:root {
  --bg-deepest: #020b17;
  --bg-deep:    #030d1d;
  --bg-card:    #041826;
  --accent:         #1E88E5;
  --accent-dim:     rgba(30,136,229,0.12);
  --accent-border:  rgba(30,136,229,0.25);
  --accent-glow:    rgba(30,136,229,0.35);
  --green: #639922;
  --text-primary:   #fff;
  --text-secondary: rgba(255,255,255,0.68);
  --text-muted:     rgba(255,255,255,0.40);
  --text-micro:     rgba(255,255,255,0.25);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
}

/* ── Top bar ───────────────────────────────────────────── */
.bk-bar {
  background: var(--bg-deepest);
  border-bottom: 1px solid rgba(30,136,229,0.12);
  padding: 14px 0;
}
.bk-bar-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.bk-back {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
  flex-shrink: 0;
}
.bk-back:hover { color: var(--accent); }
.bk-bar-center {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 auto;
}
.bk-bar-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
.bk-bar-name { font-size: 0.9rem; font-weight: 700; color: var(--text-primary); }
.bk-bar-dur  { font-size: 0.75rem; color: var(--text-muted); }
.bk-teams-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--accent-dim);
  border: 1px solid var(--accent-border);
  border-radius: 4px;
  padding: 3px 9px;
  color: var(--accent);
  flex-shrink: 0;
}

/* ── Two-col layout ────────────────────────────────────── */
.bk-page { background: var(--bg-deepest); min-height: calc(100vh - 49px); }
.bk-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: calc(100vh - 49px);
}
.bk-left  { background: var(--bg-deep);    padding: 44px 48px; border-right: 1px solid rgba(255,255,255,0.05); }
.bk-right { background: var(--bg-deepest); padding: 44px 48px; }
@media (max-width: 900px) {
  .bk-layout { grid-template-columns: 1fr; }
  .bk-left, .bk-right { padding: 32px 20px; }
  .bk-right { border-top: 1px solid rgba(255,255,255,0.06); }
}

/* ── Meeting info ──────────────────────────────────────── */
.bk-mt-name { font-size: 1.3rem; font-weight: 900; color: var(--text-primary); letter-spacing: -0.02em; margin-bottom: 0.4rem; }
.bk-mt-desc { font-size: 0.84rem; line-height: 1.68; color: var(--text-secondary); margin-bottom: 1.5rem; }
.bk-info-row { display: flex; align-items: center; gap: 9px; font-size: 0.82rem; color: var(--text-secondary); margin-bottom: 7px; }
.bk-info-row svg { color: var(--accent); flex-shrink: 0; }

/* ── Timezone ──────────────────────────────────────────── */
.bk-tz-wrap { margin-top: 1.75rem; padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,0.06); }
.bk-label {
  font-size: 0.62rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  display: block;
  margin-bottom: 0.5rem;
}
.bk-label-spaced { margin-bottom: 0.75rem; }
.bk-tz-select {
  width: 100%;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 8px;
  padding: 9px 12px;
  font-size: 0.82rem;
  color: var(--text-primary);
  outline: none;
  appearance: none;
  cursor: pointer;
  transition: border-color 0.2s;
  font-family: inherit;
}
.bk-tz-select:focus { border-color: rgba(30,136,229,0.5); }
.bk-tz-hint { font-size: 0.7rem; color: var(--text-micro); margin-top: 5px; }

/* ── Calendar ──────────────────────────────────────────── */
.bk-cal-wrap { margin-top: 1.75rem; }
.bk-cal-nav { display: flex; align-items: center; justify-content: space-between; margin-bottom: 0.85rem; }
.bk-cal-month { font-size: 0.95rem; font-weight: 700; color: var(--text-primary); }
.bk-nav-btn {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 6px;
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.2s;
}
.bk-nav-btn:hover:not(:disabled) { background: var(--accent-dim); border-color: var(--accent-border); color: #fff; }
.bk-nav-btn:disabled { opacity: 0.25; cursor: not-allowed; }
.bk-cal-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 3px; }
.bk-dow { font-size: 0.62rem; font-weight: 700; text-align: center; color: var(--text-muted); padding: 5px 0; text-transform: uppercase; letter-spacing: 0.06em; }
.bk-day {
  aspect-ratio: 1;
  display: flex; align-items: center; justify-content: center;
  border-radius: 8px;
  font-size: 0.82rem; font-weight: 600;
  cursor: default;
  color: var(--text-muted);
  border: 1px solid transparent;
  transition: all 0.15s;
}
.bk-day.has-slots  { color: var(--text-primary); background: rgba(30,136,229,0.1); border-color: rgba(30,136,229,0.2); cursor: pointer; }
.bk-day.has-slots:hover { background: rgba(30,136,229,0.22); border-color: rgba(30,136,229,0.38); }
.bk-day.selected   { background: var(--accent) !important; color: #fff !important; border-color: var(--accent) !important; box-shadow: 0 4px 12px var(--accent-glow); }
.bk-day.today      { font-weight: 800; }
.bk-day.past       { opacity: 0.18; }
.bk-cal-loading    { text-align: center; padding: 1.5rem 0; color: var(--text-muted); font-size: 0.82rem; display: none; }
.bk-spinner        { width: 18px; height: 18px; border: 2px solid rgba(30,136,229,0.2); border-top-color: var(--accent); border-radius: 50%; animation: bk-spin 0.8s linear infinite; margin: 0 auto 6px; }

/* ── Time slots ────────────────────────────────────────── */
.bk-slots-wrap { margin-top: 1.5rem; }
.bk-slots-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  max-height: 210px;
  overflow-y: auto;
  padding-right: 3px;
}
.bk-slots-grid::-webkit-scrollbar { width: 3px; }
.bk-slots-grid::-webkit-scrollbar-thumb { background: rgba(30,136,229,0.3); border-radius: 2px; }
.bk-slot {
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 7px;
  padding: 9px 4px;
  text-align: center;
  font-size: 0.8rem; font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
}
.bk-slot:hover    { background: var(--accent-dim); border-color: var(--accent-border); color: #fff; }
.bk-slot.selected { background: var(--accent); border-color: var(--accent); color: #fff; box-shadow: 0 3px 10px var(--accent-glow); }
.bk-no-slots { text-align: center; padding: 1.5rem 0; color: var(--text-muted); font-size: 0.82rem; display: none; }

/* ── Form ──────────────────────────────────────────────── */
.bk-form-heading { font-size: 1.1rem; font-weight: 800; color: var(--text-primary); margin-bottom: 1.25rem; letter-spacing: -0.015em; }
.bk-slot-preview {
  background: rgba(30,136,229,0.08);
  border: 1px solid rgba(30,136,229,0.2);
  border-radius: 8px;
  padding: 10px 13px;
  margin-bottom: 14px;
  font-size: 0.83rem;
  color: var(--text-secondary);
  display: none;
}
.bk-slot-preview strong { color: var(--text-primary); }
.bk-field-group { margin-bottom: 11px; }
.bk-field {
  width: 100%;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 8px;
  padding: 11px 14px;
  font-size: 0.87rem;
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.2s, background 0.2s;
  font-family: inherit;
}
.bk-field::placeholder { color: rgba(255,255,255,0.22); }
.bk-field:focus  { border-color: rgba(30,136,229,0.5); background: rgba(30,136,229,0.04); }
.bk-field.error  { border-color: rgba(220,53,69,0.6); }
textarea.bk-field { resize: vertical; min-height: 86px; }
.bk-err { font-size: 0.72rem; color: #ef4444; margin-top: 4px; display: none; }
.bk-err-privacy-spaced { margin-top: -6px; margin-bottom: 10px; }
.bk-err-spaced { margin-bottom: 10px; }
.bk-privacy {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: rgba(255,255,255,0.02);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: 8px;
  padding: 11px 13px;
  margin-bottom: 13px;
  cursor: pointer;
}
.bk-privacy input { margin-top: 2px; flex-shrink: 0; accent-color: var(--accent); width: 15px; height: 15px; cursor: pointer; }
.bk-privacy label { font-size: 0.77rem; color: rgba(255,255,255,0.4); line-height: 1.5; cursor: pointer; }
.bk-privacy label a { color: var(--accent); text-decoration: none; }
.bk-submit {
  width: 100%;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 14px 20px;
  font-size: 0.92rem; font-weight: 700;
  cursor: pointer;
  transition: background 0.2s, transform 0.15s;
  display: flex; align-items: center; justify-content: center; gap: 8px;
  box-shadow: 0 4px 18px var(--accent-glow);
}
.bk-submit:hover:not(:disabled) { background: #1976d2; transform: translateY(-1px); }
.bk-submit:disabled { opacity: 0.6; cursor: not-allowed; }

/* ── Success state ─────────────────────────────────────── */
.bk-success { display: none; text-align: center; padding: 2rem 0; }
.bk-success-icon {
  width: 56px; height: 56px; border-radius: 50%;
  background: rgba(99,153,34,0.1);
  border: 1px solid rgba(99,153,34,0.25);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 1.25rem;
}
.bk-success-h2  { font-size: 1.3rem; font-weight: 800; color: var(--text-primary); margin-bottom: 0.5rem; }
.bk-success-sub { font-size: 0.87rem; color: var(--text-secondary); line-height: 1.65; margin-bottom: 1.5rem; }
.bk-detail-card {
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius-md);
  padding: 1.1rem;
  text-align: left;
  margin-bottom: 1.25rem;
}
.bk-detail-row { display: flex; align-items: flex-start; gap: 10px; margin-bottom: 8px; }
.bk-detail-row:last-child { margin-bottom: 0; }
.bk-detail-row svg { color: var(--accent); flex-shrink: 0; margin-top: 2px; }
.bk-detail-label { font-size: 0.68rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted); }
.bk-detail-val   { font-size: 0.88rem; font-weight: 600; color: var(--text-primary); }
.bk-teams-btn {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--accent); color: #fff !important;
  font-weight: 700; font-size: 0.9rem;
  padding: 13px 20px;
  border-radius: var(--radius-sm);
  text-decoration: none !important;
  margin-bottom: 8px;
  transition: background 0.2s;
  box-shadow: 0 4px 16px var(--accent-glow);
}
.bk-teams-btn:hover { background: #1976d2; }
.bk-action-row { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; }
.bk-action-link {
  font-size: 0.78rem; font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  padding: 8px 14px;
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-sm);
  transition: color 0.2s, border-color 0.2s;
}
.bk-action-link:hover { color: var(--accent); border-color: rgba(30,136,229,0.3); }

/* ── Slots panel visibility (was style="display:none;") ── */
.bk-hidden { display: none; }

/* ── Submit button loading spinner (was inline style on JS-injected div) ── */
.bk-btn-spinner {
  width: 16px; height: 16px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: bk-spin 0.8s linear infinite;
}

@keyframes bk-spin { to { transform: rotate(360deg); } }