:root {
  --bg: #f6f7f9; --surface: #fff; --text: #1b1f24; --muted: #5f6b7a; --border: #dde2e8;
  --primary: #1f6feb; --primary-text: #fff; --danger: #c62828; --flash: #e8f1ff;
  --ok: #2e7d32; --warn: #b26a00;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111418; --surface: #1a1f25; --text: #e6e9ed; --muted: #9aa5b1; --border: #2c333b;
    --primary: #4c8dff; --flash: #1c2a40; --danger: #ef5350;
    --ok: #66bb6a; --warn: #ffa726;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--primary); text-decoration: none; }
h1 { font-size: 1.6rem; margin: 0 0 1rem; }
h2 { font-size: 1.1rem; margin: 0 0 .75rem; }
code { background: var(--bg); padding: 0 .3em; border-radius: 4px; }

.topbar { display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  padding: .75rem 1rem; background: var(--surface); border-bottom: 1px solid var(--border); flex-wrap: wrap; }
.topbar nav { display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; }
.brand { font-weight: 700; color: var(--text); }
.who { color: var(--muted); }

.page { max-width: 960px; margin: 0 auto; padding: 1.5rem 1rem 3rem; }
.narrow { max-width: 420px; }
.center { text-align: center; padding-top: 15vh; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.big-line { font-size: 1.3rem; font-weight: 600; margin: 0 0 .25rem; }

.card { background: var(--surface); border: 1px solid var(--border); border-radius: 10px;
  padding: 1.25rem; margin-bottom: 1rem; overflow-x: auto; }
.card h2:not(:first-child) { margin-top: 1.5rem; }
.flash { background: var(--flash); border: 1px solid var(--border); border-radius: 8px;
  padding: .6rem .9rem; margin-bottom: 1rem; }
.flash.error { border-color: var(--danger); }

.tabs { display: flex; gap: .25rem; margin-bottom: 1rem; border-bottom: 1px solid var(--border); }
.tabs a { padding: .5rem .9rem; color: var(--muted); border-bottom: 2px solid transparent; }
.tabs a.active { color: var(--text); border-color: var(--primary); }

table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: .5rem .4rem; border-bottom: 1px solid var(--border); vertical-align: middle; }
th { font-size: .8rem; color: var(--muted); font-weight: 600; text-transform: uppercase; letter-spacing: .03em; }
tr.cancelled td, tr.past td { color: var(--muted); }
tr.cancelled td:first-child { text-decoration: line-through; }
td.actions { text-align: right; white-space: nowrap; }
.tag { font-size: .7rem; background: var(--bg); border: 1px solid var(--border); border-radius: 99px; padding: 0 .5em; }

label { display: block; margin-bottom: .9rem; }
label.check { display: inline-flex; gap: .35rem; align-items: center; margin-right: 1rem; }
input, textarea { font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--border);
  border-radius: 6px; padding: .45rem .6rem; }
label > input:not([type=checkbox]), label > textarea { display: block; width: 100%; margin-top: .25rem; }
fieldset { border: 0; padding: 0; margin: 0 0 .9rem; }
legend { margin-bottom: .4rem; }
form.inline { display: inline-flex; gap: .35rem; align-items: center; margin: 0; }
form.inline input { padding: .3rem .5rem; }
form.row { display: flex; gap: .75rem; align-items: flex-end; flex-wrap: wrap; }
form.row label { margin: 0; }
form.row .grow { flex: 1; min-width: 160px; }
form.dev { margin-top: 2rem; display: flex; gap: .5rem; justify-content: center; }

.btn { display: inline-block; font: inherit; cursor: pointer; border: 1px solid var(--border);
  background: var(--surface); color: var(--text); border-radius: 6px; padding: .45rem .9rem; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-text); }
.btn.danger { color: var(--danger); }
.btn.small { padding: .25rem .6rem; font-size: .85rem; }
.btn.big { padding: .75rem 1.5rem; font-size: 1.05rem; margin: 1rem 0; }

.pill { display: inline-block; font-size: .72rem; font-weight: 600; border-radius: 99px; padding: .05em .6em;
  vertical-align: middle; border: 1px solid currentColor; }
.pill.ok { color: var(--ok); }
.pill.warn { color: var(--warn); }
label.option { display: flex; gap: .6rem; align-items: flex-start; padding: .5rem .6rem; margin-bottom: .4rem;
  border: 1px solid var(--border); border-radius: 8px; cursor: pointer; }
label.option:has(input:checked) { border-color: var(--primary); }
label.option input { margin-top: .3rem; }
form.withdraw { margin-top: .75rem; }
details { margin-top: 1rem; }
fieldset.row { display: flex; gap: 1rem; flex-wrap: wrap; }
fieldset.row > label { flex: 1; min-width: 200px; }
form.bypass { border-top: 1px solid var(--border); padding-top: .75rem; }
form.bypass.on { border: 1px solid var(--danger); border-radius: 8px; padding: .75rem; }
form.bypass p { margin-top: 0; }

.checkin-card { text-align: center; }
.checkin-btn { font-size: 1.4rem; padding: 1rem 2.5rem; margin: .5rem 0 1rem; border-radius: 12px; }
.checkin-done { font-size: 1.3rem; font-weight: 600; }
.wifi { font-size: .9rem; }
.wifi.ok { color: var(--ok); }
.wifi.bad { color: var(--danger); }

/* ---------------------------------------------------------------- board */
main.board { max-width: 380px; margin: 0; padding: .75rem; min-height: 100vh; }
main.board.display { max-width: none; }
body:has(main.board.display) { font-size: 17px; }
body.wide main.board { max-width: none; }
body.wide #board-groups { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: .75rem; }
.board-head { border-bottom: 1px solid var(--border); padding-bottom: .6rem; margin-bottom: .6rem; }
.board-title { font-size: .75rem; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--muted); }
.board-date { font-weight: 600; }
.board-clock { font-size: 2rem; font-weight: 700; font-variant-numeric: tabular-nums; line-height: 1.2; }
.board-clock.running { color: var(--danger); }
.board-count { color: var(--muted); }
.board-flag { margin-top: .3rem; font-size: .8rem; color: var(--danger); font-weight: 600; }
.board-status { color: var(--muted); font-size: .8rem; }
.group { margin-bottom: .6rem; }
.group h3 { display: flex; align-items: center; gap: .4rem; font-size: .95rem; margin: 0 0 .25rem; }
.group .gtitle { flex: 1; }
.group .gcount { font-variant-numeric: tabular-nums; background: var(--surface); border: 1px solid var(--border);
  border-radius: 99px; padding: 0 .55em; font-size: .85rem; }
.group.empty { opacity: .45; }
.group.empty ul { display: none; }
.group ul { list-style: none; margin: 0; padding: 0; }
.group li { display: flex; flex-wrap: wrap; gap: .1rem .4rem; align-items: baseline; padding: .2rem .5rem;
  border-left: 3px solid var(--border); margin-bottom: 2px; background: var(--surface); border-radius: 0 4px 4px 0; }
.pname { font-weight: 600; flex: 1; }
.pdetail { font-variant-numeric: tabular-nums; color: var(--muted); font-size: .85rem; }
.pflag { font-size: .68rem; border: 1px solid currentColor; border-radius: 99px; padding: 0 .45em; }
.f-informed { color: var(--ok); }
.f-informed-late, .f-wifi-bypass { color: var(--warn); }
.g-joined li { border-left-color: var(--ok); }
.g-joined_late li { border-left-color: var(--warn); }
.g-running_late li { border-left-color: var(--warn); }
.g-virtual li, .g-absent li { border-left-color: var(--muted); }
body.started .g-not_joined li { border-left-color: var(--danger); }
body.started .g-not_joined h3 { color: var(--danger); }
.board-title a { font-weight: 400; letter-spacing: 0; text-transform: none; margin-left: .5rem; }
.group .dot { width: .7rem; height: .7rem; border-radius: 50%; background: var(--muted); flex: none; }
.g-joined .dot { background: var(--ok); }
.g-joined_late .dot, .g-running_late .dot { background: var(--warn); }
.g-not_joined .dot { background: transparent; border: 2px solid var(--muted); }
body.started .g-not_joined .dot { border-color: var(--danger); }
.checkin-done { color: var(--ok); }

/* -------------------------------------------------------------- reports */
form.filter { margin-bottom: 1rem; }
select { font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--border);
  border-radius: 6px; padding: .4rem .5rem; display: block; margin-top: .25rem; }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: .75rem; margin-bottom: 1rem; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: .8rem 1rem; }
.stat .label { font-size: .78rem; color: var(--muted); text-transform: uppercase; letter-spacing: .03em; }
.stat .value { font-size: 1.7rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.stat .sub { font-size: .8rem; color: var(--muted); }
table.num td:not(:first-child), table.num th:not(:first-child) { text-align: right; font-variant-numeric: tabular-nums; }
table.num th { white-space: normal; vertical-align: bottom; }
td.bad { color: var(--danger); font-weight: 600; }
td.warnc { color: var(--warn); font-weight: 600; }
.pill.muted-pill { color: var(--muted); }
table.num td:first-child { white-space: nowrap; }

/* -------------------------------------------------------------- sandbox */
.sandbox-bar { background: #ffd54f; color: #3e2c00; padding: .45rem 1rem; font-size: .9rem;
  position: sticky; top: 0; z-index: 10; border-bottom: 1px solid #e0b000; }
.sandbox-bar #sim-clock { font-variant-numeric: tabular-nums; font-weight: 600; }
.sb-tag { display: inline-block; background: #3e2c00; color: #ffd54f; border-radius: 99px; padding: 0 .55em;
  font-size: .75rem; margin-left: .35rem; }
.sandbox-panel { margin-top: .35rem; }
.sandbox-panel summary { cursor: pointer; font-weight: 600; }
.sb-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: .75rem 1.5rem; padding: .5rem 0; }
.sb-grid h4 { margin: .25rem 0 .35rem; font-size: .85rem; }
.sb-row { display: flex; flex-wrap: wrap; gap: .3rem; align-items: center; margin-bottom: .4rem; }
.sb-row form { margin: 0; }
.sandbox-bar .btn { background: #fff8e1; color: #3e2c00; border-color: #c9a000; }
.sandbox-bar .btn.primary { background: #3e2c00; color: #ffd54f; }
.sandbox-bar input, .sandbox-bar select { background: #fff8e1; color: #3e2c00; border-color: #c9a000; margin: 0; display: inline-block; }
.sandbox-bar p { margin: .25rem 0 0; }