:root {
  --tg-bg: var(--tg-theme-bg-color, #ffffff);
  --tg-text: var(--tg-theme-text-color, #1c1c1e);
  --tg-hint: var(--tg-theme-hint-color, #8e8e93);
  --tg-link: var(--tg-theme-link-color, #2481cc);
  --tg-button: var(--tg-theme-button-color, #2481cc);
  --tg-button-text: var(--tg-theme-button-text-color, #ffffff);
  --tg-secondary-bg: var(--tg-theme-secondary-bg-color, #f2f2f7);
  --card-radius: 14px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--tg-secondary-bg);
  color: var(--tg-text);
  padding-bottom: 72px;
}

.screen { display: none; padding: 16px; }
.screen.active { display: block; }

.topbar {
  padding: 16px 16px 8px;
  font-size: 20px;
  font-weight: 600;
}

.card {
  background: var(--tg-bg);
  border-radius: var(--card-radius);
  padding: 16px;
  margin-bottom: 12px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.card-title { font-size: 13px; color: var(--tg-hint); margin-bottom: 6px; }
.card-value { font-size: 17px; font-weight: 600; }

.quick-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

.quick-btn {
  flex: 1;
  background: var(--tg-secondary-bg);
  border: none;
  border-radius: 10px;
  padding: 10px 6px;
  font-size: 12px;
  color: var(--tg-text);
}

.btn-primary {
  width: 100%;
  background: var(--tg-button);
  color: var(--tg-button-text);
  border: none;
  border-radius: 10px;
  padding: 12px;
  font-size: 15px;
  font-weight: 600;
}

.list-item {
  background: var(--tg-bg);
  border-radius: var(--card-radius);
  padding: 12px 16px;
  margin-bottom: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.list-item .meta { font-size: 13px; color: var(--tg-hint); }

.status-badge {
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 20px;
  background: var(--tg-secondary-bg);
}
.status-scheduled { color: #2481cc; }
.status-completed { color: #34c759; }
.status-cancelled { color: #ff3b30; }
.status-rescheduled { color: #ff9500; }

.tabbar {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  display: flex;
  background: var(--tg-bg);
  border-top: 1px solid var(--tg-secondary-bg);
}

.tab-btn {
  flex: 1;
  padding: 10px 4px;
  background: none;
  border: none;
  font-size: 11px;
  color: var(--tg-hint);
}
.tab-btn.active { color: var(--tg-link); font-weight: 600; }

.student-switch {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  margin-bottom: 12px;
}

.student-chip {
  padding: 6px 12px;
  border-radius: 20px;
  background: var(--tg-secondary-bg);
  font-size: 13px;
  white-space: nowrap;
  border: none;
}
.student-chip.active { background: var(--tg-button); color: var(--tg-button-text); }

.empty-state { text-align: center; color: var(--tg-hint); padding: 40px 16px; font-size: 14px; }

.toggle-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid var(--tg-secondary-bg);
}
.toggle-row:last-child { border-bottom: none; }

.switch { position: relative; width: 44px; height: 26px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute; cursor: pointer; inset: 0;
  background: var(--tg-hint); border-radius: 26px; transition: .2s;
}
.slider:before {
  content: ""; position: absolute; height: 20px; width: 20px;
  left: 3px; bottom: 3px; background: #fff; border-radius: 50%; transition: .2s;
}
input:checked + .slider { background: var(--tg-button); }
input:checked + .slider:before { transform: translateX(18px); }

.loader { text-align: center; padding: 24px; color: var(--tg-hint); font-size: 13px; }
.error-banner {
  background: #ffe5e5; color: #d70015; padding: 10px 12px;
  border-radius: 10px; font-size: 13px; margin-bottom: 12px;
}