body { max-width: 900px; margin: 0 auto; padding: 16px; font: 16px/1.5 system-ui, sans-serif; color: #222; }
#tabs { display: flex; flex-wrap: wrap; gap: 4px; border-bottom: 1px solid #ccc; }
#tabs button { padding: 8px 12px; border: 0; background: none; font: inherit; cursor: pointer; }
#tabs [aria-selected="true"] { border-bottom: 2px solid #2563eb; color: #2563eb; }
table { border-collapse: collapse; margin: 6px 0 16px; }
caption { text-align: left; font-weight: 600; padding: 4px 0; }
td, th { border: 1px solid #ccc; padding: 3px 9px; text-align: center; }
svg { width: 100%; max-width: 460px; }
line { stroke: #2563eb; stroke-width: 2; }
line.removed { stroke: #d33; stroke-dasharray: 6 4; }
circle { fill: #e8f0fe; stroke: #2563eb; stroke-width: 2; }
text { text-anchor: middle; dominant-baseline: central; font-size: 14px; }
input { width: 260px; font: inherit; }
select, input, button { margin: 4px 4px 4px 0; }
section { padding-top: 12px; }
li { margin-bottom: 6px; }
math[display="block"] { margin: 6px 0; }
.equation { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin: 8px 0; }
.equation > span { font-size: 1.5rem; }
.crossed { background: #fde2e2; }