:root {
  --bg: #f4f6f8;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --surface-3: #f1f5f9;
  --border: #e2e8f0;
  --border-2: #cbd5e1;
  --text: #1c2733;
  --muted: #64748b;
  --muted-2: #94a3b8;
  --accent: #2563eb;
  --accent-2: #1d4ed8;
  --error-bg: #fee2e2;
  --error-border: #fecaca;
  --error-text: #991b1b;
  --toast-bg: #1c2733;
  --toast-text: #ffffff;
  --shadow: rgba(0, 0, 0, 0.25);
  --badge-ch-bg: #dbeafe;
  --badge-ch-text: #1e40af;
  --badge-zn-bg: #fef3c7;
  --badge-zn-text: #92400e;
  --badge-kv-bg: #e2e8f0;
  --badge-kv-text: #334155;
  --badge-always-bg: #dcfce7;
  --badge-always-text: #166534;
  --badge-ch-active-bg: #2563eb;
  --badge-ch-active-text: #ffffff;
  --badge-zn-active-bg: #f59e0b;
  --badge-zn-active-text: #ffffff;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --surface: #1e293b;
  --surface-2: #24334a;
  --surface-3: #334155;
  --border: #334155;
  --border-2: #475569;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --muted-2: #64748b;
  --accent: #3b82f6;
  --accent-2: #2563eb;
  --error-bg: #7f1d1d;
  --error-border: #991b1b;
  --error-text: #fecaca;
  --toast-bg: #f8fafc;
  --toast-text: #1c2733;
  --shadow: rgba(0, 0, 0, 0.5);
  --badge-ch-bg: #1e3a5f;
  --badge-ch-text: #93c5fd;
  --badge-zn-bg: #4b3a10;
  --badge-zn-text: #fcd34d;
  --badge-kv-bg: #334155;
  --badge-kv-text: #cbd5e1;
  --badge-always-bg: #14532d;
  --badge-always-text: #86efac;
  --badge-ch-active-bg: #3b82f6;
  --badge-ch-active-text: #ffffff;
  --badge-zn-active-bg: #f59e0b;
  --badge-zn-active-text: #1c2733;
}

* { box-sizing: border-box; }

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

header {
  position: sticky;
  top: 0;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  z-index: 10;
}

h1 { font-size: 18px; margin: 0; }

.controls { display: flex; align-items: center; gap: 8px; }

#group-select {
  font-size: 15px;
  padding: 8px 12px;
  border: 1px solid var(--border-2);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  min-width: 180px;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 1px solid var(--border-2);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

.theme-toggle:hover { border-color: var(--accent); }

.theme-toggle .icon { width: 18px; height: 18px; }

.icon-sun { display: none; }
.icon-moon { display: block; }

[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

main { max-width: 900px; margin: 0 auto; padding: 20px; }

.schedule-title .badge {
  margin-left: 8px;
  font-size: 12px;
  vertical-align: middle;
}

.period .lessons {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  align-items: start;
}

@media (min-width: 1024px) {
  .period .lessons { grid-template-columns: 1fr 1fr; }
}

.error {
  background: var(--error-bg);
  color: var(--error-text);
  border: 1px solid var(--error-border);
  border-radius: 8px;
  padding: 12px 16px;
  margin-bottom: 16px;
}

.loading { color: var(--muted); text-align: center; padding: 24px; }

.hidden { display: none; }

.schedule-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.schedule-meta { color: var(--muted); font-size: 13px; margin-bottom: 20px; }

.day-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
}

.day-block.today { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }

.day-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.day-title { font-size: 15px; font-weight: 700; text-transform: capitalize; }

.today-badge {
  background: var(--accent);
  color: #fff;
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 999px;
}

.period {
  border-top: 1px solid var(--border);
  padding: 10px 0;
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 12px;
}

.period-num { font-weight: 600; color: var(--muted); }

.period-time { font-size: 13px; color: var(--muted); margin-top: 2px; }

.lesson {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  margin-bottom: 8px;
  background: var(--surface-2);
}

.lesson:last-child { margin-bottom: 0; }

.lesson .subject { font-weight: 600; font-size: 14px; }

.lesson .details { font-size: 13px; color: var(--muted); margin-top: 2px; }

.badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  padding: 1px 6px;
  border-radius: 4px;
  margin-right: 6px;
  vertical-align: 1px;
}

.badge-ch { background: var(--badge-ch-bg); color: var(--badge-ch-text); }
.badge-zn { background: var(--badge-zn-bg); color: var(--badge-zn-text); }
.badge-kv { background: var(--badge-kv-bg); color: var(--badge-kv-text); }
.badge-always { background: var(--badge-always-bg); color: var(--badge-always-text); }

.badge-ch.active { background: var(--badge-ch-active-bg); color: var(--badge-ch-active-text); }
.badge-zn.active { background: var(--badge-zn-active-bg); color: var(--badge-zn-active-text); }

.empty-day { color: var(--muted-2); font-size: 13px; }

.lesson.full { grid-column: 1 / -1; }

.lesson.empty {
  grid-column: 1 / -1;
  text-align: center;
  color: var(--muted);
  background: var(--surface-3);
  border: 1px dashed var(--border-2);
  font-weight: 600;
}

.window { border-style: dashed; color: var(--muted-2); background: var(--surface); }

.toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--toast-bg);
  color: var(--toast-text);
  padding: 12px 18px;
  border-radius: 10px;
  font-size: 13px;
  box-shadow: 0 4px 16px var(--shadow);
  z-index: 100;
  max-width: 90vw;
  text-align: center;
}