:root {
  --bg: #f7f7f4; --fg: #1d2330; --muted: #5d6475; --card: #fff; --line: #dfe1e6;
  --accent: #2f5bd3; --accent-fg: #fff; --notice: #fff5d6; --notice-line: #e9cf7a;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171d; --fg: #e8eaf0; --muted: #a2a9b8; --card: #1d212a; --line: #2e3440;
    --accent: #7c9cff; --accent-fg: #0d1020; --notice: #3a3218; --notice-line: #7a6624;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 17px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; }
a { color: var(--accent); }
.top { padding: 12px 16px; border-bottom: 1px solid var(--line); background: var(--card); }
.brand { font-weight: 700; font-size: 1.2rem; text-decoration: none; color: var(--fg); }
main { max-width: 760px; margin: 0 auto; padding: 24px 16px 48px; }
h1 { font-size: 1.7rem; margin: 0 0 12px; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin-top: 24px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px 20px; }
.card h2 { margin: 0 0 4px; font-size: 1.2rem; }
.card.link { text-decoration: none; color: inherit; }
.card.link:hover, .card.link:focus-visible { border-color: var(--accent); }
.stack { display: grid; gap: 14px; max-width: 380px; }
label { display: grid; gap: 4px; font-weight: 600; font-size: .95rem; }
input { font: inherit; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--fg); }
input:focus-visible, button:focus-visible, a:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
button { font: inherit; font-weight: 600; padding: 10px 16px; border: 0; border-radius: 8px; background: var(--accent); color: var(--accent-fg); cursor: pointer; justify-self: start; }
button.linkish { background: none; color: var(--accent); padding: 0; text-decoration: underline; font-weight: 400; }
.notice { background: var(--notice); border: 1px solid var(--notice-line); border-radius: 8px; padding: 10px 14px; }
.alt { margin-top: 20px; color: var(--muted); }
.teachnav { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; margin-bottom: 20px; color: var(--muted); }
.teachnav span { font-weight: 600; color: var(--fg); margin-right: auto; }
.teachnav form { margin: 0; }

/* ---- Stage 2: tables, switches, forms, login cards ---- */
:root { --danger: #b42318; --danger-fg: #fff; --ok: #e3f4e6; --ok-line: #8cc79a; --bad: #fde8e6; --bad-line: #e8a39b; --warnbg: #fff5d6; }
@media (prefers-color-scheme: dark) {
  :root { --danger: #f97066; --danger-fg: #1a0b0a; --ok: #16301c; --ok-line: #2f6b3c; --bad: #3a1714; --bad-line: #7a2e27; --warnbg: #3a3218; }
}
main.wide { max-width: 1040px; }
h2 { font-size: 1.25rem; margin: 28px 0 10px; }
.notice.ok { background: var(--ok); border-color: var(--ok-line); }
.notice.error { background: var(--bad); border-color: var(--bad-line); }
select, textarea { font: inherit; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--fg); }
textarea { width: 100%; font-family: ui-monospace, Menlo, monospace; font-size: .95rem; }
.stack.wide { max-width: 560px; }
.row { display: flex; flex-wrap: wrap; gap: 12px; align-items: end; }
.spaced { margin-top: 12px; }
.buttons { display: flex; flex-wrap: wrap; gap: 10px; }
.buttons form, td.actions form { margin: 0; display: inline; }
button.secondary { background: var(--card); color: var(--accent); border: 1px solid var(--accent); }
button.danger { background: var(--danger); color: var(--danger-fg); }
button.small { padding: 4px 10px; font-size: .85rem; }
.grid { width: 100%; border-collapse: collapse; background: var(--card); border: 1px solid var(--line); border-radius: 8px; overflow: hidden; font-size: .95rem; }
.grid th, .grid td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); vertical-align: middle; }
.grid th { font-size: .85rem; color: var(--muted); font-weight: 600; }
.grid tr.bad td { background: var(--bad); }
.grid tr.warn td { background: var(--warnbg); }
.grid tr.muted td { color: var(--muted); }
td.actions { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.table-scroll { overflow-x: auto; }
.switchbar { display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; align-items: center; background: var(--ok); border: 1px solid var(--ok-line); border-radius: 10px; padding: 12px 16px; margin-bottom: 20px; }
.switchbar.off { background: var(--bad); border-color: var(--bad-line); }
.switchbar form { margin: 0; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 16px; margin-bottom: 16px; }
.panel h3 { margin: 0 0 10px; font-size: 1.05rem; }
.crumbs { margin: 0 0 4px; font-size: .9rem; }
.tag { font-size: .8rem; font-weight: 600; background: var(--line); border-radius: 999px; padding: 2px 10px; vertical-align: middle; }
.archived { margin-top: 28px; color: var(--muted); }
code { font-family: ui-monospace, Menlo, monospace; }
@media (max-width: 640px) {
  .grid { display: block; overflow-x: auto; white-space: nowrap; }
}

.logincards { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 12px; margin-top: 16px; }
.logincard { border: 2px dashed var(--line); border-radius: 10px; padding: 12px 14px; background: var(--card); break-inside: avoid; }
.lc-top { display: flex; justify-content: space-between; font-size: .85rem; color: var(--muted); }
.lc-name { font-size: 1.25rem; font-weight: 700; margin-top: 6px; }
.lc-class { font-size: .85rem; color: var(--muted); }
.logincard dl { display: grid; grid-template-columns: auto 1fr; gap: 2px 10px; margin: 8px 0 0; }
.logincard dt { font-size: .8rem; color: var(--muted); align-self: center; }
.logincard dd { margin: 0; font-size: 1.1rem; white-space: nowrap; }

@media print {
  :root { --bg: #fff; --fg: #000; --card: #fff; --line: #888; --muted: #333; }
  .top, .no-print { display: none !important; }
  main, main.wide { max-width: none; padding: 0; }
  .logincards { grid-template-columns: repeat(3, 1fr); gap: 0; }
  .logincard { border-radius: 0; border: 1px dashed #888; }
}