/* ══════════════════════════════════════════════════════════════════
   PK Design System v1.0 — Enterprise UI Components
   Used by: pk-core, pk-exam, pk-job, pk-game, pk-notice, pk-video,
            pk-lp-bridge, pk-pay, pk-cpt-ebook-seller, pk-pdf-ebook-seller
   ══════════════════════════════════════════════════════════════════ */

/* ── CSS Custom Properties ──────────────────────────────────────── */
:root {
  /* Primary palette */
  --pk-primary:       #6366f1;
  --pk-primary-light: #818cf8;
  --pk-primary-dark:  #4f46e5;
  --pk-primary-bg:    #eef2ff;

  /* Semantic colors */
  --pk-success:    #10b981;
  --pk-success-bg: #ecfdf5;
  --pk-warning:    #f59e0b;
  --pk-warning-bg: #fffbeb;
  --pk-danger:     #ef4444;
  --pk-danger-bg:  #fef2f2;
  --pk-info:       #3b82f6;
  --pk-info-bg:    #eff6ff;

  /* Neutral palette */
  --pk-bg:           #f8fafc;
  --pk-surface:      #ffffff;
  --pk-border:       #e2e8f0;
  --pk-border-light: #f1f5f9;
  --pk-text:         #1e293b;
  --pk-text-secondary: #64748b;
  --pk-text-muted:   #94a3b8;

  /* Shadows */
  --pk-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --pk-shadow:    0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --pk-shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
  --pk-shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --pk-shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);

  /* Typography */
  --pk-font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --pk-font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;

  /* Border radius */
  --pk-radius-sm: 6px;
  --pk-radius:    8px;
  --pk-radius-md: 12px;
  --pk-radius-lg: 16px;
  --pk-radius-xl: 24px;
  --pk-radius-full: 9999px;

  /* Transitions */
  --pk-transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --pk-transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Wrapper ─────────────────────────────────────────────────────── */
.pk-wrap {
  font-family: var(--pk-font-sans);
  color: var(--pk-text);
  line-height: 1.6;
}

/* ── Section Title ───────────────────────────────────────────────── */
.pk-section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--pk-text);
  margin: 0 0 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--pk-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ── Card Component ─────────────────────────────────────────────── */
.pk-card {
  background: var(--pk-surface);
  border: 1px solid var(--pk-border);
  border-radius: var(--pk-radius-md);
  box-shadow: var(--pk-shadow-sm);
  transition: box-shadow var(--pk-transition), border-color var(--pk-transition),
              transform var(--pk-transition);
  overflow: hidden;
}
.pk-card:hover {
  box-shadow: var(--pk-shadow-md);
  border-color: var(--pk-primary-light);
  transform: translateY(-2px);
}
.pk-card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--pk-border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--pk-bg);
}
.pk-card-body {
  padding: 20px;
}
.pk-card-footer {
  padding: 12px 20px;
  border-top: 1px solid var(--pk-border-light);
  background: var(--pk-bg);
}

/* ── Button Component ────────────────────────────────────────────── */
.pk-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: none;
  border-radius: var(--pk-radius);
  font-family: var(--pk-font-sans);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--pk-transition);
  text-decoration: none;
  line-height: 1.4;
  white-space: nowrap;
  -webkit-user-select: none;
  user-select: none;
}
.pk-btn:focus-visible {
  outline: 2px solid var(--pk-primary);
  outline-offset: 2px;
}
.pk-btn-primary {
  background: var(--pk-primary);
  color: #fff;
}
.pk-btn-primary:hover {
  background: var(--pk-primary-dark);
  color: #fff;
  box-shadow: var(--pk-shadow-md);
  transform: translateY(-1px);
}
.pk-btn-success {
  background: var(--pk-success);
  color: #fff;
}
.pk-btn-success:hover {
  background: #059669;
  color: #fff;
}
.pk-btn-danger {
  background: var(--pk-danger);
  color: #fff;
}
.pk-btn-danger:hover {
  background: #dc2626;
  color: #fff;
}
.pk-btn-warning {
  background: var(--pk-warning);
  color: #fff;
}
.pk-btn-outline {
  background: transparent;
  border: 1px solid var(--pk-border);
  color: var(--pk-text);
}
.pk-btn-outline:hover {
  border-color: var(--pk-primary);
  color: var(--pk-primary);
  background: var(--pk-primary-bg);
}
.pk-btn-ghost {
  background: transparent;
  color: var(--pk-text-secondary);
}
.pk-btn-ghost:hover {
  background: var(--pk-bg);
  color: var(--pk-text);
}
.pk-btn-sm { padding: 6px 12px; font-size: 13px; }
.pk-btn-lg { padding: 14px 28px; font-size: 16px; }
.pk-btn-xl { padding: 16px 36px; font-size: 17px; border-radius: var(--pk-radius-md); }
.pk-btn:disabled,
.pk-btn[disabled] {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none !important;
}

/* ── Form Components ─────────────────────────────────────────────── */
.pk-form-group { margin-bottom: 20px; }
.pk-label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--pk-text);
  margin-bottom: 6px;
}
.pk-label-required::after {
  content: ' *';
  color: var(--pk-danger);
}
.pk-input,
.pk-select,
.pk-textarea {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--pk-border);
  border-radius: var(--pk-radius);
  font-family: var(--pk-font-sans);
  font-size: 14px;
  color: var(--pk-text);
  background: var(--pk-surface);
  transition: border-color var(--pk-transition), box-shadow var(--pk-transition);
  box-sizing: border-box;
}
.pk-input:focus,
.pk-select:focus,
.pk-textarea:focus {
  outline: none;
  border-color: var(--pk-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}
.pk-input.pk-input-error { border-color: var(--pk-danger); }
.pk-input.pk-input-success { border-color: var(--pk-success); }
.pk-field-hint {
  font-size: 12px;
  color: var(--pk-text-muted);
  margin-top: 4px;
}
.pk-field-error {
  font-size: 12px;
  color: var(--pk-danger);
  margin-top: 4px;
}

/* ── Shared form/status utilities (used across pk-* frontend forms) ── */
.pk-form-row { margin-bottom: 14px; }
.pk-form-row label { display: block; font-size: 13px; font-weight: 600; color: var(--pk-text); margin-bottom: 4px; }
.pk-form-status { min-height: 1.2em; margin-bottom: 10px; font-size: 13px; }
.pk-success { color: var(--pk-success); }
.pk-error { color: var(--pk-danger); }
.pk-link-btn { background: none; border: none; color: var(--pk-primary); font-weight: 600; cursor: pointer; padding: 0; font-size: 14px; }
.pk-link-btn:hover { text-decoration: underline; }

/* ── Badge Component ─────────────────────────────────────────────── */
.pk-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  border-radius: var(--pk-radius-full);
  font-size: 12px;
  font-weight: 500;
  line-height: 1.6;
  white-space: nowrap;
}
.pk-badge-primary { background: var(--pk-primary-bg); color: var(--pk-primary); }
.pk-badge-success { background: var(--pk-success-bg); color: var(--pk-success); }
.pk-badge-warning { background: var(--pk-warning-bg); color: #92400e; }
.pk-badge-danger  { background: var(--pk-danger-bg);  color: var(--pk-danger); }
.pk-badge-info    { background: var(--pk-info-bg);    color: var(--pk-info); }
.pk-badge-neutral { background: var(--pk-border-light); color: var(--pk-text-secondary); }

/* ── Alert Component ─────────────────────────────────────────────── */
.pk-alert {
  padding: 14px 18px;
  border-radius: var(--pk-radius);
  font-size: 14px;
  line-height: 1.5;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 16px;
}
.pk-alert-success { background: var(--pk-success-bg); color: #065f46; border-left: 4px solid var(--pk-success); }
.pk-alert-warning { background: var(--pk-warning-bg); color: #92400e; border-left: 4px solid var(--pk-warning); }
.pk-alert-danger  { background: var(--pk-danger-bg);  color: #991b1b; border-left: 4px solid var(--pk-danger); }
.pk-alert-info    { background: var(--pk-info-bg);    color: #1e40af; border-left: 4px solid var(--pk-info); }

/* ── Empty State ─────────────────────────────────────────────────── */
.pk-empty {
  text-align: center;
  padding: 60px 20px;
  color: var(--pk-text-muted);
}
.pk-empty-icon  { font-size: 48px; margin-bottom: 16px; opacity: 0.5; display: block; }
.pk-empty-title { font-size: 18px; font-weight: 600; color: var(--pk-text-secondary); margin-bottom: 8px; }
.pk-empty-text  { font-size: 14px; line-height: 1.6; }

/* ── Loading Skeleton ────────────────────────────────────────────── */
.pk-skeleton {
  background: linear-gradient(90deg, var(--pk-border-light) 25%, var(--pk-bg) 50%, var(--pk-border-light) 75%);
  background-size: 200% 100%;
  animation: pk-shimmer 1.5s infinite;
  border-radius: var(--pk-radius);
}
@keyframes pk-shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}
.pk-skeleton-text  { height: 16px; margin-bottom: 8px; }
.pk-skeleton-title { height: 24px; margin-bottom: 12px; width: 60%; }
.pk-skeleton-card  { height: 200px; }

/* ── Loading Spinner ─────────────────────────────────────────────── */
.pk-spinner {
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 3px solid var(--pk-border);
  border-top-color: var(--pk-primary);
  border-radius: 50%;
  animation: pk-spin 0.8s linear infinite;
}
.pk-spinner-sm { width: 16px; height: 16px; border-width: 2px; }
.pk-spinner-lg { width: 36px; height: 36px; border-width: 4px; }
@keyframes pk-spin {
  to { transform: rotate(360deg); }
}

/* ── Grid Layout ─────────────────────────────────────────────────── */
.pk-grid   { display: grid; gap: 20px; }
.pk-grid-2 { grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); }
.pk-grid-3 { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.pk-grid-4 { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }

/* ── Progress Bar ────────────────────────────────────────────────── */
.pk-progress-track {
  width: 100%;
  background: var(--pk-border-light);
  border-radius: var(--pk-radius-full);
  height: 8px;
  overflow: hidden;
}
.pk-progress-fill {
  height: 100%;
  border-radius: var(--pk-radius-full);
  background: var(--pk-primary);
  transition: width var(--pk-transition-slow);
}
.pk-progress-fill.pk-progress-success { background: var(--pk-success); }
.pk-progress-fill.pk-progress-warning { background: var(--pk-warning); }
.pk-progress-fill.pk-progress-danger  { background: var(--pk-danger); }

/* ── Table Component ─────────────────────────────────────────────── */
.pk-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.pk-table th {
  background: var(--pk-primary);
  color: #fff;
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
}
.pk-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--pk-border-light);
  color: var(--pk-text);
}
.pk-table tr:last-child td { border-bottom: none; }
.pk-table tr:hover td { background: var(--pk-bg); }
.pk-table-wrap {
  border: 1px solid var(--pk-border);
  border-radius: var(--pk-radius-md);
  overflow: hidden;
  overflow-x: auto;
}

/* ── Pagination ──────────────────────────────────────────────────── */
.pk-pagination {
  display: flex;
  gap: 4px;
  justify-content: center;
  align-items: center;
  margin-top: 28px;
  flex-wrap: wrap;
}
.pk-page-btn {
  padding: 8px 14px;
  border: 1px solid var(--pk-border);
  border-radius: var(--pk-radius);
  background: var(--pk-surface);
  color: var(--pk-text);
  cursor: pointer;
  font-size: 14px;
  transition: all var(--pk-transition);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
}
.pk-page-btn:hover,
.pk-page-btn.active {
  background: var(--pk-primary);
  color: #fff;
  border-color: var(--pk-primary);
}

/* ── Stats/Metric Cards ──────────────────────────────────────────── */
.pk-stat-card {
  background: var(--pk-surface);
  border: 1px solid var(--pk-border);
  border-radius: var(--pk-radius-md);
  padding: 20px;
  text-align: center;
}
.pk-stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--pk-primary);
  line-height: 1.2;
}
.pk-stat-label {
  font-size: 13px;
  color: var(--pk-text-secondary);
  margin-top: 6px;
  font-weight: 500;
}

/* ── Auth Required State ─────────────────────────────────────────── */
.pk-auth-prompt {
  text-align: center;
  padding: 40px 20px;
  background: var(--pk-bg);
  border: 1px solid var(--pk-border);
  border-radius: var(--pk-radius-md);
}
.pk-auth-prompt p { color: var(--pk-text-secondary); margin-bottom: 16px; }

/* ── Responsive ──────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .pk-grid-2,
  .pk-grid-3,
  .pk-grid-4 { grid-template-columns: 1fr; }
  .pk-card-header { flex-direction: column; gap: 8px; align-items: flex-start; }
  .pk-section-title { font-size: 1.25rem; }
}
@media (max-width: 480px) {
  .pk-card-body { padding: 16px; }
  .pk-btn-lg { padding: 12px 20px; font-size: 15px; }
}