*{margin:0;padding:0;box-sizing:border-box}
:root{
  --blue:#1a73e8;--blue-dark:#1558b0;
  --bg:#ffffff;--card:#ffffff;--line:#e6eaf0;
  --text:#000000;--muted:#555555;
  --shadow:0 10px 30px rgba(16,35,75,.08);
  --radius:14px;
  color-scheme:light;
}
html,body{height:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Microsoft YaHei",Arial,sans-serif;
  background:var(--bg);color:var(--text);
  padding:32px 16px 48px;line-height:1.5;
}
.app{max-width:1080px;margin:0 auto}
.hero{text-align:center;margin-bottom:28px}
.hero h1{font-size:34px;font-weight:800;color:var(--blue);letter-spacing:.5px}
.hero .sub{color:var(--muted);margin-top:8px;font-size:15px}

.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px;margin-bottom:20px}
.hidden{display:none !important}

/* upload */
.drop{
  border:2px dashed #c3cfe0;border-radius:var(--radius);
  padding:48px 24px;text-align:center;cursor:pointer;
  transition:.2s ease;background:rgba(26,115,232,.02);
}
.drop:hover,.drop.dragover{border-color:var(--blue);background:rgba(26,115,232,.06)}
.drop-icon{font-size:48px;margin-bottom:10px}
.drop-title{font-size:18px;font-weight:700;margin-bottom:6px}
.drop-tip{color:var(--muted);font-size:13px;margin-bottom:18px}

/* buttons */
.btn{
  display:inline-block;border:none;cursor:pointer;
  padding:10px 20px;border-radius:999px;font-size:14px;font-weight:600;
  transition:.15s ease;
}
.btn.primary{background:var(--blue);color:#fff}
.btn.primary:hover:not(:disabled){background:var(--blue-dark)}
.btn.primary:disabled{opacity:.5;cursor:not-allowed}
.btn.ghost{background:transparent;color:var(--muted);border:1px solid var(--line)}
.btn.ghost:hover{color:var(--text);border-color:#b9c3d4}

/* editor */
.editor{display:grid;grid-template-columns:1.2fr 1fr;gap:24px}
@media(max-width:780px){.editor{grid-template-columns:1fr}}

.preview-wrap{display:flex;flex-direction:column;gap:14px}
.preview{
  position:relative;background:
    linear-gradient(45deg,#eef1f6 25%,transparent 25%),
    linear-gradient(-45deg,#eef1f6 25%,transparent 25%),
    linear-gradient(45deg,transparent 75%,#eef1f6 75%),
    linear-gradient(-45deg,transparent 75%,#eef1f6 75%);
  background-size:18px 18px;
  background-position:0 0,0 9px,9px -9px,-9px 0;
  border:1px solid var(--line);border-radius:12px;
  min-height:360px;display:flex;align-items:center;justify-content:center;
  overflow:hidden;
}
.preview canvas{max-width:100%;max-height:520px;display:block}
.loader{position:absolute;inset:0;background:rgba(255,255,255,.85);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;font-size:14px;color:var(--muted)}
.spinner{width:38px;height:38px;border-radius:50%;border:3px solid #d6e0f0;border-top-color:var(--blue);animation:spin .9s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

.actions{display:flex;gap:10px;justify-content:space-between}

/* 抠图模型选择卡片 */
.engine-picker{
  border:1px solid var(--line);border-radius:12px;padding:14px;background:#fafbff;
}
.engine-picker-label{
  font-size:13px;color:var(--muted);font-weight:700;margin-bottom:10px;
  text-transform:uppercase;letter-spacing:.5px;
}
.engine-cards{display:grid;grid-template-columns:1fr 1fr;gap:10px}
@media(max-width:540px){.engine-cards{grid-template-columns:1fr}}
.engine-card{
  position:relative;display:block;cursor:pointer;
  border:2px solid var(--line);border-radius:10px;padding:12px 14px;
  background:#fff;transition:.15s ease;
}
.engine-card:hover{border-color:#b9d2ff}
.engine-card.active{border-color:var(--blue);background:rgba(26,115,232,.05);box-shadow:0 0 0 3px rgba(26,115,232,.08)}
.engine-card input[type=radio]{position:absolute;opacity:0;pointer-events:none}
.engine-card-title{font-size:15px;font-weight:700;color:#000;margin-bottom:6px}
.engine-card-desc{font-size:13px;color:#444;line-height:1.7}
.engine-card-desc strong{color:var(--blue)}
.engine-tag{
  display:inline-block;margin-top:6px;font-size:12px;color:var(--muted);
  background:rgba(0,0,0,.04);padding:2px 8px;border-radius:999px;
}
.engine-note{
  margin-top:10px;font-size:12px;color:var(--muted);text-align:center;
  padding-top:10px;border-top:1px dashed var(--line);
}

/* controls */
.controls{display:flex;flex-direction:column;gap:18px}
.group{border:1px solid var(--line);border-radius:12px;padding:14px}
.label{font-size:13px;color:var(--muted);font-weight:600;margin-bottom:10px;text-transform:uppercase;letter-spacing:.5px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{
  border:1px solid var(--line);background:var(--card);color:var(--text);
  padding:8px 12px;border-radius:999px;font-size:13px;cursor:pointer;
  display:inline-flex;align-items:center;gap:6px;transition:.15s ease;
}
.chip:hover{border-color:#b9d2ff}
.chip.active{background:var(--blue);color:#fff;border-color:var(--blue)}
.chip .dot{width:14px;height:14px;border-radius:50%;border:1px solid rgba(0,0,0,.15);display:inline-block}
.size-info{font-size:13px;color:var(--text);margin-top:10px;line-height:1.6;padding:10px 12px;background:rgba(26,115,232,.04);border-radius:8px;border:1px solid rgba(26,115,232,.10)}
.size-info strong{color:var(--blue)}

/* 分类 tab */
.cat-tabs{display:flex;gap:4px;flex-wrap:wrap;margin-bottom:10px;border-bottom:1px solid var(--line);padding-bottom:8px}
.cat-tab{
  background:transparent;border:none;color:var(--muted);cursor:pointer;
  padding:6px 10px;border-radius:6px;font-size:13px;font-weight:600;transition:.15s;
}
.cat-tab:hover{color:var(--text);background:rgba(26,115,232,.06)}
.cat-tab.active{color:var(--blue);background:rgba(26,115,232,.10)}
.size-chip-row{display:flex;flex-wrap:wrap;gap:6px;max-height:140px;overflow-y:auto}
.size-chip-row .chip{font-size:12px;padding:6px 10px}

.row{display:flex;gap:14px;flex-wrap:wrap;align-items:center;margin-top:8px}
.row:first-of-type{margin-top:0}
.row-item{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--muted);flex:1;min-width:140px}
.row-item input[type=range]{flex:1}
.row-item select{padding:6px 10px;border-radius:8px;border:1px solid var(--line);background:var(--card);color:var(--text);font-size:13px}

.foot{text-align:center;color:var(--muted);font-size:13px;margin-top:32px;padding-top:24px;border-top:1px solid var(--line)}
.foot a{color:var(--blue);text-decoration:none}
.foot a:hover{text-decoration:underline}

/* 落地页:hero badges */
.badge-row{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;margin-bottom:14px}
.hero-badge{font-size:12px;padding:5px 11px;border-radius:999px;background:rgba(26,115,232,.08);color:var(--blue);font-weight:600;border:1px solid rgba(26,115,232,.18)}

/* 落地页:步骤卡片 */
.seo{max-width:980px;margin:48px auto 0;padding:0 4px;line-height:1.75}
.seo h2{font-size:24px;color:var(--text);margin:32px 0 14px;font-weight:800}
.seo h3{font-size:16px;color:var(--text);margin-bottom:6px}
.seo p{color:var(--muted);font-size:15px}
.seo strong{color:var(--text)}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:8px}
@media(max-width:780px){.steps{grid-template-columns:1fr}}
.step-card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:18px}
.step-num{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;border-radius:50%;background:var(--blue);color:#fff;font-weight:800;font-size:14px;margin-bottom:8px}
.bullets{list-style:none;padding:0;display:grid;gap:10px}
.bullets li{padding-left:24px;position:relative;color:var(--muted);font-size:15px}
.bullets li::before{content:'✓';position:absolute;left:0;top:0;color:var(--blue);font-weight:800}

/* 尺寸表 */
.size-table{
  width:100%;border-collapse:collapse;margin:10px 0 8px;
  font-size:14px;background:var(--card);
  border:1px solid var(--line);border-radius:10px;overflow:hidden;
  display:block;overflow-x:auto;
}
.size-table thead{background:rgba(26,115,232,.06)}
.size-table th,.size-table td{
  padding:10px 14px;text-align:left;border-bottom:1px solid var(--line);
  white-space:nowrap;
}
.size-table th{color:var(--text);font-weight:700;font-size:13px}
.size-table td{color:var(--muted)}
.size-table td:first-child{color:var(--text);font-weight:600;white-space:nowrap}
.size-table tbody tr:last-child td{border-bottom:none}
.size-table tbody tr:hover{background:rgba(26,115,232,.03)}
@media(max-width:780px){
  .size-table{font-size:13px}
  .size-table th,.size-table td{padding:8px 10px}
}

/* FAQ */
.seo details{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:12px 16px;margin-bottom:8px}
.seo details summary{cursor:pointer;font-weight:600;color:var(--text);list-style:none;outline:none}
.seo details summary::-webkit-details-marker{display:none}
.seo details summary::before{content:'▸';color:var(--blue);margin-right:8px;display:inline-block;transition:.15s}
.seo details[open] summary::before{transform:rotate(90deg)}
.seo details p{margin-top:8px}