:root {
  --bg: #f4f5f7;
  --card: #ffffff;
  --text: #1c1f24;
  --muted: #6b7280;
  --line: #e3e6ea;
  --accent: #1d5bd8;
  --accent-text: #ffffff;
  --ok: #1f8a4c;
  --warn: #b7791f;
  --err: #c53030;
  --new: #fff4c2;
  --overtime: #1d5bd8;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121418;
    --card: #1b1e24;
    --text: #e8eaed;
    --muted: #9aa1ab;
    --line: #2c3038;
    --accent: #5b8def;
    --accent-text: #0d1117;
    --ok: #4cc283;
    --warn: #e0a643;
    --err: #f07070;
    --new: #4a3f12;
    --overtime: #7ea6f5;
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
h1, h2 { margin: 0 0 12px; line-height: 1.2; }
h2 { font-size: 18px; }
.muted { color: var(--muted); }
.error { color: var(--err); margin: 8px 0; }

.topbar {
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
  padding: 12px 16px; background: var(--card); border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 2; flex-wrap: wrap;
}
.brand { font-weight: 700; font-size: 17px; }
.top-actions { display: flex; gap: 8px; }
main { max-width: 1000px; margin: 0 auto; padding: 16px; display: grid; gap: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px; }
.section-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; }

.btn {
  font: inherit; border-radius: 8px; padding: 7px 14px; cursor: pointer;
  border: 1px solid var(--line); background: var(--card); color: var(--text);
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); font-weight: 600; }
.btn.ghost:hover { border-color: var(--muted); }
.btn.small { padding: 4px 10px; font-size: 13px; }
.btn.danger { color: var(--err); }
.btn.link { display: inline-block; margin-top: 12px; text-decoration: none; }

.scanners { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 12px; }
.scanner { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; }
.scanner .title { display: flex; align-items: center; gap: 8px; font-weight: 600; }
.scanner .msg { margin-top: 4px; font-size: 13px; }
.dot { width: 10px; height: 10px; border-radius: 50%; background: var(--muted); flex: none; }
.dot.ok, .dot.checking { background: var(--ok); }
.dot.login { background: var(--warn); }
.dot.error { background: var(--err); }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); white-space: nowrap; }
th { font-size: 12px; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); font-weight: 600; }
tr.new td { background: var(--new); }
.overtime { color: var(--overtime); }
.empty { color: var(--muted); margin: 8px 0 0; }
td.who { white-space: normal; }

.students { display: grid; gap: 10px; }
.student {
  display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap;
  border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px;
}
.student.paused { opacity: .55; }
.student .name { font-weight: 600; }
.student .meta { font-size: 13px; color: var(--muted); }
.student .actions { display: flex; gap: 6px; }
.badge { display: inline-block; font-size: 12px; padding: 1px 8px; border-radius: 999px; border: 1px solid currentColor; margin-left: 6px; }
.badge.ok { color: var(--ok); }
.badge.booked { color: var(--warn); }
.badge.bad_login { color: var(--err); }
.badge.unknown { color: var(--muted); }

.student-form { border: 1px dashed var(--line); border-radius: 10px; padding: 12px; margin-bottom: 12px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
label { display: grid; gap: 4px; font-size: 13px; font-weight: 600; }
label small { font-weight: 400; }
input, select {
  font: inherit; padding: 8px 10px; border-radius: 8px; border: 1px solid var(--line);
  background: var(--bg); color: var(--text); width: 100%;
}
.form-actions { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: 12px; grid-column: 1 / -1; }

.events { list-style: none; margin: 0; padding: 0; max-height: 320px; overflow-y: auto; font-size: 13px; }
.events li { padding: 4px 0; border-bottom: 1px solid var(--line); }
.events time { color: var(--muted); margin-right: 8px; font-variant-numeric: tabular-nums; }
.events .slot { font-weight: 600; }
.events .error { color: var(--err); margin: 0; }
.events .warn { color: var(--warn); }

.steps { margin: 0 0 12px; padding-left: 20px; font-size: 14px; }
.steps li { margin: 3px 0; }
code { background: var(--bg); border: 1px solid var(--line); border-radius: 4px; padding: 0 4px; }
.inline-form { display: flex; gap: 8px; flex-wrap: wrap; }
.inline-form input { flex: 1 1 240px; width: auto; }
.tg-status { margin: 8px 0 0; }
.tg-status.ok { color: var(--ok); font-weight: 600; }

.login-page { display: grid; place-items: center; min-height: 100vh; padding: 16px; }
.login-card { width: 100%; max-width: 340px; display: grid; gap: 12px; }

@media (max-width: 600px) {
  main { padding: 12px; }
  th:nth-child(6), td:nth-child(6) { display: none; }
}