:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;color:#17202a;--panel:#fff;--line:#d8e0e8;--ink-soft:#5d6b78;--primary:#0f766e;--primary-dark:#115e59;--amber:#b45309;--red:#b42318;--green:#157347;--navy:#1d3557;background:#eef2f6;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}*{box-sizing:border-box}body{min-width:320px;margin:0}button,select,input,textarea{font:inherit}button{background:var(--primary);color:#fff;cursor:pointer;border:0;border-radius:7px;padding:.72rem 1rem;font-weight:700}button:hover{background:var(--primary-dark)}button.secondary{color:var(--navy);background:#e7edf3}button.active{color:#fff;background:var(--navy)}input,select,textarea{border:1px solid var(--line);color:#17202a;background:#fff;border-radius:6px;width:100%;padding:.65rem .72rem}textarea{resize:vertical;min-height:260px;font-family:Cascadia Mono,Consolas,monospace;line-height:1.45}table{border-collapse:collapse;background:#fff;width:100%}th,td{border:1px solid var(--line);text-align:left;vertical-align:top;padding:.6rem}th{background:#edf3f7}pre{border:1px solid var(--line);color:#e9f5f2;white-space:pre-wrap;background:#101820;border-radius:6px;padding:.85rem;line-height:1.45;overflow:auto}.app-shell{min-height:100vh}.app-header{z-index:20;border-bottom:1px solid var(--line);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:#fffffff5;justify-content:space-between;align-items:center;gap:1rem;padding:.8rem 1rem;display:flex;position:sticky;top:0}.app-header>div{white-space:nowrap;align-items:center;gap:.6rem;display:flex}.brand-mark{background:var(--navy);color:#fff;border-radius:6px;justify-content:center;align-items:center;width:48px;height:32px;font-weight:800;display:inline-flex}nav{gap:.35rem;padding-bottom:.1rem;display:flex;overflow-x:auto}nav button{color:#273747;background:0 0;padding:.55rem .7rem}.app-main{padding:1rem}.dashboard,.page-section,.single-pane{max-width:1260px;margin:0 auto}.hero-lab{border:1px solid var(--line);background:linear-gradient(135deg,#fff 0%,#f7fbfa 55%,#eef7f0 100%);border-radius:8px;grid-template-columns:1fr minmax(220px,320px);align-items:stretch;gap:1rem;padding:1.2rem;display:grid}.hero-lab h1{letter-spacing:0;margin:.15rem 0 .6rem;font-size:clamp(2rem,4vw,4rem)}.eyebrow{color:var(--primary-dark);text-transform:uppercase;margin:0 0 .25rem;font-size:.78rem;font-weight:800}.progress-card,.dashboard-grid article,.info-band,.pane,.component-card,.task-box,.part,.note article{border:1px solid var(--line);background:var(--panel);border-radius:8px}.progress-card{padding:1rem}.progress-card strong{font-size:3rem;display:block}.action-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:.75rem;margin:1rem 0;display:grid}.dashboard-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:1rem;display:grid}.dashboard-grid article,.info-band{padding:1rem}progress{width:100%;height:16px}.split{grid-template-columns:minmax(0,1.35fr) minmax(320px,.65fr);align-items:start;gap:1rem;max-width:1460px;margin:0 auto;display:grid}.pane{padding:1rem}.side{max-height:calc(100vh - 92px);position:sticky;top:76px;overflow:auto}.section-head,.component-head,.button-row{justify-content:space-between;align-items:center;gap:.75rem;display:flex}.task-box,.warning,.success-box,.error-box,.learning-plan,.solution{border-radius:8px;margin:1rem 0;padding:1rem}.warning{color:#7c2d12;background:#fff7ed;border:1px solid #f3d19e}.success-box{color:#0f5132;background:#f0fbf5;border:1px solid #badbcc}.error-box{color:#7a1d16;background:#fff5f5;border:1px solid #f1b6b1}.form-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:.75rem;margin:1rem 0;display:grid}label span{color:#415161;margin-bottom:.3rem;font-size:.9rem;font-weight:700;display:block}.textarea-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:.8rem;display:grid}.learn-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;display:grid}.note.compact .learn-grid{grid-template-columns:1fr}.note article,.page-section article{padding:1rem}.cable-toolbar{grid-template-columns:minmax(220px,300px) 1fr;align-items:end;gap:.75rem;margin:1rem 0;display:grid}.reference-topology{border:1px solid var(--line);background:#fff;border-radius:8px;grid-template-columns:minmax(90px,.7fr) minmax(120px,1fr) minmax(90px,.7fr) minmax(120px,1fr) minmax(90px,.7fr) minmax(120px,1fr) minmax(90px,.7fr);align-items:center;gap:.35rem;margin:1rem 0;padding:2rem .8rem .85rem;display:grid;position:relative;overflow-x:auto}.ref-lan{color:#17202a;font-size:.9rem;font-weight:800;position:absolute;top:.45rem}.ref-lan.lan1{left:26%}.ref-lan.lan2{left:68%}.ref-device{color:#102a43;text-align:center;background:#e9f3f7;border:2px solid #8fb0c7;border-radius:8px;justify-content:center;align-items:center;min-width:88px;min-height:56px;padding:.45rem;font-weight:900;display:flex}.ref-router{background:#dff4e8;border-color:#0f766e;border-radius:999px}.ref-switch{background:#e7edf7;border-color:#1d3557}.ref-pc{background:#fff7ed;border-color:#b45309}.ref-link{color:#334155;text-align:center;grid-template-columns:1fr;justify-items:center;gap:.2rem;min-width:120px;font-size:.74rem;display:grid;position:relative}.ref-link:before{content:"";background:#c2410c;border-radius:999px;order:2;width:100%;height:5px;display:block}.ref-link b{color:#7c2d12;order:1;font-size:.68rem}.ref-link span:first-child{justify-self:start}.ref-link span:last-child{justify-self:end}.ref-console{color:var(--ink-soft);grid-column:span 3;padding-top:.45rem;font-size:.82rem}.cable-hint{color:#334155;background:#f8fbfd;border:1px dashed #9fb3c8;border-radius:8px;align-items:center;min-height:45px;padding:.65rem .8rem;display:flex}.topology-canvas{border:1px solid var(--line);background-color:#fff;background-image:linear-gradient(#eef4f7 1px,#0000 1px),linear-gradient(90deg,#eef4f7 1px,#0000 1px),none;background-position:0 0,0 0,0 0;background-repeat:repeat,repeat,repeat;background-size:28px 28px;background-attachment:scroll,scroll,scroll;background-origin:padding-box,padding-box,padding-box;background-clip:border-box,border-box,border-box;border-radius:8px;min-height:430px;position:relative;overflow:hidden}.cable-lines{pointer-events:none;z-index:1;width:100%;height:100%;position:absolute;inset:0}.device-box{z-index:2;background:#fbfdff;border:1px solid #9fb3c8;border-radius:8px;width:min(230px,34%);padding:.75rem;position:absolute;transform:translate(-50%,-50%);box-shadow:0 10px 24px #0f172a1a}.device-box.router{border-top:5px solid #0f766e}.device-box.switch{border-top:5px solid #1d3557}.device-box.pc{border-top:5px solid #b45309}.device-title{justify-content:space-between;align-items:baseline;gap:.5rem;margin-bottom:.6rem;display:flex}.drag-handle{cursor:grab;-webkit-user-select:none;user-select:none;touch-action:none}.drag-handle:active{cursor:grabbing}.device-title span{color:var(--ink-soft);font-size:.82rem;font-weight:700}.port-list{gap:.45rem;display:grid}.port-dot{color:#17202a;cursor:crosshair;background:#edf3f7;border:1px solid #c8d4df;border-radius:6px;justify-content:center;align-items:center;width:100%;min-height:38px;padding:.35rem .45rem;font-size:.86rem;display:flex}.port-dot:hover,.port-dot.selected{border-color:var(--primary);color:#0f5132;background:#dff4e8}.empty-cables{color:var(--ink-soft);margin:.9rem 0}.visual-connection-list{gap:.45rem;margin:.9rem 0;display:grid}.visual-connection-row{border:1px solid var(--line);background:#fff;border-radius:7px;grid-template-columns:minmax(0,1fr) minmax(150px,.65fr) minmax(0,1fr) 36px;align-items:center;gap:.5rem;padding:.5rem;display:grid}.visual-connection-row span,.visual-connection-row strong{overflow-wrap:anywhere}.icon-button{color:#991b1b;background:#fee2e2;border-radius:6px;justify-content:center;align-items:center;width:32px;height:32px;padding:0;display:inline-flex}.part{margin:1rem 0;padding:1rem}.submit{background:#9a3412;width:100%;margin:1rem 0}.submit:hover{background:#7c2d12}.score-banner{border-radius:8px;grid-template-columns:repeat(4,minmax(0,1fr));gap:.6rem;margin-bottom:1rem;padding:1rem;display:grid}.score-banner div{background:#ffffffb8;border-radius:6px;padding:.75rem}.score-banner span{color:#415161;font-size:.78rem;display:block}.score-banner strong{font-size:1.45rem}.score-banner.good{background:#dff4e8}.score-banner.warn{background:#fff1d6}.score-banner.bad{background:#ffe1df}.component-list{gap:.75rem;display:grid}.component-card{padding:.85rem}.pill{background:#edf3f7;border-radius:999px;padding:.18rem .55rem;font-size:.78rem;font-weight:800}.pill.correct{color:var(--green);background:#dff4e8}.pill.partial{color:var(--amber);background:#fff1d6}.pill.incorrect{color:var(--red);background:#ffe1df}.error-list{padding-left:1.1rem}.feedback-item{border-top:1px solid #0000001a;margin-top:.75rem;padding-top:.75rem}.check-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:.5rem;margin-top:1rem;display:grid}.muted{color:var(--ink-soft)}.table-wrap{overflow-x:auto}@media (width<=980px){.app-header,.section-head{flex-direction:column;align-items:stretch}.split,.hero-lab,.dashboard-grid,.learn-grid,.textarea-grid{grid-template-columns:1fr}.side{max-height:none;position:static}.action-grid,.form-grid,.score-banner,.check-list{grid-template-columns:repeat(2,minmax(0,1fr))}.cable-toolbar,.reference-topology,.visual-connection-row{grid-template-columns:1fr}.reference-topology{padding-top:.85rem}.ref-lan{position:static}.ref-console{grid-column:1}.topology-canvas{min-height:720px}.device-box{width:min(270px,78%)}}@media (width<=620px){.app-main{padding:.6rem}.pane,.part{padding:.75rem}.action-grid,.form-grid,.score-banner,.check-list{grid-template-columns:1fr}}
