:root{
  --bg:#f4f6fa;
  --card:#ffffff;
  --ink:#1c2434;
  --sub:#5b6678;
  --line:#e3e8f0;
  --brand:#2f6df6;
  --brand-dark:#1f57d6;
  --accent:#ff7a59;
  --ok:#1faa6a;
  --shadow:0 6px 24px rgba(28,36,52,.08);
  --radius:16px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  font-family:"Hiragino Sans","Hiragino Kaku Gothic ProN",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.6;
}
img,canvas{max-width:100%;display:block}

/* header */
.site-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 18px;background:var(--card);border-bottom:1px solid var(--line);
  position:sticky;top:0;z-index:20;
}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:18px}
.logo{font-size:22px}
.badge-privacy{font-size:12px;color:var(--ok);background:#e9f8f1;border:1px solid #c6ecda;padding:4px 10px;border-radius:999px;white-space:nowrap}

main{max-width:960px;margin:0 auto;padding:24px 18px 60px}

/* steps */
.step{display:none;animation:fade .35s ease}
.step.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

h1{font-size:30px;line-height:1.3;margin:18px 0 10px;letter-spacing:.5px}
.lead{color:var(--sub);font-size:15px;margin:0 0 26px}
h2{font-size:20px;margin:0 0 14px}
h3{font-size:15px;margin:0 0 10px;color:var(--sub)}

/* dropzone */
.dropzone{display:block;cursor:pointer}
.dropzone-inner{
  border:2px dashed #c3cee0;border-radius:var(--radius);background:var(--card);
  padding:48px 20px;text-align:center;transition:.2s;box-shadow:var(--shadow);
}
.dropzone.drag .dropzone-inner,.dropzone:hover .dropzone-inner{border-color:var(--brand);background:#f0f5ff}
.dz-icon{font-size:40px}
.dz-title{font-weight:800;font-size:18px;margin-top:10px}
.dz-sub{color:var(--sub);font-size:13px;margin-top:6px}
.tips{list-style:none;padding:0;margin:24px 0 0;color:var(--sub);font-size:14px}
.tips li{margin:6px 0}

/* editor */
.editor-grid{display:grid;grid-template-columns:1fr 320px;gap:24px;align-items:start}
.canvas-wrap{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;display:flex;justify-content:center}
#editor{touch-action:none;border-radius:8px;cursor:grab;background:#eef1f6}
#editor:active{cursor:grabbing}
.controls{margin-top:16px;background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px}
.ctrl{display:flex;align-items:center;gap:12px;margin:10px 0}
.ctrl>span{width:48px;font-size:13px;color:var(--sub);flex:none}
.ctrl input[type=range]{flex:1;accent-color:var(--brand)}
.ctrl-row{display:flex;gap:8px;margin-top:8px}
.btn-mini{flex:1;font-size:13px;padding:8px;border:1px solid var(--line);background:#fff;border-radius:10px;cursor:pointer}
.btn-mini:active{background:#f0f5ff}
.hint{font-size:12px;color:var(--sub);margin:10px 0 0}

.editor-right{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px}
.preset-list{display:flex;flex-direction:column;gap:8px;max-height:340px;overflow:auto;margin-bottom:14px}
.preset{
  display:flex;justify-content:space-between;align-items:center;gap:8px;
  border:1.5px solid var(--line);border-radius:12px;padding:11px 13px;cursor:pointer;transition:.15s;background:#fff;
}
.preset:hover{border-color:#b9c8e6}
.preset.selected{border-color:var(--brand);background:#f0f5ff;box-shadow:0 0 0 2px rgba(47,109,246,.12)}
.preset .p-name{font-weight:700;font-size:14px}
.preset .p-size{font-size:12px;color:var(--sub)}
.size-readout{font-size:13px;color:var(--sub);text-align:center;margin-bottom:14px;min-height:18px}

/* download / result */
.result-grid{display:grid;grid-template-columns:1fr 1.4fr;gap:20px;margin-bottom:24px}
.preview-box{background:#dfe4ec;border-radius:12px;padding:14px;display:flex;justify-content:center;align-items:center}
.preview-box canvas{box-shadow:0 2px 10px rgba(0,0,0,.18)}
.download-actions{display:grid;grid-template-columns:1fr 1.3fr;gap:16px}
.plan{border:1.5px solid var(--line);border-radius:var(--radius);padding:20px;background:var(--card);position:relative}
.plan.paid{border-color:var(--brand);box-shadow:0 8px 28px rgba(47,109,246,.16)}
.plan h4{margin:0 0 4px;font-size:16px}
.plan .price{font-size:30px;font-weight:900;margin:4px 0 12px}
.plan ul{margin:0 0 16px;padding-left:18px;color:var(--sub);font-size:13px}
.plan ul li{margin:4px 0}
.ribbon{position:absolute;top:-11px;right:16px;background:var(--accent);color:#fff;font-size:12px;font-weight:700;padding:4px 12px;border-radius:999px}

/* buttons */
.btn-primary,.btn-secondary{font-family:inherit;font-weight:800;font-size:15px;border:none;border-radius:12px;padding:14px 20px;cursor:pointer;transition:.15s}
.btn-primary{background:var(--brand);color:#fff}
.btn-primary:hover{background:var(--brand-dark)}
.btn-secondary{background:#eef1f6;color:var(--ink)}
.btn-secondary:hover{background:#e3e8f0}
.btn-block{display:block;width:100%}
.btn-text{background:none;border:none;color:var(--sub);font-size:14px;cursor:pointer;margin-top:14px;padding:8px}
.btn-text:hover{color:var(--brand)}

/* modal */
.modal-overlay{position:fixed;inset:0;background:rgba(20,28,44,.55);display:none;align-items:center;justify-content:center;z-index:50;padding:18px}
.modal-overlay.open{display:flex}
.modal{background:#fff;border-radius:var(--radius);max-width:380px;width:100%;padding:28px 24px;position:relative;box-shadow:0 20px 60px rgba(0,0,0,.3)}
.modal-close{position:absolute;top:10px;right:12px;background:none;border:none;font-size:26px;color:var(--sub);cursor:pointer;line-height:1}
.modal h3{color:var(--ink);font-size:19px;margin:0 0 12px}
.modal-price{font-size:26px;font-weight:900;text-align:center;margin:16px 0}
.modal-note{font-size:12px;color:var(--sub);margin-top:14px;text-align:center}
.dev-note{margin-top:18px;font-size:12px;color:var(--sub);border-top:1px dashed var(--line);padding-top:12px}
.dev-note summary{cursor:pointer}
.dev-note code{background:#f0f2f6;padding:1px 5px;border-radius:5px;font-size:11px}

/* footer */
.site-footer{text-align:center;padding:28px 18px;color:var(--sub);font-size:13px;border-top:1px solid var(--line);background:var(--card)}
.footer-note{font-size:12px;margin-top:6px}

/* AI background block */
.ai-block{margin-top:14px;padding:14px;border:1.5px solid #d9e3fb;background:linear-gradient(180deg,#f5f8ff,#fff);border-radius:12px}
.ai-head{display:flex;align-items:center;justify-content:space-between;font-weight:800;font-size:14px}
.tag-premium{font-size:11px;font-weight:700;color:#fff;background:linear-gradient(90deg,#ff7a59,#ff5b8a);padding:3px 9px;border-radius:999px}
.ai-desc{font-size:12px;color:var(--sub);margin:8px 0 10px}
.btn-mini.ai-main{background:var(--brand);color:#fff;border-color:var(--brand);font-weight:700}
.btn-mini.ai-main.active{background:var(--ok);border-color:var(--ok)}
.bg-swatches{display:flex;align-items:center;gap:8px;margin-top:12px}
.sw-label{font-size:12px;color:var(--sub)}
.swatch{width:26px;height:26px;border-radius:50%;border:2px solid #cfd6e2;cursor:pointer;padding:0}
.swatch.selected{border-color:var(--brand);box-shadow:0 0 0 3px rgba(47,109,246,.2)}

/* premium plan */
.download-actions.three{grid-template-columns:1fr 1fr 1.25fr}
.plan.premium{border-color:var(--accent);background:linear-gradient(180deg,#fff6f2,#fff)}
.plan.premium.applied{box-shadow:0 8px 28px rgba(255,122,89,.22)}
.plan.premium .ribbon{background:linear-gradient(90deg,#ff7a59,#ff5b8a)}

/* segmentation overlay */
.seg-overlay{position:fixed;inset:0;background:rgba(20,28,44,.6);display:none;align-items:center;justify-content:center;z-index:60;padding:20px}
.seg-overlay.open{display:flex}
.seg-box{background:#fff;border-radius:var(--radius);padding:30px 34px;text-align:center;max-width:340px;box-shadow:0 20px 60px rgba(0,0,0,.3)}
.spinner{width:44px;height:44px;border:4px solid #e3e8f0;border-top-color:var(--brand);border-radius:50%;margin:0 auto 16px;animation:spin .9s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.seg-msg{font-weight:700;margin:0 0 6px}
.seg-sub{font-size:12px;color:var(--sub);margin:0}

@media(max-width:760px){
  h1{font-size:24px}
  .editor-grid{grid-template-columns:1fr}
  .result-grid{grid-template-columns:1fr}
  .download-actions,.download-actions.three{grid-template-columns:1fr}
  .badge-privacy{display:none}
}