.de-lesson{max-width:1100px;margin:auto;color:#173950}.de-lesson h1{font-size:clamp(19px,3vw,27px);margin:4px;text-align:center}.de-controls,.de-navigation{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:6px;margin:7px 0}.de-lesson button,.de-lesson input,.de-lesson select{font:inherit}.de-board{border:2px solid #476b87;border-radius:16px;background:white;padding:10px}.de-caption{background:#fff0b4;border:1px solid #a35c00;border-radius:8px;padding:9px;text-align:center;font-weight:800;margin:0}.de-operands{display:flex;gap:18px;justify-content:center;align-items:center;margin:12px 0;font-size:clamp(27px,4vw,42px);font-weight:900}.de-operands>div{display:flex;flex-direction:column;align-items:center;min-width:90px}.de-operands>div:first-child{color:#075bb6}.de-operands>div:last-child{color:#b40d56}.de-operands span{font-size:.85em;background:#fff1b7;padding:0 7px;border-radius:7px}.de-model svg{display:block;width:100%;max-height:310px}.de-equation{font-size:clamp(25px,4vw,37px);font-weight:900;text-align:center;padding:9px}.de-comparison{border:2px solid #006943;border-radius:10px;background:#e3fff0;padding:9px;text-align:center;font-weight:800}.de-comparison>div{font-size:clamp(22px,3vw,31px)}.de-comparison p{margin:5px}.de-question{background:#fff1ba;border:3px solid #a85800;border-radius:12px;padding:12px;text-align:center}.de-choices{display:flex;gap:12px;flex-wrap:wrap;justify-content:center;margin:10px}.de-choices button{background:#075bb6;color:white;font-size:28px;padding:8px 16px;border:2px solid #003573;border-radius:9px;cursor:pointer}.de-lesson form{display:flex;gap:8px;flex-wrap:wrap;align-items:center}.de-lesson input{width:140px;max-width:100%}.de-lesson input[type=checkbox]{width:auto}.de-lesson form small{flex-basis:100%}.de-lesson [hidden]{display:none!important}.de-lesson button:disabled{opacity:.45;cursor:not-allowed}.de-lesson button:focus-visible{outline:4px solid #e99500;outline-offset:3px}@media(max-width:500px){.de-board{padding:6px}.de-operands{gap:10px}.de-comparison{font-size:13px}.de-controls label{font-size:13px}}
.de-lesson .de-board,.de-lesson .de-caption,.de-lesson .de-comparison,.de-lesson .de-question,.de-lesson .de-operands span{border-radius:0}
.de-lesson .de-board{padding:6px}
.de-lesson .de-caption{padding:5px;line-height:1.4;font-size:15px}
.de-lesson .de-controls,.de-lesson .de-navigation{margin:4px 0;gap:5px}
.de-lesson .de-operands{margin:5px 0;gap:12px;font-size:clamp(25px,3.5vw,36px)}
.de-operands [data-a-est],.de-operands [data-b-est]{display:inline-flex;direction:rtl;gap:5px;justify-content:center;align-items:center}
.de-lesson .de-model svg{max-height:190px}
.de-lesson .de-equation{padding:3px;font-size:clamp(24px,3.3vw,32px)}
.de-lesson .de-comparison{padding:4px;font-size:13px;line-height:1.4}
.de-lesson .de-comparison>div{font-size:clamp(21px,3vw,27px)}
.de-lesson .de-comparison p{margin:3px 0}
@media(max-width:500px){.de-model svg text{font-size:30px}}
@media(max-height:600px) and (min-width:650px){.de-lesson .de-model svg{max-height:125px}.de-lesson .de-operands{font-size:24px;margin:2px 0}}
.de-model svg text{text-anchor:middle;direction:ltr;font:800 24px system-ui;fill:#173950}
.de-model svg [data-exact-label]{fill:#075bb6}.de-model svg [data-estimate-label]{fill:#b40d56}.de-model svg [data-gap-label]{fill:#754000}
.de-operands>div{min-width:0;max-width:46%}.de-operands bdi{max-width:100%}
@media(max-width:500px){.de-lesson .de-operands{font-size:clamp(18px,5vw,25px)}.de-model svg text{font-size:28px}}