:root{color-scheme:light;font-family:Inter,Avenir Next,Segoe UI,sans-serif;--page: #f5f7fb;--paper: #ffffff;--paper-strong: #f9fbff;--ink: #18202f;--ink-soft: #5b6475;--line: #d8dee9;--line-strong: #202a3a;--accent: #2864d8;--accent-soft: #dce8ff;--success: #11845b;--danger: #bf2f45;--shadow: 0 18px 48px rgba(24, 32, 47, .08)}*{box-sizing:border-box}html,body,#root{min-height:100%}body{margin:0;color:var(--ink);background:linear-gradient(180deg,#f8faff 0%,var(--page) 52%,#eef2f8 100%)}button,input{font:inherit}button,input{transition:background-color .16s ease,border-color .16s ease,box-shadow .16s ease,transform .16s ease}button:hover:not(:disabled){transform:translateY(-1px)}button:focus-visible,input:focus-visible{outline:3px solid rgba(40,100,216,.2);outline-offset:2px}h1,h2,h3,p{margin:0}strong{font-weight:700}.app-shell{display:grid;grid-template-columns:minmax(280px,340px) minmax(0,1fr);gap:20px;padding:20px;width:min(100%,1480px);margin:0 auto}.workspace{display:grid;gap:20px}.paper-card{background:#fffffff0;border:1px solid rgba(32,42,58,.1);border-radius:8px;box-shadow:var(--shadow);padding:24px;position:relative;overflow:hidden}.paper-card:after{content:none}.hero{display:grid;gap:14px}.hero h1,.reference-panel h2,.panel-heading h2{font-family:Iowan Old Style,Palatino Linotype,serif;font-weight:700;letter-spacing:0}.hero h1{font-size:clamp(2rem,3.4vw,3.25rem);line-height:1;max-width:16ch}.eyebrow{text-transform:uppercase;letter-spacing:.12em;font-size:.75rem;color:var(--ink-soft)}.supporting-copy{color:var(--ink-soft);line-height:1.6}.hero-meta,.issue-summary,.status-stack,.actions-row,.solution-tabs{display:flex;flex-wrap:wrap;gap:12px}.hero-meta span,.issue-chip,.solution-tab{border-radius:999px;border:1px solid rgba(32,42,58,.12);padding:8px 14px;background:var(--paper-strong)}.issue-chip-active,.solution-tab.active{border-color:#2864d859;background:var(--accent-soft);color:#153c8c}.reference-panel{position:sticky;top:24px;display:grid;gap:14px;align-content:start;max-height:calc(100vh - 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11px)}.edge-toggle-vertical{bottom:-11px;left:calc(50% - 11px)}.edge-toggle.invalid{box-shadow:0 0 0 3px #b33e3e2e}.edge-legend{display:flex;flex-wrap:wrap;gap:10px 14px;align-items:center;color:var(--ink-soft)}.edge-legend-item{display:inline-flex;align-items:center;gap:8px}.edge-legend-swatch{position:relative;width:16px;height:16px;border-radius:999px;border:1px solid rgba(32,42,58,.18);flex:none}.edge-legend-required{background:#11845bf2;border-color:#0b6343cc}.edge-legend-forbidden{background:#fff;border-color:#bf2f4573}.edge-legend-forbidden:before,.edge-legend-forbidden:after{content:"";position:absolute;left:50%;top:50%;width:8px;height:2px;border-radius:999px;background:#bf2f45e6;transform-origin:center}.edge-legend-forbidden:before{transform:translate(-50%,-50%) rotate(45deg)}.edge-legend-forbidden:after{transform:translate(-50%,-50%) rotate(-45deg)}.edge-legend-empty{background:#fff;border-style:dashed;border-color:#202a3a47}.solve-panel,.solutions-panel,.export-panel{display:grid;gap:16px}.solve-summary{font-family:Iowan Old Style,Palatino Linotype,serif;font-size:1.4rem}.primary-button,.secondary-button,.accent-button{border:0;border-radius:8px;padding:12px 18px;cursor:pointer;font-weight:700}.primary-button{background:var(--accent);color:#fff}.secondary-button{background:#202a3a14;color:var(--ink)}.accent-button{background:var(--success);color:#fff}.primary-button:disabled,.secondary-button:disabled,.accent-button:disabled{cursor:wait;opacity:.7}.error-text{color:var(--danger)}.solution-preview{display:grid;gap:1px;max-width:520px;background:#202a3a2e;padding:1px;border-radius:8px;overflow:hidden}.solution-empty-state{max-width:520px;padding:18px;border-radius:8px;border:1px dashed rgba(32,42,58,.18);background:var(--paper-strong);color:var(--ink-soft);line-height:1.6}.solution-cell{aspect-ratio:1;display:grid;place-items:center;background:#ffffffeb;font-family:Iowan Old Style,Palatino Linotype,serif;font-size:1.05rem;position:relative}.solution-edge{position:absolute;width:16px;height:16px;border-radius:999px;pointer-events:none;z-index:1}.solution-edge-required{border:1px solid rgba(11,99,67,.8);background:#11845bf2;box-shadow:0 0 0 1px #fff6}.solution-edge-forbidden{border:1px solid rgba(191,47,69,.45);background:#fff}.solution-edge-forbidden:before,.solution-edge-forbidden:after{content:"";position:absolute;left:50%;top:50%;width:10px;height:2px;border-radius:999px;background:#bf2f45e6;transform-origin:center}.solution-edge-forbidden:before{transform:translate(-50%,-50%) rotate(45deg)}.solution-edge-forbidden:after{transform:translate(-50%,-50%) rotate(-45deg)}.solution-edge-horizontal{right:-8px;top:50%;transform:translateY(-50%)}.solution-edge-vertical{bottom:-8px;left:50%;transform:translate(-50%)}.common-parts-panel{display:grid;gap:14px;margin-top:6px;padding:18px;border-radius:8px;background:var(--paper-strong);border:1px solid rgba(32,42,58,.08)}.common-parts-header{display:flex;align-items:flex-start;justify-content:space-between;gap:16px}.common-parts-header h3{font-family:Iowan Old Style,Palatino Linotype,serif;font-size:1.3rem;line-height:1.1;margin-top:4px}.common-parts-badge{align-self:flex-start;border-radius:999px;padding:8px 12px;border:1px solid rgba(32,42,58,.14);background:#fff;color:var(--ink-soft);font-size:.95rem}.common-grid{display:grid;gap:1px;background:#202a3a29;padding:1px;max-width:520px;border-radius:8px;overflow:hidden}.common-cell{aspect-ratio:1;display:grid;place-items:center;background:#fff;font-family:Iowan Old Style,Palatino Linotype,serif;font-size:1rem;color:var(--ink)}.common-cell-empty{color:#5b647573;background:#f1f4f9}@media(max-width:1080px){.app-shell{grid-template-columns:1fr}.reference-panel{position:static;max-height:none}}@media(max-width:680px){.app-shell{padding:16px}.paper-card{padding:18px;border-radius:8px}.edge-toggle{width:18px;height:18px}.edge-toggle-horizontal{right:-9px;top:calc(50% - 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