:root{
  --bg:#fff;
  --fg:#111;
  --muted:#666;
  --line:#111;
  --line-soft:#d8d8d8;
  --soft:#f5f5f5;
  --accent:#ff4f81;
  --success:#111;
}
*{box-sizing:border-box}
html,body{margin:0;background:var(--bg);color:var(--fg);font-family:Arial,"Noto Sans JP",sans-serif}
body{min-height:100vh;min-height:100dvh;overflow-x:hidden;-webkit-text-size-adjust:100%}
button,input{font:inherit}
button{touch-action:manipulation;-webkit-tap-highlight-color:transparent}
button:focus-visible,input:focus-visible{outline:3px solid var(--accent);outline-offset:3px}
.app{width:100%;max-width:920px;margin:0 auto;padding:max(16px,env(safe-area-inset-top)) max(20px,env(safe-area-inset-right)) max(48px,env(safe-area-inset-bottom)) max(20px,env(safe-area-inset-left))}
.topbar{display:flex;justify-content:space-between;align-items:center;border-bottom:2px solid var(--fg);padding-bottom:12px;gap:14px}
.brand{display:flex;align-items:center;gap:10px;color:inherit;text-decoration:none;font-weight:900;letter-spacing:-.03em}
.brand-mark{width:30px;height:30px;display:grid;place-items:center;border:2px solid var(--fg);border-radius:3px;font-weight:900}
.top-actions{display:flex;align-items:center;gap:10px}
.text-btn,.langs button,.text-link{border:0;background:transparent;color:var(--fg);cursor:pointer}
.text-btn{font-size:13px;font-weight:800;padding:7px 4px}
.langs{display:flex;gap:3px}
.langs button{min-height:36px;padding:5px 8px;font-size:12px;font-weight:800;border-radius:4px}
.langs button.on{background:var(--fg);color:var(--bg)}
.screen{display:none;padding:34px 0 10px}.screen.on{display:block;animation:screen-in .24s ease both}
@keyframes screen-in{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:none}}
.hero-copy{min-height:430px;display:flex;flex-direction:column;justify-content:center;align-items:flex-start;max-width:720px}
.eyebrow{font-size:12px;font-weight:900;letter-spacing:.08em;color:var(--muted);margin:0 0 12px;text-transform:none}
h1,h2{letter-spacing:-.055em;line-height:1;margin:0}
h1{font-size:clamp(46px,8vw,78px);max-width:820px}
h2{font-size:clamp(31px,5vw,48px)}
.lead{max-width:650px;color:var(--muted);line-height:1.7;margin:18px 0 25px}.lead.compact{margin:12px 0 20px}.lead.centered{margin-left:auto;margin-right:auto}
.hero-actions,.invite-actions,.result-actions{display:flex;gap:12px;flex-wrap:wrap}.hero-rules{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;width:100%;max-width:720px;margin-top:26px}.hero-rules>div{display:flex;align-items:flex-start;gap:9px;border-top:2px solid var(--fg);padding-top:10px;font-size:12px;line-height:1.45;color:var(--muted)}.hero-rules b{flex:0 0 auto;width:22px;height:22px;display:grid;place-items:center;background:var(--fg);color:var(--bg);border-radius:3px;font-size:11px}.hero-rules span{padding-top:2px}
.btn{min-height:48px;border:2px solid var(--fg);background:var(--bg);color:var(--fg);padding:12px 18px;border-radius:5px;font-weight:900;box-shadow:4px 4px 0 var(--fg);cursor:pointer;transition:transform .08s,box-shadow .08s}
.btn.primary{background:var(--fg);color:var(--bg)}.btn:active{transform:translate(3px,3px);box-shadow:1px 1px 0 var(--fg)}.btn:disabled{opacity:.45;cursor:not-allowed;transform:none}
.explainer,.cut-demo,.reference-block{border-top:2px solid var(--fg);padding:34px 0 40px}.explainer-head{max-width:700px}
.outcomes{display:grid;grid-template-columns:1fr 1fr;gap:14px}.outcome{border:2px solid var(--fg);border-radius:7px;padding:20px;background:var(--bg)}.outcome strong{display:block;font-size:19px;margin-top:24px}.outcome p{margin:7px 0 0;color:var(--muted);line-height:1.55;font-size:14px}
.mini-deck{display:flex;align-items:center;gap:6px}.mini-card{width:46px;aspect-ratio:.68;display:grid;place-items:center;border:2px solid var(--fg);border-radius:4px;background:#fff;font:30px Georgia,serif;box-shadow:2px 2px 0 var(--fg)}.mini-card.heart{color:var(--accent)}.adjacent-pair{display:inline-flex;flex:0 0 auto;align-items:center;gap:6px;padding:6px;border:3px solid var(--accent);border-radius:9px;margin:-6px;position:relative;background:rgba(255,79,129,.06)}.adjacent-pair::after{content:"↔";position:absolute;left:50%;bottom:-22px;transform:translateX(-50%);color:var(--accent);font-size:15px;font-weight:900;line-height:1}
.cut-example{max-width:590px;border:2px solid var(--fg);border-radius:7px;padding:20px;margin-top:16px}.cut-demo-status{text-align:center;font-size:12px;font-weight:900;margin-bottom:13px;color:var(--muted)}.cut-row{display:flex;align-items:center;justify-content:center;gap:8px;min-height:74px}.demo-cut-line{height:62px;border-left:3px dashed var(--accent);margin:0 3px;animation:cut-line-in .45s ease both}@keyframes cut-line-in{from{opacity:0;transform:scaleY(.5)}to{opacity:1;transform:scaleY(1)}}.back-mini{width:54px;height:72px;border-radius:5px;background:var(--fg);color:#fff;display:grid;place-items:center;font-weight:900;box-shadow:3px 3px 0 #777}.cut-arrow{text-align:center;font-size:25px;margin:10px}.micro{font-size:12px;color:var(--muted);line-height:1.55;margin:12px 0 0}.reference-copy{max-width:720px;margin:0 0 12px;color:var(--muted);line-height:1.65}.reference-link{display:inline-block;color:var(--fg);font-size:13px;line-height:1.55;font-weight:800;text-underline-offset:3px}
.panel{max-width:720px;margin:0 auto;padding-top:20px}.panel.narrow{max-width:620px}.centered-panel{text-align:center}.hidden{display:none!important}
.invite-box{border:2px solid var(--fg);border-radius:7px;padding:18px;margin:22px 0}.invite-box label{display:block;font-size:13px;font-weight:900;margin-bottom:8px}.invite-box input{width:100%;min-height:46px;border:2px solid var(--line-soft);border-radius:5px;padding:10px;background:var(--soft);color:var(--fg);font-size:13px}.invite-actions{margin-top:12px}
.connection-state{display:flex;align-items:center;gap:9px;margin:20px 0 12px;font-size:14px;font-weight:800}.connection-dot{width:10px;height:10px;border-radius:50%;background:#aaa}.connection-dot.waiting{background:#e0a500;animation:pulse 1.2s infinite}.connection-dot.connected{background:#28a745}.connection-dot.error{background:#d33}@keyframes pulse{50%{opacity:.35}}
.text-link{padding:8px 0;text-decoration:underline;color:var(--muted)}
.status{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:28px}.status-card{border:2px solid var(--line-soft);padding:12px;border-radius:6px;font-weight:900}.status-card.active{border-color:var(--fg)}.status-card.done{background:var(--soft)}.status-card small{display:block;margin-top:4px;color:var(--muted);font-size:11px}
.answer-center{text-align:center}.meaning{display:inline-block;border:2px solid var(--fg);border-radius:999px;padding:7px 13px;font-weight:900;margin:6px 0 18px}.meaning.yes{background:var(--fg);color:var(--bg)}
.pair{display:flex;justify-content:center;align-items:center;gap:14px;min-height:222px;max-width:100%}.answer-card{width:118px;aspect-ratio:.68;perspective:900px;position:relative;border:0;background:transparent;padding:0;cursor:pointer}.card-inner{position:absolute;inset:0;display:block;transform-style:preserve-3d;transition:transform .82s cubic-bezier(.2,.75,.2,1)}.answer-card.down .card-inner{transform:rotateY(180deg)}.card-front,.card-back,.deck-front,.deck-back{position:absolute;inset:0;display:grid;place-items:center;border:3px solid var(--fg);border-radius:8px;background:var(--bg);backface-visibility:hidden;box-shadow:5px 5px 0 var(--fg)}.card-front{font:72px Georgia,serif}.card-front.heart,.deck-front.heart{color:var(--accent)}.card-back,.deck-back{transform:rotateY(180deg);background:var(--fg);color:#fff}.card-back::after,.deck-back::after{content:"?";font-size:28px}.swap{width:52px;height:52px;min-width:52px;border:2px solid var(--fg);border-radius:50%;background:var(--bg);font-size:24px;font-weight:900;cursor:pointer}.hint{font-size:13px;color:var(--muted);margin:5px 0 21px}.answer-lock{min-width:225px}
.handoff-box{max-width:620px;margin:45px auto 0;border:3px solid var(--fg);border-radius:8px;padding:30px;text-align:center;box-shadow:7px 7px 0 var(--fg)}.people{display:flex;align-items:center;justify-content:center;gap:18px;margin:24px 0}.person{width:82px;height:82px;border:2px solid var(--fg);border-radius:50%;display:grid;place-items:center;font-weight:900}
.ready-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:28px 0}.ready-card{border:2px solid var(--line-soft);border-radius:7px;padding:20px;text-align:left}.ready-card span{font-weight:900}.ready-card strong{display:block;margin-top:8px;font-size:21px}.ready-card.ready{border-color:var(--fg);background:var(--soft)}.ready-card.ready strong{color:var(--fg)}
.progress{display:grid;grid-template-columns:repeat(4,1fr);gap:5px;margin-bottom:24px}.progress i{height:5px;background:#ddd;border-radius:4px}.progress i.on{background:var(--fg)}.op{min-height:118px}
.table{position:relative;border:3px solid var(--fg);border-radius:8px;padding:28px 12px 24px;min-height:335px;display:grid;align-content:center;overflow:hidden;background:var(--bg);color:var(--fg);transition:background .5s,color .5s}.table.reveal{background:var(--fg);color:var(--bg)}.camera{position:relative;transition:transform .8s}.table.reveal .camera{transform:scale(1.065)}
.group-labels{display:grid;grid-template-columns:2fr 1fr 2fr;max-width:590px;margin:0 auto 8px;text-align:center;font-size:11px;color:#888;font-weight:900;transition:opacity .3s}.group-labels.hidden-labels{opacity:0}
.deck{position:relative;display:flex;justify-content:center;align-items:center;gap:10px;min-height:180px;max-width:100%}.deck-card{width:86px;aspect-ratio:.68;perspective:850px;position:relative;flex:0 0 auto}.deck-inner{position:absolute;inset:0;transform-style:preserve-3d;transition:transform 1.05s cubic-bezier(.2,.75,.2,1)}.deck-card.face-up .deck-inner{transform:rotateY(180deg)}.deck-front,.deck-back{box-shadow:3px 3px 0 currentColor}.deck-front{transform:rotateY(180deg);font:54px Georgia,serif}.deck-back{transform:none;background:var(--fg);color:var(--bg)}.deck-card{transition:transform .45s ease}.deck-card.peek{transform:translateY(-13px) scale(1.05)}.deck-card.hit .deck-front{outline:4px solid var(--accent);outline-offset:3px}.deck-card.wrap-hit .deck-front{box-shadow:0 0 0 4px var(--accent),3px 3px 0 currentColor}.match-outline{position:absolute;border:4px solid var(--accent);border-radius:11px;pointer-events:none;z-index:25;animation:match-outline-in .65s cubic-bezier(.2,.8,.2,1) both}@keyframes match-outline-in{from{opacity:0;transform:scale(.9)}to{opacity:1;transform:scale(1)}}
.cut-marker{position:absolute;top:18px;bottom:18px;width:0;border-left:3px dashed var(--accent);pointer-events:none;z-index:20}.cut-marker span{position:absolute;top:-25px;left:0;transform:translateX(-50%);white-space:nowrap;background:var(--bg);color:var(--fg);border:1px solid var(--fg);border-radius:999px;padding:4px 7px;font-size:10px;font-weight:900}.table.reveal .cut-marker span{background:var(--fg);color:var(--bg);border-color:var(--bg)}
.privacy-mask{position:absolute;inset:28px 4%;z-index:30;border:2px solid var(--fg);border-radius:8px;background:var(--bg);display:none;place-content:center;text-align:center;padding:20px}.privacy-mask.on{display:grid}.privacy-mask strong{font-size:21px;letter-spacing:-.03em}.privacy-mask span{display:block;color:var(--muted);font-size:13px;margin-top:7px;line-height:1.5}
.counter{text-align:center;font-size:12px;font-weight:900;min-height:20px;margin-top:10px}.circle-note{text-align:center;font-size:12px;color:#aaa;min-height:18px;margin-top:7px}
.result-box{max-width:650px;margin:50px auto 0;text-align:center}.result-mark{width:92px;height:92px;margin:0 auto 19px;border:3px solid var(--fg);border-radius:8px;display:grid;place-items:center;font:60px Georgia,serif;box-shadow:5px 5px 0 var(--fg)}.result-mark.ok{background:var(--fg);color:var(--accent)}.result-actions{justify-content:center}
.toast{position:fixed;left:50%;bottom:max(22px,env(safe-area-inset-bottom));transform:translate(-50%,18px);opacity:0;pointer-events:none;background:var(--fg);color:var(--bg);border-radius:999px;padding:9px 14px;font-size:13px;font-weight:800;transition:.2s;z-index:100}.toast.on{transform:translate(-50%,0);opacity:1}
.project-footer{padding:24px 0;text-align:center;font-size:12px;opacity:.65}.project-footer a{color:inherit;text-underline-offset:3px}
@media(max-width:620px){
  .app{padding:max(12px,env(safe-area-inset-top)) max(14px,env(safe-area-inset-right)) max(34px,env(safe-area-inset-bottom)) max(14px,env(safe-area-inset-left))}
  .topbar{padding-bottom:10px}.brand{font-size:14px;gap:8px}.brand-mark{width:28px;height:28px}.top-actions{gap:5px}.text-btn{padding:6px}.langs button{min-height:36px;padding:4px 7px}
  .screen{padding-top:25px}.hero-copy{min-height:min(68dvh,560px);padding:34px 0 36px}
  h1{font-size:clamp(43px,13vw,59px);max-width:370px}h2{font-size:clamp(30px,9vw,40px)}.lead{font-size:15px}.hero-actions{width:100%}.hero-actions .btn{flex:1 1 180px}
  .hero-rules{grid-template-columns:1fr;gap:5px;margin-top:22px}.hero-rules>div{padding-top:7px}.outcomes{grid-template-columns:1fr}.outcome{padding:17px}.mini-card{width:min(15vw,52px)}
  .cut-example{padding:16px 7px}.cut-row{gap:5px}.back-mini{width:min(14vw,49px);height:auto;aspect-ratio:.72}.cut-row i{height:56px}
  .panel{padding-top:8px}.status{gap:7px;margin-bottom:23px}.status-card{padding:9px 10px;font-size:13px}.status-card small{font-size:10px}
  .pair{gap:8px;min-height:195px}.answer-card{width:min(27vw,100px)}.swap{width:46px;height:46px;min-width:46px;font-size:21px}.card-front{font-size:62px}.answer-lock{width:min(100%,280px)}
  .handoff-box{margin-top:25px;padding:24px 15px}.person{width:72px;height:72px;font-size:14px}.people{gap:14px}
  .ready-grid{gap:8px}.ready-card{padding:15px}
  .op{min-height:136px}.op .lead{font-size:14px}.table{min-height:305px;padding:24px 5px 20px}.deck{gap:clamp(4px,1.4vw,6px);min-height:155px}.deck-card{width:min(15.7vw,59px)}.deck-front{font-size:clamp(31px,10vw,42px)}.group-labels{font-size:9px}.privacy-mask{inset:24px 2%}.counter,.circle-note{font-size:11px}.result-box{margin-top:36px;padding:0 5px}.result-mark{width:84px;height:84px}
  .invite-actions .btn,.result-actions .btn{flex:1 1 160px}
}
@media(max-width:360px){.brand>span:last-child{display:none}.mini-deck{gap:4px}.adjacent-pair{gap:4px;padding:4px;margin:-4px}.answer-card{width:92px}.deck-card{width:51px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}