:root{
  color-scheme:light;--paper:#fbf8f2;--card:#ffffff;--ink:#1b1a17;--ink-2:#55524a;--ink-3:#8b877b;
  --line:#e6e1d3;--line-2:#d3cebf;--sunk:#ece8dc;--accent:#f2600c;--accent-soft:#ffe6d2;
  --display:"Helvetica Neue",Inter,ui-sans-serif,system-ui,Arial,sans-serif;
  --r:16px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.5 var(--display);-webkit-font-smoothing:antialiased}
a{color:inherit}
button{font:inherit;color:inherit}
.top{display:flex;align-items:center;justify-content:space-between;max-width:1120px;margin:0 auto;padding:20px 20px}
.mark{display:inline-flex;align-items:center;gap:8px;font-weight:800;font-size:22px;letter-spacing:-.04em;text-decoration:none;color:var(--accent)}
.mark b{font-weight:800}.mark span{color:var(--ink)}
.top nav{display:flex;gap:20px;font-size:14.5px;color:var(--ink-2)}
.top nav a{text-decoration:none}.top nav a:hover{color:var(--ink)}
main{max-width:1120px;margin:0 auto;padding:0 20px 60px}
h1,h2,h3{font-family:var(--display);letter-spacing:-.035em;margin:0}
.hero{padding:44px 0 28px;max-width:720px}
.hero h1{font-size:clamp(40px,6vw,68px);font-weight:800;line-height:1.02}
.lead{color:var(--ink-2);font-size:18px;margin:16px 0 0;max-width:560px}
.try{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:22px;font-size:14px;color:var(--ink-3)}
.chip{border:0;background:var(--sunk);padding:7px 13px;border-radius:99px;font-size:14px;cursor:pointer;text-decoration:none;color:var(--ink);transition:background .2s}
.chip:hover{background:var(--line-2)}.chip.on{background:var(--accent);color:#fff}
.btn{display:inline-flex;align-items:center;gap:8px;height:44px;padding:0 20px;border:0;border-radius:99px;background:var(--accent);color:#fff;font-weight:600;cursor:pointer;text-decoration:none;transition:transform .15s,opacity .2s}
.btn:hover{opacity:.88}.btn:active{transform:scale(.98)}
.btn.ghost{background:var(--sunk);color:var(--ink)}.btn.ghost:hover{background:var(--line-2);opacity:1}
.btn:disabled{opacity:.35;cursor:default}
.search{width:100%;max-width:520px;height:52px;border:0;border-radius:14px;box-shadow:0 0 0 1px var(--line-2);background:var(--card);padding:0 18px;font:inherit;color:var(--ink);outline:none}
.search:focus{box-shadow:0 0 0 2px var(--accent)}
.bar{display:flex;flex-direction:column;gap:14px;margin:22px 0 26px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.grid{align-items:start;display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px}
.card{display:flex;flex-direction:column;background:var(--card);border-radius:var(--r);box-shadow:0 0 0 1px var(--line);text-decoration:none;overflow:hidden;transition:box-shadow .2s,transform .2s}
.card:hover{box-shadow:0 0 0 2px var(--accent);transform:translateY(-2px)}
.card .art{position:relative;aspect-ratio:4/3;overflow:hidden;background:var(--sunk)}
.card .art svg{position:absolute;top:10%;left:8%;width:84%;height:80%}
.card .meta{padding:14px 16px 16px}.card h3{font-size:16.5px;font-weight:700;letter-spacing:-.015em;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.card p{margin:4px 0 0;font-size:13.5px;color:var(--ink-3)}
.more{display:flex;justify-content:center;margin-top:28px}
.sec{margin-top:64px}.sec h2{font-size:clamp(28px,3.6vw,40px);font-weight:800}
.how{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:24px;margin-top:24px}
.how div{border-top:1px solid var(--line-2);padding-top:16px}
.how b{font-size:30px;font-weight:800;letter-spacing:-.05em;display:block}
.how h3{font-size:18px;margin:8px 0 6px;letter-spacing:-.015em}.how p{margin:0;color:var(--ink-2);font-size:15px}
/* iso art */
.iso{width:100%;height:100%;display:block;overflow:visible}
.iso .part polygon{stroke:var(--ink);stroke-width:1.1;stroke-linejoin:round;vector-effect:non-scaling-stroke}
.iso .f-top{fill:#ffffff}.iso .f-left{fill:#f1ece0}.iso .f-right{fill:#e0d9c8}
.stage .part.now .f-top{fill:#ffb27a}.stage .part.now .f-left{fill:#f98a3f}.stage .part.now .f-right{fill:#e06a14}
/* product page */
.crumb{display:inline-block;margin:6px 0 14px;font-size:14px;color:var(--ink-2);text-decoration:none}.crumb:hover{color:var(--ink)}
.prod{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);gap:28px;align-items:start}
@media(max-width:860px){.prod{grid-template-columns:1fr}}
.stage-wrap{background:var(--card);border-radius:22px;box-shadow:0 0 0 1px var(--line);padding:28px;aspect-ratio:5/4;display:grid;grid-template-columns:minmax(0,1fr);grid-template-rows:minmax(0,1fr);place-items:center;overflow:hidden}
.stage-wrap .stage{width:100%;height:100%;max-height:100%}
.prod h1{font-size:clamp(28px,3.8vw,42px);font-weight:800;line-height:1.05}
.kind{color:var(--ink-3);font-size:14px;margin:8px 0 18px}
.steppanel{margin-top:6px;border-top:1px solid var(--line-2);padding-top:18px}
.stepn{font-size:13px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.steppanel h2{font-size:24px;font-weight:800;margin:6px 0 8px;letter-spacing:-.025em}
.steppanel p{margin:0;color:var(--ink-2)}
.tools{display:flex;flex-wrap:wrap;gap:6px;margin-top:14px}.tools span{background:var(--sunk);border-radius:8px;padding:4px 10px;font-size:13px}
.dots{display:flex;gap:6px;margin:20px 0 16px}
.dots button{flex:1;height:8px;border:0;border-radius:99px;background:var(--line-2);cursor:pointer;padding:0;transition:background .2s}
.dots button.done{background:#f7b27f}.dots button.cur{background:var(--accent)}
.ctl{display:flex;flex-wrap:wrap;gap:8px}
.note{margin-top:22px;font-size:13.5px;color:var(--ink-3);border-left:2px solid var(--line-2);padding-left:12px}
.foot{max-width:1120px;margin:0 auto;padding:30px 20px 50px;border-top:1px solid var(--line);color:var(--ink-3);font-size:13px}
.foot p{margin:6px 0;max-width:760px}
.badge{color:var(--accent);font-weight:600}
.kit{display:flex;flex-wrap:wrap;gap:6px;margin-top:14px}.kit span{background:var(--accent-soft);border-radius:8px;padding:4px 10px;font-size:13px}.kit .hw{background:#fff;box-shadow:0 0 0 1px var(--line-2)}
.iso .fastener .f-top{fill:#d9dce1}.iso .fastener .f-left{fill:#aab0b8}.iso .fastener .f-right{fill:#8a919b}
.iso .fastener.wood .f-top{fill:#f0d9ad}.iso .fastener.wood .f-left{fill:#dcbf8a}.iso .fastener.wood .f-right{fill:#c9a66b}
.stage .fastener.now .f-top{fill:#d9dce1}.stage .fastener.now .f-left{fill:#aab0b8}.stage .fastener.now .f-right{fill:#8a919b}
.stage .fastener.wood.now .f-top{fill:#f0d9ad}.stage .fastener.wood.now .f-left{fill:#dcbf8a}.stage .fastener.wood.now .f-right{fill:#c9a66b}
.callout line{stroke:var(--ink);stroke-width:1;vector-effect:non-scaling-stroke}
.callout circle{fill:#fff;stroke:var(--ink);stroke-width:1.3;vector-effect:non-scaling-stroke}
.callout rect{fill:#fff;stroke:var(--ink);stroke-width:1.3;vector-effect:non-scaling-stroke}
.callout.code rect{fill:var(--ink);stroke:none}
.callout text{fill:var(--ink);font-weight:700;text-anchor:middle;dominant-baseline:central;font-family:var(--display)}
.callout.code text{fill:#fff}
.kit b{font-weight:700;margin-right:4px}
.stage .part.ghost polygon{stroke-dasharray:3 2}
.stage .part polygon{transition:fill .6s ease,stroke .6s ease}
.stage .callouts{transition:opacity .4s ease}
.stage.finished .callouts{opacity:0}
.stage.finished .part .f-top{fill:#fff}.stage.finished .part .f-left{fill:#ececec}.stage.finished .part .f-right{fill:#d2d2d2}
.stage.finished .part polygon{stroke:#111}
/* rotate */
.stage-wrap{position:relative;touch-action:none;cursor:grab;user-select:none;-webkit-user-select:none}
.stage-wrap.dragging{cursor:grabbing}
.viewbtn{position:absolute;right:12px;bottom:12px;border:0;border-radius:99px;padding:6px 12px;font-size:12.5px;background:var(--sunk);color:var(--ink-2);cursor:pointer}
.viewbtn.on{background:var(--accent);color:#fff}
/* phones */
@media (max-width:640px){
  .top{padding:14px 16px}
  .top nav{gap:14px;font-size:14px}
  .top nav a[href*="github"]{display:none}
  main{padding:0 16px 24px}
  .hero{padding:20px 0 12px}
  .lead{font-size:16px}
  .search{height:48px}
  .grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
  .card{border-radius:14px}
  .card .meta{padding:10px 12px 12px}
  .card h3{font-size:14px;line-height:1.3}
  .card p{font-size:12px;line-height:1.4;margin-top:3px}
  .card p .badge{display:block}
  .card p .dot{display:none}
  .sec{margin-top:40px}
  .prod{gap:14px}
  .crumb{margin:0 0 10px}
  .stage-wrap{padding:8px;border-radius:16px;aspect-ratio:1/1}
  .prod h1{font-size:24px}
  .kind{margin:6px 0 10px}
  .steppanel{padding-top:12px}
  .steppanel h2{font-size:20px}
  .dots{margin:14px 0 10px}
  .ctl{position:sticky;bottom:0;z-index:5;display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:0 -16px;padding:10px 16px calc(10px + env(safe-area-inset-bottom));background:color-mix(in srgb,var(--paper) 92%,transparent);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);border-top:1px solid var(--line)}
  .ctl .btn{justify-content:center;padding:0 10px;height:46px}
  .note{font-size:12.5px}
  .foot{padding:24px 16px 40px}
}
.congrats{position:absolute;left:12px;right:12px;top:16px;text-align:center;font-weight:800;font-size:clamp(17px,2.3vw,24px);letter-spacing:-.02em;line-height:1.2;color:var(--ink);opacity:0;pointer-events:none}
.congrats b{color:var(--accent);font-weight:800}