:root{font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans JP",sans-serif;color:#253d45;background:#f6f8f7;font-synthesis:none;--teal:#247c73;--red:#ed8d87;--blue:#7eb4e2}
*{box-sizing:border-box}body{margin:0}button,input{font:inherit}button{cursor:pointer;min-height:46px;border:1px solid #d3dedc;border-radius:10px;background:#fff;color:inherit;font-weight:600;padding:10px 15px;transition:background .15s,box-shadow .15s}button:hover{background:#eef5f2}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #cf9b30;outline-offset:3px}button:disabled{cursor:default}button:active:not(:disabled){filter:brightness(.96)}[hidden]{display:none!important}.header{max-width:1160px;margin:auto;padding:30px 32px 23px;border-bottom:1px solid #dfe7e3}.brand{text-decoration:none;color:#243e45;display:flex;align-items:center;gap:12px;font-size:23px;font-weight:750;letter-spacing:-.6px}.brand strong{color:var(--teal)}.brand-icon{display:grid;place-items:center;color:white;background:var(--teal);width:40px;height:40px;border-radius:11px;font-size:32px}.header p{font-size:13px;color:#6d7e80;margin:10px 0 0 52px}main{max-width:1096px;margin:auto;padding:36px 24px 60px}.home{text-align:center;padding:12px 0}.eyebrow{font-size:12px;font-weight:750;letter-spacing:1.6px;color:var(--teal)}h1{font-size:clamp(30px,4vw,46px);line-height:1.55;letter-spacing:1.5px;margin:20px 0 14px}.intro{color:#708185;font-size:15px;line-height:1.9}.hero-art{display:flex;gap:24px;justify-content:center;align-items:center;margin:28px 0 34px;height:90px}.hero-art>span{color:#95a9a4;font-size:24px}.mini-piece{width:64px;height:64px;clip-path:polygon(0 0,50% 0,50% 50%,100% 50%,100% 100%,0 100%);background-color:var(--red);background-image:linear-gradient(#ffffff80 1px,transparent 1px),linear-gradient(90deg,#ffffff80 1px,transparent 1px);background-size:32px 32px}.blue-piece{background-color:var(--blue);transform:rotate(180deg)}.mini-union{width:96px;height:64px;border:2px solid #7c9590;border-radius:3px;background:repeating-linear-gradient(90deg,transparent 0 30px,#d3deda 30px 32px),repeating-linear-gradient(0deg,#fff 0 30px,#d3deda 30px 32px)}.choices{display:grid;grid-template-columns:1fr 1fr;gap:22px;max-width:790px;margin:auto}.choice{text-align:left;padding:26px 28px;display:flex;flex-direction:column;align-items:flex-start;gap:10px;border:1px solid #bcd7cc;box-shadow:0 8px 24px #294b3910}.choice-icon{width:42px;height:42px;display:grid;place-items:center;background:#e7f2ed;border-radius:12px;font-size:27px;color:var(--teal)}.choice strong{font-size:23px;margin-top:3px}.choice>span:not(.choice-icon){font-size:13px;color:#788884;font-weight:400}.choice b{font-size:13px;color:var(--teal);margin-top:16px}.secondary{border-color:#d3dfeb}.secondary .choice-icon{background:#eaf1f9;color:#4a79a6}.secondary b{color:#4a79a6}.home-note{font-size:12px;color:#869590;margin-top:30px}.workspace-top{display:flex;align-items:center;justify-content:space-between;font-size:12px;color:#6d817d;margin-bottom:18px}.text-button{border:0;background:transparent;padding-left:0}.steps{list-style:none;display:grid;grid-template-columns:repeat(4,1fr);padding:0;margin:0 0 30px;border:1px solid #dce5e0;border-radius:12px;overflow:hidden;background:#fff}.steps li{font-size:10px;letter-spacing:1px;padding:13px 18px;color:#93a19e;border-right:1px solid #e4eae7}.steps li:last-child{border:0}.steps li span{display:block;font-size:13px;font-weight:650;letter-spacing:0;margin-top:5px}.steps li.active{background:#e5f1eb;color:#26776c}.steps li.done{color:#628b80}.work-layout{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:36px;align-items:start}.board-panel{background:#fff;border:1px solid #e0e7e3;border-radius:18px;padding:23px;box-shadow:0 6px 30px #223e3710}.board-heading,.board-foot{display:flex;justify-content:space-between;gap:10px;color:#7d8d87;font-size:11px;letter-spacing:1px}.board-heading{margin-bottom:20px;font-weight:700}.board-foot{margin-top:18px;letter-spacing:0}.board{display:grid;grid-template-columns:repeat(var(--columns),1fr);width:100%;border-top:1px solid #ccd9d3;border-left:1px solid #ccd9d3;overflow:hidden;background:#eff4f1}.cell{border:0;border-right:1px solid #ccd9d3;border-bottom:1px solid #ccd9d3;border-radius:0;min-height:0;min-width:0;width:100%;height:100%;padding:0;background:#fafcfb;touch-action:manipulation;transition:none}.cell:focus-visible{outline-offset:-4px;z-index:1}.cell.draft{background:#77b4a2}.cell.red{background:var(--red)}.cell.blue{background:var(--blue)}.cell.white{background:white}.cell.outside{background:#eaf0ed;border-color:#e0e8e3}.mode-place .cell.selected{box-shadow:inset 0 0 0 3px #253d45}.controls{padding:9px 0}h2{font-size:25px;letter-spacing:.4px;margin:12px 0}.controls p{color:#72817e;font-size:14px;line-height:1.9}.tip{font-size:13px;line-height:1.9;background:#edf2e9;border-radius:10px;padding:18px;color:#72816c;margin:26px 0}.primary{background:var(--teal);color:#fff;border-color:var(--teal);box-shadow:0 4px 10px #247c7315}.primary:hover{background:#1a6a62}.full{width:100%;margin-top:10px}.quiet{background:transparent;border-color:transparent;font-size:13px;color:#71817b}.small{font-size:12px!important}.piece-selector{display:flex;gap:8px;margin:22px 0 16px}.piece-selector button{flex:1;font-size:13px;padding:10px 8px}.red-select{color:#bb554f}.blue-select{color:#407eaf}.piece-selector button[aria-pressed=true]{background:#eaf2ee;border-color:#497b6e;box-shadow:0 0 0 1px #497b6e}.transform-buttons{display:grid;grid-template-columns:1fr 1fr;gap:8px}.transform-buttons button{font-size:13px}.review{border-top:1px solid #dce5e0;padding-top:16px;margin-top:18px}.title-label{font-size:12px;display:block;color:#72817e;margin:22px 0 7px}input[type=text],#puzzle-title{width:100%;padding:12px;border:1px solid #d5dfd9;border-radius:9px;background:#fff;font-size:14px;color:#354b44}.color-guide{display:flex;align-items:center;gap:10px;margin-top:20px}.color-guide span{border:1px solid #d8e1db;background:white;padding:7px 14px;border-radius:7px;font-size:12px}.color-guide .red-text{background:#f7ddd9;color:#a34440;border-color:#edc3bd}.color-guide .blue-text{background:#dceafa;color:#386a95;border-color:#bfd8ee}.color-guide b{font-size:13px;color:#9aaba2}.color-counts{font-size:13px;text-align:center;background:#edf2ef;border-radius:9px;padding:12px}.file-actions{margin-top:18px;padding-top:12px;border-top:1px solid #dce5e0}.file-actions button{font-size:13px}#clear{padding:20px 10px;text-align:center;background:#e1f2df;border:1px solid #b8d9ab;border-radius:12px;margin-top:16px;color:#33714e}#clear strong{display:block;font-size:42px;letter-spacing:4px}#clear span{font-size:12px}#message{max-width:1048px;background:#fff1e4;color:#9c5725;border:1px solid #ebcdb0;border-radius:12px;padding:15px 20px;margin:24px auto 0;font-size:14px;line-height:1.7}#message.success{background:#e9f4eb;border-color:#bcd8c3;color:#3b7751}footer{border-top:1px solid #dfe7e3;max-width:1096px;margin:auto;padding:24px;color:#82918b;font-size:11px;display:flex;justify-content:space-between;gap:15px}
@media(max-width:800px){.work-layout{grid-template-columns:minmax(0,1fr) 260px;gap:22px}.board-panel{padding:16px}main{padding:24px 18px 40px}.steps li{padding:12px 10px}.brand{font-size:20px}}
@media(max-width:620px){.header{padding:22px 18px}.brand{font-size:17px;letter-spacing:-.4px;gap:9px}.brand-icon{width:32px;height:32px;font-size:26px}.header p{font-size:10px;margin-left:41px}.home{padding:9px 0}h1{font-size:30px}.choices{grid-template-columns:1fr;gap:14px}.choice{padding:20px 24px}.choice strong{font-size:21px}.choice b{margin-top:6px}.hero-art{gap:16px;margin:24px 0}.work-layout{grid-template-columns:1fr;gap:20px}.board-panel{padding:14px;border-radius:13px}.steps{margin-bottom:20px}.steps li{padding:10px 6px;font-size:9px}.steps li span{font-size:10px}.controls{padding:2px 5px}.controls h2{font-size:23px}.controls p{margin:10px 0}.tip{margin:16px 0;padding:13px}.board-foot{font-size:10px}.home-note{font-size:10px}footer{font-size:10px;flex-direction:column;gap:5px}.color-guide{justify-content:center}}

/* STEP 2: a single, touch-friendly control panel immediately below the board. */
.operating-piece{font-size:14px;font-weight:750;color:#253d45}
#placement-panel{margin-top:12px;border-top:1px solid #dce5e0;padding-top:12px}
.placement-help{font-size:12px;line-height:1.7;color:#62786e;margin:0}
#placement-panel .piece-selector{margin:12px 0;gap:12px}
#placement-panel .piece-selector button{min-height:48px}
#placement-panel .piece-selector button[aria-pressed=true]{border:2px solid #253d45;background:#edf5f1;box-shadow:none}
#placement-panel .dpad{display:grid;grid-template-columns:repeat(3,minmax(0,88px));grid-template-rows:repeat(2,60px);gap:10px;justify-content:center;margin:14px 0}
#placement-panel .dpad button{padding:5px;min-height:60px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px}
#placement-panel .dpad b{font-size:25px;line-height:1}
#placement-panel .dpad span{font-size:11px}
.move-up{grid-column:2;grid-row:1}.move-left{grid-column:1;grid-row:2}.move-down{grid-column:2;grid-row:2}.move-right{grid-column:3;grid-row:2}
#placement-panel .transform-buttons{gap:10px;max-width:380px;margin:auto}
#placement-panel .transform-buttons button{min-height:48px;padding:10px 6px}
#placement-message{font-size:13px;color:#9c5725;background:#fff1e4;border-radius:8px;padding:12px;line-height:1.6;margin:12px 0 0}

/* QR sharing is isolated from the editor and play layout. */
#share-dialog{width:min(560px,calc(100% - 24px));max-height:calc(100dvh - 24px);overflow:auto;padding:24px;border:1px solid #d3dedc;border-radius:18px;color:#253d45;background:#fff;box-shadow:0 20px 80px #162b3440}
#share-dialog::backdrop{background:#18382e88}
.share-heading{display:flex;align-items:center;justify-content:space-between;gap:12px}
.share-heading h2{font-size:21px}
#share-dialog p{font-size:14px;line-height:1.7}
#share-qr{width:min(100%,400px);margin:16px auto;background:white}
#share-qr svg{display:block;width:100%;height:auto}
#share-dialog label{display:block;font-size:12px;margin-bottom:6px}
#share-url{display:block;width:100%;resize:vertical;box-sizing:border-box;border:1px solid #d3dedc;border-radius:8px;padding:10px;font-size:12px;overflow-wrap:anywhere;color:#486056;background:#f6f8f7}
#share-local-note{background:#fff1e4;padding:12px;border-radius:8px;color:#9c5725}
#share-status{margin-bottom:0;color:#247c73}
@media(max-width:620px){#share-dialog{padding:16px}.share-heading h2{font-size:18px}}