:root{
  --bg:#f4f6f8; --card:#fff; --line:#e3e8ee; --text:#1c2430; --muted:#6b7683;
  --brand:#0d6efd; --green:#0f9d58; --amber:#f0a202; --red:#d64545; --gray:#8a94a0;
}
*{box-sizing:border-box}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--text);font-size:15px}
a{color:var(--brand);text-decoration:none}
.topbar{display:flex;align-items:center;gap:14px;padding:10px 16px;background:#fff;border-bottom:1px solid var(--line);flex-wrap:wrap;position:sticky;top:0;z-index:10}
.brand{font-weight:700;font-size:17px;color:var(--text)}
.nav{display:flex;gap:14px;flex:1;flex-wrap:wrap}
.nav a{color:var(--muted);font-weight:500;padding:4px 2px}
.nav a:hover{color:var(--brand)}
.user{display:flex;align-items:center;gap:8px}
.user .name{color:var(--muted);font-size:14px}
.wrap{max-width:1000px;margin:20px auto;padding:0 16px}
.foot{text-align:center;color:var(--muted);font-size:12px;padding:24px}
.card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:16px;margin-bottom:16px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:14px;text-align:center}
.stat .num{font-size:24px;font-weight:700}
.stat .lbl{color:var(--muted);font-size:12px;margin-top:2px}
table{width:100%;border-collapse:collapse}
th,td{text-align:left;padding:9px 8px;border-bottom:1px solid var(--line);font-size:14px}
th{color:var(--muted);font-weight:600;font-size:12px;text-transform:uppercase}
.badge{display:inline-block;padding:3px 10px;border-radius:999px;font-size:12px;font-weight:600}
.badge-xanh{background:#e6f6ed;color:var(--green)}
.badge-vang{background:#fdf3e0;color:var(--amber)}
.badge-do{background:#fbeaea;color:var(--red)}
.badge-xam{background:#eef1f4;color:var(--gray)}
.btn{display:inline-block;padding:8px 14px;border-radius:8px;border:1px solid var(--brand);background:var(--brand);color:#fff;cursor:pointer;font-size:14px}
.btn.ghost{background:transparent;color:var(--brand)}
.btn.danger{border-color:var(--red);background:var(--red)}
.btn.sm{padding:5px 10px;font-size:13px}
label{display:block;margin:10px 0 4px;font-size:13px;color:var(--muted);font-weight:500}
input,select,textarea{width:100%;padding:9px 10px;border:1px solid var(--line);border-radius:8px;font-size:14px;background:#fff}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.alert{padding:10px 14px;border-radius:8px;margin-bottom:14px;font-size:14px}
.alert.err{background:#fbeaea;color:var(--red)}
.alert.ok{background:#e6f6ed;color:var(--green)}
.alert.info{background:#e8f1fe;color:var(--brand)}
.muted{color:var(--muted);font-size:13px}
@media(max-width:640px){
  .form-row{grid-template-columns:1fr}
  .wrap{padding:0 12px}
  .nav{gap:10px;font-size:13px}
  .grid{grid-template-columns:1fr 1fr}
  .grid5 .stat:last-child{grid-column:1 / -1}
  .badge{white-space:nowrap;max-width:100%;overflow:hidden;text-overflow:ellipsis}
  table,thead,tbody,tr,th,td{display:block}
  thead{display:none}
  tr.card-row{display:grid;grid-template-columns:1fr;gap:4px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px;margin:6px 0}
  tr.card-row td{border:none;padding:3px 0;font-size:13px}
  tr.card-row td::before{content:attr(data-label);color:var(--muted);font-weight:600;font-size:11px;display:block}
  /* header hamburger (CSS-only) */
  .topbar{flex-wrap:nowrap;align-items:center}
  .brand{flex:1}
  label.menu-toggle{display:inline-flex;align-items:center;justify-content:center;width:36px;height:34px;border:1px solid var(--line);border-radius:8px;cursor:pointer;font-size:16px;color:var(--text);background:#fff;margin:0}
  input#menuChk{display:none}
  input#menuChk:checked ~ .nav{max-height:240px;opacity:1}
  .nav{order:3;flex-basis:100%;max-height:0;opacity:0;overflow:hidden;flex-direction:column;gap:8px;background:#fff;border-top:1px solid var(--line);margin-top:6px;padding-top:8px;transition:max-height .2s ease,opacity .15s ease}
}
@media(min-width:641px){
  label.menu-toggle{display:none}
  input#menuChk{display:none}
}