.learning-lesson{display:grid;gap:2.75rem}.learning-section{min-width:0}.learning-section-head{display:flex;flex-wrap:wrap;align-items:baseline;gap:.3rem .9rem;margin-bottom:1.1rem;padding-bottom:.5rem;border-bottom:2px solid var(--color-forest-900,#14382b)}.learning-section-number{font-size:.95rem;font-weight:800;font-variant-numeric:tabular-nums;color:var(--color-ink-muted,#566257)}.learning-section h2{margin:0;font-size:1.45rem;font-weight:800;letter-spacing:-.015em;line-height:1.2;color:var(--color-forest-950,#102b22);text-wrap:balance}.learning-section-role{margin-left:auto;font-size:.75rem;font-weight:800;letter-spacing:.07em;text-transform:uppercase;color:var(--color-sage-700,#356b4a)}.learning-section[data-role=example] .learning-section-role{color:var(--color-earth-700,#6a452b)}.learning-page-link{min-width:0}.learning-lab{display:grid;gap:1.5rem}.learning-lab-instructions{max-width:70ch;margin:0;line-height:1.65}.learning-activity-failure,.learning-balance,.learning-unavailable{--learning-ink:var(--color-forest-800,#245342);--learning-surface:var(--color-surface,#fffdf9);--learning-soft:var(--color-sage-100,#eef8ef);--learning-edge:var(--color-line,#cfc8bb);--learning-text:var(--color-ink,#1b1c19);--learning-muted:var(--color-ink-secondary,#39423c);color:var(--learning-text)}.learning-balance{padding:1.5rem;background:var(--learning-soft);border-radius:var(--radius-surface,1rem);min-width:0}.learning-balance ::selection{background:var(--learning-ink);color:var(--learning-surface)}.learning-balance-heading{display:flex;align-items:center;justify-content:space-between;gap:1rem}.learning-balance-heading h2{font-size:1.125rem;font-weight:750;margin:0;line-height:1.3}.learning-button{color:var(--learning-ink,#245342);background:var(--learning-surface,#fffdf9);border:1px solid var(--learning-edge,#cfc8bb);border-radius:999px;padding:.55rem .9rem;cursor:pointer;font:inherit;font-size:.875rem;font-weight:650;min-height:44px}.learning-button:hover{background:var(--color-sage-200,#d4ead8)}.learning-activity-failure button:focus-visible,.learning-balance :is(button,select):focus-visible{outline:3px solid var(--learning-ink,#245342);outline-offset:3px}.learning-scenario{margin-top:1.25rem;display:flex;gap:.75rem;align-items:center;font-size:.875rem;font-weight:650}.learning-scenario select{min-height:44px;max-width:100%;border:1px solid var(--learning-edge);border-radius:var(--radius-control,.75rem);color:var(--learning-text);background:var(--learning-surface);padding:.5rem .75rem;font:inherit}.learning-equation{font-family:KaTeX_Main,serif;font-size:clamp(1.5rem,4vw,2.5rem);font-variant-numeric:tabular-nums;margin:1.75rem 0 1.25rem;text-align:center;color:var(--learning-ink);overflow-wrap:anywhere}.learning-scale{max-width:42rem;margin:0 auto 1rem}.learning-pans{display:grid;grid-template-columns:1fr 1fr;gap:1.5rem}.learning-pan{min-width:0;display:flex;align-items:center;flex-direction:column}.learning-pan-label{color:var(--learning-muted);font-size:.75rem;font-weight:650}.learning-pan-tokens{display:flex;flex-wrap:wrap;gap:.5rem;align-items:end;justify-content:center;flex:1;min-height:5.5rem;padding:.75rem .25rem;width:100%;border-bottom:3px solid var(--learning-ink)}.learning-tokens{display:flex;flex-wrap:wrap;justify-content:center;gap:.25rem;max-width:10rem}.learning-token{display:grid;place-content:center;width:1.5rem;height:1.5rem;background:var(--learning-surface);border:1px solid var(--learning-edge);border-radius:.3rem;font-size:.75rem;font-weight:650}.learning-variable-tokens .learning-token{background:var(--learning-ink);border-color:var(--learning-ink);color:var(--learning-surface);font-family:KaTeX_Main,serif;font-size:1rem}.learning-token-group{width:auto;padding:0 .6rem;white-space:nowrap}.learning-pan-expression{font-size:.875rem;padding-top:.5rem;font-variant-numeric:tabular-nums}.learning-empty-pan{align-self:center;color:var(--learning-muted)}.learning-scale-frame{display:block;width:100%;max-height:4rem;color:var(--learning-ink)}.learning-operations{border:0;padding:0;min-width:0;margin:0}.learning-operations legend{font-size:.875rem;font-weight:650;margin-bottom:.75rem}.learning-operation-buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem}.learning-operation{border:1px solid var(--learning-edge);background:var(--learning-surface);color:var(--learning-ink);min-height:48px;padding:.5rem;border-radius:var(--radius-control,.75rem);font-size:1.25rem;font-weight:650;cursor:pointer;transition:background-color .16s ease-out,color .16s ease-out}.learning-operation:hover:not(:disabled){background:var(--learning-ink);color:var(--learning-surface)}.learning-operation:disabled{cursor:not-allowed;opacity:.45}.learning-hint,.learning-operation-limits{font-size:.8125rem;line-height:1.6;color:var(--learning-muted);margin:.75rem 0 0}.learning-balance-feedback{margin-top:1rem}.learning-transformation{margin:0 0 .5rem;text-align:center;font-variant-numeric:tabular-nums;overflow-wrap:anywhere;font-size:.9375rem}.learning-solved{color:var(--learning-ink);font-weight:750;margin:.75rem 0 0}.learning-balance-expanded{padding:clamp(1.25rem,3vw,2.5rem)}.learning-balance-expanded .learning-pan-tokens{min-height:8rem}.learning-unavailable{padding:1rem;border:1px solid var(--learning-edge);border-radius:var(--radius-control,.75rem)}.learning-unavailable p{margin:0;line-height:1.6}.learning-unavailable p+p{font-size:.875rem;margin-top:.4rem}.learning-activity-failure{display:grid;justify-items:start;gap:.75rem}.learning-loading{padding:1.5rem 0;font-size:.875rem}.learning-visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}@media (max-width:480px){.learning-balance{padding:1rem}.learning-balance-heading{gap:.5rem}.learning-balance-heading h2{font-size:1rem}.learning-pans{gap:1rem}.learning-token{width:1.25rem;height:1.25rem;font-size:.6875rem}.learning-token-group{width:auto}.learning-balance-expanded .learning-pan-tokens{min-height:6rem}}@media (prefers-reduced-motion:reduce){.learning-operation{transition:none}}