:root {
  --primary: #0f172a;
  --accent: #3b82f6;
  --accent-dark: #2563eb;
  --accent-soft: #e0f2fe;
  --accent-soft-text: #0369a1;
  --text: #334155;
  --muted: #64748b;
  --faint: #94a3b8;
  --border: #e2e8f0;
  --bg: #f8fafc;
  --card: #ffffff;
  --ok: #16a34a;
  --ok-bg: #dcfce7;
  --warn: #b45309;
  --warn-bg: #fef3c7;
  --danger: #b91c1c;
  --danger-bg: #fee2e2;
  --radius: 16px;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 12px 30px -8px rgba(15, 23, 42, 0.18);
}

* { box-sizing: border-box; }

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  margin: 0;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.page {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px 80px;
}
.page.wide { max-width: 1180px; }

/* Top bar */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: inherit; }
.brand-badge {
  width: 42px; height: 42px; border-radius: 12px;
  background: var(--accent); color: #fff;
  display: grid; place-items: center; font-weight: 800; font-size: 1.1rem;
  box-shadow: 0 6px 16px rgba(59, 130, 246, 0.35);
}
.brand-text b { display: block; color: var(--primary); font-size: 1.02rem; line-height: 1.2; }
.brand-text span { font-size: 0.82rem; color: var(--faint); }

.topbar-actions { display: flex; align-items: center; gap: 10px; }

h1 { font-size: 2rem; color: var(--primary); margin: 0 0 6px; letter-spacing: -0.02em; }
h2 { color: var(--primary); }
.lead { color: var(--muted); margin: 0 0 26px; font-size: 1.05rem; }

/* Buttons */
button, .btn {
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: 10px;
  padding: 11px 18px;
  cursor: pointer;
  transition: transform 0.12s ease, background 0.15s ease, box-shadow 0.15s ease;
}
.btn-primary { background: var(--accent); color: #fff; box-shadow: 0 6px 16px rgba(59, 130, 246, 0.3); }
.btn-primary:hover { background: var(--accent-dark); transform: translateY(-1px); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }
.btn-ghost { background: transparent; color: var(--muted); border: 1px solid var(--border); }
.btn-ghost:hover { background: #f1f5f9; }
.btn-ok { background: var(--ok); color: #fff; }
.btn-ok:hover { background: #15803d; }
.btn-danger { background: var(--danger-bg); color: var(--danger); }
.btn-danger:hover { background: #fecaca; }
.btn-sm { padding: 7px 12px; font-size: 0.85rem; border-radius: 8px; }
.lang-toggle {
  background: var(--card); color: var(--accent); border: 1px solid var(--border);
  border-radius: 999px; padding: 8px 16px; font-weight: 700;
}
.lang-toggle:hover { background: #f1f5f9; }
:focus-visible { outline: 3px solid #93c5fd; outline-offset: 2px; }

/* Cards */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}
.card + .card { margin-top: 20px; }
.card h2 { margin: 0 0 4px; font-size: 1.15rem; }
.card h3 { margin: 0 0 10px; font-size: 1rem; color: var(--primary); }
.section-label { font-size: 0.78rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--accent); margin-bottom: 12px; }

/* Teacher picker */
.teacher-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.teacher-card {
  display: flex; gap: 14px; align-items: center;
  background: var(--card); border: 2px solid var(--border); border-radius: var(--radius);
  padding: 16px; cursor: pointer; text-align: left;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, transform 0.12s ease;
}
.teacher-card:hover { border-color: #bfdbfe; transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.teacher-card.active { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(59,130,246,0.15); }
.teacher-card img { width: 56px; height: 56px; border-radius: 12px; object-fit: cover; background: #e2e8f0; flex-shrink: 0; }
.teacher-card b { display: block; color: var(--primary); }
.teacher-card small { color: var(--faint); }

/* Day strip */
.day-strip { display: flex; gap: 10px; overflow-x: auto; padding: 4px 2px 12px; }
.day-chip {
  flex: 0 0 auto; min-width: 74px;
  background: #f1f5f9; border: 1px solid transparent; border-radius: 12px;
  padding: 10px 8px; text-align: center; cursor: pointer; color: var(--text);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.day-chip:hover { background: #e2e8f0; }
.day-chip.active { background: var(--accent); color: #fff; border-color: var(--accent); }
.day-chip .dow { display: block; font-size: 0.78rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; }
.day-chip .dnum { display: block; font-size: 1.15rem; font-weight: 700; line-height: 1.2; }
.day-chip .dmon { display: block; font-size: 0.72rem; opacity: 0.8; }
.day-chip.empty { opacity: 0.4; cursor: not-allowed; }

/* Slot buttons */
.slot-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(104px, 1fr)); gap: 10px; }
.slot-btn {
  background: var(--accent-soft); color: var(--accent-soft-text);
  border: 1px solid #bae6fd; border-radius: 10px; padding: 12px 8px;
  font-weight: 700; cursor: pointer; transition: transform 0.12s ease, background 0.15s ease;
}
.slot-btn:hover { background: #bae6fd; transform: translateY(-1px); }
.slot-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* Forms */
.field { margin-bottom: 16px; }
.field label { display: block; font-weight: 600; color: var(--primary); font-size: 0.9rem; margin-bottom: 6px; }
.field .opt { color: var(--faint); font-weight: 400; }
.field input, .field select, .field textarea {
  width: 100%; font-family: inherit; font-size: 0.95rem; color: var(--text);
  padding: 11px 13px; border: 1px solid var(--border); border-radius: 10px; background: #fff;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(59,130,246,0.15);
}
.field textarea { resize: vertical; min-height: 84px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-error { color: var(--danger); font-size: 0.9rem; margin-top: 8px; min-height: 1.2em; }
.help { font-size: 0.82rem; color: var(--faint); margin-top: 4px; }
.field label.consent { display: flex; gap: 10px; align-items: flex-start; font-weight: 400; color: var(--text); font-size: 0.92rem; }
.field label.consent input[type="checkbox"] { width: auto; padding: 0; margin: 3px 0 0; flex-shrink: 0; }
.field label.consent a { color: var(--accent); }
.policy-footer { text-align: center; margin-top: 28px; font-size: 0.85rem; }
.policy-footer a { color: var(--muted); text-decoration: none; }
.policy-footer a:hover { color: var(--accent); }

.policy h2 { font-size: 1.1rem; margin: 26px 0 8px; color: var(--primary); }
.policy h2:first-of-type { margin-top: 18px; }
.policy p { margin: 0 0 10px; }
.policy ul { margin: 8px 0 12px 22px; padding: 0; }
.policy li { margin: 5px 0; }
.policy a { color: var(--accent); }

.location-note {
  background: var(--accent-soft); color: var(--accent-soft-text);
  border: 1px solid #bae6fd; border-radius: 10px;
  padding: 10px 14px; font-size: 0.9rem; font-weight: 600; margin-bottom: 16px;
}
.booked-note {
  background: #fef3c7; color: #92400e; border: 1px solid #fcd34d;
  border-radius: 10px; padding: 12px 14px; font-size: 0.92rem; font-weight: 600;
}
.booked-badge {
  display: inline-block; margin-top: 4px; background: #fef3c7; color: #92400e;
  border: 1px solid #fcd34d; border-radius: 999px; padding: 1px 9px;
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.02em;
}
.photo-preview { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.thumb { width: 72px; height: 72px; object-fit: cover; border-radius: 8px; border: 1px solid var(--border); }
.modal-photos { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }
.modal-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--border); }
.modal-select { width: 100%; font-family: inherit; font-size: 0.95rem; padding: 11px 13px; border: 1px solid var(--border); border-radius: 10px; margin: 4px 0 8px; }

/* Radio pills */
.pill-group { display: flex; gap: 10px; flex-wrap: wrap; }
.pill-opt { position: relative; }
.pill-opt input { position: absolute; opacity: 0; inset: 0; cursor: pointer; }
.pill-opt span {
  display: inline-block; padding: 9px 16px; border-radius: 999px;
  border: 1px solid var(--border); background: #fff; font-weight: 600; font-size: 0.9rem; color: var(--muted);
}
.pill-opt input:checked + span { background: var(--accent); border-color: var(--accent); color: #fff; }
.pill-opt input:focus-visible + span { outline: 3px solid #93c5fd; outline-offset: 2px; }

/* Badges */
.badge { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px; border-radius: 999px; font-size: 0.78rem; font-weight: 700; }
.badge.pending { background: var(--warn-bg); color: var(--warn); }
.badge.approved { background: var(--ok-bg); color: var(--ok); }
.badge.declined { background: var(--danger-bg); color: var(--danger); }
.badge.open { background: #f1f5f9; color: var(--muted); }
.badge.blocked { background: #f1f5f9; color: var(--faint); text-decoration: line-through; }
.badge.booked { background: var(--accent-soft); color: var(--accent-soft-text); }

/* Summary */
.summary { background: #f8fafc; border: 1px dashed var(--border); border-radius: 12px; padding: 16px 18px; margin-bottom: 20px; }
.summary .row { display: flex; justify-content: space-between; gap: 12px; padding: 4px 0; font-size: 0.95rem; }
.summary .row span:first-child { color: var(--muted); }
.summary .row span:last-child { font-weight: 600; color: var(--primary); text-align: right; }

/* Success */
.success { text-align: center; padding: 20px 10px; }
.success .tick {
  width: 64px; height: 64px; border-radius: 50%; background: var(--ok-bg); color: var(--ok);
  display: grid; place-items: center; font-size: 2rem; margin: 0 auto 16px;
}
.pending-icon {
  width: 64px; height: 64px; border-radius: 50%; background: var(--warn-bg); color: var(--warn);
  display: grid; place-items: center; font-size: 1.9rem; margin: 0 auto 16px;
}
.pending-note {
  max-width: 540px; margin: 0 auto;
  background: var(--warn-bg); color: var(--warn);
  border: 1px solid #fcd34d; border-radius: 12px;
  padding: 14px 18px; font-weight: 600; font-size: 0.95rem; line-height: 1.5;
}

/* Admin */
.tabs { display: flex; gap: 6px; margin-bottom: 20px; flex-wrap: wrap; }
.tab {
  background: transparent; border: 1px solid var(--border); color: var(--muted);
  border-radius: 999px; padding: 8px 16px; font-weight: 600; cursor: pointer;
}
.tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.tab .count {
  display: inline-block; margin-left: 6px; background: var(--accent); color: #fff;
  border-radius: 999px; padding: 1px 7px; font-size: 0.75rem;
}
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; margin-bottom: 22px; }
.stat { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 16px; }
.stat b { display: block; font-size: 1.6rem; color: var(--primary); line-height: 1.1; }
.stat span { font-size: 0.82rem; color: var(--faint); }

.request {
  border: 1px solid var(--border); border-radius: 12px; padding: 16px 18px; background: var(--card);
}
.request + .request { margin-top: 12px; }
.request-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; flex-wrap: wrap; }
.request-when { font-weight: 700; color: var(--primary); }
.request-meta { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 6px 18px; margin: 12px 0; font-size: 0.9rem; }
.request-meta div span { color: var(--faint); display: block; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.04em; }
.request-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.decline-form { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--border); }
.decline-form label { display: block; font-weight: 600; color: var(--primary); font-size: 0.9rem; margin-bottom: 6px; }
.decline-form textarea {
  width: 100%; font-family: inherit; font-size: 0.95rem; color: var(--text); background: #fff;
  padding: 11px 13px; border: 1px solid var(--border); border-radius: 10px; margin-bottom: 10px;
  resize: vertical; transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.decline-form textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(59,130,246,0.15); }

.schedule-list { display: flex; flex-direction: column; gap: 8px; }
.schedule-row { display: flex; align-items: center; gap: 12px; padding: 10px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--card); }
.schedule-row .when { font-weight: 600; color: var(--primary); min-width: 190px; }
.schedule-row .who { flex: 1; color: var(--muted); font-size: 0.9rem; }

.avail-row { display: flex; align-items: center; gap: 12px; padding: 10px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--card); }
.avail-row .dow { font-weight: 600; color: var(--primary); min-width: 90px; }

.empty { color: var(--faint); text-align: center; padding: 30px; font-size: 0.95rem; }
.hidden { display: none !important; }
.muted { color: var(--muted); }
.spinner { display: inline-block; width: 16px; height: 16px; border: 2px solid rgba(255,255,255,0.5); border-top-color: #fff; border-radius: 50%; animation: spin 0.7s linear infinite; vertical-align: -3px; }
@keyframes spin { to { transform: rotate(360deg); } }
.login-wrap { max-width: 420px; margin: 8vh auto 0; }

@media (max-width: 640px) {
  h1 { font-size: 1.6rem; }
  .field-row { grid-template-columns: 1fr; }
  .page { padding: 20px 14px 60px; }
}

/* Calendar */
.cal-legend { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 14px; font-size: 0.82rem; color: var(--muted); }
.cal-legend i { display: inline-block; width: 11px; height: 11px; border-radius: 3px; margin-right: 5px; vertical-align: -1px; }
.cal-legend i.open { background: var(--accent-soft); border: 1px solid #bae6fd; }
.cal-legend i.booked { background: var(--ok-bg); border: 1px solid #bbf7d0; }
.cal-legend i.pending { background: var(--warn-bg); border: 1px solid #fcd34d; }
.cal-legend i.blocked { background: #e2e8f0; border: 1px solid #cbd5e1; }
.cal-scroll { overflow-x: auto; padding-bottom: 4px; }
.cal-week-label { font-weight: 700; color: var(--primary); font-size: 0.88rem; margin: 20px 0 10px; }
.cal-week-label:first-child { margin-top: 0; }
.cal-grid {
  display: grid;
  grid-template-columns: 56px repeat(7, minmax(84px, 1fr));
  gap: 5px;
  min-width: 680px;
}
.cal-day-head { text-align: center; font-size: 0.8rem; font-weight: 700; color: var(--primary); padding-bottom: 4px; }
.cal-day-head .dnum { display: block; font-weight: 400; color: var(--faint); font-size: 0.72rem; }
.cal-time { font-size: 0.72rem; color: var(--faint); text-align: right; padding-right: 8px; display: flex; align-items: center; justify-content: flex-end; min-height: 42px; }
.cal-cell {
  min-height: 42px; border-radius: 8px; background: #f1f5f9;
  padding: 3px; display: flex; flex-direction: column; gap: 3px;
  transition: background 0.12s ease;
}
.cal-cell.addable { cursor: pointer; }
.cal-cell.addable:hover { background: #e2e8f0; }
.cal-cell.addable:hover::after { content: '+'; color: var(--faint); font-weight: 700; text-align: center; margin: auto; }
.cal-chip { font-size: 0.73rem; font-weight: 700; padding: 4px 5px; border-radius: 6px; text-align: center; white-space: nowrap; }
.cal-chip.open { background: var(--accent-soft); color: var(--accent-soft-text); cursor: pointer; }
.cal-chip.open:hover { background: #bae6fd; }
.cal-chip.booked { background: var(--ok-bg); color: var(--ok); cursor: pointer; }
.cal-chip.booked:hover { filter: brightness(0.96); }
.cal-chip.pending { background: var(--warn-bg); color: var(--warn); cursor: pointer; }
.cal-chip.pending:hover { filter: brightness(0.96); }
.cal-chip.blocked { background: #e2e8f0; color: var(--faint); text-decoration: line-through; cursor: pointer; }
.cal-chip.avail { background: var(--accent); color: #fff; cursor: pointer; }
.cal-chip.avail:hover { background: var(--accent-dark); }
.cal-chip .who { display: block; font-weight: 400; font-size: 0.66rem; overflow: hidden; text-overflow: ellipsis; }
.cal-nav { display: flex; align-items: center; gap: 12px; margin: 12px 0; }
.cal-nav span { font-weight: 700; color: var(--primary); }
.cal-grid .cal-chip { align-self: stretch; display: flex; flex-direction: column; justify-content: center; }

/* Modal */
.modal-overlay {
  position: fixed; inset: 0; z-index: 100; padding: 20px;
  background: rgba(15, 23, 42, 0.5);
  display: grid; place-items: center;
  animation: fade 0.12s ease;
}
.modal {
  background: #fff; border-radius: 16px; width: 100%; max-width: 520px;
  box-shadow: var(--shadow-lg); max-height: 88vh; display: flex; flex-direction: column;
  animation: pop 0.14s ease;
}
.modal-head { display: flex; align-items: center; justify-content: space-between; padding: 16px 20px; border-bottom: 1px solid var(--border); }
.modal-head h3 { margin: 0; font-size: 1.05rem; }
.modal-close { background: transparent; border: 0; font-size: 1.7rem; line-height: 1; color: var(--faint); cursor: pointer; padding: 0 4px; }
.modal-close:hover { color: var(--primary); }
.modal-body { padding: 18px 20px; overflow-y: auto; }
.modal-row { display: flex; justify-content: space-between; gap: 16px; padding: 7px 0; border-bottom: 1px solid #f1f5f9; font-size: 0.95rem; }
.modal-row:last-child { border-bottom: 0; }
.modal-row .k { color: var(--muted); flex-shrink: 0; }
.modal-row .v { font-weight: 600; color: var(--primary); text-align: right; word-break: break-word; }
@keyframes fade { from { opacity: 0; } }
@keyframes pop { from { transform: scale(0.97); opacity: 0; } }

.copy-row { display: flex; gap: 8px; margin-top: 12px; }
.copy-row input { flex: 1; font-family: inherit; font-size: 0.82rem; padding: 9px 11px; border: 1px solid var(--border); border-radius: 8px; background: #f8fafc; color: var(--muted); }