:root{
  --bg:#f4f6fb; --panel:#fff; --ink:#1f2937; --muted:#6b7280; --line:#e5e7eb;
  --brand:#2563eb; --brand2:#1d4ed8; --ok:#16a34a; --warn:#d97706; --err:#dc2626;
  --chip:#eef2ff; --shadow:0 1px 3px rgba(0,0,0,.08),0 1px 2px rgba(0,0,0,.04);
  --strong:#334155;
}
*{box-sizing:border-box}
body{margin:0;font-family:"Segoe UI",Roboto,Arial,sans-serif;background:var(--bg);color:var(--ink);font-size:14px}
header{background:linear-gradient(90deg,var(--brand),var(--brand2));color:#fff;padding:10px 16px;display:flex;align-items:center;gap:12px;flex-wrap:wrap}
header h1{font-size:17px;margin:0;font-weight:600}
header .sub{font-size:12px;opacity:.9}
header .spacer{flex:1}
header button{background:rgba(255,255,255,.15);color:#fff;border:1px solid rgba(255,255,255,.35);padding:6px 10px;border-radius:6px;cursor:pointer;font-size:13px}
header button:hover{background:rgba(255,255,255,.28)}

nav{display:flex;gap:2px;background:var(--panel);padding:0 8px;border-bottom:1px solid var(--line);overflow-x:auto;position:sticky;top:0;z-index:20}
nav button{border:none;background:none;padding:11px 12px;cursor:pointer;font-size:13.5px;color:var(--muted);border-bottom:3px solid transparent;white-space:nowrap;display:flex;align-items:center;gap:6px}
nav button.active{color:var(--brand);border-bottom-color:var(--brand);font-weight:600}
nav button:hover{color:var(--ink)}
nav .num{display:inline-flex;align-items:center;justify-content:center;width:19px;height:19px;border-radius:50%;background:#e2e8f0;color:#475569;font-size:11px;font-weight:700}
nav button.active .num{background:var(--brand);color:#fff}

main{padding:16px;max-width:1360px;margin:0 auto}
.tab{display:none}
.tab.active{display:block}
.card{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:16px;margin-bottom:16px;box-shadow:var(--shadow)}
.card h2{margin:0 0 4px;font-size:16px;display:flex;align-items:center;gap:8px}
.card h3{margin:14px 0 8px;font-size:14px;color:var(--brand2)}
.hn{display:inline-flex;align-items:center;justify-content:center;width:24px;height:24px;border-radius:50%;background:var(--brand);color:#fff;font-size:13px;font-weight:700}
.hint{color:var(--muted);font-size:12.5px;margin:2px 0 12px;line-height:1.55}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:flex-end}
.field{display:flex;flex-direction:column;gap:4px;margin-bottom:8px}
.field label{font-size:12.5px;color:var(--muted)}
input,select,textarea{padding:7px 9px;border:1px solid var(--line);border-radius:6px;font-size:14px;font-family:inherit;background:#fff;color:var(--ink)}
input:focus,select:focus{outline:2px solid #bfdbfe;border-color:var(--brand)}
.chk{display:inline-flex;align-items:center;gap:6px;font-size:13.5px}
.chk.block{display:flex;margin:6px 0}
.chk input{width:16px;height:16px}

button.btn{background:var(--brand);color:#fff;border:none;padding:8px 14px;border-radius:7px;cursor:pointer;font-size:14px;font-weight:500}
button.btn:hover{background:var(--brand2)}
button.btn.gray{background:#eef2f7;color:var(--ink);border:1px solid var(--line)}
button.btn.gray:hover{background:#e2e8f0}
button.btn.ok{background:var(--ok)} button.btn.ok:hover{filter:brightness(.94)}
button.mini{font-size:12px;padding:3px 8px;border-radius:5px;border:1px solid var(--line);background:#fff;cursor:pointer;color:var(--ink)}
button.mini:hover{background:#f1f5f9}
button.mini.del{color:var(--err);border-color:#fecaca}

table{border-collapse:collapse;width:100%;font-size:13px;margin-top:4px}
th,td{border:1px solid var(--line);padding:6px 8px;text-align:left;vertical-align:middle}
th{background:#f8fafc;font-weight:600;font-size:12.5px}
tr:nth-child(even) td{background:#fcfdff}

.tag{display:inline-block;background:var(--chip);color:var(--brand2);border-radius:20px;padding:1px 9px;font-size:12px;margin:1px}
.tag.spec{background:#fff7ed;color:#c2410c}
.pill{border-radius:6px;padding:2px 8px;font-size:11.5px;font-weight:700}
.pill.ok{background:#dcfce7;color:#166534}.pill.err{background:#fee2e2;color:#991b1b}.pill.warn{background:#fef3c7;color:#92400e}
.small{font-size:12px;color:var(--muted)}
.toolbar{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-bottom:10px}
.toolbar .spacer{flex:1}
.toolbar .lbl{font-size:13px;display:inline-flex;align-items:center;gap:6px}
.stat{display:inline-flex;flex-direction:column;background:#f8fafc;border:1px solid var(--line);border-radius:8px;padding:8px 14px;margin:4px}
.stat b{font-size:20px;color:var(--brand2)} .stat span{font-size:12px;color:var(--muted)}
.msg{padding:10px 12px;border-radius:8px;margin:8px 0;font-size:13px}
.msg.ok{background:#dcfce7;color:#166534}.msg.err{background:#fee2e2;color:#991b1b}.msg.warn{background:#fef3c7;color:#92400e}.msg.info{background:#e0f2fe;color:#075985}
ul.rep{margin:6px 0;padding-left:20px;line-height:1.7;font-size:13px}
ul.rep li.err{color:#991b1b}ul.rep li.warn{color:#92400e}
ol.guide{line-height:1.9}

/* ---- Lưới TKB ---- */
.grid-tkb{border-collapse:collapse;width:100%}
.grid-tkb th,.grid-tkb td{border:1px solid #cbd5e1;text-align:center;padding:0}
.grid-tkb.strong th,.grid-tkb.strong td{border:2px solid var(--strong)}
.grid-tkb th{background:#dce6f1;padding:7px 4px;font-size:12.5px;font-weight:700}
.grid-tkb .sesscol{writing-mode:vertical-rl;transform:rotate(180deg);background:#eef2f7;font-weight:700;color:#475569;width:28px;font-size:12px}
.grid-tkb .pcol{background:#f1f5f9;font-weight:700;width:34px;font-size:12px;color:#475569}
.cell{min-height:46px;height:46px;padding:3px;cursor:grab;font-size:12px;line-height:1.25;display:flex;flex-direction:column;justify-content:center}
.cell .subj{font-weight:700}
.cell .tea{color:#475569;font-size:11px}
.cell.empty{color:#cbd5e1;cursor:default}
.cell.fixed{background:#eef2f7;cursor:default}
.cell.clash{outline:3px solid var(--err);outline-offset:-3px}
.cell.dragover{background:#dbeafe}
.tkb-title{text-align:center;font-weight:700;font-size:15px;margin:2px 0}
.tkb-sub{text-align:center;font-size:12px;color:var(--muted);margin-bottom:8px}

/* ---- split panes ---- */
.split{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:1000px){.split{grid-template-columns:1fr}}
.pane{margin-bottom:0}
.pane-h{font-weight:700;color:var(--brand2);margin-bottom:8px;font-size:13.5px;display:flex;align-items:center;justify-content:space-between;gap:8px;flex-wrap:wrap}
.corner-sel{font-size:12.5px;padding:4px 6px;max-width:60%}
.syncdot{width:12px;height:12px;border-radius:50%;background:#94a3b8;display:inline-block;margin-right:2px}
.guide{line-height:1.9;margin:0;padding-left:20px}

/* ---- busy grid ---- */
.busygrid td{cursor:pointer;text-align:center;padding:5px 3px;font-size:11px;user-select:none}
.busygrid td.off{background:#fee2e2;color:#991b1b;font-weight:700}

.legend{display:flex;gap:14px;flex-wrap:wrap;font-size:12px;color:var(--muted);margin:8px 0}
.legend span{display:inline-flex;align-items:center;gap:5px}
.sw{width:14px;height:14px;border-radius:3px;display:inline-block;border:1px solid rgba(0,0,0,.1)}

/* ---- modal ---- */
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:55}
.modal{position:fixed;left:50%;top:50%;transform:translate(-50%,-50%);background:#fff;border-radius:12px;padding:20px;z-index:60;box-shadow:0 20px 60px rgba(0,0,0,.3);max-width:90vw;max-height:85vh;overflow:auto;min-width:320px}
.modal h2{margin:0 0 10px;font-size:16px}

#toast{position:fixed;bottom:20px;left:50%;transform:translateX(-50%);background:#111827;color:#fff;padding:10px 18px;border-radius:8px;opacity:0;transition:.3s;z-index:100;font-size:13px;pointer-events:none}
#toast.show{opacity:1}

code{background:#f1f5f9;padding:1px 5px;border-radius:4px;font-size:12px}

/* ---- header: nút đồng bộ trạng thái + icon ---- */
.card-head{display:flex;align-items:flex-start;justify-content:space-between;gap:10px;flex-wrap:wrap}
.apply-wrap{display:flex;align-items:center;gap:8px}
#btnSync.sync-dirty{background:#f59e0b;border-color:#f59e0b;color:#fff;font-weight:600}
#btnSync.sync-ok{background:#16a34a;border-color:#16a34a;color:#fff;font-weight:600}
#btnSync.sync-off{opacity:.55}
header .icon-btn{font-size:15px;padding:6px 9px;line-height:1}

/* ---- màn hình khóa PIN ---- */
#pinOverlay{position:fixed;inset:0;background:linear-gradient(135deg,#1e3a8a,#2563eb);display:none;align-items:center;justify-content:center;z-index:200}
.pin-card{background:#fff;border-radius:16px;padding:30px 34px;width:340px;max-width:92vw;text-align:center;box-shadow:0 20px 60px rgba(0,0,0,.35)}
.pin-card h2{margin:6px 0 4px;font-size:19px}
.pin-logo{font-size:44px}
.pin-input{display:block;width:100%;margin:12px 0;text-align:center;font-size:26px;letter-spacing:10px;padding:12px;border:2px solid var(--line);border-radius:10px}
.pin-input.sm{font-size:18px;letter-spacing:6px;margin:4px 0}
.pin-err{color:var(--err);font-size:13px;min-height:18px;margin-bottom:6px}

/* ---- hộp Xuất TKB ---- */
.exp-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}
.exp-grid .btn{text-align:center;line-height:1.3}
.exp-grid .small{color:#64748b}
.modal .exp-grid .btn.gray .small{font-weight:400}
/* ---- select có xung đột ---- */
.corner-sel.sel-bad{border-color:#dc2626;color:#dc2626;font-weight:600}
/* ---- khu chẩn đoán trong Xem&Sửa ---- */
.diag-box{border:1px solid #fecaca;background:#fff7f7;margin-top:8px}
.diag-box summary{color:#991b1b}
/* ---- giải thích trọng số mềm ---- */
.explain{font-size:13px;line-height:1.6;background:#f8fafc;border-radius:8px;padding:8px 12px;margin-top:6px}
.explain ul{margin:6px 0;padding-left:20px}