/* Wireframe low-fi: chỉ thang xám, không chọn màu/font thương hiệu. */
:root {
  --bg: #f4f4f5;
  --surface: #fff;
  --sunken: #ececee;
  --border: #d4d4d8;
  --border-strong: #a1a1aa;
  --text: #18181b;
  --muted: #52525b;
  --ink: #27272a;
  --r: 4px;
  --gap: 16px;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font: 14px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: inherit; }
h1, h2, h3, p { margin: 0; }
.num { font-variant-numeric: tabular-nums; text-align: right; }
.muted { color: var(--muted); }
.mono { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 13px; }

/* Shell */
.shell { display: grid; grid-template-columns: 240px 1fr; grid-template-rows: 56px 1fr; min-height: 100vh; }
.top {
  grid-column: 1 / -1; display: flex; align-items: center; gap: 12px;
  padding: 0 24px; background: var(--surface); border-bottom: 1px solid var(--border);
}
.top .brand { font-weight: 700; width: 192px; }
.top .spacer { flex: 1; }
.tag { border: 1px dashed var(--border-strong); border-radius: 999px; padding: 2px 10px; font-size: 12px; color: var(--muted); }
.side { background: var(--surface); border-right: 1px solid var(--border); padding: 12px 8px; overflow-y: auto; }
.side .grp { font-size: 11px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); padding: 12px 12px 4px; }
.side a {
  display: flex; justify-content: space-between; align-items: center; gap: 8px;
  padding: 7px 12px; border-radius: var(--r); text-decoration: none; color: var(--ink);
}
.side a:hover { background: var(--sunken); }
.side a.on { background: var(--sunken); font-weight: 600; box-shadow: inset 3px 0 0 var(--ink); }
.side a small { color: var(--muted); font-size: 11px; }
.main { padding: 24px 32px 64px; min-width: 0; max-width: 1360px; }
@media (max-width: 900px) {
  .shell { grid-template-columns: 1fr; }
  .side { display: none; }
  .main { padding: 16px; }
}

/* Page */
.page-head { display: flex; align-items: flex-start; gap: 16px; margin-bottom: var(--gap); }
.page-head .t { flex: 1; }
.page-head h1 { font-size: 22px; font-weight: 600; }
.page-head p { color: var(--muted); margin-top: 2px; }
.crumbs { font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.row.end { justify-content: flex-end; }
.grid2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--gap); }
.grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--gap); }
.grid4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--gap); }
.grid2 > *, .grid3 > *, .grid4 > * { min-width: 0; }
@media (max-width: 900px) { .grid2, .grid3, .grid4 { grid-template-columns: 1fr !important; } }
.stack > * + * { margin-top: var(--gap); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 6px; height: 34px; padding: 0 14px;
  border: 1px solid var(--border-strong); border-radius: var(--r); background: var(--surface);
  color: var(--ink); font: inherit; cursor: pointer; text-decoration: none; white-space: nowrap;
}
.btn:hover { background: var(--sunken); }
.btn.primary { background: var(--ink); color: #fff; border-color: var(--ink); }
.btn.primary:hover { background: #3f3f46; }
.btn.danger { border-style: dashed; border-width: 2px; }
.btn.ghost { border-color: transparent; background: transparent; }
.btn.sm { height: 28px; padding: 0 10px; font-size: 13px; }
.btn[disabled], .btn.off { opacity: .45; cursor: not-allowed; }

/* Fields */
.field { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.field label { font-size: 12px; font-weight: 600; color: var(--ink); }
.field label .req { color: var(--text); }
.field .help { font-size: 12px; color: var(--muted); }
.input, .select, .textarea {
  height: 36px; width: 100%; padding: 0 10px; background: var(--surface);
  border: 1px solid var(--border-strong); border-radius: var(--r); font: inherit; color: var(--text);
}
.select { appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--muted) 50%), linear-gradient(135deg, var(--muted) 50%, transparent 50%); background-position: calc(100% - 16px) 15px, calc(100% - 11px) 15px; background-size: 5px 5px; background-repeat: no-repeat; padding-right: 28px; }
.textarea { height: 72px; padding: 8px 10px; }
.input.ro { background: var(--sunken); color: var(--muted); }
.input.err { border: 2px solid var(--text); }
.err-msg { font-size: 12px; font-weight: 600; }
.check { display: inline-flex; align-items: center; gap: 6px; }

/* Cards */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 6px; }
.card > .hd { display: flex; align-items: center; gap: 8px; min-height: 52px; padding: 8px 16px; border-bottom: 1px solid var(--border); font-weight: 600; }
.card > .hd .sp { flex: 1; }
.card > .bd { padding: 16px; }
.card > .ft { padding: 12px 16px; border-top: 1px solid var(--border); background: var(--bg); border-radius: 0 0 6px 6px; }
.kv { display: grid; grid-template-columns: 160px 1fr; gap: 6px 12px; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; }
.stat { padding: 12px 16px; }
.stat .k { font-size: 12px; color: var(--muted); }
.stat .v { font-size: 20px; font-weight: 600; font-variant-numeric: tabular-nums; }

/* Filters */
.filters { display: flex; gap: 8px; flex-wrap: wrap; align-items: flex-end; padding: 12px 16px; border-bottom: 1px solid var(--border); }
.filters .field { width: 160px; }
.filters .field.wide { width: 240px; }

/* Tables */
.tbl-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 9px 14px; border-bottom: 1px solid var(--border); text-align: left; white-space: nowrap; vertical-align: middle; }
th { position: sticky; top: 0; background: var(--sunken); font-size: 12px; font-weight: 600; color: var(--ink); }
td.num, th.num { text-align: right; }
tbody tr:hover { background: #fafafa; }
tr.diff td { background: repeating-linear-gradient(135deg, #fff, #fff 6px, #f4f4f5 6px, #f4f4f5 12px); }
.pager { display: flex; align-items: center; gap: 8px; padding: 10px 16px; color: var(--muted); font-size: 13px; }
.pager .sp { flex: 1; }

/* Status badge: khác nhau bằng kiểu viền/đậm, không bằng màu */
.badge { display: inline-flex; align-items: center; gap: 5px; border: 1px solid var(--border-strong); border-radius: 999px; padding: 1px 9px; font-size: 12px; background: var(--surface); }
.badge::before { content: ""; width: 7px; height: 7px; border-radius: 50%; border: 1.5px solid var(--ink); }
.badge.s-fill::before { background: var(--ink); }
.badge.s-half::before { background: linear-gradient(90deg, var(--ink) 50%, transparent 50%); }
.badge.s-cancel { border-style: dashed; color: var(--muted); text-decoration: line-through; }
.badge.s-cancel::before { border-color: var(--muted); }

/* Tabs */
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-bottom: var(--gap); }
.tabs a, .tabs button { padding: 9px 14px; border: 0; background: none; font: inherit; cursor: pointer; text-decoration: none; color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px; }
.tabs .on { color: var(--text); font-weight: 600; border-bottom-color: var(--ink); }
.tab-panel { display: none; }
.tab-panel.on { display: block; }

/* Notes cho dev/UX: chỉ có trong wireframe */
.note { border: 1px dashed var(--border-strong); background: #fcfcfc; border-radius: var(--r); padding: 10px 12px; font-size: 13px; color: var(--ink); }
.note b:first-child { display: inline-block; margin-right: 6px; }
.note ul { margin: 6px 0 0; padding-left: 18px; }
.note code, code { font: 12px ui-monospace, Menlo, Consolas, monospace; background: var(--sunken); color: var(--text); padding: 1px 5px; border-radius: 3px; }
.alert { border: 1px solid var(--ink); border-left-width: 4px; border-radius: var(--r); padding: 10px 12px; background: var(--surface); }
.alert.soft { border-color: var(--border-strong); border-left-color: var(--border-strong); }

/* Hộp thoại mô phỏng (tĩnh, hiển thị trực tiếp) */
.dialog { max-width: 560px; border: 2px solid var(--ink); border-radius: 8px; background: var(--surface); }
.dialog > .hd { padding: 12px 16px; font-weight: 600; border-bottom: 1px solid var(--border); }
.dialog > .bd { padding: 16px; }
.dialog > .ft { padding: 12px 16px; border-top: 1px solid var(--border); display: flex; gap: 8px; justify-content: flex-end; }
.cap { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; margin-bottom: 6px; }

/* Lịch khoá kỳ */
.cal { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; }
.cal .h { text-align: center; font-size: 12px; color: var(--muted); padding: 4px; }
.cal .d { border: 1px solid var(--border); background: var(--surface); border-radius: var(--r); min-height: 56px; padding: 4px 6px; font-size: 13px; cursor: pointer; }
.cal .d.lock { background: repeating-linear-gradient(135deg, #d4d4d8, #d4d4d8 5px, #e4e4e7 5px, #e4e4e7 10px); font-weight: 600; }
.cal .d.pad { border: 0; background: none; cursor: default; }

/* Storyboard index */
.flow { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.flow .node { border: 1px solid var(--ink); border-radius: 6px; padding: 8px 12px; background: var(--surface); text-decoration: none; }
.flow .node small { display: block; color: var(--muted); }
.flow .arrow { color: var(--muted); }