.dist-lesson{max-width:1100px;margin:auto;color:#173950}.dist-lesson h1{text-align:center;font-size:clamp(18px,3vw,25px);margin:3px}.dist-controls,.dist-navigation,.dist-choices{display:flex;gap:5px;flex-wrap:wrap;justify-content:center;align-items:center;margin:5px 0}.dist-lesson label{display:inline-flex;align-items:center;gap:4px}.dist-lesson button,.dist-lesson input,.dist-lesson select{font:inherit}.dist-lesson button{padding:5px 9px;border:2px solid #075bb6;background:#e4f1ff;color:#064278;font-weight:800;cursor:pointer}.dist-lesson button.dist-correct{background:#006344;color:white;border-color:#004d35}.dist-lesson button.dist-wrong{background:#fff0bc;border-color:#9a5500}.dist-lesson button:disabled{opacity:.4;cursor:not-allowed}.dist-lesson button:focus-visible{outline:3px solid #a85c00;outline-offset:2px}.dist-board{background:white;border:2px solid #486d87;padding:6px}.dist-caption{background:#fff0b4;color:#693d00;border:1px solid #a96c00;margin:0;padding:5px;font-weight:800;text-align:center;min-height:2.5em}.dist-original,.dist-question-equation{text-align:center;font-size:clamp(21px,4vw,30px);font-weight:900;margin:3px;color:#075bb6;line-height:1.4}.dist-board svg{display:block;width:100%;max-height:min(270px,30dvh)}.dist-parts{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;font-size:clamp(19px,3vw,26px);font-weight:900}.dist-parts>div{padding:2px 6px;border:2px solid currentColor;color:#075bb6;background:#f0f7ff}.dist-parts>div:last-child{color:#b40d56;background:#fff0f7}.dist-sum{display:flex;align-items:center;justify-content:center;gap:8px;font-weight:900;font-size:clamp(22px,4vw,32px);margin:3px}.dist-sum [data-sum="0"]{color:#075bb6}.dist-sum [data-sum="1"]{color:#b40d56}.dist-sum [data-total]{color:#006344}.dist-split{display:flex!important;justify-content:center;font-size:13px;margin:4px}.dist-split input{max-width:45%;accent-color:#075bb6}.dist-question{background:#fff0bc;border:3px solid #a75e00;padding:7px;text-align:center}.dist-question strong{display:block}.dist-choices button{min-width:60px}.dist-question p{font-weight:800;color:#693d00;margin:4px}.dist-lesson form{display:flex;gap:7px;flex-wrap:wrap;align-items:center}.dist-lesson form input{width:80px}.dist-lesson form small{width:100%}.dist-lesson [hidden]{display:none!important}.dist-lesson .dist-navigation button{font-size:12px!important;padding:5px!important}@media(max-width:500px){.dist-caption{font-size:13px}.dist-parts{font-size:18px;gap:4px}.dist-parts>div{padding:1px 3px}.dist-question{font-size:13px}.dist-choices button{font-size:14px!important}}@media(max-height:500px) and (min-width:650px){.dist-board{display:grid;grid-template-columns:1fr 1.2fr;gap:1px 7px;padding:3px}.dist-caption{grid-column:1/-1;min-height:0;font-size:11px!important;line-height:1.2;padding:2px}.dist-board svg{grid-column:2;grid-row:2/span 4;max-height:118px;align-self:center}.dist-original,.dist-parts,.dist-sum{grid-column:1;line-height:1.15!important;margin:1px;font-size:20px!important;align-self:center}.dist-parts{font-size:15px!important}.dist-split{grid-column:1/-1;margin:1px;font-size:11px}.dist-lesson h1{font-size:18px}.dist-navigation{margin:2px 0}.dist-lesson .dist-navigation button{min-height:28px!important;padding:2px 5px!important}.dist-board:has(.dist-question:not([hidden])){display:block}.dist-board:has(.dist-question:not([hidden])) svg{max-height:70px}.dist-question{font-size:12px;padding:3px}.dist-question-equation{font-size:19px;margin:0}.dist-choices button{font-size:12px!important;padding:3px!important;min-height:28px!important}.dist-question p{font-size:11px}}