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small{color:#8993a5;text-transform:uppercase;letter-spacing:.07em;font-size:.66rem}.drag-address-card--dragging{opacity:.55;transform:scale(.98)}.drag-empty{text-align:center;color:#748098;grid-column:1/-1;margin:0;padding:18px}.drop-zone-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;display:grid}.drop-zone{background:#fafcff;border:2px dashed #d7deea;border-radius:16px;flex-direction:column;justify-content:center;align-items:center;gap:9px;min-height:118px;padding:14px;transition:all .15s;display:flex}.drop-zone--ready{background:#f5f8ff;border-color:#9db0df}.drop-zone__label{letter-spacing:.07em;text-transform:uppercase;color:#66728a;font-size:.75rem;font-weight:850}.drop-zone__placeholder{color:#9aa4b5}.placed-address{color:#fff;background:#202b45;border-radius:10px;align-items:center;gap:10px;padding:9px 11px;display:flex}.placed-address button{color:#fff;background:#ffffff1f;border:0;border-radius:7px;width:24px;height:24px}.ipv6-number{font-size:clamp(1.5rem,6vw,2.6rem)}@media (width<=760px){.app-shell{width:min(100% - 24px,760px);padding:18px 0 68px}.app-header{flex-direction:column;align-items:flex-start;gap:14px}.header-actions{grid-template-columns:1fr 1fr;gap:8px;width:100%;display:grid}.header-actions .level-select-wrap{grid-column:1/-1;width:100%}.level-select{width:100%;min-height:44px}.button{min-height:44px;padding:10px 13px}h1{font-size:clamp(1.8rem,9vw,2.5rem)}.topology-card,.exercise-card,.knowledge-card,.feedback-card,.calculator-card{border-radius:16px;padding:16px}.exercise-card{display:block}.answer-form,.calculator-form,.calculator-grid,.boss-grid,.drop-zone-grid,.drag-source-grid{grid-template-columns:1fr}.calculator-hero{font-size:1rem}.comparison-card{grid-template-columns:1fr}.comparison-vs{min-height:24px}.gateway-dnd-diagram{grid-template-columns:1fr}.network-svg{min-height:0}.difficulty-panel{bottom:66px;right:12px}.difficulty-fab{bottom:12px;right:12px}.network-inventory{grid-template-columns:1fr}}.range-bucket-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:14px;display:grid}.choice-button--wide{text-align:left;min-height:68px}.choice-list{gap:10px;margin:16px 0;display:grid}@media (width<=760px){.range-bucket-grid{grid-template-columns:1fr}.choice-button--wide{min-height:76px}}.segmented-control{background:#f1f4f8;border-radius:12px;grid-template-columns:1fr 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