:root{--bg:#f4f6f9;--surface:#fff;--surface-2:#eef1f6;--border:#e2e6ed;--text:#1b2430;--text-muted:#667085;--text-faint:#98a2b3;--primary:#1d4ed8;--primary-dark:#1734a0;--primary-tint:#eaf0fe;--accent:#0f766e;--accent-tint:#e6f5f3;--amber:#b45309;--amber-tint:#fffbeb;--amber-border:#d97706;--success:#16a34a;--success-tint:#f0fdf4;--success-text:#166534;--danger:#dc2626;--danger-tint:#fef2f2;--danger-text:#991b1b;--radius-lg:20px;--radius-md:14px;--radius-sm:10px;--shadow-card:0 1px 2px #1018280a, 0 1px 3px #1018280f;--shadow-pop:0 8px 24px #1018281a;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;line-height:1.5}ul{margin:0;padding:0;list-style:none}h1,h2,h3,p{margin:0}.lesson-body{padding:22px 20px 24px}.eyebrow{letter-spacing:.07em;text-transform:uppercase;color:var(--primary);margin-bottom:8px;font-size:11.5px;font-weight:800}.step-h{letter-spacing:-.015em;margin-bottom:14px;font-size:21px;font-weight:800}.step-text{color:#374151;margin-bottom:12px;font-size:15px}.step-text strong{color:var(--text)}.step-sub{margin:18px 0 10px;font-size:15.5px;font-weight:800}.callout{border-radius:var(--radius-md);border-left:4px solid var(--primary);background:var(--primary-tint);margin:16px 0;padding:13px 14px;font-size:13.5px}.callout.analogy{border-left-color:var(--accent);background:var(--accent-tint)}.callout.example{border-left-color:var(--amber-border);background:var(--amber-tint)}.callout-label{text-transform:uppercase;letter-spacing:.05em;margin-bottom:4px;font-size:11px;font-weight:800;display:block}.callout:not(.analogy):not(.example) .callout-label{color:var(--primary)}.callout.analogy .callout-label{color:var(--accent)}.callout.example .callout-label{color:var(--amber)}.example-list{margin:12px 0}.example-list li{color:#374151;align-items:flex-start;gap:9px;padding:5px 0;font-size:14px;display:flex}.example-list svg{flex-shrink:0;margin-top:3px}.pdu-tag{background:var(--surface);border:1px solid var(--border);border-radius:100px;align-items:center;gap:6px;margin-top:4px;padding:6px 12px;font-size:12.5px;font-weight:700;display:inline-flex}.pdu-tag b{color:var(--primary);font-weight:800}.gloss-term{border-bottom:1.5px dotted var(--text-faint);cursor:help;transition:border-color .12s,color .12s}.gloss-term:hover,.gloss-term:focus{border-bottom-color:var(--primary);color:var(--primary-dark);outline:none}.gloss-tooltip{z-index:999;background:var(--surface);border:1px solid var(--border);max-width:260px;box-shadow:var(--shadow-pop);pointer-events:none;border-radius:12px;padding:12px 14px;font-size:12.5px;line-height:1.45;animation:.12s fadeIn;position:fixed}.gloss-tooltip-term{text-transform:uppercase;letter-spacing:.05em;color:var(--primary);margin-bottom:4px;font-size:11px;font-weight:800}.gloss-tooltip-def{color:#374151}@keyframes fadeIn{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}.complete-badge{background:var(--success-tint);width:64px;height:64px;color:var(--success);border-radius:50%;justify-content:center;align-items:center;margin:8px auto 18px;display:flex}.step-list{margin:0 0 16px;padding-left:22px}.step-list li{color:#374151;padding:4px 0;font-size:14.5px}.hop-diagram{flex-direction:column;gap:2px;margin:14px 0;display:flex}.hop-node{background:var(--surface);border:1px solid var(--border);text-align:center;box-shadow:var(--shadow-card);border-radius:12px;padding:12px 14px}.hop-node.start{background:var(--primary-tint);border-color:var(--primary)}.hop-node.start .hop-title{color:var(--primary-dark)}.hop-node.end{background:var(--accent-tint);border-color:var(--accent)}.hop-node.end .hop-title{color:var(--accent)}.hop-title{font-size:13.5px;font-weight:800}.hop-sub{color:var(--text-muted);margin-top:2px;font-size:11.5px}.hop-arrow{color:var(--text-faint);text-align:center;flex-direction:column;align-items:center;gap:2px;padding:3px 0;font-size:11px;font-weight:600;display:flex}.hop-arrow span{max-width:240px}.hop-arrow.up{color:var(--accent)}.resp-legend{flex-wrap:wrap;gap:16px;margin-bottom:14px;display:flex}.resp-legend-item{color:var(--text-muted);align-items:center;gap:6px;font-size:12px;font-weight:600;display:flex}.resp-dot{border-radius:50%;width:10px;height:10px;display:inline-block}.resp-dot.you{background:var(--primary)}.resp-dot.provider{background:var(--accent)}.resp-row{margin-bottom:12px}.resp-label{margin-bottom:6px;font-size:13px;font-weight:800}.resp-bar{gap:3px;display:flex}.resp-seg{text-align:center;border-radius:7px;flex:1;padding:9px 4px;font-size:10px;font-weight:700}.resp-seg.you{background:var(--primary-tint);color:var(--primary-dark)}.resp-seg.provider{background:var(--accent-tint);color:var(--accent)}.traffic-diagram{flex-direction:column;gap:14px;display:flex}.traffic-row{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);padding:12px 14px}.traffic-label{font-size:13.5px;font-weight:800}.traffic-desc{color:var(--text-muted);margin-top:2px;margin-bottom:10px;font-size:12px}.traffic-visual{align-items:center;gap:10px;display:flex}.traffic-sender{background:var(--primary-tint);color:var(--primary-dark);border-radius:8px;flex-shrink:0;padding:8px 12px;font-size:12px;font-weight:800}.traffic-arrow{color:var(--text-faint);flex-shrink:0}.traffic-receivers{flex-wrap:wrap;gap:8px;display:flex}.traffic-dot{background:var(--border);border-radius:50%;flex-shrink:0;width:22px;height:22px}.traffic-dot.hit{background:var(--accent)}.ip-split-diagram{flex-direction:column;gap:12px;display:flex}.ip-split-row{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);padding:12px 14px}.ip-split-label{margin-bottom:8px;font-size:12.5px;font-weight:800}.ip-split-cidr{color:var(--primary);font-size:11.5px;font-weight:700}.ip-split-octets{align-items:center;gap:2px;display:flex}.ip-octet{text-align:center;border-radius:8px;flex:1;padding:10px 4px;font-size:14px;font-weight:800}.ip-octet.network{background:var(--primary-tint);color:var(--primary-dark)}.ip-octet.host{background:var(--accent-tint);color:var(--accent)}.ip-octet-dot{color:var(--text-faint);padding:0 1px;font-weight:800}.ip-split-legend{color:var(--text-muted);align-items:center;gap:6px;margin-top:2px;font-size:11.5px;font-weight:600;display:flex}.ip-legend-dot{border-radius:3px;width:10px;height:10px;display:inline-block}.ip-legend-dot.network{background:var(--primary)}.ip-legend-dot.host{background:var(--accent)}.mask-bit-diagram{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin-bottom:10px;padding:12px 12px 6px}.mask-octet-row{align-items:center;gap:8px;margin-bottom:8px;display:flex}.mask-octet-label{width:54px;color:var(--text-muted);flex-shrink:0;font-size:11px;font-weight:700}.mask-octet-bits{flex:1;gap:2px;display:flex}.mask-bit{text-align:center;border-radius:5px;flex:1;padding:6px 0;font-size:12px;font-weight:800}.mask-bit.network{background:var(--primary-tint);color:var(--primary-dark)}.mask-bit.borrowed{background:var(--accent-tint);color:var(--accent)}.mask-bit.host{background:var(--surface-2);color:var(--text-faint)}.mask-bit-legend{color:var(--text-muted);flex-wrap:wrap;gap:4px 14px;margin-top:4px;padding-bottom:2px;font-size:11px;font-weight:600;display:flex}.mask-legend-dot{vertical-align:middle;border-radius:3px;width:10px;height:10px;margin-right:4px;display:inline-block}.mask-legend-dot.network{background:var(--primary)}.mask-legend-dot.borrowed{background:var(--accent)}.mask-legend-dot.host{background:var(--surface-2);border:1px solid var(--border)}.subnet-practice-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);padding:16px}.subnet-practice-ip{letter-spacing:-.01em;text-align:center;background:var(--primary-tint);color:var(--primary-dark);border-radius:var(--radius-sm);margin-bottom:12px;padding:12px;font-size:20px;font-weight:800}.subnet-practice-ask{text-align:center;margin-bottom:14px;font-size:14.5px}.subnet-answer-input{box-sizing:border-box;border:1.5px solid var(--border);border-radius:var(--radius-sm);text-align:center;width:100%;color:var(--text);padding:13px 14px;font-size:15px;font-weight:700}.subnet-answer-input:focus{border-color:var(--primary);outline:none}.cmd-drill-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);padding:14px}.cmd-drill-head{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;margin-bottom:10px;display:flex}.cmd-drill-badge{letter-spacing:.06em;text-transform:uppercase;color:var(--accent);background:var(--accent-tint);border-radius:100px;padding:4px 10px;font-size:11px;font-weight:800}.cmd-drill-count{color:var(--text-muted);font-size:12px;font-weight:700}.cmd-term{border-radius:var(--radius-sm);background:#0b1220;border:1px solid #1e293b;margin-bottom:14px;overflow:hidden}.cmd-term-bar{color:#94a3b8;background:#151e2e;align-items:center;gap:6px;padding:8px 10px;font-size:11px;display:flex}.cmd-term-dot{background:#334155;border-radius:50%;flex-shrink:0;width:9px;height:9px}.cmd-term-title{margin-left:6px}.cmd-term-body{color:#d1d9e6;white-space:pre;-webkit-overflow-scrolling:touch;tab-size:4;margin:0;padding:12px 14px;font-family:Consolas,SF Mono,Menlo,Courier New,monospace;font-size:12.5px;line-height:1.5;overflow-x:auto}.cmd-term-cmd{color:#7dd3fc;font-weight:700}.cmd-q{margin-bottom:12px;font-size:14.5px;font-weight:700;line-height:1.4}.cmd-opt{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-md);text-align:left;cursor:pointer;width:100%;color:var(--text);flex-direction:column;align-items:stretch;margin-bottom:10px;padding:12px 14px;font-size:14.5px;transition:border-color .15s,background .15s,transform 80ms;display:flex}.cmd-opt:active:not(:disabled){transform:scale(.98)}.cmd-opt:disabled{cursor:default}.cmd-opt.correct{border-color:var(--success);background:var(--success-tint)}.cmd-opt.correct .opt-letter{background:var(--success);color:#fff}.cmd-opt.incorrect{border-color:var(--danger);background:var(--danger-tint)}.cmd-opt.incorrect .opt-letter{background:var(--danger);color:#fff}.cmd-score{text-align:center;color:var(--text-muted);margin-top:12px;font-size:12.5px}.cmd-score b{color:var(--text)}.opt-row{align-items:center;gap:12px;width:100%;display:flex}.opt-text{flex:1}.opt-letter{background:var(--surface-2);width:28px;height:28px;color:var(--text-muted);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:12.5px;font-weight:800;display:flex}.bin-table{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin-bottom:14px;padding:12px 10px 14px}.bin-table-label{margin-bottom:8px;font-size:12.5px;font-weight:800}.bin-row{gap:4px;display:flex}.bin-row+.bin-row{margin-top:4px}.bin-cell{text-align:center;border-radius:6px;flex:1;padding:8px 2px;font-size:13px;font-weight:800}.bin-cell.place{background:var(--bg);color:var(--text-muted);font-size:11.5px;font-weight:700}.bin-cell.on{background:var(--primary-tint);color:var(--primary-dark)}.bin-cell.off{background:var(--bg);color:var(--text-faint)}.bin-sum{text-align:center;color:var(--primary);margin-top:9px;font-size:13px;font-weight:700}.bin-sum b{color:var(--primary-dark)}.cheat-sheet{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin-top:6px;padding:4px 14px}.cheat-row{border-bottom:1px solid var(--border);align-items:flex-start;gap:12px;padding:12px 0;display:flex}.cheat-row:last-child{border-bottom:none}.cheat-num{border-radius:8px;flex-shrink:0;justify-content:center;align-items:center;width:28px;height:28px;margin-top:1px;font-size:12.5px;font-weight:800;display:flex}.cheat-body{flex:1;min-width:0}.cheat-name{font-size:13.5px;font-weight:800}.cheat-job{color:var(--text-muted);margin-top:2px;font-size:12.5px}.cheat-examples{color:var(--text-faint);margin-top:3px;font-size:11.5px}.data-table-title{color:var(--text);margin:16px 0 6px;font-size:13.5px;font-weight:800}.data-table-wrap{border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);background:var(--surface);overflow-x:auto}.data-table{border-collapse:collapse;width:100%;font-size:12px}.data-table th{text-align:left;background:var(--surface-2);color:var(--text-muted);text-transform:uppercase;letter-spacing:.03em;border-bottom:1px solid var(--border);white-space:nowrap;padding:9px 12px;font-size:10.5px;font-weight:800}.data-table td{text-align:left;border-bottom:1px solid var(--border);color:var(--text);vertical-align:top;padding:9px 12px}.data-table tr:last-child td{border-bottom:none}.data-table td.strong{font-weight:800}.tip-list{margin-top:4px}.tip-row{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin-bottom:9px;padding:12px 14px}.tip-trigger{color:var(--text-muted);font-size:13px;font-style:italic}.tip-answer{color:var(--primary);align-items:center;gap:6px;margin-top:5px;font-size:13.5px;font-weight:800;display:flex}.callout.trap{border-left-color:var(--danger);background:var(--danger-tint);margin-top:16px}.callout.trap .callout-label{color:var(--danger-text)}.trap-list{margin:6px 0 0;padding:0;list-style:none}.trap-list li{color:var(--danger-text);align-items:flex-start;gap:8px;padding:5px 0;font-size:13px;display:flex}.trap-list svg{flex-shrink:0;margin-top:2px}.osi-diagram{border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin:14px 0 6px;overflow:hidden}.osi-layer{align-items:center;gap:12px;padding:11px 14px;display:flex;position:relative}.osi-layer.full{padding:13px 14px}.osi-num{background:#ffffff47;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:26px;height:26px;font-size:12.5px;font-weight:800;display:flex}.osi-info{flex:1;min-width:0}.osi-name{font-size:13.5px;font-weight:800}.osi-purpose{opacity:.85;margin-top:1px;font-size:11.5px}.osi-pdu{opacity:.8;white-space:nowrap;font-size:10.5px;font-weight:700}.mini-osi{border-radius:12px;flex-direction:column;gap:3px;margin-bottom:16px;display:flex;overflow:hidden}.mini-osi-layer{opacity:.35;align-items:center;gap:8px;padding:6px 10px;font-size:11px;font-weight:700;transition:opacity .2s,transform .2s;display:flex}.mini-osi-layer.current{opacity:1;transform:scale(1.02);box-shadow:0 2px 6px #00000026}.mini-osi-num{background:#ffffff4d;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:18px;height:18px;font-size:10px;display:flex}.legend-row{flex-wrap:wrap;justify-content:center;gap:16px;margin:10px 0 14px;display:flex}.legend-item{color:var(--text-muted);align-items:center;gap:6px;font-size:12px;font-weight:600;display:flex}.legend-dot{border-radius:50%;flex-shrink:0;width:10px;height:10px;display:inline-block}.legend-dot.ns{background:var(--primary)}.legend-dot.ew{background:var(--accent)}.btn{cursor:pointer;text-align:center;border:none;border-radius:14px;justify-content:center;align-items:center;gap:8px;min-height:52px;padding:15px 18px;font-size:15px;font-weight:750;transition:transform .1s,background .15s,opacity .15s;display:flex}.btn:active{transform:scale(.97)}.btn.primary{background:var(--primary);color:#fff;flex:2}.btn.primary:disabled{background:var(--surface-2);color:var(--text-faint);cursor:not-allowed}.btn.ghost{background:var(--surface);color:var(--text);border:1px solid var(--border);flex:1}.btn.full{width:100%}.btn.success{background:var(--success);color:#fff}.icon-btn{border:1px solid var(--border);background:var(--surface);width:40px;height:40px;color:var(--text);cursor:pointer;border-radius:12px;flex-shrink:0;justify-content:center;align-items:center;transition:transform .12s,background .15s;display:flex}.icon-btn:active{background:var(--surface-2);transform:scale(.94)}.lesson-header{z-index:20;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);padding:calc(env(safe-area-inset-top,0px) + 12px) 20px 12px;border-bottom:1px solid var(--border);background:#f4f6f9f0;position:sticky;top:0}.lesson-header-row{align-items:center;gap:12px;display:flex}.lesson-header-title{flex:1;font-size:14.5px;font-weight:700}.progress-track{background:var(--surface-2);border-radius:100px;height:6px;margin-top:12px;overflow:hidden}.progress-fill{background:linear-gradient(90deg, var(--primary), var(--accent));border-radius:100px;height:100%;transition:width .35s}.step-label{color:var(--text-faint);margin-top:6px;font-size:11px;font-weight:600}.quiz-scenario{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin-bottom:14px;padding:15px 16px;font-size:14.5px}.quiz-result-banner{border-radius:100px;align-items:center;gap:6px;margin-bottom:14px;padding:6px 12px;font-size:13px;font-weight:800;display:inline-flex}.quiz-result-banner.ok{background:var(--success-tint);color:var(--success-text)}.quiz-result-banner.no{background:var(--danger-tint);color:var(--danger-text)}.quiz-option{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-md);text-align:left;cursor:pointer;width:100%;color:var(--text);flex-direction:column;align-items:stretch;margin-bottom:10px;padding:13px 14px;font-size:14.5px;transition:border-color .15s,background .15s,transform 80ms;display:flex}.quiz-option:active:not(:disabled){transform:scale(.98)}.quiz-option:disabled{cursor:default}.quiz-option.correct{border-color:var(--success);background:var(--success-tint)}.quiz-option.correct .opt-letter{background:var(--success);color:#fff}.quiz-option.incorrect{border-color:var(--danger);background:var(--danger-tint)}.quiz-option.incorrect .opt-letter{background:var(--danger);color:#fff}.opt-check{flex-shrink:0;margin-left:auto}.opt-why{color:var(--text-muted);margin-top:7px;padding-left:40px;font-size:12.5px;line-height:1.4;animation:.2s fadeIn}.quiz-option.correct .opt-why{color:var(--success-text)}.quiz-option.incorrect .opt-why{color:var(--danger-text)}.review-pointer{border-radius:var(--radius-sm);background:var(--surface-2);color:var(--text-muted);align-items:flex-start;gap:8px;margin-top:2px;padding:9px 12px;font-size:12.5px;line-height:1.4;display:flex}.review-pointer b{color:var(--text)}.results-wrap{text-align:center;padding:26px 20px 10px}.score-ring{border-radius:50%;justify-content:center;align-items:center;width:150px;height:150px;margin:0 auto 20px;display:flex;position:relative}.score-ring-inner{background:var(--bg);border-radius:50%;flex-direction:column;justify-content:center;align-items:center;width:120px;height:120px;display:flex}.score-num{letter-spacing:-.02em;font-size:30px;font-weight:800}.score-den{color:var(--text-muted);font-size:12px;font-weight:600}.results-msg{margin-bottom:6px;font-size:16px;font-weight:750}.results-sub{color:var(--text-muted);max-width:34ch;margin:0 auto 22px;font-size:13.5px}.recap-list{text-align:left;max-height:280px;margin:0 0 22px;overflow-y:auto}.recap-item{border-bottom:1px solid var(--border);align-items:flex-start;gap:10px;padding:10px 4px;font-size:13px;display:flex}.recap-item:last-child{border-bottom:none}.recap-dot{border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:22px;height:22px;margin-top:1px;display:flex}.recap-dot.ok{background:var(--success-tint);color:var(--success)}.recap-dot.no{background:var(--danger-tint);color:var(--danger)}.recap-q{color:var(--text-muted)}.lesson-icon{background:var(--primary-tint);width:38px;height:38px;color:var(--primary);border-radius:10px;flex-shrink:0;justify-content:center;align-items:center;display:flex}.lesson-icon.done{background:var(--success-tint);color:var(--success)}.final-block-title{text-align:left;text-transform:uppercase;letter-spacing:.05em;color:var(--text-muted);margin:6px 2px 10px;font-size:12.5px;font-weight:800}.focus-areas{text-align:left;margin:0 0 22px}.focus-ok{background:var(--success-tint);color:var(--success-text);border-radius:var(--radius-md);padding:12px 14px;font-size:13.5px;font-weight:700}.focus-sub{color:var(--text-muted);margin:12px 2px 6px;font-size:12px;font-weight:800}.focus-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);overflow:hidden}.focus-row{border-bottom:1px solid var(--border);align-items:center;gap:10px;padding:10px 12px;font-size:13px;display:flex}.focus-row:last-child{border-bottom:none}.focus-name{flex:1;min-width:0;font-weight:650}.focus-name small{color:var(--text-faint);margin-top:1px;font-size:11.5px;font-weight:600;display:block}.focus-count{font-variant-numeric:tabular-nums;white-space:nowrap;color:var(--danger-text);font-weight:800}.focus-count.none{color:var(--success-text)}.focus-rank{background:var(--danger-tint);width:22px;height:22px;color:var(--danger-text);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:11.5px;font-weight:800;display:flex}.lesson-score{color:var(--success-text);margin-top:1px;font-size:12px;font-weight:700}.final-dist{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);margin-bottom:18px;padding:4px 14px}.final-dist-row{border-bottom:1px solid var(--border);align-items:center;gap:10px;padding:9px 0;font-size:13.5px;display:flex}.final-dist-row:last-child{border-bottom:none}.final-dist-name{flex:1;font-weight:650}.final-dist-w{color:var(--text-faint);font-size:12px;font-weight:600}.final-dist-n{text-align:right;min-width:88px;font-weight:800}.final-mode-h{text-transform:uppercase;letter-spacing:.05em;color:var(--text-muted);margin:6px 0 10px;font-size:12.5px;font-weight:800}.final-mode{text-align:left;background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-md);cursor:pointer;width:100%;color:var(--text);box-shadow:var(--shadow-card);align-items:center;gap:14px;margin-bottom:10px;padding:14px;transition:border-color .15s,transform 80ms;display:flex}.final-mode:hover{border-color:var(--primary)}.final-mode:active{transform:scale(.98)}.final-mode-icon{background:var(--primary-tint);width:40px;height:40px;color:var(--primary);border-radius:12px;flex-shrink:0;justify-content:center;align-items:center;display:flex}.final-mode-title{font-size:15px;font-weight:800;display:block}.final-mode-desc{color:var(--text-muted);margin-top:2px;font-size:12.5px;line-height:1.4}.final-note{color:var(--text-muted);margin-top:14px;font-size:12px;line-height:1.5}.exam-timer{font-variant-numeric:tabular-nums;background:var(--primary-tint);color:var(--primary-dark);border-radius:100px;align-items:center;gap:6px;padding:5px 11px;font-size:14px;font-weight:800;display:inline-flex}.exam-timer.warn{color:#92400e;background:#fef3c7}.exam-timer.crit{background:var(--danger-tint);color:var(--danger-text)}.final-q-top{justify-content:space-between;align-items:center;gap:10px;margin-bottom:8px;display:flex}.final-opt{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-md);text-align:left;cursor:pointer;width:100%;color:var(--text);flex-direction:column;align-items:stretch;margin-bottom:10px;padding:13px 14px;font-size:14.5px;transition:border-color .15s,background .15s,transform 80ms;display:flex}.final-opt:active{transform:scale(.98)}.final-opt.selected{border-color:var(--primary);background:var(--primary-tint)}.final-opt.selected .opt-letter{background:var(--primary);color:#fff}.final-link{color:var(--primary);cursor:pointer;text-underline-offset:2px;background:0 0;border:none;padding:4px 2px;font-size:12.5px;font-weight:700;text-decoration:underline}.final-link[hidden]{display:none}.final-opt-foot{justify-content:space-between;align-items:center;gap:10px;margin-top:4px;display:flex}.final-hint{color:var(--text-faint);font-size:12px;line-height:1.4}.final-map{grid-template-columns:repeat(auto-fill,minmax(44px,1fr));gap:8px;margin:6px 0 12px;display:grid}.final-map-cell{border:1.5px dashed var(--border);background:var(--surface);height:40px;color:var(--text-muted);cursor:pointer;font-variant-numeric:tabular-nums;border-radius:10px;font-size:13px;font-weight:700}.final-map-cell.answered{border-style:solid;border-color:var(--primary);background:var(--primary-tint);color:var(--primary-dark)}.final-map-cell.current{box-shadow:0 0 0 3px var(--primary-tint);outline:2px solid var(--primary);outline-offset:1px}.final-map-legend{color:var(--text-muted);gap:16px;margin-bottom:10px;font-size:12px;display:flex}.final-map-key{border:1.5px dashed var(--border);vertical-align:-2px;background:var(--surface);border-radius:4px;width:12px;height:12px;margin-right:6px;display:inline-block}.final-map-key.answered{border-style:solid;border-color:var(--primary);background:var(--primary-tint)}.final-pct{color:var(--text-muted);margin:-6px 0 10px;font-size:14px;font-weight:800}.final-verdict{border-radius:100px;align-items:center;gap:8px;margin-bottom:12px;padding:8px 18px;font-size:14.5px;font-weight:800;display:inline-flex}.final-verdict.pass{background:var(--success-tint);color:var(--success-text);border:1.5px solid var(--success)}.final-verdict.fail{background:var(--danger-tint);color:var(--danger-text);border:1.5px solid var(--danger)}.final-scale-note{color:var(--text-muted);max-width:44ch;margin:0 auto 18px;font-size:12px;line-height:1.5}.final-banner{color:#92400e;border-radius:var(--radius-sm);text-align:left;background:#fef3c7;margin:0 0 16px;padding:10px 14px;font-size:13px;font-weight:600}.final-dom{text-align:left;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);margin-bottom:8px;padding:12px 14px}.final-dom-top{justify-content:space-between;gap:8px;font-size:13.5px;font-weight:700;display:flex}.final-dom-score{font-variant-numeric:tabular-nums;white-space:nowrap}.final-dom-bar{background:var(--surface-2);border-radius:100px;height:6px;margin-top:8px;overflow:hidden}.final-dom-fill{border-radius:100px;height:100%}.final-dom-flag{color:var(--danger-text);margin-top:6px;font-size:11.5px;font-weight:800}.final-recap{text-align:left;margin:0 0 22px}.final-rev{border-bottom:1px solid var(--border)}.final-rev summary{cursor:pointer;align-items:flex-start;gap:10px;padding:10px 4px;font-size:13px;list-style:none;display:flex}.final-rev summary::-webkit-details-marker{display:none}.final-rev-main{flex:1;min-width:0;display:block}.final-rev-top{font-weight:600;display:block}.final-rev-dom{color:var(--text-faint);font-weight:600}.final-rev-body{padding:2px 4px 14px 32px}.final-rev-opt{border:1px solid var(--border);background:var(--surface);border-radius:8px;margin-bottom:6px;padding:8px 10px;font-size:12.5px}.final-rev-opt.correct{border-color:var(--success);background:var(--success-tint)}.final-rev-opt.incorrect{border-color:var(--danger);background:var(--danger-tint)}.final-rev-tag{text-transform:uppercase;letter-spacing:.04em;margin-bottom:2px;font-size:10.5px;font-weight:800;display:block}.final-rev-why{color:var(--text-muted);margin-top:3px;display:block}.final-rev .review-pointer{margin-top:8px}.def-tools{flex-wrap:wrap;gap:10px;margin-top:16px;display:flex}.def-search{border:1.5px solid var(--border);background:var(--surface);min-width:180px;color:var(--text);border-radius:12px;flex:1;padding:12px 14px;font-family:inherit;font-size:15px}.def-search:focus{border-color:var(--primary);outline:none}.def-seg{background:var(--surface-2);border-radius:12px;padding:3px;display:flex}.def-seg button{color:var(--text-muted);cursor:pointer;background:0 0;border:none;border-radius:9px;padding:9px 12px;font-size:13px;font-weight:750}.def-seg button.on{background:var(--surface);color:var(--primary-dark);box-shadow:var(--shadow-card)}.def-count{color:var(--text-faint);margin:12px 2px 4px;font-size:12px;font-weight:700}.def-group-h{text-transform:uppercase;letter-spacing:.05em;color:var(--text-muted);align-items:center;gap:8px;margin:18px 2px 8px;font-size:12.5px;font-weight:800;display:flex}.def-group-h span{background:var(--surface-2);letter-spacing:0;border-radius:100px;padding:2px 8px;font-size:11px}.def-group{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-md);box-shadow:var(--shadow-card);overflow:hidden}.def-item{border-bottom:1px solid var(--border);padding:12px 14px}.def-item:last-child{border-bottom:none}.def-term{font-size:14.5px;font-weight:800}.def-text{color:var(--text-muted);margin-top:3px;font-size:13.5px;line-height:1.5}.def-src{color:var(--text-faint);margin-top:5px;font-size:11.5px;font-weight:600}.def-empty{text-align:center;color:var(--text-muted);margin-top:20px;padding:24px 10px;font-size:14px}.fc-controls{flex-direction:column;gap:10px;margin-top:16px;display:flex}.fc-field{text-transform:uppercase;letter-spacing:.05em;color:var(--text-faint);flex-direction:column;gap:4px;font-size:11.5px;font-weight:800;display:flex}.fc-field select{font:inherit;letter-spacing:0;text-transform:none;color:var(--text);border:1.5px solid var(--border);background:var(--surface);border-radius:12px;width:100%;padding:11px 12px;font-size:14px;font-weight:650}.fc-field select:disabled{opacity:.5}.fc-toggles{flex-wrap:wrap;gap:8px;display:flex}.fc-toggle{border:1.5px solid var(--border);background:var(--surface);color:var(--text-muted);cursor:pointer;border-radius:100px;padding:8px 14px;font-size:13px;font-weight:750}.fc-toggle.on{border-color:var(--primary);background:var(--primary-tint);color:var(--primary-dark)}.fc-pos{text-align:center;color:var(--text-muted);font-variant-numeric:tabular-nums;margin:18px 0 8px;font-size:13px;font-weight:800}.fc-card{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-lg);min-height:250px;box-shadow:var(--shadow-pop);text-align:center;cursor:pointer;-webkit-user-select:none;user-select:none;-webkit-tap-highlight-color:transparent;flex-direction:column;justify-content:center;align-items:center;padding:34px 22px 30px;display:flex;position:relative}.fc-card.back{background:var(--primary-tint);border-color:var(--primary)}.fc-card:focus-visible{outline:3px solid var(--primary-tint);outline-offset:2px}.fc-side{text-transform:uppercase;letter-spacing:.07em;color:var(--text-faint);font-size:10.5px;font-weight:800;position:absolute;top:14px;left:16px}.fc-flag{color:var(--amber);background:var(--amber-tint);border:1px solid var(--amber-border);border-radius:100px;padding:2px 9px;font-size:10.5px;font-weight:800;position:absolute;top:11px;right:12px}.fc-face{letter-spacing:-.01em;overflow-wrap:anywhere;font-size:26px;font-weight:800;line-height:1.25;animation:.22s fcPop}.fc-face.def{letter-spacing:0;font-size:16.5px;font-weight:600;line-height:1.55}@keyframes fcPop{0%{opacity:0;transform:scale(.96)}to{opacity:1;transform:scale(1)}}.fc-foot{color:var(--text-faint);margin-top:16px;font-size:11.5px;font-weight:600}.fc-tap{color:var(--text-faint);font-size:11px;font-weight:700;position:absolute;bottom:11px;left:0;right:0}.fc-nav,.fc-mark{gap:10px;margin-top:12px;display:flex}.fc-nav .btn,.fc-mark .btn{flex:1}.fc-review{background:var(--amber-tint);color:var(--amber);border:1.5px solid var(--amber-border)}.fc-nav .btn:disabled{opacity:.45;cursor:not-allowed}.fc-empty{text-align:center;color:var(--text-muted);background:var(--surface);border:1px dashed var(--border);border-radius:var(--radius-lg);margin-top:22px;padding:26px 12px;font-size:14px}.sh-page{padding:22px 20px 48px}.sh-h1{letter-spacing:-.015em;font-size:23px;font-weight:800}.sh-lead{color:var(--text-muted);margin-top:6px;font-size:14.5px}.sh-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);margin-top:14px;padding:16px}.sh-card-title{text-transform:uppercase;letter-spacing:.07em;color:var(--text-faint);margin-bottom:10px;font-size:11.5px;font-weight:800}.sh-big{letter-spacing:-.02em;font-size:28px;font-weight:800}.sh-unit{color:var(--text-muted);letter-spacing:0;font-size:13px;font-weight:650}.sh-sub{color:var(--text-muted);margin-top:8px;font-size:13px}.sh-bar{background:var(--surface-2);border-radius:100px;height:8px;margin-top:12px;overflow:hidden}.sh-bar>i,.sh-mini>i{background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:100px;height:100%;display:block}.sh-dom-list{border-top:1px solid var(--border);margin-top:14px;padding-top:6px}.sh-dom-row{align-items:center;gap:10px;padding:7px 0;font-size:13px;display:flex}.sh-dom-name{flex:1;min-width:0;font-weight:650}.sh-mini{background:var(--surface-2);border-radius:100px;flex-shrink:0;width:70px;height:5px;overflow:hidden}.sh-dom-n{text-align:right;font-variant-numeric:tabular-nums;width:34px;color:var(--text-muted);font-size:12px;font-weight:700}.sh-exam-row{justify-content:space-between;align-items:center;gap:12px;display:flex}.sh-chip{white-space:nowrap;border-radius:100px;padding:6px 12px;font-size:12px;font-weight:800}.sh-chip.pass{background:var(--success-tint);color:var(--success-text);border:1.5px solid var(--success)}.sh-chip.fail{background:var(--danger-tint);color:var(--danger-text);border:1.5px solid var(--danger)}.sh-link-btn{color:var(--primary);cursor:pointer;text-underline-offset:2px;white-space:nowrap;background:0 0;border:none;padding:4px 2px;font-size:12.5px;font-weight:800;text-decoration:underline}.sh-cta .btn{margin-top:2px}.ld-wrap{max-width:1080px;margin:0 auto;padding:0 20px}.ld-eyebrow{letter-spacing:.08em;text-transform:uppercase;color:var(--primary);margin-bottom:10px;font-size:12px;font-weight:800}.ld-hero{background:radial-gradient(900px 380px at 85% -10%,#1d4ed81a,#0000 60%),radial-gradient(700px 320px at 0 0,#0f766e14,#0000 60%);padding:44px 0 40px}.ld-hero-in{grid-template-columns:1fr;align-items:center;gap:26px;display:grid}.ld-h1{letter-spacing:-.025em;font-size:clamp(30px,5.4vw,48px);font-weight:800;line-height:1.08}.ld-sub{color:var(--text-muted);max-width:58ch;margin-top:16px;font-size:16.5px;line-height:1.6}.ld-cta{flex-wrap:wrap;gap:12px;margin-top:24px;display:flex}.ld-btn{font:inherit;cursor:pointer;border:none;border-radius:14px;min-height:50px;padding:14px 24px;font-size:15.5px;font-weight:750;transition:transform .1s,background .15s}.ld-btn:active{transform:scale(.97)}.ld-btn.primary{background:var(--primary);color:#fff;box-shadow:0 8px 20px #1d4ed840}.ld-btn.primary:hover{background:var(--primary-dark)}.ld-btn.ghost{background:var(--surface);color:var(--text);border:1.5px solid var(--border)}.ld-btn.ghost:hover{border-color:var(--primary)}.ld-micro{color:var(--text-faint);margin-top:14px;font-size:12.5px;font-weight:600}.ld-preview{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-pop);padding:18px}.ld-prev-tag{letter-spacing:.07em;text-transform:uppercase;color:var(--text-faint);font-size:10.5px;font-weight:800}.ld-prev-top{justify-content:space-between;align-items:center;gap:10px;margin:8px 0 14px;display:flex}.ld-prev-score{letter-spacing:-.02em;font-size:30px;font-weight:800}.ld-prev-pass{background:var(--success-tint);color:var(--success-text);border:1.5px solid var(--success);border-radius:100px;padding:6px 12px;font-size:12px;font-weight:800}.ld-prev-h{color:var(--text-muted);margin-bottom:6px;font-size:11.5px;font-weight:800}.ld-prev-row{border-top:1px solid var(--border);align-items:center;gap:10px;padding:9px 0;font-size:13px;display:flex}.ld-prev-row i{background:var(--danger-tint);width:22px;height:22px;color:var(--danger-text);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:11.5px;font-style:normal;font-weight:800;display:flex}.ld-prev-row span{flex:1;font-weight:650}.ld-prev-row b{color:var(--danger-text);white-space:nowrap;font-size:12.5px}.ld-prev-note{border-radius:var(--radius-sm);background:var(--surface-2);color:var(--text-muted);margin-top:10px;padding:9px 12px;font-size:12.5px}.ld-trust{background:var(--surface);border-top:1px solid var(--border);border-bottom:1px solid var(--border);padding:22px 0}.ld-trust-grid{grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:18px 24px;display:grid}.ld-trust-t{font-size:14.5px;font-weight:800}.ld-trust-s{color:var(--text-muted);margin-top:2px;font-size:12.5px;line-height:1.45}.ld-section{padding:60px 0}.ld-section.alt{background:var(--surface);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}.ld-h2{letter-spacing:-.02em;font-size:clamp(24px,4vw,32px);font-weight:800;line-height:1.15}.ld-lead{color:var(--text-muted);max-width:66ch;margin-top:10px;font-size:15.5px;line-height:1.6}.ld-feat-grid{grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin-top:28px;display:grid}.ld-feat{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);padding:20px 18px;position:relative}.ld-feat-ic{background:var(--primary-tint);width:44px;height:44px;color:var(--primary);border-radius:13px;justify-content:center;align-items:center;display:flex}.ld-feat-t{letter-spacing:-.01em;margin:14px 0 6px;font-size:17px;font-weight:800}.ld-feat-d{color:var(--text-muted);font-size:14px;line-height:1.55}.ld-feat.featured{color:#fff;background:linear-gradient(140deg,#1734a0 0%,#1d4ed8 60%,#0f766e 140%);border-color:#0000;box-shadow:0 12px 28px #1d4ed847}.ld-feat.featured .ld-feat-ic{color:#fff;background:#ffffff2e}.ld-feat.featured .ld-feat-d{color:#ffffffeb}.ld-feat-badge{letter-spacing:.06em;text-transform:uppercase;color:var(--primary-dark);background:#fff;border-radius:100px;padding:4px 10px;font-size:10.5px;font-weight:800;position:absolute;top:16px;right:16px}.ld-feat-x{color:#ffffffd9;margin-top:10px;font-size:12px;font-weight:700}.ld-course-grid{grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:16px;margin-top:26px;display:grid}.ld-course{text-align:left;font:inherit;color:inherit;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);flex-direction:column;gap:6px;padding:20px 18px;display:flex}.ld-course.avail{cursor:pointer;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-tint), var(--shadow-card);transition:transform .1s}.ld-course.avail:active{transform:scale(.985)}.ld-course.soon{opacity:.55;background:var(--surface-2);box-shadow:none;cursor:not-allowed}.ld-course-tag{letter-spacing:.07em;text-transform:uppercase;color:var(--accent);font-size:10.5px;font-weight:800}.ld-course.soon .ld-course-tag{color:var(--text-faint)}.ld-course-name{letter-spacing:-.01em;font-size:18px;font-weight:800}.ld-course-d{color:var(--text-muted);font-size:13.5px;line-height:1.5}.ld-course-go{color:var(--primary);align-items:center;gap:6px;margin-top:8px;font-size:14px;font-weight:800;display:inline-flex}.ld-center{text-align:center;margin-top:26px}.ld-price{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);max-width:560px;box-shadow:var(--shadow-card);margin-top:22px;padding:22px 20px}.ld-price-big{letter-spacing:-.02em;font-size:36px;font-weight:800}.ld-price-big span{color:var(--text-muted);letter-spacing:0;font-size:15px;font-weight:650}.ld-price p{color:var(--text-muted);margin:8px 0 18px;font-size:14.5px;line-height:1.6}.ld-mail{color:var(--primary);text-underline-offset:3px;overflow-wrap:anywhere;margin-top:16px;font-size:20px;font-weight:800;text-decoration:underline;display:inline-block}.ld-note{color:var(--text-faint);margin-top:8px;font-size:12.5px}.ld-foot{border-top:1px solid var(--border);background:var(--bg);padding:30px 0 40px}.ld-foot-links{flex-wrap:wrap;gap:6px 22px;display:flex}.ld-foot-links a{font:inherit;color:var(--text-muted);cursor:pointer;background:0 0;border:none;padding:6px 0;font-size:14px;font-weight:700}.ld-foot-links a:hover{color:var(--primary);text-decoration:underline}.ld-legal{color:var(--text-faint);max-width:80ch;margin-top:16px;font-size:12px;line-height:1.55}.ld-copy{color:var(--text-faint);margin-top:8px;font-size:12px}@media (min-width:1240px){.ld-hero-in{grid-template-columns:1.15fr .85fr;gap:36px}}@media (min-width:1360px){.ld-trust-grid{grid-template-columns:repeat(5,1fr)}}@media (max-width:759px){.ld-hero{padding:30px 0}.ld-section{padding:44px 0}.ld-cta .ld-btn{flex:100%}}