:root {
  --bg: #f5f6f8; --card: #fff; --text: #1d2330; --muted: #6b7280; --line: #e5e7eb;
  --brand: #2563eb; --brand-soft: #e8efff; --ok: #16a34a; --warn: #d97706; --bad: #dc2626;
  --fb: #1877f2; --zalo: #0068ff; --web: #7c3aed;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1218; --card: #171b23; --text: #e6e8ee; --muted: #9aa3b2; --line: #2a303b; --brand-soft: #1c2740; }
}
* { box-sizing: border-box; }
body { margin: 0; font: 14px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; background: var(--bg); color: var(--text); }
.hidden { display: none !important; }
.muted { color: var(--muted); } .small { font-size: 12px; } .center { text-align: center; margin-top: 40px; }
button, .btn { font: inherit; padding: 6px 12px; border: 1px solid var(--line); background: var(--card); color: var(--text); border-radius: 8px; cursor: pointer; display: inline-block; }
button.primary { background: var(--brand); border-color: var(--brand); color: #fff; }
button.danger { color: var(--bad); border-color: var(--bad); }
input, select, textarea { font: inherit; padding: 6px 10px; border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--text); }
textarea { width: 100%; resize: vertical; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px; margin: 12px 0; }
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-bottom: 12px; }
.row input { flex: 1; min-width: 200px; }
.row input[type=checkbox], label input[type=checkbox] { flex: none; min-width: 0; width: auto; }
.login { display: grid; place-items: center; min-height: 100vh; padding: 16px; }
.login form { display: grid; gap: 12px; width: min(380px, 100%); }
.login h1 { font-size: 20px; margin: 0; }

.topbar { display: flex; align-items: center; gap: 16px; padding: 10px 16px; background: var(--card); border-bottom: 1px solid var(--line); flex-wrap: wrap; position: sticky; top: 0; z-index: 5; }
.topbar nav { display: flex; gap: 4px; flex: 1; flex-wrap: wrap; }
.topbar nav button { border: 0; background: none; }
.topbar nav button.active { background: var(--brand-soft); color: var(--brand); font-weight: 600; }
.badge { background: var(--bad); color: #fff; border-radius: 10px; padding: 0 6px; font-size: 11px; }
.pause { font-weight: 600; }
.pause.on { background: var(--ok); color: #fff; border-color: var(--ok); }
.pause.off { background: var(--warn); color: #fff; border-color: var(--warn); }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 8px; padding: 12px 16px 0; }
.stat { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; }
.stat b { display: block; font-size: 20px; }
.stat span { color: var(--muted); font-size: 12px; }
main { padding: 12px 16px 40px; }

.inbox { display: grid; grid-template-columns: 320px 1fr; gap: 12px; height: calc(100vh - 190px); min-height: 480px; }
.convList, .convDetail { background: var(--card); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; display: flex; flex-direction: column; }
.filters { display: flex; gap: 6px; padding: 8px; border-bottom: 1px solid var(--line); }
.filters select { flex: 1; }
#convs { list-style: none; margin: 0; padding: 0; overflow-y: auto; flex: 1; }
#convs li { padding: 10px 12px; border-bottom: 1px solid var(--line); cursor: pointer; }
#convs li.active { background: var(--brand-soft); }
#convs li .top { display: flex; justify-content: space-between; gap: 6px; }
#convs li .last { color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 13px; }
.ch { font-size: 11px; font-weight: 700; padding: 1px 6px; border-radius: 6px; color: #fff; }
.ch.facebook { background: var(--fb); } .ch.zalo { background: var(--zalo); } .ch.web { background: var(--web); }
.tag { font-size: 11px; padding: 1px 6px; border-radius: 6px; border: 1px solid var(--line); margin-left: 4px; }
.tag.human { background: var(--bad); color: #fff; border-color: var(--bad); }
.tag.score { font-weight: 700; }
.tag.good { color: var(--ok); border-color: var(--ok); } .tag.mid { color: var(--warn); border-color: var(--warn); } .tag.low { color: var(--bad); border-color: var(--bad); }

.convHead { padding: 10px 14px; border-bottom: 1px solid var(--line); display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.convHead .title { flex: 1; font-weight: 600; }
.msgs { flex: 1; overflow-y: auto; padding: 14px; display: flex; flex-direction: column; gap: 8px; }
.msg { max-width: 75%; padding: 8px 12px; border-radius: 12px; white-space: pre-wrap; word-wrap: break-word; }
.msg.customer { background: var(--bg); align-self: flex-start; border: 1px solid var(--line); }
.msg.bot { background: var(--brand-soft); align-self: flex-end; }
.msg.human { background: #dcfce7; color: #14532d; align-self: flex-end; }
.msg .meta { font-size: 11px; color: var(--muted); margin-top: 2px; }
.msg details { font-size: 12px; color: var(--muted); }
.msg details pre { white-space: pre-wrap; max-height: 200px; overflow: auto; }
.gradeBox { margin: 0 14px; padding: 10px; border: 1px dashed var(--line); border-radius: 10px; font-size: 13px; }
.composer { border-top: 1px solid var(--line); padding: 10px; display: grid; gap: 6px; }
.composer .row { margin: 0; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 12px; }
.grid .card { margin: 0; }
.list .card { display: grid; gap: 6px; }
.table { width: 100%; border-collapse: collapse; background: var(--card); border-radius: 12px; overflow: hidden; }
.table th, .table td { text-align: left; padding: 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
.settings { display: grid; gap: 12px; }
.settings fieldset { border: 1px solid var(--line); border-radius: 12px; padding: 12px; background: var(--card); display: grid; gap: 8px; }
.settings label { display: grid; gap: 4px; }
pre { white-space: pre-wrap; background: var(--bg); padding: 10px; border-radius: 8px; overflow-x: auto; }
dialog { border: 1px solid var(--line); border-radius: 12px; background: var(--card); color: var(--text); width: min(560px, 95vw); }
dialog form { display: grid; gap: 8px; }
dialog label { display: grid; gap: 4px; }
.toast { position: fixed; bottom: 16px; left: 50%; transform: translateX(-50%); background: var(--text); color: var(--bg); padding: 10px 16px; border-radius: 10px; max-width: 90vw; white-space: pre-wrap; z-index: 20; }

@media (max-width: 800px) {
  .inbox { grid-template-columns: 1fr; height: auto; }
  .convList { max-height: 40vh; }
  .convDetail { min-height: 70vh; }
  .msg { max-width: 90%; }
}