/* ==========================================================================
   CARDS.CSS — Card Component System
   CRM + HRMS Platform | Infusion Business Intelligence
   ==========================================================================
   Cards are the primary content container across the platform:
   dashboards, detail views, settings panels, stat summaries.
   
   Variants:
     .card              — default white card with border + shadow
     .card--flat        — no shadow, border only
     .card--elevated    — stronger shadow, for emphasis
     .card--interactive — hover lift effect, clickable
   
   Sub-components:
     .card-header  — title row with optional actions
     .card-body    — main content area
     .card-footer  — bottom row (pagination, actions, meta)
   
   Stat cards:
     .stat-card    — compact KPI card for dashboards
   ========================================================================== */

/* ------------------------------------------------------------------
   1. Base card
   ------------------------------------------------------------------ */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

/* ------------------------------------------------------------------
   2. Card header — title + actions row
   ------------------------------------------------------------------ */
.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--border-color);
}

.card-title {
  font-size: var(--text-md);
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
  margin: 0;
}

.card-subtitle {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-top: 2px;
}

.card-actions {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex-shrink: 0;
}

/* ------------------------------------------------------------------
   3. Card body — main content area
   ------------------------------------------------------------------ */
.card-body {
  padding: var(--space-3);
}

/* Compact body variant */
.card-body--compact {
  padding: var(--space-2);
}

/* No-padding variant (for tables, charts flush to edges) */
.card-body--flush {
  padding: 0;
}

/* ------------------------------------------------------------------
   4. Card footer — bottom row
   ------------------------------------------------------------------ */
.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-top: 1px solid var(--border-color);
  background: var(--content-bg);
}

/* ------------------------------------------------------------------
   5. Card variants
   ------------------------------------------------------------------ */

/* Flat — border only, no shadow */
.card--flat {
  box-shadow: none;
}

/* Elevated — stronger shadow for emphasis */
.card--elevated {
  box-shadow: var(--shadow-md);
}

/* Interactive — clickable card with hover lift */
.card--interactive {
  cursor: pointer;
  transition: box-shadow var(--transition-fast),
              transform var(--transition-fast);
}

.card--interactive:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card--interactive:active {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

/* ------------------------------------------------------------------
   6. Card grid — responsive card layout
   ------------------------------------------------------------------ */
.card-grid {
  display: grid;
  gap: var(--space-3);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .card-grid--2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .card-grid--3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1024px) {
  .card-grid--4 {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ------------------------------------------------------------------
   7. Stat card — compact KPI card for dashboards
      Used with Skeleton.stat() from SKILL 03
   ------------------------------------------------------------------ */
.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-2) var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-fast),
              transform var(--transition-fast);
}

.stat-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.stat-card-label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.stat-card-value {
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.stat-card-change {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: var(--text-sm);
  font-weight: 500;
}

.stat-card-change--up {
  color: var(--success);
}

.stat-card-change--down {
  color: var(--danger);
}

.stat-card-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}

/* Stat card with icon layout — horizontal */
.stat-card--horizontal {
  flex-direction: row;
  align-items: center;
}

.stat-card--horizontal .stat-card-content {
  flex: 1;
  min-width: 0;
}

.stat-card--horizontal .stat-card-icon {
  order: -1;
}

/* Stat grid */
.stat-grid {
  display: grid;
  gap: var(--space-2);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .stat-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .stat-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ------------------------------------------------------------------
   8. Empty state — shown inside cards when no data
      Matches PAGE-03 from RULES.md
   ------------------------------------------------------------------ */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-5) var(--space-3);
  text-align: center;
}

.empty-state__icon {
  font-size: 48px;
  margin-bottom: var(--space-2);
  opacity: 0.6;
}

.empty-state__text {
  font-size: var(--text-md);
  color: var(--text-muted);
  margin-bottom: var(--space-3);
  max-width: 320px;
}

/* ------------------------------------------------------------------
   9. Error state — shown inside cards on API failure
      Matches PAGE-04 from RULES.md
   ------------------------------------------------------------------ */
.error-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-5) var(--space-3);
  text-align: center;
}

.error-state__icon {
  font-size: 48px;
  margin-bottom: var(--space-2);
}

.error-state__text {
  font-size: var(--text-md);
  color: var(--danger);
  margin-bottom: var(--space-3);
  max-width: 360px;
}