@font-face{font-family:Geist Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-cyrillic-ext-wght-normal-DjL33-gN.woff2) format("woff2-variations");unicode-range:U+0460-052F,U+1C80-1C8A,U+20B4,U+2DE0-2DFF,U+A640-A69F,U+FE2E-FE2F}@font-face{font-family:Geist Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-cyrillic-wght-normal-BEAKL7Jp.woff2) format("woff2-variations");unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}@font-face{font-family:Geist Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-vietnamese-wght-normal-6IgcOCM7.woff2) format("woff2-variations");unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB}@font-face{font-family:Geist Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-latin-ext-wght-normal-DC-KSUi6.woff2) format("woff2-variations");unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}@font-face{font-family:Geist Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-latin-wght-normal-BgDaEnEv.woff2) format("woff2-variations");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}@font-face{font-family:Geist Mono Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-mono-cyrillic-ext-wght-normal-X_5orZeX.woff2) format("woff2-variations");unicode-range:U+0460-052F,U+1C80-1C8A,U+20B4,U+2DE0-2DFF,U+A640-A69F,U+FE2E-FE2F}@font-face{font-family:Geist Mono Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-mono-cyrillic-wght-normal-DiZS0aHC.woff2) format("woff2-variations");unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}@font-face{font-family:Geist Mono Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-mono-symbols2-wght-normal-CO5SzqOn.woff2) format("woff2-variations");unicode-range:U+2000-2001,U+2004-2008,U+200A,U+23B8-23BD,U+2500-259F}@font-face{font-family:Geist Mono Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-mono-vietnamese-wght-normal-DadHysG0.woff2) format("woff2-variations");unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB}@font-face{font-family:Geist Mono Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-mono-latin-ext-wght-normal-Bwz-egvJ.woff2) format("woff2-variations");unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}@font-face{font-family:Geist Mono Variable;font-style:normal;font-display:swap;font-weight:100 900;src:url(/assets/geist-mono-latin-wght-normal-XN7g48iV.woff2) format("woff2-variations");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}:root{--paper: #f4efe6;--paper-deep: #eae3d6;--paper-card: #faf7f1;--ink: #1e2433;--ink-soft: #5c5c66;--ink-faint: #6b6b74;--line: rgba(30, 36, 51, .14);--line-strong: rgba(30, 36, 51, .28);--sofa: #3149c9;--sofa-tint: rgba(49, 73, 201, .13);--clear: #2e7d57;--clear-tint: rgba(46, 125, 87, .12);--tight: #8f5d12;--tight-tint: rgba(183, 121, 31, .14);--stuck: #c0392b;--stuck-tint: rgba(192, 57, 43, .12);--sans: "Geist Variable", ui-sans-serif, system-ui, sans-serif;--mono: "Geist Mono Variable", ui-monospace, "SF Mono", Menlo, monospace;--radius: 8px;color-scheme:light}*{box-sizing:border-box}html,body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}button,input{font:inherit;color:inherit}.num,.mono{font-family:var(--mono);font-variant-numeric:tabular-nums}a{color:var(--ink);text-decoration-color:var(--line-strong);text-underline-offset:3px}a:hover{text-decoration-color:var(--ink)}:focus-visible{outline:2px solid var(--sofa);outline-offset:2px}.page{max-width:1240px;margin:0 auto;padding:22px 24px 48px}@media(max-width:640px){.page{padding:20px 16px 40px}}.drawing{display:block;width:100%;height:auto}.drawing .wall-face{stroke:var(--ink);stroke-width:2.4;fill:none;stroke-linecap:square}.drawing .wall-mass{fill:url(#hatch);stroke:none}.drawing .dim line{stroke:var(--ink-soft);stroke-width:1}.drawing .dim text,.drawing .label{font-family:var(--mono);font-size:11px;fill:var(--ink-soft)}.drawing .dim rect{fill:var(--paper-card)}.drawing .label.strong{fill:var(--ink)}.drawing .ghost{fill:none;stroke:var(--sofa);stroke-opacity:.22;stroke-width:1;stroke-dasharray:4 4}.drawing .sofa-body{fill:var(--sofa-tint);stroke:var(--sofa);stroke-width:2;stroke-linejoin:round}.drawing .sofa-mark{stroke:var(--sofa);stroke-width:2;stroke-linecap:round;fill:none}.drawing .sofa-back{fill:var(--sofa);fill-opacity:.35;stroke:none}.drawing.is-stuck .sofa-body{fill:var(--stuck-tint)}.drawing .overlap{fill:var(--stuck);fill-opacity:.55;stroke:var(--stuck);stroke-width:1.5}.drawing .contact-ring{fill:none;stroke:var(--stuck);stroke-width:1.5}.drawing .contact-label{font-family:var(--sans);font-size:12px;font-weight:600;fill:var(--stuck);stroke:var(--paper);paint-order:stroke;stroke-linejoin:round}.top{max-width:none;margin:0 0 20px}.brand{display:flex;align-items:center;gap:10px;font-weight:600;font-size:17px;letter-spacing:-.01em;margin-bottom:16px}.logo{width:26px;height:26px;color:var(--ink)}h1{font-size:clamp(27px,2.5vw,36px);line-height:1.12;letter-spacing:-.025em;font-weight:600;margin:0 0 12px;text-wrap:balance}.lede{color:var(--ink-soft);font-size:17px;margin:0;max-width:700px}.muted{color:var(--ink-soft)}.layout{display:grid;grid-template-columns:minmax(300px,380px) minmax(0,1fr);gap:32px;align-items:start}@media(max-width:900px){.layout{grid-template-columns:1fr}.answer{order:-1}}.answer{display:flex;flex-direction:column;gap:16px;min-width:0}.verdict{border-left:4px solid var(--ink-faint);padding:4px 0 4px 18px}.verdict h2{font-size:clamp(22px,2.6vw,28px);line-height:1.2;letter-spacing:-.02em;font-weight:600;margin:0 0 6px}.verdict p{margin:0;color:var(--ink-soft);font-size:16px;max-width:62ch}.verdict--stuck{border-color:var(--stuck)}.verdict--stuck h2{color:var(--stuck)}.verdict--tight{border-color:var(--tight)}.verdict--clear{border-color:var(--clear)}.verdict--clear h2{color:var(--clear)}.fix{display:flex;align-items:center;justify-content:space-between;gap:10px 16px;flex-wrap:wrap;background:var(--clear-tint);border:1px solid rgba(46,125,87,.3);border-radius:var(--radius);padding:10px 10px 10px 16px}.fix p{margin:0;color:var(--ink);flex:1 1 320px}.btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:1px solid var(--line-strong);background:var(--paper-card);border-radius:var(--radius);padding:8px 14px;font-size:14px;font-weight:500;cursor:pointer;white-space:nowrap;transition:background-color .12s ease,border-color .12s ease}.btn:hover{border-color:var(--ink)}.btn--solid{background:var(--ink);color:var(--paper-card);border-color:var(--ink)}.btn--solid:hover{background:#2c3447}.dot{width:8px;height:8px;border-radius:50%;background:var(--ink-faint);flex:none}.tile--clear .dot,.chip--clear .dot,.step--clear .step-n{background:var(--clear)}.tile--tight .dot,.chip--tight .dot,.step--tight .step-n{background:var(--tight)}.tile--stuck .dot,.chip--stuck .dot,.step--stuck .step-n{background:var(--stuck)}.strip{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:8px}.tile{width:100%;text-align:left;-webkit-appearance:none;-moz-appearance:none;appearance:none;background:var(--paper-card);border:1px solid var(--line);border-radius:var(--radius);padding:10px 12px;cursor:pointer;display:flex;flex-direction:column;gap:6px;transition:border-color .12s ease,box-shadow .12s ease}.tile:hover{border-color:var(--line-strong)}.tile.is-active{border-color:var(--ink);box-shadow:inset 0 0 0 1px var(--ink)}.tile-top{display:flex;gap:8px;align-items:baseline;font-weight:500;font-size:14px}.tile-n{color:var(--ink-faint);font-size:12px}.tile-status{display:flex;align-items:center;gap:7px;font-size:13px;color:var(--ink-soft)}.card{background:var(--paper-card);border:1px solid var(--line);border-radius:12px;box-shadow:0 1px 2px #1e24330a}.stage{padding:16px 16px 14px}.stage-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:12px}.stage-head h3{margin:0;font-size:17px;font-weight:600}.stage-head p{margin:2px 0 0;font-size:14px}.ways{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:8px}.chip{-webkit-appearance:none;-moz-appearance:none;appearance:none;display:inline-flex;align-items:center;gap:7px;border:1px solid var(--line);background:transparent;border-radius:999px;padding:5px 12px 5px 10px;font-size:13px;font-weight:500;cursor:pointer;transition:border-color .12s ease,background-color .12s ease}.chip:hover{border-color:var(--line-strong)}.chip.is-active{background:var(--paper);border-color:var(--ink)}.chip-note{font-variant-numeric:tabular-nums;color:var(--ink-soft);font-weight:400;font-size:12px}.figure{background:var(--paper);border-radius:var(--radius);padding:8px}.figure .drawing{max-height:460px;margin:0 auto}.caption{font-size:14px;color:var(--ink-soft);margin:10px 2px 0;max-width:70ch}.plan h3{font-size:17px;font-weight:600;margin:8px 0 10px}.plan ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}.step{display:grid;grid-template-columns:26px 1fr;gap:12px;align-items:start}.step-n{width:26px;height:26px;border-radius:50%;display:grid;place-items:center;font-size:13px;color:#fff;background:var(--ink-faint)}.step strong{font-weight:600;font-size:15px}.step p{margin:2px 0 0;color:var(--ink-soft);font-size:15px}.verdict .size-line{margin-top:8px;color:var(--ink)}.verdict .options{margin-top:8px}.btn--good{border-color:var(--clear);color:var(--clear);background:var(--paper-card);font-weight:600}.btn--good:hover{background:#fff;border-color:var(--clear)}.btn--play{display:inline-flex;align-items:center;gap:8px}.play-icon{width:0;height:0;border-left:8px solid currentColor;border-top:5px solid transparent;border-bottom:5px solid transparent}.legend{display:flex;flex-wrap:wrap;gap:4px 16px;margin:-6px 0 0;font-size:12px;color:var(--ink-faint)}.lg{display:inline-flex;align-items:center;gap:6px}.lg:before{content:"";width:7px;height:7px;border-radius:50%;background:var(--ink-faint)}.lg--clear:before{background:var(--clear)}.lg--tight:before{background:var(--tight)}.lg--stuck:before{background:var(--stuck)}.is-playing .btn--play .play-icon{border:0;width:9px;height:9px;background:currentColor;border-radius:1px}@media(max-width:640px){.strip{display:flex;overflow-x:auto;scrollbar-width:none;margin:0 -16px;padding:0 16px 2px;scroll-padding:16px}.strip::-webkit-scrollbar{display:none}.strip li{flex:0 0 62%}}.drawing .sofa-box{fill:none;stroke:var(--sofa);stroke-opacity:.45;stroke-width:1;stroke-dasharray:5 4}.figure .drawing.door{height:min(360px,70vw);width:auto;max-width:100%}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.toolbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 20px;padding:10px 0;margin-bottom:20px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.toolbar-group{display:flex;flex-wrap:wrap;align-items:center;gap:10px}.toolbar-label{font-size:14px;color:var(--ink-soft)}.segs{display:inline-flex;flex-wrap:wrap;background:var(--paper-deep);border-radius:var(--radius);padding:3px;gap:2px}.seg{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:0;background:transparent;border-radius:6px;padding:6px 12px;font-size:14px;font-weight:500;color:var(--ink-soft);cursor:pointer;transition:background-color .12s ease,color .12s ease}.seg:hover{color:var(--ink)}.seg.is-active{background:var(--paper-card);color:var(--ink);box-shadow:0 1px 2px #1e24331a}.units .seg{font-family:var(--mono);padding:6px 10px}.inputs{display:flex;flex-direction:column;gap:16px}.panel{padding:18px 18px 16px}.panel h2{font-size:17px;font-weight:600;margin:0 0 4px;letter-spacing:-.01em}.small{font-size:14px;margin:0 0 12px}.sofa-diagram{display:block;width:100%;max-width:330px;margin:10px 0 14px}.diag-label{font-family:var(--sans);font-size:11px;fill:var(--ink-soft)}.grid2,.grid3{display:grid;gap:10px}.grid2{grid-template-columns:repeat(2,minmax(0,1fr))}.grid3{grid-template-columns:repeat(3,minmax(0,1fr))}.field label{display:block;font-size:13px;font-weight:500;color:var(--ink-soft);margin-bottom:4px}.num-wrap{position:relative}.num-input{width:100%;font-family:var(--mono);font-size:15px;font-variant-numeric:tabular-nums;padding:8px 34px 8px 10px;border:1px solid var(--line-strong);border-radius:var(--radius);background:#fff;transition:border-color .12s ease,box-shadow .12s ease}.num-input:hover{border-color:var(--ink-faint)}.num-input:focus{outline:none;border-color:var(--sofa);box-shadow:0 0 0 3px #3149c926}.num-input.has-problem{border-color:var(--stuck)}.num-input::placeholder{color:var(--ink-faint)}.unit{position:absolute;right:10px;top:50%;transform:translateY(-50%);font-family:var(--mono);font-size:12px;color:var(--ink-faint);pointer-events:none}.field-msg{margin:4px 0 0;font-size:12px;color:var(--stuck);min-height:0}.field-msg:empty{display:none}.hint{margin:8px 0 0;font-size:13px;line-height:1.45;color:var(--ink-faint)}.legs-row{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,2fr);gap:10px;align-items:end;margin-top:10px}.switch{display:inline-flex;align-items:center;gap:10px;font-size:14px;cursor:pointer;padding-bottom:9px;-webkit-user-select:none;user-select:none}.switch-input{position:absolute;opacity:0;width:1px;height:1px}.switch-track{width:34px;height:20px;border-radius:999px;background:var(--paper-deep);border:1px solid var(--line-strong);position:relative;flex:none;transition:background-color .15s ease,border-color .15s ease}.switch-track:after{content:"";position:absolute;top:2px;left:2px;width:14px;height:14px;border-radius:50%;background:#fff;box-shadow:0 1px 2px #1e243340;transition:transform .15s ease}.switch-input:checked+.switch-track{background:var(--sofa);border-color:var(--sofa)}.switch-input:checked+.switch-track:after{transform:translate(14px)}.switch-input:focus-visible+.switch-track{outline:2px solid var(--sofa);outline-offset:2px}.spots{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}.spot{border:1px solid var(--line);border-radius:var(--radius);padding:10px 12px 12px;background:#fff}.spot-head{display:flex;align-items:center;gap:10px;margin-bottom:10px}.spot-n{width:22px;height:22px;border-radius:50%;background:var(--ink);color:#fff;display:grid;place-items:center;font-size:12px;flex:none}.spot-title{flex:1;min-width:0;display:flex;flex-direction:column}.spot-name{border:1px solid transparent;background:transparent;border-radius:6px;padding:2px 6px;margin-left:-6px;font-weight:600;font-size:15px;width:100%}.spot-name:hover{border-color:var(--line)}.spot-name:focus{outline:none;border-color:var(--sofa);background:#fff}.spot-kind{font-size:12px;color:var(--ink-faint)}.spot-tools{display:flex;gap:2px}.icon-btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:0;background:transparent;color:var(--ink-soft);width:28px;height:28px;border-radius:6px;display:grid;place-items:center;cursor:pointer}.icon-btn:hover:not([disabled]){background:var(--paper-deep);color:var(--ink)}.icon-btn[disabled]{opacity:.3;cursor:default}.add-row{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}.empty{font-size:14px;color:var(--ink-soft);margin:0}.stage--waiting{padding:24px}.stage--waiting .drawing{max-height:280px;margin:0 auto}@media(max-width:420px){.grid3{grid-template-columns:repeat(2,minmax(0,1fr))}}.sample-note{margin:-8px 0 20px;font-size:14px;color:var(--ink-soft);background:var(--paper-deep);border-radius:var(--radius);padding:10px 12px}.sample-note strong{color:var(--ink);font-weight:600}.foot{margin-top:56px;padding-top:24px;border-top:1px solid var(--line);display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px}.foot h2{font-size:14px;font-weight:600;margin:0 0 6px}.foot p{font-size:14px;color:var(--ink-soft);margin:0;line-height:1.55}@media(max-width:820px){.foot{grid-template-columns:1fr;gap:18px}}@media(max-width:640px){.toolbar-group:first-child{width:100%}.toolbar-group:first-child .segs{flex-wrap:nowrap;overflow-x:auto;max-width:100%;scrollbar-width:none}.toolbar-group:first-child .segs::-webkit-scrollbar{display:none}.seg{white-space:nowrap}}