#lessonV2InstructionalRoot{font-family:Arial,sans-serif;color:#13213a;max-width:1050px;margin:18px auto;padding:0 14px;box-sizing:border-box}#lessonV2InstructionalRoot *{box-sizing:border-box}.lv2-card{background:#fff;border:2px solid #cbd8ea;border-radius:18px;padding:20px;margin:14px 0;box-shadow:0 6px 18px rgba(20,40,80,.08)}.lv2-head{display:flex;gap:16px;align-items:flex-start;justify-content:space-between}.lv2-kicker{font-size:12px;font-weight:900;letter-spacing:.12em;text-transform:uppercase;color:#345b95}.lv2-title{font-size:30px;font-weight:900;margin:4px 0}.lv2-model{min-height:250px;display:flex;align-items:center;justify-content:center;overflow:auto}.lv2-math-grid{display:grid;grid-template-columns:44px repeat(5,54px);font-size:34px;text-align:center;align-items:center}.lv2-line{border-top:4px solid #17233a;grid-column:1/-1;height:8px}.lv2-carry{font-size:18px;color:#b45309;border:2px dashed #f59e0b;border-radius:8px;min-height:28px}.lv2-numberline{position:relative;width:min(760px,92vw);height:140px}.lv2-axis{position:absolute;left:5%;right:5%;top:72px;border-top:5px solid #243b60}.lv2-tick{position:absolute;top:55px;width:3px;height:36px;background:#243b60}.lv2-dot{position:absolute;top:57px;width:28px;height:28px;border-radius:50%;background:#fff;border:7px solid #2563eb;transform:translateX(-50%)}.lv2-label{position:absolute;top:100px;transform:translateX(-50%);font-weight:800}.lv2-array{display:grid;gap:8px}.lv2-dotcell{width:26px;height:26px;border-radius:50%;background:#2563eb}.lv2-fraction{display:flex;width:480px;max-width:90vw;height:120px;border:3px solid #243b60}.lv2-fracpart{flex:1;border-right:2px solid #243b60}.lv2-fracpart:last-child{border-right:0}.lv2-fracpart.on{background:#93c5fd}.lv2-bars{display:flex;align-items:flex-end;gap:22px;height:250px}.lv2-barwrap{text-align:center;font-weight:800}.lv2-bar{width:54px;background:#60a5fa;border:2px solid #1e40af;border-bottom:0}.lv2-practice{display:grid;gap:14px}.lv2-item{padding:16px;border:2px solid #d7e0ee;border-radius:14px}.lv2-input{font-size:22px;padding:10px 12px;border:2px solid #64748b;border-radius:10px;width:180px;max-width:100%}.lv2-btn{font-size:18px;font-weight:800;padding:11px 18px;border:0;border-radius:10px;background:#1d4ed8;color:#fff;cursor:pointer;margin-left:8px}.lv2-feedback{font-weight:800;min-height:24px;margin-top:10px}.lv2-workstation-overlay{position:fixed;inset:0;z-index:2147483000;background:#f3f7fc;overflow:auto}.lv2-step{padding:10px 14px;border-left:5px solid #60a5fa;background:#eff6ff;margin:8px 0;border-radius:8px}.lv2-warning{border-color:#dc2626;background:#fef2f2}.lv2-hidden-answer{display:none!important}@media(max-width:700px){.lv2-title{font-size:24px}.lv2-math-grid{grid-template-columns:36px repeat(5,44px);font-size:28px}.lv2-btn{margin:8px 0 0}.lv2-head{display:block}}