:root{color-scheme:light;--ink:#18202a;--muted:#5e6875;--soft:#f5f7fb;--line:#d9e0ea;--blue:#1f6feb;--green:#11875d;--orange:#b85c00;--red:#c3342f;--violet:#6741d9;--teal:#0f766e;--card:#fff}*{box-sizing:border-box}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:#fff;line-height:1.55}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}.topbar{border-bottom:1px solid var(--line);background:rgba(255,255,255,0.94);position:sticky;top:0;z-index:10}.nav{max-width:1160px;margin:0 auto;padding:12px 20px;display:flex;align-items:center;justify-content:space-between;gap:16px}.brand{color:var(--ink);font-weight:750;letter-spacing:0}.navlinks{display:flex;gap:10px;flex-wrap:wrap;justify-content:flex-end}.navlinks a{color:var(--muted);font-size:14px}.navlinks a.active{color:var(--ink);font-weight:700}.page{max-width:1160px;margin:0 auto;padding:24px 20px 56px}.eyebrow{color:var(--teal);font-size:13px;font-weight:800;text-transform:uppercase;letter-spacing:.08em;margin-bottom:8px}h1{font-size:clamp(34px,5vw,62px);line-height:1.02;margin:0 0 16px;letter-spacing:0}h2{font-size:26px;line-height:1.15;margin:0 0 14px;letter-spacing:0}h3{font-size:18px;margin:0 0 8px;letter-spacing:0}p{margin:0 0 14px}ul,ol{margin-top:8px}li{margin:6px 0}.lead{color:var(--muted);font-size:18px;max-width:74ch}.section{border-top:1px solid var(--line);padding-top:28px;margin-top:28px}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.two-col{display:grid;grid-template-columns:minmax(0,1fr) minmax(320px,0.9fr);gap:22px;align-items:start}.card{border:1px solid var(--line);border-radius:8px;background:var(--card);padding:18px}a.card{display:block;color:var(--ink)}.card p{color:var(--muted)}.card .num{width:32px;height:32px;border-radius:50%;display:inline-grid;place-items:center;color:#fff;background:var(--teal);font-weight:800;margin-bottom:12px}.formula{background:#f8fbff;color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:18px;font-size:17px;overflow-x:auto;margin:14px 0}.formula mjx-container{margin:6px 0!important}.note{border-left:4px solid var(--teal);background:#eefcf9;padding:14px 16px;border-radius:0 8px 8px 0;color:#134e4a;margin:14px 0}.warning{border-left-color:var(--orange);background:#fff6e8;color:#5f3700}.activity{border:1px solid #c9d8ff;border-left:5px solid var(--violet);background:#f7f5ff;border-radius:8px;padding:16px;margin:18px 0}.activity h3{color:#42259a}.activity p,.activity li{color:#3f3a55}.activity .prompt{font-weight:750;color:var(--ink)}.visual,.wide-visual{border:1px solid var(--line);border-radius:8px;background:linear-gradient(#fff,#f8fbff);padding:16px}.wide-visual{margin-top:14px}.compact-visual{max-width:760px;margin-left:auto;margin-right:auto}.plot{width:100%;aspect-ratio:4 / 3;min-height:260px;display:block}.plot-wide{width:100%;aspect-ratio:16 / 7;min-height:280px;display:block}.axis-label{fill:var(--muted);font-size:12px}.plot-title{fill:var(--ink);font-size:15px;font-weight:700}.caption{color:var(--muted);font-size:13px;margin-top:10px}.mini-flow{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:8px;margin-top:12px}.mini-flow span{border:1px solid var(--line);border-radius:8px;padding:10px;background:#fff;text-align:center;color:var(--muted);font-size:13px;min-height:48px;display:grid;place-items:center}.pill-row{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}.pill{border:1px solid var(--line);border-radius:999px;padding:6px 10px;color:var(--muted);font-size:13px;background:#fff}table{border-collapse:collapse;width:100%;margin:16px 0;font-size:14px}th,td{border:1px solid var(--line);padding:10px;text-align:left;vertical-align:top}th{background:var(--soft)}.codebox{background:#172033;color:#eef4ff;border-radius:8px;padding:14px 16px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;overflow-x:auto;margin:14px 0}.token-list{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0}.token{border:1px solid var(--line);background:#fff;border-radius:8px;padding:7px 10px;font-weight:700}.token.spam{border-color:#f1b2a0;background:#fff3ef;color:#9f341f}.token.ham{border-color:#a9ded4;background:#ecfdf8;color:#0f766e}.pager{border-top:1px solid var(--line);margin-top:34px;padding-top:18px;display:flex;justify-content:space-between;gap:12px}.button{display:inline-flex;align-items:center;justify-content:center;min-height:40px;border-radius:8px;padding:8px 14px;border:1px solid var(--line);color:var(--ink);background:#fff;font-weight:700}.button.primary{background:var(--teal);border-color:var(--teal);color:#fff}@media(max-width:860px){.two-col,.grid{grid-template-columns:1fr}.nav{align-items:flex-start;flex-direction:column}.navlinks{justify-content:flex-start}.mini-flow{grid-template-columns:1fr 1fr}}@media print{.topbar,.pager{display:none}body{color:#000}.page{max-width:none;padding:18px}}