 24px;gap:13px;align-items:start;border:1px solid var(--line);border-radius:18px;padding:18px;background:#fff;transition:.2s}.section-card:hover{border-color:#cfd0ff;box-shadow:0 14px 35px rgba(49,49,101,.07);transform:translateY(-2px)}.section-num{width:40px;height:40px;border-radius:12px;background:#eff0ff;color:#4c4dce;display:grid;place-items:center;font-weight:900}.section-card div{display:grid;gap:5px}.section-card b{font-size:17px;letter-spacing:-.25px}.section-card p{margin:0;color:var(--muted);font-size:13px}.section-card small{color:#8b93a3;font-size:11px;line-height:1.35}.section-card i{font-style:normal;color:#a3a8b3}.intent-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:20px 0 40px}.intent-card{border:1px solid var(--line);border-radius:17px;padding:16px;display:grid;gap:12px;align-content:start;transition:.2s}.intent-card:hover{border-color:#cfd0ff;transform:translateY(-2px)}.intent-card>span{width:38px;height:38px;border-radius:12px;background:#f0f1ff;display:grid;place-items:center;color:#4d4ed7;font-weight:900}.intent-card div{display:grid;gap:5px}.intent-card small{color:var(--muted);font-size:11px;line-height:1.4}.related-grades{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:18px 0;margin:0 0 35px;display:flex;gap:16px;align-items:center;flex-wrap:wrap}.related-grades>b{font-size:13px}.related-grades>div{display:flex;flex-wrap:wrap;gap:7px}.related-grades a,.seo-links a{border:1px solid var(--line);border-radius:999px;padding:7px 10px;font-size:12px;color:#4d4ed7;background:#fff}.back-section{margin:-4px 0 28px;border:1px solid var(--line);border-radius:14px;padding:12px 14px;display:flex;gap:8px;align-items:center;font-size:13px;color:var(--muted)}.back-section a{font-weight:850;color:var(--brand)}.seo-copy{margin:0 0 55px;padding:26px;border-radius:22px;background:var(--soft);border:1px solid #edf0f5}.seo-copy h2{margin:0 0 8px;font-size:25px;letter-spacing:-.7px}.seo-copy p{margin:0;color:var(--muted)}.seo-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}.tool-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:22px}.tool-grid a{border:1px solid var(--line);border-radius:17px;padding:16px;display:flex;gap:12px;align-items:center;transition:.2s}.tool-grid a:hover{border-color:#cfd0ff;transform:translateY(-2px)}.tool-grid a>span{width:42px;height:42px;border-radius:12px;background:#f0f1ff;color:#4d4ed7;display:grid;place-items:center;font-weight:900}.tool-grid a>div{display:grid;gap:3px}.tool-grid small{color:var(--muted);font-size:11px}.topic-chips a{border:1px solid var(--line);background:var(--soft);border-radius:999px;padding:8px 12px;font-size:13px;color:#475467}.topic-chips a:hover{border-color:#cfd0ff;color:var(--brand)}
@media(max-width:900px){.intent-grid{grid-template-columns:repeat(2,1fr)}.tool-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:600px){.section-grid,.intent-grid,.tool-grid{grid-template-columns:1fr}.section-card{grid-template-columns:40px 1fr 18px}.related-grades{align-items:flex-start}.back-section{align-items:flex-start;display:grid}}