:root{--bg:#f5f6f8;--card:#fff;--text:#20242a;--muted:#68707d;--primary:#1f6feb;--danger:#c9352b;--ok:#238636;--border:#d9dee7}
*{box-sizing:border-box}body{margin:0;font-family:Arial,sans-serif;background:var(--bg);color:var(--text)}a{color:var(--primary);text-decoration:none}.wrap{max-width:1250px;margin:auto;padding:20px}.top{background:#111827;color:#fff}.top .wrap{display:flex;justify-content:space-between;align-items:center}.nav a{color:#fff;margin-left:16px}.card{background:var(--card);border:1px solid var(--border);border-radius:10px;padding:20px;margin:18px 0;box-shadow:0 2px 8px #0000000a}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:14px}.form-row{margin:12px 0}label{display:block;font-weight:700;margin-bottom:5px}input,select,textarea{width:100%;padding:10px;border:1px solid var(--border);border-radius:7px;background:#fff}textarea{min-height:90px}.btn{display:inline-block;border:0;border-radius:7px;padding:10px 14px;background:var(--primary);color:#fff;cursor:pointer}.btn.secondary{background:#596273}.btn.danger{background:var(--danger)}.btn.ok{background:var(--ok)}table{width:100%;border-collapse:collapse}th,td{padding:10px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}.muted{color:var(--muted)}.flash{padding:12px;border-radius:7px;margin:10px 0}.flash.success{background:#dcfce7}.flash.error{background:#fee2e2}.badge{padding:4px 8px;border-radius:20px;background:#e5e7eb;font-size:12px}.actions{display:flex;gap:8px;flex-wrap:wrap}.tree ul{list-style:none;padding-left:22px}.product-img{width:60px;height:60px;object-fit:cover;border-radius:6px;background:#eee}.login{max-width:440px;margin:50px auto}.right{text-align:right}@media(max-width:700px){table{display:block;overflow:auto}.top .wrap{display:block}.nav{margin-top:10px}.nav a{display:inline-block;margin:6px 12px 6px 0}}
.category-node{padding-left:calc(var(--depth) * 30px);display:flex;align-items:center;gap:8px;min-height:34px}.tree-branch{color:var(--muted);width:18px;text-align:center}.category-level-0 td{background:#f8fafc}.category-level-0 .category-node strong{font-size:16px}.category-level-1 .category-node strong{font-weight:600}.category-level-2 .category-node strong{font-weight:400}
.category-details,.category-leaf{border:1px solid var(--border);border-radius:8px;margin:8px 0;background:#fff}.category-details>summary{display:flex;align-items:center;gap:10px;padding:12px;cursor:pointer;list-style:none}.category-details>summary::-webkit-details-marker{display:none}.category-details>summary:before{content:'▶';font-size:12px;color:var(--muted);transition:.15s}.category-details[open]>summary:before{transform:rotate(90deg)}.category-children{padding:0 10px 10px 24px;border-top:1px solid var(--border)}.category-leaf{display:flex;align-items:center;gap:10px;padding:11px 12px}.depth-0{background:#f8fafc}.depth-1{margin-left:8px}.depth-2{margin-left:18px;background:#fbfdff}.depth-2 .category-name{font-weight:500}.category-name{font-weight:700;flex:1}.category-level-label{font-size:12px;color:var(--muted);min-width:55px}.category-actions{display:flex;gap:6px;align-items:center}.category-actions form{margin:0}.category-actions .btn{padding:6px 9px;font-size:12px}.leaf-dot{color:var(--primary);font-size:20px}

/* Nested collapsible category tree */
.category-tree .category-details{overflow:hidden}
.category-tree .category-details.depth-0{border-width:2px;margin:12px 0}
.category-tree .category-details.depth-0>summary{font-size:16px;background:#f8fafc}
.category-tree .category-details.depth-1{margin:8px 0 8px 10px;border-left:3px solid var(--border)}
.category-tree .category-details.depth-1>summary{background:#fff}
.category-tree .category-leaf.depth-2{margin:7px 0 7px 20px;background:#f8fafc;border-style:dashed}
.category-tree .category-children{display:block}
.category-tree details:not([open])>.category-children{display:none}

/* Polished category tree rows */
.category-tree{overflow:hidden}
.category-tree .category-details,
.category-tree .category-leaf{margin:7px 0;border:1px solid var(--border);border-radius:8px;background:#fff;box-shadow:none}
.category-tree .category-details>summary,
.category-tree .category-leaf{min-height:46px;padding:8px 10px}
.category-tree .category-details>summary{display:flex;align-items:center;gap:8px;cursor:pointer;list-style:none}
.category-tree .category-details>summary::-webkit-details-marker{display:none}
.category-tree .category-details>summary:before{content:'›';display:flex;align-items:center;justify-content:center;width:22px;height:22px;flex:0 0 22px;border-radius:5px;color:#4b5563;font-size:20px;line-height:1;transition:transform .15s ease,background .15s ease}
.category-tree .category-details>summary:hover:before{background:#e9eef6}
.category-tree .category-details[open]>summary:before{transform:rotate(90deg)}
.category-tree .category-title{display:flex;align-items:center;gap:9px;min-width:0;flex:1}
.category-tree .category-name{font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.category-tree .category-details.depth-0{margin:10px 0;border-width:1px}
.category-tree .category-details.depth-0>summary{background:#f7f9fc}
.category-tree .category-details.depth-0 .category-name{font-size:16px;font-weight:700}
.category-tree .category-details.depth-1{margin:7px 0;border-left:3px solid #cbd5e1}
.category-tree .category-details.depth-1>summary{background:#fff}
.category-tree .category-details.depth-1 .category-name{font-weight:600}
.category-tree .category-children{padding:6px 10px 10px 26px;border-top:1px solid #edf0f4;background:#fbfcfe}
.category-tree .category-leaf{display:flex;align-items:center;gap:8px}
.category-tree .category-leaf.depth-2{margin:6px 0;background:#fff;border:1px solid #e6eaf0;border-style:solid}
.category-tree .category-leaf.depth-2 .category-name{font-weight:500}
.category-tree .leaf-dot{display:inline-flex;align-items:center;justify-content:center;width:22px;color:#94a3b8;font-size:18px}
.category-tree .category-actions{display:flex;align-items:center;justify-content:flex-end;gap:6px;flex:0 0 auto;margin-left:auto}
.category-tree .category-actions form{display:inline-flex;margin:0}
.category-tree .category-action{display:inline-flex;align-items:center;justify-content:center;min-height:28px;padding:4px 9px;border:1px solid transparent;border-radius:6px;background:#fff;font:600 12px/1 Arial,sans-serif;cursor:pointer;text-decoration:none;transition:background .15s ease,border-color .15s ease,color .15s ease}
.category-tree .category-action.edit{color:#475569;border-color:#cbd5e1}
.category-tree .category-action.edit:hover{color:#1f2937;background:#f1f5f9;border-color:#94a3b8}
.category-tree .category-action.delete{color:#b42318;border-color:#f0b9b5}
.category-tree .category-action.delete:hover{color:#8f1d14;background:#fff1f0;border-color:#df8f89}
@media(max-width:700px){
  .category-tree .category-children{padding-left:12px;padding-right:4px}
  .category-tree .category-details>summary,.category-tree .category-leaf{padding:8px}
  .category-tree .category-action{padding:4px 7px;font-size:11px}
}