:root{color-scheme:light;--ink:#20343a;--muted:#65777d;--teal:#165e63;--teal-dark:#10464b;--mint:#e9f3ef;--line:#cfdfda;--cream:#f7f8f3;--white:#fff;--warning:#8b5727}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{background:var(--white);scroll-behavior:smooth}
body{margin:0;padding:24px;font:15px/1.55 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--white)}
button,input,a{font:inherit}
button,a,input,summary,pre{touch-action:manipulation}
button{cursor:pointer}
button:disabled{cursor:default;opacity:.55}
button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,pre:focus-visible{outline:3px solid #4ba9a0;outline-offset:3px}
a{color:var(--teal);text-underline-offset:3px}
p{margin:0 0 16px}
h1,h2,h3{line-height:1.2;letter-spacing:-.02em}
h1{font-size:clamp(26px,4.3vw,38px);margin:12px 0 14px;max-width:680px}
h2{font-size:clamp(23px,3.7vw,30px);margin:12px 0}
h3{font-size:21px;margin:12px 0}
code{font:12px/1.5 ui-monospace,SFMono-Regular,Consolas,monospace;background:#edf2ef;border-radius:4px;padding:2px 5px;overflow-wrap:anywhere;color:#28585b}
kbd{display:inline-block;border:1px solid #bfceca;border-bottom-width:2px;background:#fff;padding:1px 5px;font:12px/1.5 system-ui,sans-serif;border-radius:4px;white-space:nowrap}
.devlab{max-width:1100px;margin:0 auto;min-width:0}
.lab-kicker,.panel-number,.mini-label{font-size:11px;font-weight:750;letter-spacing:.11em;text-transform:uppercase;color:var(--teal)}
.lab-kicker{display:flex;align-items:center;gap:8px}
.lab-dot{height:8px;width:8px;display:inline-block;border-radius:50%;background:#72b9a3}
.lab-intro>p{max-width:750px;color:var(--muted)}
.lab-start-note{background:var(--cream);border:1px solid var(--line);border-radius:12px;padding:14px 16px;font-size:13px;color:#53666c}
.lab-start-note strong{color:var(--ink)}
.scenario-nav{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px;margin:24px 0 26px}
.scenario-button{position:relative;border:1px solid var(--line);border-radius:12px;padding:16px 12px;min-height:83px;min-width:0;background:#fff;color:var(--ink);display:flex;align-items:center;gap:10px;text-align:left;transition:background .15s,border-color .15s,box-shadow .15s}
.scenario-button:hover{background:#f3f7f4;border-color:#75a69a;color:var(--ink)}
.scenario-button.is-active{border:2px solid var(--teal);padding:15px 11px;background:var(--mint);box-shadow:0 4px 12px #254e3d08;color:var(--ink)}
.scenario-button .icon{width:24px;height:24px;color:var(--teal);flex:0 0 24px}
.scenario-button span{display:block;min-width:0}
.scenario-button b{font-size:14px;display:block;line-height:1.3}
.scenario-button small{font-size:11px;display:block;color:var(--muted);margin-top:5px;line-height:1.3}
.scenario-button em{font-size:10px;font-style:normal;position:absolute;right:8px;top:6px;color:#93a49f}
.icon{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;flex:0 0 20px}
.panel-heading{max-width:750px}
.panel-heading>p{color:var(--muted);font-size:14px;max-width:660px}
.demo-surface{border:1px solid var(--line);border-radius:16px;background:var(--cream);padding:22px;margin:22px 0 18px;min-width:0}
.elements-stage{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:24px;align-items:center}
.practice-card{padding:20px;background:#fff;border:1px solid #ccded8;border-radius:16px;box-shadow:0 8px 25px #31554b0b;max-width:370px;--card-accent:#8bbfaf;--card-dark:#296d64}
.practice-card.is-warm{--card-accent:#e3b18b;--card-dark:#86572e}
.practice-art{height:76px;position:relative;overflow:hidden;border-radius:10px;background:color-mix(in srgb,var(--card-accent) 25%,white);margin-bottom:20px}
.practice-art span{display:block;position:absolute;background:var(--card-accent);height:70px;width:70px;border-radius:18px;transform:rotate(30deg);bottom:-30px;left:22px}
.practice-art span:nth-child(2){height:90px;width:90px;left:88px;bottom:-45px;background:var(--card-dark)}
.practice-art span:nth-child(3){height:33px;width:33px;border-radius:50%;right:30px;left:auto;bottom:28px;background:#eccd8c}
.practice-card .mini-label{font-size:10px;color:var(--card-dark)}
.practice-card p{font-size:13px;color:var(--muted);margin-bottom:20px}
.practice-action{min-height:44px;border:0;border-radius:9px;background:var(--card-dark);color:#fff;padding:10px 14px;display:flex;gap:10px;align-items:center;justify-content:space-between;width:100%;font-size:13px;font-weight:650;transition:transform .15s,box-shadow .15s,background .15s}
.practice-action:hover,.practice-action:focus-visible{background:#203d36;box-shadow:0 5px 12px #203d3633;transform:translateY(-2px);color:#fff}
.demo-controls .lab-button{width:100%;margin:0 0 9px}
.control-hint{font-size:13px;color:var(--muted)}
.lab-button{border:1px solid #b8ceca;min-height:44px;border-radius:9px;background:#fff;color:var(--ink);padding:10px 14px;display:inline-flex;align-items:center;justify-content:center;gap:7px;text-align:center;font-size:13px;font-weight:600;line-height:1.4;max-width:100%;white-space:normal;transition:background .15s,border-color .15s,box-shadow .15s}
.lab-button:hover:not(:disabled){border-color:var(--teal);background:#e5efeb;color:var(--ink)}
.lab-button.button-primary{background:var(--teal);border-color:var(--teal);color:#fff}
.lab-button.button-primary:hover:not(:disabled){background:var(--teal-dark);border-color:var(--teal-dark);color:#fff}
.lab-button.button-warning{background:#faf2e9;border-color:#dec7ae;color:#73451f}
.lab-button.button-warning:hover:not(:disabled){background:#f3e4d3;border-color:#b48b64;color:#623a1b}
.lab-button.button-subtle{background:transparent}
.lab-button.button-small{font-size:12px;padding:9px 12px}
.button-row{display:flex;flex-wrap:wrap;gap:8px;margin:16px 0}
.button-row .lab-button{flex:1 1 auto}
.action-feedback{margin:14px 0 0;font-size:13px;color:var(--muted);overflow-wrap:anywhere}
.steps-card{border:1px solid var(--line);border-radius:13px;background:#fff;padding:0 18px;margin-bottom:24px}
.steps-card summary{font-size:14px;font-weight:750;min-height:50px;cursor:pointer;padding:14px 0;list-style-position:inside;color:var(--ink)}
.steps-card ol{padding-left:21px;margin:0 0 16px;font-size:13px;color:#53666c}
.steps-card li{padding-left:3px;margin:0 0 10px}
.steps-card li strong{color:var(--ink)}
.steps-card>p{border-top:1px solid #e3ebe7;padding-top:14px;font-size:12px;color:var(--muted)}
.fixture-heading{display:flex;justify-content:space-between;align-items:center;gap:14px;margin-bottom:14px;flex-wrap:wrap}
.fixture-heading strong{font-size:13px}
.fixture-list{border:1px solid var(--line);border-radius:10px;overflow:hidden;background:#fff}
.fixture-row{display:flex;justify-content:space-between;gap:8px;border-bottom:1px solid #e4ede8;padding:11px 12px;font-size:13px;align-items:center}
.fixture-row:last-child{border-bottom:0}
.fixture-row span:last-child{color:var(--muted);font-size:12px;text-align:right}
.network-diagram{display:flex;align-items:center;justify-content:center;gap:15px;margin:3px 0 22px}
.network-diagram span{border:1px solid #c2d8d0;border-radius:10px;padding:16px 22px;background:#fff;font-size:13px;font-weight:650}
.network-diagram .icon{color:var(--teal)}
.resource-label{color:var(--muted);font-size:13px}
.result-box{border:1px solid #c8dcd4;border-radius:11px;background:#fff;padding:16px;font-size:13px;overflow-wrap:anywhere}
.result-box strong{display:block;font-size:20px;font-weight:750;margin:4px 0 7px;line-height:1.3}
.result-box p:last-child{margin-bottom:0;color:var(--muted)}
.result-box.is-error{border-color:#d8c4b2;background:#fffaf4}
.network-result strong{font-size:16px}
.network-result .fixture-list{margin-top:14px}
.result-meta{display:flex;flex-wrap:wrap;gap:8px;font-size:11px;color:var(--muted);margin-top:10px}
.result-meta span{background:#f1f5f2;border-radius:4px;padding:3px 6px}
.input-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
label{font-size:12px;color:#52686f;font-weight:600;display:block;min-width:0}
input[type=number]{display:block;width:100%;min-width:0;min-height:44px;border:1px solid #bcd1ca;border-radius:8px;background:#fff;color:var(--ink);padding:10px 12px;margin-top:7px;font-size:15px;font-weight:600}
.source-result strong{font-size:26px}
.source-result .mini-label{font-size:10px}
.code-heading{display:flex;gap:8px;align-items:center;justify-content:space-between;flex-wrap:wrap;margin-top:24px;font-size:12px}
.code-block{border:1px solid #cddcd6;border-radius:10px;background:#1d3337;color:#dcefe7;margin:10px 0 0;padding:16px;font:12px/1.6 ui-monospace,SFMono-Regular,Consolas,monospace;overflow:auto;max-width:100%;white-space:pre;tab-size:2}
.code-block code{background:none;padding:0;color:inherit;font:inherit;overflow-wrap:normal}
.count-label{max-width:370px}
.count-label input{max-width:170px}
.count-label small{display:block;font-size:11px;font-weight:400;color:var(--muted);margin-top:9px;line-height:1.5}
.performance-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(85px,1fr));gap:7px;max-height:230px;overflow-y:auto;margin-top:16px;overscroll-behavior:contain;scrollbar-gutter:stable}
.performance-grid:empty{display:none}
.performance-item{border:1px solid #c7dbd2;border-radius:8px;background:#fff;padding:12px 8px;min-height:54px;text-align:center;font-size:11px;color:#4a696b}
.performance-item b{display:block;font-size:13px;color:var(--teal)}
.small-note{font-size:12px;color:var(--muted);margin:16px 0 0}
.memory-status{display:flex;align-items:center;gap:13px;flex-wrap:wrap;margin:4px 0 20px}
.memory-status>.icon{width:34px;height:34px;flex-basis:34px;color:var(--teal)}
.memory-status strong{display:block;font-size:30px;line-height:1.15;margin-top:5px}
.memory-status .mini-label{font-size:10px;letter-spacing:.08em}
.status-chip{font-size:11px;white-space:nowrap;padding:5px 9px;border:1px solid #ccddd6;border-radius:20px;background:#fff;margin-left:auto;color:var(--muted)}
.status-chip.is-retained{background:#dfede6;color:var(--teal);border-color:#b6d2c5}
.memory-code{margin-top:20px}
.memory-code>code{display:block;margin:10px 0;font-size:12px;overflow-wrap:anywhere}
.lab-footer{border-top:1px solid var(--line);padding-top:21px;display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;font-size:12px;color:var(--muted)}
.lab-footer>a{font-size:13px;font-weight:650;min-height:44px;display:inline-flex;gap:8px;align-items:center}
.lab-footer p{width:100%;font-size:11px;margin:0;color:var(--muted)}
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);clip-path:inset(50%);white-space:nowrap}
.noscript-note{border:1px solid #d1b891;background:#fff7e8;padding:14px;margin-top:20px;font-size:13px}
@media(max-width:600px){body{padding:16px}.scenario-nav{gap:7px;margin:20px 0 24px}.scenario-button{flex-direction:column;align-items:flex-start;gap:8px;padding:13px 10px;min-height:100px}.scenario-button.is-active{padding:12px 9px}.scenario-button small{font-size:10px}.elements-stage{grid-template-columns:minmax(0,1fr);gap:18px}.practice-card{max-width:100%;}.demo-controls{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:8px}.demo-controls .control-hint,.demo-controls .action-feedback{grid-column:1/-1}.demo-controls .control-hint{margin:0}.demo-controls .lab-button{margin:0}.demo-controls .action-feedback{margin-top:3px}.demo-surface{padding:17px}.network-diagram span{padding:12px 15px}.memory-status .status-chip{margin-left:0}.button-row .lab-button{flex-basis:100%}.steps-card{padding:0 14px}}
@media(max-width:420px){.scenario-nav{grid-template-columns:repeat(2,minmax(0,1fr));gap:7px}.scenario-button{min-height:94px}.lab-start-note{padding:12px;font-size:12px}.demo-surface{padding:14px}.practice-card{padding:16px}.demo-controls{grid-template-columns:minmax(0,1fr)}.demo-controls .control-hint,.demo-controls .action-feedback{grid-column:auto}.input-grid{grid-template-columns:minmax(0,1fr);gap:12px}.network-diagram{gap:9px}.network-diagram span{padding:11px 9px;font-size:11px}.network-diagram .icon{width:16px;flex-basis:16px}.fixture-row{align-items:flex-start}.fixture-row span:last-child{max-width:100px}.fixture-heading{gap:7px}.memory-status{gap:10px}.memory-status .mini-label{font-size:9px}.memory-status strong{font-size:27px}.memory-status>.icon{width:28px;height:28px;flex-basis:28px}.code-block{padding:12px;font-size:11px}.lab-footer>a{width:100%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}.practice-action:hover,.practice-action:focus-visible{transform:none}}