/* ==========================================================
   UI Library — a small, consistent CSS component library.
   All styling in the project uses only the classes below
   (prefix: ui-). Design tokens live in :root.
   ========================================================== */

/* ---------- Design tokens ---------- */
:root {
  --ui-bg: #f3f5f9;
  --ui-surface: #ffffff;
  --ui-text: #1f2937;
  --ui-muted: #6b7280;
  --ui-border: #d9dee7;
  --ui-primary: #4f46e5;
  --ui-primary-dark: #4338ca;
  --ui-danger: #dc2626;
  --ui-danger-soft: #fee2e2;
  --ui-success: #15803d;
  --ui-success-soft: #dcfce7;
  --ui-warning: #b45309;
  --ui-warning-soft: #fef3c7;
  --ui-radius: 10px;
  --ui-gap: 16px;
  --ui-shadow: 0 1px 3px rgba(16, 24, 40, 0.08), 0 1px 2px rgba(16, 24, 40, 0.06);
  --ui-font: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }

.ui-body {
  margin: 0;
  font-family: var(--ui-font);
  background: var(--ui-bg);
  color: var(--ui-text);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- Layout ---------- */
.ui-container {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 20px;
}

.ui-stack {
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding-top: 24px;
  padding-bottom: 40px;
  flex: 1;
}

.ui-grid { display: grid; gap: var(--ui-gap); }
.ui-grid-2 { grid-template-columns: repeat(2, 1fr); }
.ui-grid-3 { grid-template-columns: repeat(3, 1fr); }

@media (max-width: 760px) {
  .ui-grid-2, .ui-grid-3 { grid-template-columns: 1fr; }
}

/* ---------- Header / Footer ---------- */
.ui-header {
  background: var(--ui-primary);
  color: #fff;
  padding: 28px 0;
}
.ui-title { margin: 0; font-size: 1.9rem; }
.ui-subtitle { margin: 4px 0 0; opacity: 0.9; }

.ui-footer {
  padding: 16px 0;
  color: var(--ui-muted);
  font-size: 0.85rem;
  text-align: center;
  border-top: 1px solid var(--ui-border);
}

/* ---------- Card ---------- */
.ui-card {
  background: var(--ui-surface);
  border: 1px solid var(--ui-border);
  border-radius: var(--ui-radius);
  box-shadow: var(--ui-shadow);
  padding: 20px;
}
.ui-card-title { margin: 0 0 16px; font-size: 1.15rem; }

/* ---------- Stat (summary) ---------- */
.ui-stat { display: flex; flex-direction: column; gap: 4px; }
.ui-stat-label {
  color: var(--ui-muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.ui-stat-value { font-size: 2.4rem; font-weight: 700; color: var(--ui-primary); }
.ui-stat-danger .ui-stat-value { color: var(--ui-danger); }

/* ---------- Form ---------- */
.ui-field { display: flex; flex-direction: column; gap: 6px; }
.ui-field-action { justify-content: flex-end; }
.ui-label { font-size: 0.9rem; font-weight: 600; }

.ui-input {
  width: 100%;
  padding: 10px 12px;
  font: inherit;
  color: var(--ui-text);
  background: #fff;
  border: 1px solid var(--ui-border);
  border-radius: 8px;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.ui-input:focus {
  outline: none;
  border-color: var(--ui-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.2);
}
.ui-input-invalid { border-color: var(--ui-danger); }

.ui-error {
  color: var(--ui-danger);
  font-size: 0.82rem;
  min-height: 1.2em;
}

/* ---------- Buttons ---------- */
.ui-btn {
  font: inherit;
  font-weight: 600;
  padding: 10px 16px;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}
.ui-btn:active { transform: translateY(1px); }
.ui-btn-primary { background: var(--ui-primary); color: #fff; }
.ui-btn-primary:hover { background: var(--ui-primary-dark); }
.ui-btn-success { background: var(--ui-success-soft); color: var(--ui-success); }
.ui-btn-success:hover { background: #bbf7d0; }
.ui-btn-danger { background: var(--ui-danger-soft); color: var(--ui-danger); }
.ui-btn-danger:hover { background: #fecaca; }
.ui-btn-sm { padding: 6px 10px; font-size: 0.85rem; }
.ui-actions { display: flex; gap: 6px; flex-wrap: wrap; }

/* ---------- Table ---------- */
.ui-table-wrap { overflow-x: auto; }
.ui-table { width: 100%; border-collapse: collapse; min-width: 720px; }
.ui-table th, .ui-table td {
  text-align: left;
  padding: 12px 10px;
  border-bottom: 1px solid var(--ui-border);
  vertical-align: middle;
}
.ui-table th {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ui-muted);
}
.ui-table tbody tr:hover { background: #f9fafb; }
.ui-row-overdue { background: #fff7f7; }

/* ---------- Badges ---------- */
.ui-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
}
.ui-badge-success { background: var(--ui-success-soft); color: var(--ui-success); }
.ui-badge-danger { background: var(--ui-danger-soft); color: var(--ui-danger); }
.ui-badge-warning { background: var(--ui-warning-soft); color: var(--ui-warning); }

/* ---------- Misc ---------- */
.ui-empty { margin: 16px 0 0; text-align: center; color: var(--ui-muted); }
.ui-hidden { display: none; }