:root{
  --bg:#f5f6f8; --surface:#fff; --line:#e6e8ec; --line2:#eef0f3;
  --text:#111418; --muted:#6b7280; --accent:#2563eb; --accent-d:#1d4ed8;
  --gold:#f5a623; --good:#059669; --danger:#dc2626; --warn:#b45309;
  --radius:10px;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text);font-size:13px}

.topbar{height:52px;display:flex;align-items:center;justify-content:space-between;
  padding:0 18px;background:var(--surface);border-bottom:1px solid var(--line)}
.brand{font-weight:700}.brand .dot{color:var(--accent)}
.topbar-right{display:flex;gap:14px;align-items:center}
.meta{color:var(--muted)}.who{color:var(--muted);font-size:12px}

.layout{display:grid;grid-template-columns:230px 1fr;height:calc(100vh - 52px)}
.side{background:var(--surface);border-right:1px solid var(--line);padding:14px;overflow:auto}
.side-title{font-size:11px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted);margin-bottom:8px;font-weight:600}
.dataset-list .ds{padding:8px 10px;border-radius:8px;cursor:pointer;font-weight:500}
.dataset-list .ds.active{background:#eff4ff;color:var(--accent-d)}
.dataset-list .ds:hover{background:var(--line2)}

.version-list .v{padding:6px 8px;border-radius:6px;font-size:12px;border:1px solid transparent}
.version-list .v:hover{background:var(--line2)}
.version-list .v .vh{display:flex;justify-content:space-between;gap:6px}
.version-list .v .vn{font-weight:700}
.version-list .v .vr{color:var(--muted);font-size:11px;margin-top:2px}
.version-list .v .restore{font-size:11px;color:var(--accent);cursor:pointer;display:none}
.version-list .v:hover .restore{display:inline}

.main{display:flex;flex-direction:column;overflow:hidden}
.collection-tabs{display:flex;gap:4px;padding:10px 16px;border-bottom:1px solid var(--line);background:var(--surface);overflow-x:auto;flex-wrap:wrap}
.collection-tabs .tab{padding:7px 12px;border-radius:8px;cursor:pointer;color:var(--muted);white-space:nowrap}
.collection-tabs .tab.active{background:#eff4ff;color:var(--accent-d);font-weight:600}
.collection-tabs .tab:hover{background:var(--line2)}

.editor{flex:1;overflow:auto;padding:16px}
.group-block{margin-bottom:22px}
.group-head{display:flex;align-items:center;gap:10px;margin-bottom:8px}
.group-head h4{margin:0;font-size:14px}
.group-head .add-row{font-size:12px;color:var(--accent);cursor:pointer}

table.grid{border-collapse:collapse;width:100%;background:var(--surface);border:1px solid var(--line);border-radius:8px;overflow:hidden}
table.grid th{background:#fafbfc;text-align:left;padding:7px 9px;font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.03em;border-bottom:1px solid var(--line);white-space:nowrap}
table.grid td{padding:3px 5px;border-bottom:1px solid var(--line2)}
table.grid input{width:100%;min-width:70px;border:1px solid transparent;background:transparent;padding:5px 6px;border-radius:6px;font:inherit;color:var(--text)}
table.grid input:focus{outline:0;border-color:var(--accent);background:#fff;box-shadow:0 0 0 2px rgba(37,99,235,.12)}
table.grid input.changed{background:#fffbeb;border-color:#fde68a}
table.grid input.formula{background:#eef6ff;border-color:#93c5fd;font-family:ui-monospace,Menlo,Consolas,monospace}
table.grid th.col-formula{cursor:pointer}
table.grid th.col-formula:hover{color:var(--accent-d);background:#eff4ff}
table.grid th.col-formula::after{content:" ƒ";color:var(--accent);opacity:.5;font-size:11px}
table.grid td.highlight input{font-weight:700;color:var(--accent-d)}
table.grid td.readonly input{color:var(--muted)}
.row-del{color:var(--danger);cursor:pointer;font-weight:700;padding:0 6px;opacity:.4}
.row-del:hover{opacity:1}

.kv-editor textarea{width:100%;min-height:380px;font-family:ui-monospace,Menlo,Consolas,monospace;font-size:12px;border:1px solid var(--line);border-radius:8px;padding:12px;background:var(--surface)}
.kv-editor .err{color:var(--danger);font-size:12px;margin-top:6px;min-height:16px}
.kv-hint{color:var(--muted);margin-bottom:8px}

.actionbar{display:flex;align-items:center;gap:10px;padding:12px 16px;border-top:1px solid var(--line);background:var(--surface)}
.spacer{flex:1}
.dirty-flag{color:var(--warn);font-weight:600;font-size:12px}
.btn{padding:8px 16px;border:1px solid var(--line);background:var(--surface);border-radius:8px;font:inherit;cursor:pointer}
.btn:hover{background:var(--line2)}
.btn-primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-d)}
.btn:disabled{opacity:.5;cursor:not-allowed}

.modal{position:fixed;inset:0;background:rgba(15,23,42,.45);display:flex;align-items:center;justify-content:center;z-index:50}
.modal[hidden]{display:none}   /* author rule must beat .modal's display:flex, else [hidden] is ignored */
.modal-card{background:#fff;border-radius:12px;padding:22px;width:460px;max-width:92vw;box-shadow:0 20px 60px rgba(0,0,0,.25)}
.modal-card h3{margin:0 0 12px}
.diff-summary{background:var(--line2);border-radius:8px;padding:10px 12px;font-size:12px;margin-bottom:14px;max-height:200px;overflow:auto}
.modal-label{font-size:12px;color:var(--muted);font-weight:600}
#reasonInput{width:100%;padding:9px 11px;border:1px solid var(--line);border-radius:8px;font:inherit;margin-top:6px}
.modal-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:16px}
.checkrow{display:flex;gap:8px;align-items:center;margin-top:12px;font-size:13px;color:var(--text)}
.group-head .per-watt{font-size:12px;color:var(--accent);cursor:pointer;margin-left:4px}
.group-head .per-watt:hover{text-decoration:underline}

.toast{position:fixed;bottom:20px;right:20px;background:var(--text);color:#fff;padding:11px 16px;border-radius:9px;z-index:60;font-weight:500}
.toast.ok{background:var(--good)}.toast.err{background:var(--danger)}