/* Giao diện chung của teachers., students., parents.bbenglish.cloud */
:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #1d4ed8;
  --primary-text: #ffffff;
  --danger: #b91c1c;
  --ok: #047857;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --card: #1f2937;
    --text: #f3f4f6;
    --muted: #9ca3af;
    --border: #374151;
    --primary: #60a5fa;
    --primary-text: #111827;
    --danger: #f87171;
    --ok: #34d399;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}
a { color: var(--primary); }
header.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  padding: 12px 16px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
header.top .brand { font-weight: 700; font-size: 1.25rem; color: var(--primary); }
header.top .brand small { font-weight: 500; color: var(--text); margin-left: 6px; }
header.top .account { display: flex; align-items: center; gap: 8px; color: var(--muted); }
main { max-width: 960px; margin: 0 auto; padding: 16px; }
main.narrow { max-width: 420px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
}
.card h2 { margin: 0 0 12px; font-size: 1.125rem; }
.center-title { text-align: center; margin: 32px 0 16px; }
.center-title h1 { margin: 0; font-size: 2.5rem; color: var(--primary); }
.center-title p { margin: 4px 0 0; font-size: 1.25rem; }
form .field { display: flex; flex-direction: column; gap: 4px; margin-bottom: 12px; }
form .row { display: flex; gap: 8px; flex-wrap: wrap; align-items: flex-end; }
form .row .field { flex: 1 1 160px; margin-bottom: 0; }
label { font-size: 0.875rem; color: var(--muted); }
input, select {
  font: inherit;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  min-width: 0;
}
button {
  font: inherit;
  padding: 8px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
}
button.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-text); }
button.danger { color: var(--danger); }
button.small { padding: 4px 8px; font-size: 0.875rem; }
button:disabled { opacity: 0.6; cursor: default; }
button.link { border: none; background: none; color: var(--primary); padding: 0; text-decoration: underline; }
.message { min-height: 1.25em; margin-top: 8px; font-size: 0.875rem; }
.message.error { color: var(--danger); }
.message.ok { color: var(--ok); }
.tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.tabs button.active { background: var(--primary); border-color: var(--primary); color: var(--primary-text); }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 0.9375rem; }
th, td { text-align: left; padding: 8px; border-bottom: 1px solid var(--border); vertical-align: top; }
th { color: var(--muted); font-weight: 500; font-size: 0.875rem; }
td .actions { display: flex; gap: 4px; flex-wrap: wrap; }
.badge { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 0.75rem; border: 1px solid var(--border); }
.badge.locked { color: var(--danger); border-color: var(--danger); }
.badge.pending { color: var(--muted); }
.chip { display: inline-flex; align-items: center; gap: 4px; padding: 2px 4px 2px 8px; margin: 0 4px 4px 0; border-radius: 999px; background: var(--bg); border: 1px solid var(--border); font-size: 0.8125rem; }
.chip button { padding: 0 6px; border: none; background: none; color: var(--muted); }
.muted { color: var(--muted); }
dl.profile { display: grid; grid-template-columns: max-content 1fr; gap: 6px 16px; margin: 0; }
dl.profile dt { color: var(--muted); }
dl.profile dd { margin: 0; }