/**
 * ResumaryAI Design System
 * Linear / Notion / Stripe / Vercel inspired — professional, minimal, unified SaaS
 * 
 * Usage: Add <link rel="stylesheet" href="css/design-system.css"> after Tailwind
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

/* ==========================================================================
   1. DESIGN TOKENS
   ========================================================================== */
:root {
  /* Colors */
  --ds-page-bg: #f8fafc;
  --ds-surface: #ffffff;
  --ds-surface-muted: #f1f5f9;
  --ds-border: rgba(148, 163, 184, 0.22);
  --ds-border-strong: rgba(148, 163, 184, 0.35);
  --ds-text-primary: #0f172a;
  --ds-text-secondary: #475569;
  --ds-text-muted: #64748b;
  --ds-brand: #4f46e5;
  --ds-brand-hover: #4338ca;
  --ds-success: #059669;
  --ds-warning: #d97706;
  --ds-danger: #dc2626;
  --ds-info: #0284c7;

  /* Spacing (4px base) */
  --ds-space-1: 4px;
  --ds-space-2: 8px;
  --ds-space-3: 12px;
  --ds-space-4: 16px;
  --ds-space-5: 20px;
  --ds-space-6: 24px;
  --ds-space-8: 32px;
  --ds-space-10: 40px;
  --ds-space-12: 48px;

  /* Radius */
  --ds-radius-sm: 8px;
  --ds-radius-md: 12px;
  --ds-radius-lg: 16px;
  --ds-radius-xl: 20px;
  --ds-radius-2xl: 24px;

  /* Shadow - subtle only */
  --ds-shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --ds-shadow-md: 0 4px 12px rgba(15, 23, 42, 0.06);
  --ds-shadow-lg: 0 10px 35px rgba(15, 23, 42, 0.08);

  /* Layout */
  --ds-max-content: 1200px;
  --ds-sidebar-width: 272px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ds-page-bg: #0f172a;
    --ds-surface: rgba(15, 23, 42, 0.82);
    --ds-surface-muted: rgba(30, 41, 59, 0.6);
    --ds-border: rgba(148, 163, 184, 0.18);
    --ds-border-strong: rgba(148, 163, 184, 0.28);
    --ds-text-primary: #f8fafc;
    --ds-text-secondary: #cbd5e1;
    --ds-text-muted: #94a3b8;
    --ds-brand: #6366f1;
    --ds-brand-hover: #818cf8;
  }
}

/* ==========================================================================
   2. BASE
   ========================================================================== */
.ds-body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ds-text-primary);
  background: var(--ds-page-bg);
}

/* ==========================================================================
   3. TYPOGRAPHY
   ========================================================================== */
.ds-page-title {
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--ds-text-primary);
}

.ds-section-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--ds-text-primary);
}

.ds-panel-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ds-text-primary);
}

.ds-body {
  font-size: 14px;
  color: var(--ds-text-secondary);
}

.ds-caption {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ds-text-muted);
}

.ds-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ds-text-muted);
}

/* ==========================================================================
   4. LAYOUT
   ========================================================================== */
.ds-shell {
  display: grid;
  grid-template-columns: var(--ds-sidebar-width) minmax(0, 1fr);
  min-height: 100vh;
}

@media (max-width: 1024px) {
  .ds-shell,
  .shell {
    grid-template-columns: 1fr;
  }
  .ds-sidebar,
  .sidebar {
    display: none;
  }
}

/* App layout aliases (shell + sidebar used by dashboard, applications, etc.) */
.shell {
  display: grid;
  grid-template-columns: 272px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  background: rgba(255, 255, 255, 0.7);
  border-right: 1px solid var(--ds-border);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

@media (prefers-color-scheme: dark) {
  .sidebar {
    background: rgba(2, 6, 23, 0.76);
    border-right-color: rgba(148, 163, 184, 0.18);
  }
}

.nav-item {
  transition: all 0.18s ease;
}

.nav-item:hover {
  transform: translateX(4px);
  background: rgba(255, 255, 255, 0.7);
}

@media (prefers-color-scheme: dark) {
  .nav-item:hover {
    background: rgba(148, 163, 184, 0.12);
  }
}

.ds-main {
  min-width: 0;
  overflow-y: auto;
}

.ds-content {
  max-width: var(--ds-max-content);
  margin: 0 auto;
  padding: var(--ds-space-6) var(--ds-space-6);
}

@media (min-width: 1024px) {
  .ds-content {
    padding: var(--ds-space-8) var(--ds-space-8);
  }
}

/* ==========================================================================
   5. SIDEBAR
   ========================================================================== */
.ds-sidebar {
  background: rgba(255, 255, 255, 0.7);
  border-right: 1px solid var(--ds-border);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  display: flex;
  flex-direction: column;
}

@media (prefers-color-scheme: dark) {
  .ds-sidebar {
    background: rgba(2, 6, 23, 0.76);
  }
}

.ds-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: var(--ds-radius-lg);
  font-size: 14px;
  line-height: 1.4;
  color: var(--ds-text-secondary);
  transition: all 0.18s ease;
}

.ds-nav-item:hover {
  background: rgba(255, 255, 255, 0.7);
  color: var(--ds-text-primary);
  transform: translateX(4px);
}

@media (prefers-color-scheme: dark) {
  .ds-nav-item {
    color: #cbd5e1;
  }
  .ds-nav-item:hover {
    background: rgba(148, 163, 184, 0.15);
    color: #f9fafb;
  }
}

.ds-nav-item.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  font-weight: 500;
}

/* ==========================================================================
   6. SURFACES (replaces heavy cards)
   ========================================================================== */
.ds-surface {
  background: var(--ds-surface);
  border: 1px solid var(--ds-border);
  border-radius: var(--ds-radius-2xl);
  box-shadow: var(--ds-shadow-lg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.ds-surface-strong {
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid var(--ds-border);
  border-radius: 28px;
  box-shadow: 0 24px 80px rgba(79, 70, 229, 0.14);
}

@media (prefers-color-scheme: dark) {
  .ds-surface {
    background: rgba(15, 23, 42, 0.78);
    box-shadow: 0 14px 36px rgba(2, 6, 23, 0.28);
  }
  .ds-surface-strong {
    background: rgba(15, 23, 42, 0.92);
    box-shadow: 0 24px 70px rgba(2, 6, 23, 0.34);
  }
}

.ds-panel {
  background: rgba(248, 250, 252, 0.8);
  border: 1px solid var(--ds-border);
  border-radius: var(--ds-radius-xl);
}

@media (prefers-color-scheme: dark) {
  .ds-panel {
    background: rgba(15, 23, 42, 0.64);
  }
}

/* ==========================================================================
   7. BUTTONS
   ========================================================================== */
.ds-btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  color: white;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  border-radius: var(--ds-radius-lg);
  cursor: pointer;
  transition: opacity 0.2s;
}

.ds-btn-primary:hover:not(:disabled) {
  opacity: 0.92;
}

.ds-btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.ds-btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ds-text-secondary);
  background: var(--ds-surface);
  border: 1px solid var(--ds-border);
  border-radius: var(--ds-radius-lg);
  cursor: pointer;
  transition: all 0.18s;
}

.ds-btn-secondary:hover {
  background: var(--ds-surface-muted);
  border-color: var(--ds-border-strong);
}

.ds-btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ds-text-secondary);
  background: transparent;
  border: none;
  border-radius: var(--ds-radius-md);
  cursor: pointer;
  transition: all 0.18s;
}

.ds-btn-ghost:hover {
  background: var(--ds-surface-muted);
  color: var(--ds-text-primary);
}

/* ==========================================================================
   8. INPUTS
   ========================================================================== */
.ds-input {
  width: 100%;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--ds-text-primary);
  background: var(--ds-surface);
  border: 1px solid var(--ds-border);
  border-radius: var(--ds-radius-lg);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.ds-input::placeholder {
  color: var(--ds-text-muted);
}

.ds-input:focus {
  border-color: var(--ds-brand);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.ds-search-bar {
  width: 100%;
  padding: 12px 16px 12px 44px;
  font-size: 14px;
  color: var(--ds-text-primary);
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--ds-border);
  border-radius: var(--ds-radius-lg);
  outline: none;
}

.ds-search-bar:focus {
  border-color: var(--ds-brand);
  box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.14);
}

@media (prefers-color-scheme: dark) {
  .ds-input,
  .ds-search-bar {
    background: rgba(15, 23, 42, 0.72);
    border-color: rgba(148, 163, 184, 0.18);
  }
}

/* ==========================================================================
   9. BADGES
   ========================================================================== */
.ds-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 999px;
  border: 1px solid var(--ds-border);
  background: rgba(255, 255, 255, 0.78);
}

@media (prefers-color-scheme: dark) {
  .ds-badge {
    background: rgba(15, 23, 42, 0.72);
  }
}

.ds-badge-success {
  background: rgba(5, 150, 105, 0.12);
  border-color: rgba(5, 150, 105, 0.3);
  color: var(--ds-success);
}

.ds-badge-warning {
  background: rgba(217, 119, 6, 0.12);
  border-color: rgba(217, 119, 6, 0.3);
  color: var(--ds-warning);
}

.ds-badge-danger {
  background: rgba(220, 38, 38, 0.12);
  border-color: rgba(220, 38, 38, 0.3);
  color: var(--ds-danger);
}

/* ==========================================================================
   10. TABLES
   ========================================================================== */
.ds-table-shell {
  overflow: hidden;
}

.ds-table-row {
  border-top: 1px solid rgba(226, 232, 240, 0.8);
  transition: background 0.15s;
}

.ds-table-row:hover {
  background: rgba(248, 250, 252, 0.9);
}

@media (prefers-color-scheme: dark) {
  .ds-table-row {
    border-top-color: rgba(148, 163, 184, 0.12);
  }
  .ds-table-row:hover {
    background: rgba(15, 23, 42, 0.66);
  }
}

.ds-table-th {
  padding: 16px 24px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ds-text-muted);
  text-align: left;
}

.ds-table-td {
  padding: 20px 24px;
  font-size: 14px;
  color: var(--ds-text-primary);
}

/* ==========================================================================
   11. PROGRESS
   ========================================================================== */
.ds-progress-track {
  height: 8px;
  background: rgba(148, 163, 184, 0.18);
  border-radius: 999px;
  overflow: hidden;
}

.ds-progress-bar {
  height: 100%;
  border-radius: 999px;
  transition: width 0.45s ease;
}

/* ==========================================================================
   12. METRIC TILE (lightweight, not heavy card)
   ========================================================================== */
.ds-metric-tile {
  border: 1px solid var(--ds-border);
  background: rgba(255, 255, 255, 0.68);
  border-radius: var(--ds-radius-xl);
  padding: 16px 20px;
}

@media (prefers-color-scheme: dark) {
  .ds-metric-tile {
    background: rgba(15, 23, 42, 0.72);
  }
}

/* ==========================================================================
   13. EMPTY STATE
   ========================================================================== */
.ds-empty {
  text-align: center;
  padding: 48px 24px;
}

.ds-empty-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 16px;
  border-radius: var(--ds-radius-lg);
  background: var(--ds-surface-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ds-text-muted);
}

.ds-empty-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ds-text-primary);
  margin-bottom: 4px;
}

.ds-empty-desc {
  font-size: 14px;
  color: var(--ds-text-muted);
}

/* ==========================================================================
   14. DIVIDER
   ========================================================================== */
.ds-divider {
  border-top: 1px solid var(--ds-border);
  margin: 32px 0;
}

/* ==========================================================================
   15. UTILITY CLASSES (preserve for existing gradients)
   ========================================================================== */
.ds-gradient-bg {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.ds-gradient-blue {
  background: linear-gradient(135deg, #4facfe 0%, #00c6ff 100%);
}

.ds-gradient-green {
  background: linear-gradient(135deg, #22c55e 0%, #14b8a6 100%);
}

.ds-gradient-purple {
  background: linear-gradient(135deg, #8b5cf6 0%, #ec4899 100%);
}

.ds-gradient-orange {
  background: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
}

/* ==========================================================================
   16. GRID LAYOUTS
   ========================================================================== */
.ds-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.95fr);
  gap: 24px;
}

.ds-content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(300px, 0.85fr);
  gap: 24px;
}

@media (max-width: 1200px) {
  .ds-hero-grid,
  .ds-content-grid {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   17. PILL (for usage display, etc.)
   ========================================================================== */
.ds-pill {
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px solid var(--ds-border);
  background: rgba(255, 255, 255, 0.78);
  font-size: 13px;
  font-weight: 500;
  color: var(--ds-text-secondary);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.ds-pill:hover {
  background: rgba(248, 250, 252, 0.95);
  color: var(--ds-text-primary);
}

.ds-pill-active {
  background: var(--ds-text-primary);
  color: #fff;
  border-color: var(--ds-text-primary);
}

.ds-pill-active:hover {
  background: var(--ds-text-primary);
  color: #fff;
}

@media (prefers-color-scheme: dark) {
  .ds-pill {
    background: rgba(15, 23, 42, 0.72);
    color: var(--ds-text-secondary);
  }
  .ds-pill:hover {
    background: rgba(30, 41, 59, 0.9);
    color: var(--ds-text-primary);
  }
  .ds-pill-active {
    background: #f8fafc;
    color: #0f172a;
    border-color: #f8fafc;
  }
  .ds-pill-active:hover {
    background: #f8fafc;
    color: #0f172a;
  }
}