:root{
  --bg:#f4f6f9;--panel:#ffffff;--panel-soft:#f8fafc;--ink:#1f2937;--muted:#687386;--line:#dce2ea;
  --accent:#f4b63f;--accent-dark:#6b4700;--teal:#3157a4;--teal-soft:#e8eefb;--tension:#2678d9;--compression:#df5b55;
  --critical:#e9a91c;--ok:#198754;--danger:#c43d45;--water:#dceff5;--shadow:0 10px 30px rgba(32,64,55,.08);
}
*{box-sizing:border-box}html{background:#f6f7f9}body{margin:0;color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:linear-gradient(180deg,#fafbfc 0,#f2f4f7 360px)}button,input,select{font:inherit}button{touch-action:manipulation}.app-shell{max-width:1720px;margin:0 auto;padding:20px}.hero{display:flex;align-items:flex-end;justify-content:space-between;gap:24px;padding:20px 8px 24px}.eyebrow{font-size:0.75rem;letter-spacing:.14em;font-weight:900;color:var(--teal)}.hero h1{font-size:clamp(32px,4.5vw,58px);letter-spacing:-.035em;line-height:1;margin:6px 0 10px}.hero p{margin:0;color:var(--muted);max-width:760px;font-size:1.0625rem;line-height:1.5}.challenge-chip{min-width:220px;background:var(--ink);color:white;border-radius:18px;padding:15px 18px;box-shadow:var(--shadow)}.challenge-chip span,.challenge-chip small{display:block;color:#c6d7d2}.challenge-chip span{font-size:0.6875rem;text-transform:uppercase;letter-spacing:.1em;font-weight:800}.challenge-chip strong{display:block;font-size:1.5rem;margin:3px 0}.challenge-chip small{font-size:0.75rem}.step-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-bottom:14px}.step{display:flex;align-items:center;gap:10px;border:1px solid var(--line);background:rgba(255,255,255,.68);padding:10px 14px;border-radius:13px;color:var(--muted)}.step b{display:grid;place-items:center;width:29px;height:29px;border-radius:50%;background:#e8efed;color:var(--muted);flex:0 0 auto}.step span{min-width:0}.step strong,.step small{display:block}.step strong{color:var(--ink);font-size:0.8125rem}.step small{font-size:0.6875rem;margin-top:1px}.step.active{border-color:#9bc9c2;background:white}.step.active b{background:var(--teal);color:white}.panel{background:rgba(255,255,255,.94);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow)}.workspace{display:grid;grid-template-columns:270px minmax(520px,1fr) 320px;gap:14px;align-items:start}.build-panel,.result-panel{padding:16px;position:sticky;top:10px}.panel-heading{display:flex;gap:10px;align-items:flex-start;margin-bottom:14px}.panel-heading h2{font-size:1.1875rem;margin:0}.panel-heading p{font-size:0.75rem;color:var(--muted);margin:3px 0 0}.step-number{display:grid;place-items:center;width:30px;height:30px;background:var(--teal);color:white;border-radius:9px;font-weight:900;flex:0 0 auto}.tool-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}.tool-btn{border:1px solid var(--line);background:var(--panel-soft);color:var(--ink);border-radius:12px;padding:10px 8px;min-height:76px;cursor:pointer;text-align:left;transition:.15s ease}.tool-btn:hover{border-color:#a8c1ba;transform:translateY(-1px)}.tool-btn.active{border:2px solid var(--teal);background:var(--teal-soft);padding:9px 7px}.tool-btn.danger{color:var(--danger)}.tool-icon{display:block;font-size:1.375rem;line-height:1;margin-bottom:6px}.tool-btn b,.tool-btn small{display:block}.tool-btn b{font-size:0.8125rem}.tool-btn small{font-size:0.625rem;color:var(--muted);margin-top:2px}.field{display:block;margin-top:15px}.field>span,.mini-label{display:block;font-size:0.6875rem;font-weight:800;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin-bottom:6px}.field select{width:100%;border:1px solid var(--line);background:white;color:var(--ink);border-radius:10px;padding:11px}.material-note{margin-top:7px;font-size:0.6875rem;line-height:1.45;color:var(--muted)}.button-row{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:14px}.button-row button,.test-actions button{border:1px solid var(--line);background:white;color:var(--ink);border-radius:11px;padding:11px;cursor:pointer;font-weight:750}.button-row button:hover,.test-actions button:hover{border-color:#9ab6ae}.coach-box{margin-top:14px;border:1px solid #d9e0ea;background:#f7f9fc;border-radius:13px;padding:12px}.coach-label{display:block;font-size:0.625rem;font-weight:900;letter-spacing:.11em;color:var(--teal);margin-bottom:5px}.coach-box strong{display:block;font-size:0.8125rem;line-height:1.35}.coach-box p{font-size:0.6875rem;color:var(--muted);line-height:1.45;margin:5px 0 0}.selection-wrap{margin-top:15px}.selection-panel{border:1px solid var(--line);background:var(--panel-soft);border-radius:11px;padding:11px;font-size:0.75rem;line-height:1.5}.muted{color:var(--muted)}.canvas-panel{overflow:hidden}.canvas-toolbar{display:flex;justify-content:space-between;gap:16px;align-items:end;padding:14px;border-bottom:1px solid var(--line)}.load-control{flex:1;max-width:600px}.load-control>label{display:block;font-weight:850;font-size:0.8125rem;margin-bottom:6px}.load-row{display:grid;grid-template-columns:minmax(160px,1fr) 118px;gap:10px;align-items:center}.load-row input[type=range]{width:100%;accent-color:var(--teal)}.load-number{display:grid;grid-template-columns:1fr auto;align-items:center;gap:6px;border:1px solid var(--line);border-radius:10px;background:white;padding:2px 8px}.load-number input{width:100%;border:0;outline:0;padding:8px 0;color:var(--ink);font-weight:800}.load-number b{font-size:0.75rem;color:var(--muted)}.load-help{font-size:0.6875rem;color:var(--muted);margin-top:5px}.test-actions{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}.test-actions button{min-height:46px}.test-actions .primary{background:var(--accent);border-color:#e3a62f;color:#3d2a05;font-size:0.875rem}.break-btn{background:#fff7f5!important;color:#8f3038!important;border-color:#efc8ca!important}.test-actions button:disabled{opacity:.55;cursor:not-allowed}.canvas-stage{position:relative;background:#fbfbfc}.challenge-flag{position:absolute;z-index:3;left:14px;top:14px;background:rgba(23,49,44,.91);color:white;border-radius:11px;padding:8px 11px;pointer-events:none}.challenge-flag span,.challenge-flag strong{display:block}.challenge-flag span{font-size:0.5625rem;text-transform:uppercase;letter-spacing:.09em;color:#cce0da}.challenge-flag strong{font-size:0.875rem;margin-top:1px}#bridgeSvg{display:block;width:100%;aspect-ratio:5/3;touch-action:none;cursor:crosshair;background:linear-gradient(#ffffff,#f4f6f8)}.grid-bg{color:#a8b3c5}.water-gap{fill:var(--water);opacity:.78}.ground{stroke:#6d817b;stroke-width:3}.member{stroke:var(--beam-stroke,#768b85);stroke-width:var(--beam-width,10);stroke-linecap:round;cursor:pointer;transition:stroke .1s,stroke-width .1s,opacity .15s}.member.selected{stroke:var(--accent);stroke-width:14}.member.tension{stroke:var(--tension)}.member.compression{stroke:var(--compression)}.member.critical{stroke:var(--critical);stroke-width:14}.member.broken{stroke:var(--danger);stroke-dasharray:9 8;opacity:.5}.deformed{stroke:#243a34;stroke-width:2;stroke-dasharray:7 7;opacity:.52;pointer-events:none}.preview{stroke:var(--teal);stroke-width:7;stroke-dasharray:10 8;opacity:.65;pointer-events:none}.node{fill:white;stroke:#1d4037;stroke-width:4;cursor:grab}.node.support{fill:var(--accent)}.node.load-node{stroke:#7e5b00;stroke-width:7}.node.selected{fill:#fff5cf;stroke:var(--teal);stroke-width:7}.support-symbol{fill:#cf9a2f;stroke:#5a430a;stroke-width:2}.load-line{stroke:#795600;stroke-width:5}.load-arrow-head{fill:#795600}.failure-x{fill:var(--danger);font-size:2.5rem;font-weight:900;pointer-events:none}.canvas-status{display:flex;justify-content:space-between;gap:12px;padding:10px 14px;border-top:1px solid var(--line);font-size:0.75rem;color:var(--muted);background:white}.force-legend{display:flex;gap:16px;flex-wrap:wrap;padding:10px 14px;border-top:1px solid var(--line);font-size:0.6875rem;background:#fbfdfc}.force-legend span{display:flex;gap:5px;align-items:center}.dot{display:inline-block;width:10px;height:10px;border-radius:50%}.dot.tension{background:var(--tension)}.dot.compression{background:var(--compression)}.dot.critical{background:var(--critical)}.dot.broken{background:var(--danger)}.result-hero{border-radius:14px;padding:15px;border:1px solid var(--line);background:var(--panel-soft)}.result-hero .result-kicker{display:block;font-size:0.625rem;font-weight:900;letter-spacing:.11em;margin-bottom:6px}.result-hero strong{display:block;font-size:1.125rem;line-height:1.25}.result-hero p{font-size:0.75rem;color:var(--muted);line-height:1.45;margin:6px 0 0}.result-hero.pass{background:#edf8f2;border-color:#b4ddc6}.result-hero.pass .result-kicker{color:var(--ok)}.result-hero.warn{background:#fff9e8;border-color:#ecd489}.result-hero.warn .result-kicker{color:#9d6a00}.result-hero.fail{background:#fff1f1;border-color:#efb9bd}.result-hero.fail .result-kicker{color:var(--danger)}.simple-metrics{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:10px}.simple-metrics>div{border:1px solid var(--line);background:var(--panel-soft);border-radius:11px;padding:9px}.simple-metrics span,.simple-metrics small{display:block;color:var(--muted)}.simple-metrics span{font-size:0.625rem}.simple-metrics strong{display:block;font-size:1.0625rem;margin:3px 0}.simple-metrics small{font-size:0.5625rem}.result-coach{margin-top:10px}.result-card{margin-top:10px;border:1px solid var(--line);border-radius:11px;padding:11px;background:var(--panel-soft)}.result-card h3{font-size:0.75rem;margin:0 0 6px}.result-card div{font-size:0.75rem;line-height:1.45}.advanced-details{margin-top:10px;border-top:1px solid var(--line);padding-top:10px}.advanced-details summary{cursor:pointer;font-size:0.75rem;font-weight:800;color:var(--muted)}.advanced-body{font-size:0.6875rem;color:var(--muted);line-height:1.5;padding-top:8px}.advanced-body>div+div{margin-top:10px}.advanced-body ul{margin:6px 0 0;padding-left:17px}.good{color:var(--ok)}.bad{color:var(--danger)}.state-tension{color:var(--tension)}.state-compression{color:var(--compression)}.state-critical{color:#a26a00;font-weight:800}.learn-panel{margin-top:14px;padding:18px;display:grid;grid-template-columns:minmax(220px,.65fr) minmax(0,1.35fr);gap:20px}.learn-panel h2{font-size:1.3125rem;margin:4px 0 7px}.learn-panel>div>p{color:var(--muted);font-size:0.8125rem;line-height:1.55;margin:0}.learn-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.learn-cards article{border:1px solid var(--line);border-radius:12px;padding:10px;display:flex;gap:9px;align-items:flex-start;background:var(--panel-soft)}.learn-cards strong{font-size:0.75rem}.learn-cards p{font-size:0.625rem;color:var(--muted);line-height:1.4;margin:3px 0 0}.learn-icon{display:grid;place-items:center;width:36px;height:36px;border-radius:10px;font-size:0.875rem;font-weight:900;flex:0 0 auto}.tension-bg{background:#e7f1ff;color:var(--tension)}.compression-bg{background:#ffebe9;color:var(--compression)}.critical-bg{background:#fff2c8;color:#936200}.data-panel{margin-top:14px;padding:0 16px 14px}.data-panel>summary{list-style:none;cursor:pointer;padding:14px 0;display:flex;justify-content:space-between;align-items:center;gap:16px}.data-panel>summary::-webkit-details-marker{display:none}.data-panel summary span:first-child b,.data-panel summary span:first-child small{display:block}.data-panel summary span:first-child small{font-size:0.625rem;color:var(--muted);margin-top:2px}.data-panel summary>span:last-child{font-size:0.6875rem;color:var(--muted)}.table-scroll{overflow:auto;border-top:1px solid var(--line)}table{width:100%;border-collapse:collapse;font-size:0.75rem}th,td{text-align:left;padding:9px;border-bottom:1px solid var(--line);white-space:nowrap}th{font-size:0.625rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}td{color:var(--muted)}td strong{color:var(--ink)}.canvas-stage.testing{animation:stagePulse .55s ease}.canvas-stage.collapse{animation:shake .35s linear 2}@keyframes stagePulse{50%{background:#fff7d8}}@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}
@media(max-width:1250px){.workspace{grid-template-columns:250px minmax(480px,1fr)}.result-panel{position:static;grid-column:1/-1;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.result-panel>.panel-heading,.result-panel>.result-hero,.result-panel>.advanced-details{grid-column:1/-1}.simple-metrics{margin-top:0}.result-coach,.result-card{margin-top:0}}
@media(max-width:820px){.app-shell{padding:10px}.hero{display:block;padding:14px 2px}.hero p{font-size:0.875rem}.challenge-chip{margin-top:14px;min-width:0;display:inline-block}.step-strip{gap:4px}.step{padding:8px}.step small{display:none}.workspace{display:block}.build-panel,.result-panel{position:static;margin-bottom:10px}.canvas-panel{margin-bottom:10px}.result-panel{display:block}.canvas-toolbar{display:block}.test-actions{justify-content:stretch;margin-top:12px}.test-actions button{flex:1}.load-row{grid-template-columns:minmax(100px,1fr) 112px}#bridgeSvg{aspect-ratio:4/3}.canvas-status{display:block}.canvas-status span{display:block}.canvas-status span+span{margin-top:3px}.learn-panel{display:block}.learn-cards{margin-top:12px}.tool-btn{min-height:70px}.result-coach,.result-card{margin-top:10px}}
@media(max-width:520px){.step span small{display:none}.step{justify-content:center}.step span{display:none}.tool-grid{grid-template-columns:1fr 1fr}.secondary-actions{grid-template-columns:1fr}.test-actions{display:grid;grid-template-columns:1fr}.learn-cards{grid-template-columns:1fr}.simple-metrics{grid-template-columns:1fr 1fr}.challenge-flag{top:8px;left:8px}.build-panel,.result-panel{padding:13px}.canvas-toolbar{padding:12px}.hero h1{font-size:2.125rem}}

/* v0.4 younger-builder UX */
.compact-hero{padding-bottom:18px}.compact-hero h1{font-size:clamp(30px,4vw,52px)}
.mission-bar{display:grid;grid-template-columns:auto minmax(0,1fr) auto auto;gap:12px;align-items:center;margin-bottom:14px;padding:12px 14px}.mission-icon{display:grid;place-items:center;width:42px;height:42px;border-radius:12px;background:var(--teal-soft);color:var(--teal);font-size:1.375rem;font-weight:900}.mission-copy{min-width:0}.mission-copy .mini-label{margin-bottom:2px}.mission-copy strong{font-size:0.875rem;line-height:1.3}.readiness-badge{border-radius:999px;padding:8px 11px;font-size:0.625rem;font-weight:900;letter-spacing:.07em}.readiness-badge.building{background:#eef2f1;color:var(--muted)}.readiness-badge.fix{background:#fff2c8;color:#815600}.readiness-badge.ready{background:#e8f7ef;color:var(--ok)}.readiness-badge.done{background:#e7f1ff;color:var(--tension)}.triangle-badge{min-width:70px;border-left:1px solid var(--line);padding-left:12px;text-align:center}.triangle-badge span,.triangle-badge strong{display:block}.triangle-badge span{font-size:0.5625rem;text-transform:uppercase;color:var(--muted);letter-spacing:.06em}.triangle-badge strong{font-size:1.375rem;margin-top:1px}.kid-panel .panel-heading{margin-bottom:10px}.simple-tools{grid-template-columns:1fr 1fr}.simple-tools .utility-tool{grid-column:1/-1;min-height:58px}.kid-panel .tool-btn{min-height:68px}.lab-tools{margin-top:12px;border-top:1px solid var(--line);padding-top:10px}.lab-tools summary,.custom-test summary{cursor:pointer;font-size:0.6875rem;font-weight:850;color:var(--muted)}.lab-tools-body{padding-top:4px}.kid-toolbar{align-items:center}.weight-picker{min-width:0;flex:1}.weight-title b,.weight-title small{display:block}.weight-title b{font-size:0.875rem}.weight-title small{font-size:0.6875rem;color:var(--muted);margin-top:2px}.weight-presets{display:grid;grid-template-columns:repeat(3,minmax(85px,1fr));gap:7px;margin-top:9px;max-width:520px}.weight-preset{border:1px solid var(--line);background:var(--panel-soft);border-radius:11px;min-height:62px;padding:7px 9px;cursor:pointer;text-align:left;color:var(--ink)}.weight-preset span,.weight-preset b,.weight-preset small{display:block}.weight-preset span{font-size:1.125rem}.weight-preset b{font-size:0.875rem;margin-top:1px}.weight-preset small{font-size:0.5625rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}.weight-preset.active{border:2px solid var(--teal);background:var(--teal-soft);padding:6px 8px}.kid-test-actions{min-width:180px}.kid-test-actions .big-test{width:100%;min-height:64px;font-size:1.125rem!important;border-radius:15px!important}.panel-inline{border-bottom:1px solid var(--line);padding:9px 14px;background:#fbfdfc}.custom-test-body{display:flex;align-items:center;gap:10px;padding-top:9px}.custom-test-body .load-control{max-width:none}.custom-test-body .break-btn{border:1px solid #efc8ca;background:#fff7f5;color:#8f3038;border-radius:10px;padding:10px 12px;font-weight:800;white-space:nowrap}.load-crate{fill:#e8b859;stroke:#6b4700;stroke-width:3}.load-crate-line{stroke:#9a6d10;stroke-width:2}.load-kg-label{fill:#4f3909;font-size:1.0625rem;font-weight:900;text-anchor:middle}.node-halo{fill:none;stroke:var(--teal);stroke-width:4;stroke-dasharray:8 6;opacity:.55;pointer-events:none}.canvas-stage.ready-to-test{box-shadow:inset 0 0 0 3px rgba(8,125,117,.18)}
@media(max-width:1000px){.mission-bar{grid-template-columns:auto minmax(0,1fr) auto}.triangle-badge{display:none}.kid-test-actions{min-width:150px}.weight-presets{max-width:none}}
@media(max-width:820px){.mission-bar{grid-template-columns:auto minmax(0,1fr);gap:9px}.readiness-badge{grid-column:1/-1;justify-self:start}.kid-toolbar{display:block}.kid-test-actions{margin-top:10px}.kid-test-actions .big-test{min-height:58px}.custom-test-body{display:block}.custom-test-body .break-btn{margin-top:8px;width:100%}.simple-tools{grid-template-columns:1fr 1fr}.selection-wrap{display:none}}
@media(max-width:520px){.compact-hero p{font-size:0.8125rem}.mission-icon{width:36px;height:36px}.mission-copy strong{font-size:0.8125rem}.weight-presets{grid-template-columns:repeat(3,1fr)}.weight-preset{min-height:58px;padding:6px}.weight-preset span{font-size:1rem}.weight-preset b{font-size:0.8125rem}.simple-tools .tool-btn{min-height:62px}.kid-panel .coach-box{margin-top:10px}}

/* v0.5 visual-build pass */
.beam-size-tools{margin-top:13px;padding-top:12px;border-top:1px solid var(--line)}
.beam-size-chips{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}
.beam-size-chips button{border:1px solid var(--line);background:#fff;border-radius:11px;padding:8px 6px;cursor:pointer;color:var(--ink)}
.beam-size-chips button i{display:block;width:76%;margin:2px auto 7px;border-radius:999px;background:#7c8796}
.beam-size-chips button[data-size="thin"] i{height:4px}.beam-size-chips button[data-size="medium"] i{height:8px}.beam-size-chips button[data-size="thick"] i{height:13px}
.beam-size-chips button b,.beam-size-chips button small{display:block}.beam-size-chips button b{font-size:0.6875rem}.beam-size-chips button small{font-size:0.5625rem;color:var(--muted);margin-top:1px}
.beam-size-chips button.active{border:2px solid var(--teal);background:var(--teal-soft);padding:7px 5px}
.member:not(.tension):not(.compression):not(.critical):not(.broken){stroke:var(--beam-stroke,#768b85)}.member.selected{stroke:var(--accent)!important}
.mission-icon{background:#eef2f7;color:var(--teal)}.panel-inline{background:#fafbfc}.water-gap{fill:#e6edf4;opacity:.7}.canvas-stage.ready-to-test{box-shadow:inset 0 0 0 3px rgba(49,87,164,.14)}
/* v0.6 visual + learning pass */
:root{--bg:#f6f3ed;--panel:#fff;--panel-soft:#f8fafc;--ink:#182033;--muted:#667085;--line:#dfe4ec;--accent:#f8c84a;--accent-dark:#5c4100;--teal:#2855d9;--teal-soft:#edf2ff;--water:#e5edf7;--shadow:0 12px 32px rgba(31,42,68,.09)}
html{background:var(--bg)}body{background:radial-gradient(circle at 15% 0,#fff 0,#faf8f3 38%,#f3f1eb 100%)}.app-shell{padding-top:14px}.panel{border-radius:22px;box-shadow:var(--shadow)}.hero{padding-top:10px}.hero h1{font-size:clamp(34px,4.5vw,60px);letter-spacing:-.045em}.challenge-chip{background:linear-gradient(145deg,#17223a,#2b3b59);border-radius:19px;box-shadow:0 16px 35px rgba(23,34,58,.2)}.step{border-radius:15px}.step b{border-radius:10px}.mission-bar{border-radius:18px}.tool-btn{border-radius:14px;background:#fafbfc}.tool-btn.active{box-shadow:inset 0 0 0 2px rgba(40,85,217,.05)}.coach-box{background:linear-gradient(145deg,#f8faff,#eef3ff);border-color:#cad6f3}.canvas-panel{border-radius:24px}.canvas-stage{background:linear-gradient(180deg,#f8faff 0,#eef2f7 100%)}#bridgeSvg{background:linear-gradient(180deg,#f9fbff,#edf2f7)}.grid-bg{color:#b6c3d7}.water-gap{fill:#dfe9f5;opacity:.86}.ground{stroke:#6f7d91;stroke-width:4}.member{filter:drop-shadow(0 2px 1px rgba(24,32,51,.08))}.node{stroke:#273653}.node.support{fill:#f8c84a}.challenge-flag{background:rgba(23,34,58,.92);border-radius:13px}.weight-preset{border-radius:13px}.weight-preset.active{border-color:#2855d9;background:#edf2ff}.kid-test-actions .big-test{background:linear-gradient(135deg,#f8c84a,#f1ac31)!important;border:0!important;box-shadow:0 9px 20px rgba(206,147,31,.22)}.result-hero{border-radius:15px}.simple-metrics>div{border-radius:12px}.learn-panel{border-radius:22px;background:linear-gradient(145deg,#fff,#f8faff)}.learn-cards article{background:#fff;border-radius:14px}.beam-size-chips button{border-radius:13px}.data-panel{border-radius:20px}

/* v0.7 premium bridge scene */
body{background:linear-gradient(180deg,#faf9f6 0,#f1f2f4 420px)}
.app-shell{max-width:1760px}.workspace{grid-template-columns:285px minmax(600px,1fr) 330px;gap:16px}.panel{border-color:#dce1e9;box-shadow:0 14px 38px rgba(24,32,51,.09)}
.canvas-panel{box-shadow:0 20px 52px rgba(24,32,51,.11)}.canvas-toolbar{background:#fff}.canvas-stage{background:#eef2f7}.challenge-flag{box-shadow:0 8px 22px rgba(23,34,58,.20)}
#bridgeSvg{background:transparent}.scene-caption{font-size:0.6875rem;font-weight:900;letter-spacing:.13em;fill:#778398}.ground{stroke:#8995a6;stroke-width:5}.member-back{stroke:#243047;stroke-linecap:round;opacity:.22;filter:url(#softShadow);pointer-events:none}.member{filter:none;stroke-linecap:round}.member:not(.tension):not(.compression):not(.critical):not(.broken){filter:url(#softShadow)}.member.tension,.member.compression,.member.critical{filter:url(#softShadow)}
.node{fill:#fff;stroke:#1e2d46;stroke-width:5;filter:url(#softShadow)}.node.support{fill:#f6c84f}.support-symbol{fill:#e6aa39;stroke:#5b3b08;stroke-width:3;filter:url(#softShadow)}
.load-crate-shadow{fill:#17223a;opacity:.15}.load-crate{fill:url(#crateGrad);stroke:#65410a;stroke-width:3;filter:url(#softShadow)}.load-crate-line{stroke:#9a6516;stroke-width:2.5}.load-line{stroke:#8a5c09;stroke-width:5}.load-kg-label{font-size:1.0625rem}.failure-x{filter:url(#softShadow)}
.tool-btn{background:#fff;box-shadow:0 3px 10px rgba(24,32,51,.035)}.tool-btn.active{background:#edf3ff;border-color:#315ed8}.weight-preset{background:#fff}.weight-preset.active{box-shadow:0 7px 18px rgba(49,94,216,.10)}.kid-test-actions .big-test{box-shadow:0 14px 28px rgba(207,148,31,.28)}
.learn-panel{box-shadow:0 14px 36px rgba(24,32,51,.07)}
@media(max-width:1250px){.workspace{grid-template-columns:260px minmax(500px,1fr)}}
.member-back.broken-back{opacity:.05;stroke-dasharray:9 8}

/* v0.13 bridge quality pass */
body{background:linear-gradient(180deg,#fbfaf7 0,#f3f1ec 52%,#eeece6 100%)}
.app-shell{padding-top:18px}.hero{padding-top:14px}.hero p{font-size:0.96875rem}
.panel{border-color:#d8dee8;box-shadow:0 16px 44px rgba(24,32,51,.085)}
.build-panel,.result-panel{padding:18px}.canvas-panel{border-radius:28px;box-shadow:0 24px 60px rgba(24,32,51,.12)}
.tool-btn{background:linear-gradient(180deg,#fff,#fbfcfe);border-color:#e0e5ed;box-shadow:0 4px 11px rgba(24,32,51,.035)}
.tool-btn.active{background:#edf3ff;border-color:#315ed8;box-shadow:0 7px 16px rgba(49,94,216,.08)}
.weight-preset{background:#fff;border-color:#dce2eb;box-shadow:0 4px 11px rgba(24,32,51,.03)}
.weight-preset.active{background:#edf3ff;border-color:#315ed8;box-shadow:0 8px 19px rgba(49,94,216,.10)}
.kid-test-actions .big-test{min-height:68px;border-radius:18px!important;box-shadow:0 15px 30px rgba(207,148,31,.30)!important}
.canvas-toolbar{background:linear-gradient(180deg,#fff,#fbfcfe)}
.canvas-stage{background:#eef2f7}.challenge-flag{box-shadow:0 10px 24px rgba(23,34,58,.22)}
.scene-caption{font-size:0.6875rem;font-weight:950;letter-spacing:.14em;fill:#6f7b8d}
.member-back{opacity:.24}.node{filter:url(#softShadow)}
.mission-bar{box-shadow:0 10px 28px rgba(24,32,51,.06)}
.result-hero{box-shadow:inset 0 1px 0 rgba(255,255,255,.7)}
.result-coach{background:linear-gradient(145deg,#f7faff,#edf3ff);border-color:#ccd8f1}
.learn-panel{border-radius:24px}.learn-panel:before{content:"BEOBACHTEN → VERSTEHEN → VERBESSERN";display:block;font-size:0.5625rem;font-weight:950;letter-spacing:.13em;color:#315ed8;margin-bottom:10px}