:root {
  --bg: #f6f7f9;
  --card-bg: #ffffff;
  --border: #d7dbe0;
  --text: #1f2530;
  --muted: #6b7280;
  --accent: #2563eb;
  --booking-bg: #dce3ec;
  --booking-border: #aab8c8;
  --gap-stripe: #e0554533;
  --gap-border: #c0392b;
}

* { box-sizing: border-box; }

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

/* Login */
.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}
.login-card {
  background: var(--card-bg);
  padding: 2.5rem 3rem;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  text-align: center;
  width: 320px;
}
.login-card h1 { margin: 0 0 0.25rem; }
.login-card .subtitle { color: var(--muted); margin: 0 0 1.5rem; }
.login-card form { display: flex; flex-direction: column; gap: 0.75rem; }
.login-card input {
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
}
.login-card button {
  padding: 0.6rem;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: white;
  font-size: 1rem;
  cursor: pointer;
}
.login-card .error { color: #c0392b; margin: 0; }

/* App layout */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
}
.topbar h1 { margin: 0; font-size: 1.25rem; }
.topbar-controls { display: flex; align-items: center; gap: 0.5rem; }
.topbar-controls select,
.topbar-controls button {
  padding: 0.4rem 0.7rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: white;
  cursor: pointer;
  font-size: 0.9rem;
}
.topbar-controls button:hover { background: #f0f2f5; }

main { padding: 1.5rem; }

.legend { display: flex; gap: 1.5rem; margin-bottom: 1rem; font-size: 0.85rem; color: var(--muted); }
.legend-item { display: inline-flex; align-items: center; gap: 0.4rem; }
.swatch { width: 14px; height: 14px; border-radius: 3px; display: inline-block; }
.swatch-booking { background: var(--booking-bg); border: 1px solid var(--booking-border); }
.swatch-gap { background: repeating-linear-gradient(45deg, var(--gap-border), var(--gap-border) 3px, transparent 3px, transparent 6px); border: 1px solid var(--gap-border); }
.swatch-session { background: #4a90d9; }

.hint { color: var(--muted); }

/* Week grid */
.week-grid-wrapper { background: var(--card-bg); border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.week-grid-header {
  display: grid;
  grid-template-columns: 56px repeat(7, 1fr);
  border-bottom: 1px solid var(--border);
  font-weight: 600;
  font-size: 0.85rem;
}
.week-grid-header > div { padding: 0.5rem; text-align: center; }
.week-grid-body { display: grid; grid-template-columns: 56px repeat(7, 1fr); }
.time-axis { position: relative; border-right: 1px solid var(--border); }
.time-axis .hour-label {
  position: absolute; right: 6px; transform: translateY(-50%);
  font-size: 0.7rem; color: var(--muted);
}
.day-column { position: relative; border-right: 1px solid var(--border); background-image: repeating-linear-gradient(to bottom, transparent, transparent calc(var(--px-per-hour) - 1px), #edf0f3 var(--px-per-hour)); }
.day-column:last-child { border-right: none; }

.block {
  position: absolute;
  left: 4px; right: 4px;
  border-radius: 4px;
  font-size: 0.72rem;
  padding: 2px 4px;
  overflow: hidden;
  line-height: 1.2;
}
.block-booking {
  background: var(--booking-bg);
  border: 1px solid var(--booking-border);
  color: #33404d;
  z-index: 1;
}
.block-gap {
  background: repeating-linear-gradient(45deg, var(--gap-border), var(--gap-border) 4px, #f8d7d3 4px, #f8d7d3 8px);
  border: 1px solid var(--gap-border);
  color: #7a1f14;
  z-index: 2;
  opacity: 0.85;
}
.block-session {
  left: 12px; right: 12px;
  color: white;
  z-index: 3;
  opacity: 0.8;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.15);
}

/* Dialogs */
dialog {
  border: none;
  border-radius: 10px;
  padding: 1.5rem;
  width: 620px;
  max-width: 90vw;
  box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}
dialog::backdrop { background: rgba(0,0,0,0.4); }
dialog h2 { margin-top: 0; }
dialog.dialog-form { width: 460px; }
dialog.dialog-form form { display: flex; flex-direction: column; gap: 0.9rem; }
dialog.dialog-form label { display: flex; flex-direction: column; gap: 0.35rem; font-size: 0.85rem; color: var(--muted); }
dialog.dialog-form select, dialog.dialog-form input {
  padding: 0.55rem 0.6rem; border: 1px solid var(--border); border-radius: 6px; font-size: 0.95rem; width: 100%;
}
dialog.dialog-form input[type="color"] { padding: 0.25rem; height: 2.4rem; }
dialog.dialog-form-wide { width: 560px; }
dialog.dialog-form-wide h3 { margin-bottom: 0.5rem; }
.form-actions { display: flex; gap: 0.5rem; margin-top: 0.5rem; }
.form-actions button { padding: 0.5rem 1rem; border-radius: 6px; border: 1px solid var(--border); cursor: pointer; }
.danger-zone { margin-top: 1.25rem; padding-top: 1rem; border-top: 1px solid var(--border); }
.btn-danger {
  padding: 0.5rem 1rem; border-radius: 6px; border: 1px solid #c0392b; color: #c0392b;
  background: white; cursor: pointer;
}
.btn-danger:hover { background: #fdecea; }
table { width: 100%; border-collapse: collapse; margin-bottom: 0.75rem; font-size: 0.85rem; }
table th, table td { text-align: left; padding: 0.35rem 0.4rem; border-bottom: 1px solid #eee; }
.count-hint { color: var(--muted); font-size: 0.78rem; }
table button { font-size: 0.75rem; padding: 0.2rem 0.5rem; cursor: pointer; }

#booking-form {
  display: flex; gap: 0.4rem; flex-wrap: wrap; align-items: center; margin-top: 0.5rem;
}
#booking-form input, #booking-form select {
  padding: 0.4rem; border: 1px solid var(--border); border-radius: 6px;
}
#booking-form button {
  padding: 0.4rem 0.8rem; border-radius: 6px; border: 1px solid var(--border); cursor: pointer;
}

#btn-add-department, #btn-add-session {
  margin-top: 0.5rem; padding: 0.4rem 0.9rem; border-radius: 6px; border: 1px solid var(--border);
  cursor: pointer; background: white;
}
#btn-add-department:disabled, #btn-add-session:disabled { opacity: 0.5; cursor: not-allowed; }

.dialog-close { margin-top: 1rem; padding: 0.4rem 1rem; border-radius: 6px; border: 1px solid var(--border); cursor: pointer; background: white; }