* { box-sizing: border-box; }

:root {
  --color-primary: #4f5fee;
  --color-primary-hover: #3f4ed6;
  --color-primary-soft: #eef0ff;
  --color-bg: #f5f6fb;
  --color-surface: #ffffff;
  --color-border: #e5e7f0;
  --color-text: #1a1b26;
  --color-muted: #6b7089;
  --color-success-bg: #d1fae5;
  --color-success-text: #065f46;
  --color-warning-bg: #fef3c7;
  --color-warning-text: #92400e;
  --color-danger: #e0374a;
  --color-danger-bg: #fde2e5;
  --color-danger-text: #991b1b;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(20, 21, 40, 0.05);
  --shadow-md: 0 4px 16px rgba(20, 21, 40, 0.07);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  margin: 0;
  line-height: 1.5;
}

.container { max-width: 980px; margin: 0 auto; padding: 32px 24px; }
.narrow {
  max-width: 420px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 28px;
  margin-bottom: 20px;
  transition: box-shadow 0.15s ease;
}

.card-nested {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  margin-bottom: 14px;
}
.card-nested:last-child { margin-bottom: 0; }
.approval-actions { display: flex; gap: 10px; }

h1 { font-size: 23px; font-weight: 700; margin: 0 0 18px; letter-spacing: -0.01em; }
h2 { font-size: 17px; font-weight: 600; margin: 0 0 14px; letter-spacing: -0.01em; }

label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-muted);
  margin: 16px 0 6px;
}

input, select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
  background: var(--color-surface);
  color: var(--color-text);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-soft);
}

button, .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  text-decoration: none;
  margin-top: 16px;
  transition: background-color 0.15s ease, transform 0.05s ease, box-shadow 0.15s ease;
}

button:hover, .btn:hover { background: var(--color-primary-hover); }
button:active, .btn:active { transform: translateY(1px); }
button:focus-visible, .btn:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }
button:disabled { background: var(--color-border); color: var(--color-muted); cursor: not-allowed; transform: none; }

button.secondary, .btn.secondary { background: var(--color-surface); color: var(--color-text); border: 1px solid var(--color-border); }
button.secondary:hover, .btn.secondary:hover { background: var(--color-bg); }

button.danger, .btn.danger { background: var(--color-danger); }
button.danger:hover, .btn.danger:hover { background: #c22c3d; }

table { width: 100%; border-collapse: collapse; margin-top: 4px; }
th {
  text-align: left;
  padding: 10px 12px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-muted);
  border-bottom: 1px solid var(--color-border);
}
td {
  text-align: left;
  padding: 12px;
  font-size: 14px;
  border-bottom: 1px solid var(--color-border);
}
tr:last-child td { border-bottom: none; }
tbody tr { transition: background-color 0.1s ease; }
tbody tr:hover { background: var(--color-bg); }

.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
}
.badge.pending { background: var(--color-warning-bg); color: var(--color-warning-text); }
.badge.approved { background: var(--color-success-bg); color: var(--color-success-text); }
.badge.rejected { background: var(--color-danger-bg); color: var(--color-danger-text); }

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 28px;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  flex-wrap: wrap;
  gap: 10px;
}
.topbar-user { font-size: 14px; }
.topbar-user .muted { font-size: 13px; }
.nav-links { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
.nav-links a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  transition: background-color 0.15s ease, color 0.15s ease;
}
.nav-links a:hover { background: var(--color-primary-soft); color: var(--color-primary); }
.nav-links a:last-child { color: var(--color-danger); }
.nav-links a:last-child:hover { background: var(--color-danger-bg); }

.error {
  background: var(--color-danger-bg);
  color: var(--color-danger-text);
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-danger);
  margin-bottom: 16px;
  font-size: 14px;
}
.muted { color: var(--color-muted); font-size: 13px; }

@media (max-width: 640px) {
  .container { padding: 20px 16px; }
  .card { padding: 20px; }
  .topbar { padding: 12px 16px; }
  table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
}

/* ---------- Class lists (Live now / Today / Upcoming / Past) ---------- */
.class-section { margin-top: 26px; }
.class-section:first-of-type { margin-top: 8px; }
.class-section h2 { font-size: 17px; margin: 0 0 12px; display: flex; align-items: center; gap: 8px; }
.class-count {
  background: var(--color-primary-soft); color: var(--color-primary); border-radius: 999px;
  font-size: 12px; font-weight: 700; padding: 2px 9px;
}
.class-day { font-size: 13px; font-weight: 600; color: var(--color-muted); margin: 18px 0 8px; text-transform: none; }
.class-day:first-child { margin-top: 0; }
.class-list { display: flex; flex-direction: column; gap: 8px; }

.class-card {
  display: grid; grid-template-columns: 92px 1fr auto; align-items: center; gap: 16px;
  padding: 14px 16px; background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); box-shadow: var(--shadow-sm);
}
.class-card.is-live { border-color: #34d399; box-shadow: 0 0 0 3px rgba(52, 211, 153, 0.18); }
.class-card.is-past, .class-card.is-cancelled { background: var(--color-bg); }
.class-card.is-cancelled .class-title { text-decoration: line-through; color: var(--color-muted); }

.class-time { display: flex; flex-direction: column; line-height: 1.25; }
.class-time strong { font-size: 16px; }
.class-time span { font-size: 12px; color: var(--color-muted); }
.class-title { font-weight: 600; font-size: 15px; word-break: break-word; }
.class-meta { font-size: 13px; color: var(--color-muted); margin-top: 2px; }
.class-side { display: flex; flex-direction: column; align-items: flex-end; gap: 8px; }
.class-actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
.class-note { max-width: 220px; text-align: right; }

.class-chip { display: inline-block; padding: 3px 10px; border-radius: 999px; font-size: 12px; font-weight: 600; white-space: nowrap; }
.class-chip.live { background: var(--color-success-bg); color: var(--color-success-text); }
.class-chip.soon { background: var(--color-primary-soft); color: var(--color-primary); }
.class-chip.ended { background: var(--color-border); color: var(--color-muted); }
.class-chip.cancelled { background: var(--color-danger-bg); color: var(--color-danger-text); }

@media (max-width: 640px) {
  .class-card { grid-template-columns: 1fr; gap: 8px; }
  .class-time { flex-direction: row; align-items: baseline; gap: 6px; }
  .class-side { flex-direction: row; justify-content: space-between; align-items: center; flex-wrap: wrap; }
  .class-note { text-align: left; max-width: none; }
}

/* Admin edit pages */
.edit-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.edit-flash { display: block; margin-bottom: 12px; padding: 10px 12px; }
.edit-check { display: block; font-weight: normal; margin: 8px 0; }
.edit-check input { width: auto; margin-right: 6px; }
.edit-row { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 8px 0; border-bottom: 1px solid rgba(128,128,128,.2); flex-wrap: wrap; }
.edit-add select { flex: 1; min-width: 160px; }
.edit-history { list-style: none; padding: 0; margin: 0; }
.edit-history li { padding: 8px 0; border-bottom: 1px solid rgba(128,128,128,.2); }
@media (max-width: 600px) { .edit-grid { grid-template-columns: 1fr; } }

/* Question bank */
.bank-layout { display: grid; grid-template-columns: 260px 1fr; gap: 16px; align-items: start; }
.bank-chapter { display: flex; justify-content: space-between; gap: 8px; padding: 8px 10px; border-radius: 8px; color: var(--color-text); text-decoration: none; }
.bank-chapter:hover { background: var(--color-bg); }
.bank-chapter.active { background: var(--color-bg); font-weight: 600; }
.bank-add-chapter { margin-top: 12px; display: grid; gap: 8px; }
.bank-option { display: flex; align-items: center; gap: 8px; margin: 6px 0; }
.bank-option input[type=radio] { width: auto; flex: none; }
.bank-option input[type=text] { flex: 1; }
.bank-q { padding: 12px 0; border-bottom: 1px solid rgba(128,128,128,.2); }
.bank-q.is-archived { opacity: .6; }
.bank-opts { margin: 6px 0 6px 20px; padding: 0; }
.bank-opts .is-correct { font-weight: 600; color: #1a7f4b; }
.bank-actions { display: flex; gap: 8px; align-items: center; }
.bank-actions form { margin: 0; }
@media (max-width: 800px) { .bank-layout { grid-template-columns: 1fr; } }