:root {
  --bg: #f6f7f9; --surface: #fff; --surface-2: #f1f3f6; --border: #e2e5ea; --text: #1d2430; --muted: #667085;
  --primary: #1f4fd1; --primary-ink: #fff; --primary-soft: #e8eefc;
  --ok: #157f3c; --ok-bg: #e4f5ea; --caution: #8a6100; --caution-bg: #fdf3d6; --warn: #b54708; --warn-bg: #fdebdc;
  --danger: #b42318; --danger-bg: #fde7e5; --muted-bg: #eef0f3;
  --radius: 10px; --shadow: 0 1px 2px rgba(16,24,40,.06), 0 1px 3px rgba(16,24,40,.08);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1218; --surface: #171b23; --surface-2: #1e232d; --border: #2a303c; --text: #e6e9ef; --muted: #98a2b3;
    --primary: #6d93ff; --primary-ink: #0b1020; --primary-soft: #1c2645;
    --ok: #4ade80; --ok-bg: #12301f; --caution: #f5c451; --caution-bg: #33290f; --warn: #fb9a55; --warn-bg: #3a2312;
    --danger: #f87171; --danger-bg: #3b1717; --muted-bg: #232833; --shadow: none; color-scheme: dark;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; background: var(--bg); color: var(--text); }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
h1 { font-size: 1.5rem; margin: 0 0 .25rem; }
h2 { font-size: 1.1rem; margin: 0 0 .75rem; }
h3 { font-size: 1rem; margin: 1rem 0 .5rem; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.nowrap { white-space: nowrap; }
.right { text-align: right; }

/* Khung */
.topbar { background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 10; }
.topbar .inner { max-width: 1280px; margin: 0 auto; padding: 0 16px; display: flex; align-items: center; gap: 20px; height: 56px; }
.brand { font-weight: 700; color: var(--text); white-space: nowrap; }
.brand span { color: var(--primary); }
.nav { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
.nav a { padding: 6px 10px; border-radius: 8px; color: var(--muted); white-space: nowrap; font-weight: 500; }
.nav a:hover { background: var(--surface-2); text-decoration: none; color: var(--text); }
.nav a.active { background: var(--primary-soft); color: var(--primary); }
.count { display: inline-block; min-width: 18px; padding: 0 5px; border-radius: 9px; background: var(--danger); color: #fff; font-size: .72rem; text-align: center; margin-left: 4px; line-height: 18px; }
.userbox { display: flex; gap: 10px; align-items: center; white-space: nowrap; }
.container { max-width: 1280px; margin: 0 auto; padding: 24px 16px 64px; }
.page-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 16px; flex-wrap: wrap; margin-bottom: 20px; }

/* Thẻ */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); }
.card + .card { margin-top: 16px; }
.grid { display: grid; gap: 16px; }
.g2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.g3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.g4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.split { display: grid; gap: 16px; grid-template-columns: minmax(0, 2fr) minmax(0, 1fr); align-items: start; }
@media (max-width: 960px) { .g3, .g4 { grid-template-columns: repeat(2, minmax(0, 1fr)); } .split { grid-template-columns: 1fr; } }
@media (max-width: 600px) { .g2, .g3, .g4 { grid-template-columns: 1fr; } .topbar .inner { gap: 10px; } .userbox .who { display: none; } }

.stat { display: flex; flex-direction: column; gap: 2px; }
.stat .label { color: var(--muted); font-size: .82rem; }
.stat .value { font-size: 1.6rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.stat .sub { font-size: .82rem; color: var(--muted); }

/* Thanh phân bố */
.dist { display: flex; height: 10px; border-radius: 5px; overflow: hidden; background: var(--muted-bg); margin: 8px 0 6px; }
.dist > span { display: block; height: 100%; }
.legend { display: flex; flex-wrap: wrap; gap: 4px 12px; font-size: .8rem; color: var(--muted); }
.legend i { display: inline-block; width: 9px; height: 9px; border-radius: 2px; margin-right: 4px; vertical-align: middle; }
.bg-danger { background: var(--danger); } .bg-warn { background: var(--warn); } .bg-caution { background: var(--caution); }
.bg-ok { background: var(--ok); } .bg-muted { background: var(--border); } .bg-primary { background: var(--primary); }

/* Nhãn */
.badge { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: .78rem; font-weight: 600; white-space: nowrap; }
.t-danger { background: var(--danger-bg); color: var(--danger); }
.t-warn { background: var(--warn-bg); color: var(--warn); }
.t-caution { background: var(--caution-bg); color: var(--caution); }
.t-ok { background: var(--ok-bg); color: var(--ok); }
.t-muted { background: var(--muted-bg); color: var(--muted); }
.t-primary { background: var(--primary-soft); color: var(--primary); }

/* Bảng */
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
th, td { padding: 9px 12px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { font-size: .78rem; text-transform: uppercase; letter-spacing: .03em; color: var(--muted); background: var(--surface-2); font-weight: 600; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: var(--surface-2); }
td.num, th.num { text-align: right; }
.reasons { margin: 2px 0 0; padding: 0; list-style: none; font-size: .8rem; color: var(--muted); }
.card table th:first-child, .card table td:first-child { padding-left: 0; }
.card table { margin: 0; }
.card .table-wrap table th:first-child, .card .table-wrap table td:first-child { padding-left: 12px; }

/* Form */
form.inline { display: inline; }
label { display: block; font-size: .85rem; font-weight: 600; margin-bottom: 4px; }
input[type=text], input[type=email], input[type=number], input[type=date], input[type=search], select, textarea {
  width: 100%; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); color: var(--text); font: inherit;
}
textarea { min-height: 100px; resize: vertical; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--primary); outline-offset: -1px; border-color: transparent; }
.field { margin-bottom: 12px; }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: flex-end; }
.row > .field { flex: 1 1 140px; margin-bottom: 0; }
.filters { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-bottom: 12px; }
.filters select, .filters input { width: auto; min-width: 140px; }
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--text); font: inherit; font-weight: 600; cursor: pointer; white-space: nowrap; }
.btn:hover { background: var(--surface-2); text-decoration: none; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.danger { color: var(--danger); }
.btn.sm { padding: 4px 10px; font-size: .85rem; }
.btn.link { border: 0; background: none; padding: 0; color: var(--primary); font-weight: 500; }
.check { display: flex; gap: 8px; align-items: center; font-weight: 400; }
.check input { width: auto; }
.scale { display: flex; gap: 6px; }
.scale label { flex: 1; text-align: center; border: 1px solid var(--border); border-radius: 8px; padding: 8px 0; cursor: pointer; font-weight: 500; margin: 0; }
.scale input { position: absolute; opacity: 0; pointer-events: none; }
.scale input:checked + span { color: var(--primary); font-weight: 700; }
.scale label:has(input:checked) { border-color: var(--primary); background: var(--primary-soft); }

/* Thông báo */
.alert { padding: 10px 14px; border-radius: 8px; margin-bottom: 16px; border: 1px solid transparent; }
.alert.ok { background: var(--ok-bg); color: var(--ok); }
.alert.error { background: var(--danger-bg); color: var(--danger); }
.alert.info { background: var(--primary-soft); color: var(--primary); }

/* Hội thoại phản ánh */
.thread { display: flex; flex-direction: column; gap: 12px; }
.msg { border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 14px; background: var(--surface); max-width: 85%; }
.msg.mine { align-self: flex-end; background: var(--primary-soft); border-color: transparent; }
.msg.internal { background: var(--caution-bg); border-style: dashed; }
.msg .meta { font-size: .78rem; color: var(--muted); margin-bottom: 4px; }
.msg .body { white-space: pre-wrap; }

/* Đăng nhập */
.auth { max-width: 400px; margin: 10vh auto; padding: 0 16px; }
.auth .card { padding: 28px; }
.divider { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: .85rem; margin: 18px 0; }
.divider::before, .divider::after { content: ""; flex: 1; height: 1px; background: var(--border); }
.btn.block { width: 100%; justify-content: center; }
.code-input { font-size: 1.6rem; letter-spacing: .5em; text-align: center; font-variant-numeric: tabular-nums; }

/* Biểu đồ */
.chart { width: 100%; height: auto; display: block; }
.chart text { fill: var(--muted); font-size: 11px; }
.chart .grid-line { stroke: var(--border); }
.chart .line { fill: none; stroke: var(--primary); stroke-width: 2; }
.chart .line2 { fill: none; stroke: var(--muted); stroke-width: 1.5; stroke-dasharray: 4 3; }
.chart .dot { fill: var(--primary); }
.chart .ref { stroke: var(--warn); stroke-dasharray: 3 3; }
.progress { height: 8px; background: var(--muted-bg); border-radius: 4px; overflow: hidden; }
.progress > span { display: block; height: 100%; background: var(--primary); }
.kv { display: grid; grid-template-columns: max-content 1fr; gap: 6px 14px; font-size: .92rem; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; }
details summary { cursor: pointer; font-weight: 600; }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .85rem; }
pre { background: var(--surface-2); padding: 12px; border-radius: 8px; overflow: auto; }
.empty { padding: 28px; text-align: center; color: var(--muted); }
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-bottom: 14px; flex-wrap: wrap; }
.tabs a { padding: 8px 12px; color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px; font-weight: 500; }
.tabs a.active { color: var(--primary); border-color: var(--primary); }
.tabs a:hover { text-decoration: none; color: var(--text); }

/* Màn hình hẹp: menu xuống dòng riêng, cuộn ngang được */
@media (max-width: 760px) {
  .topbar .inner { flex-wrap: wrap; height: auto; padding: 8px 16px 0; gap: 8px; }
  .brand { flex: 1; }
  .nav { order: 3; flex-basis: 100%; padding-bottom: 8px; }
  .container { padding-top: 16px; }
  .grid.g4 .stat .value { font-size: 1.3rem; }
}
.grid > .card + .card { margin-top: 0; }