:root {
  --app-sidebar: 260px;
  --app-topbar: 64px;
  --app-primary: #2563eb;
  --app-primary-600: #1d4ed8;
  --app-primary-700: #1e40af;
  --app-bg: #f8fafc;
  --app-card: #ffffff;
  --app-surface: #ffffff;
  --app-border: #e2e8f0;
  --app-text: #0f172a;
  --app-muted: #64748b;
  --app-success: #10b981;
  --app-warning: #f59e0b;
  --app-danger: #ef4444;
  --app-info: #3b82f6;
  --app-shadow: 0 10px 30px -5px rgba(15, 23, 42, 0.08);
  --app-shadow-sm: 0 4px 12px rgba(15, 23, 42, 0.04);
}

html[data-theme="dark"] {
  --app-bg: #0b1120;
  --app-card: #0f172a;
  --app-surface: #111827;
  --app-border: #1e293b;
  --app-text: #e2e8f0;
  --app-muted: #94a3b8;
  --app-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.45);
  --app-shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.25);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--app-bg);
  color: var(--app-text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--app-primary-600); text-decoration: none; }
a:hover { color: var(--app-primary-700); }

#app {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.app-sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--app-sidebar);
  background: var(--app-card);
  border-right: 1px solid var(--app-border);
  z-index: 50;
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform .25s ease;
}
.app-sidebar.open { transform: translateX(0); }

.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 40;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease;
}
.sidebar-backdrop.open { opacity: 1; pointer-events: auto; }

@media (min-width: 1024px) {
  .app-sidebar { transform: translateX(0); }
  .sidebar-backdrop { display: none; }
  .app-main { margin-left: var(--app-sidebar); }
}

.sidebar-header {
  height: var(--app-topbar);
  display: flex;
  align-items: center;
  padding: 0 1.25rem;
  border-bottom: 1px solid var(--app-border);
  gap: .75rem;
}

.sidebar-header img {
  height: 32px;
  width: 32px;
  object-fit: contain;
}

.sidebar-brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--app-text);
  line-height: 1.2;
}

.sidebar-search {
  padding: .75rem 1rem;
  border-bottom: 1px solid var(--app-border);
}

.sidebar-search input {
  width: 100%;
  border: 1px solid var(--app-border);
  background: var(--app-bg);
  color: var(--app-text);
  border-radius: .6rem;
  padding: .5rem .75rem;
  font-size: .9rem;
}

.sidebar-search input:focus {
  outline: 0;
  border-color: var(--app-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, .12);
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: .75rem 0;
}

.sidebar-section {
  margin: .25rem 0;
}

.sidebar-section-title {
  padding: .4rem 1.25rem;
  font-size: .7rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--app-muted);
  font-weight: 600;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .55rem 1rem;
  margin: 0 .75rem;
  border-radius: .6rem;
  color: var(--app-text);
  font-size: .92rem;
  font-weight: 500;
  transition: background .15s, color .15s;
}

.sidebar-link:hover {
  background: rgba(37, 99, 235, .08);
  color: var(--app-primary-600);
}

.sidebar-link.active {
  background: var(--app-primary);
  color: #fff;
  box-shadow: 0 6px 16px rgba(37, 99, 235, .22);
}

.sidebar-link svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: .85;
}

.sidebar-link.active svg { opacity: 1; }

.sidebar-footer {
  padding: 1rem;
  border-top: 1px solid var(--app-border);
  font-size: .8rem;
  color: var(--app-muted);
  text-align: center;
}

/* Topbar */
.app-topbar {
  height: var(--app-topbar);
  background: var(--app-card);
  border-bottom: 1px solid var(--app-border);
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.25rem;
}

.topbar-left, .topbar-right { display: flex; align-items: center; gap: .75rem; }

.topbar-toggle {
  background: transparent;
  border: 0;
  color: var(--app-muted);
  cursor: pointer;
  padding: .5rem;
  border-radius: .5rem;
  display: flex;
}
.topbar-toggle:hover { background: var(--app-bg); color: var(--app-text); }

.topbar-search {
  display: none;
  position: relative;
}
@media (min-width: 768px) {
  .topbar-search { display: block; }
}
.topbar-search input {
  width: 320px;
  border: 1px solid var(--app-border);
  background: var(--app-bg);
  color: var(--app-text);
  border-radius: .6rem;
  padding: .5rem .75rem .5rem 2.25rem;
  font-size: .9rem;
}
.topbar-search svg {
  position: absolute;
  left: .75rem;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--app-muted);
}

.topbar-action {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: .6rem;
  background: transparent;
  border: 0;
  color: var(--app-muted);
  cursor: pointer;
}
.topbar-action:hover { background: var(--app-bg); color: var(--app-text); }

.topbar-badge {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--app-danger);
  border: 2px solid var(--app-card);
}

.topbar-profile {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .35rem .6rem;
  border-radius: .6rem;
  border: 1px solid var(--app-border);
  background: var(--app-surface);
  color: var(--app-text);
  font-size: .9rem;
  font-weight: 500;
  cursor: pointer;
}
.topbar-profile:hover { background: var(--app-bg); }

.avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--app-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: .85rem;
}

/* Main content */
.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.app-content {
  flex: 1;
  padding: 1.25rem;
  overflow-x: hidden;
}

@media (min-width: 768px) {
  .app-content { padding: 1.75rem; }
}

.page-title {
  font-size: 1.45rem;
  font-weight: 700;
  margin: 0 0 .25rem;
  letter-spacing: -0.02em;
}

.page-subtitle {
  color: var(--app-muted);
  font-size: .95rem;
  margin: 0 0 1.5rem;
}

/* Card improvements */
.card {
  background: var(--app-card);
  border: 1px solid var(--app-border);
  border-radius: 1rem;
  box-shadow: var(--app-shadow-sm);
}

.card-header {
  background: transparent;
  border-bottom: 1px solid var(--app-border);
  padding: 1rem 1.25rem;
  font-weight: 600;
}

.card-body { padding: 1.25rem; }

/* Stat cards */
.stat-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--app-card);
  border: 1px solid var(--app-border);
  border-radius: 1rem;
  box-shadow: var(--app-shadow-sm);
  transition: transform .15s, box-shadow .15s;
}
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--app-shadow); }

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: .85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.stat-icon svg { width: 24px; height: 24px; }

.stat-icon.blue { background: rgba(37, 99, 235, .1); color: var(--app-primary); }
.stat-icon.green { background: rgba(16, 185, 129, .1); color: var(--app-success); }
.stat-icon.amber { background: rgba(245, 158, 11, .1); color: var(--app-warning); }
.stat-icon.red { background: rgba(239, 68, 68, .1); color: var(--app-danger); }

.stat-value { font-size: 1.65rem; font-weight: 700; line-height: 1.2; }
.stat-label { font-size: .85rem; color: var(--app-muted); }

/* Grid */
.app-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(1, 1fr);
}
@media (min-width: 640px) { .app-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .app-grid { grid-template-columns: repeat(4, 1fr); } }

.app-grid-3 {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(1, 1fr);
}
@media (min-width: 768px) { .app-grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1280px) { .app-grid-3 { grid-template-columns: repeat(3, 1fr); } }

.app-grid-2 {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}
@media (min-width: 768px) { .app-grid-2 { grid-template-columns: repeat(2, 1fr); } }

/* Tables */
.app-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--app-card);
  border-radius: 1rem;
  overflow: hidden;
  font-size: .92rem;
}

.app-table th,
.app-table td {
  padding: .85rem 1rem;
  border-bottom: 1px solid var(--app-border);
  text-align: left;
}

.app-table thead th {
  background: var(--app-bg);
  font-weight: 600;
  color: var(--app-muted);
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .04em;
}

.app-table tbody tr:hover { background: rgba(37, 99, 235, .04); }

.app-table tbody tr:last-child td { border-bottom: 0; }

.app-table-responsive { overflow-x: auto; border-radius: 1rem; border: 1px solid var(--app-border); }

/* Buttons */
.app-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .55rem 1rem;
  border-radius: .7rem;
  font-size: .9rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .15s, transform .1s;
}
.app-btn:active { transform: scale(.98); }

.app-btn-primary { background: var(--app-primary); color: #fff; }
.app-btn-primary:hover { background: var(--app-primary-600); }

.app-btn-secondary { background: var(--app-bg); color: var(--app-text); border-color: var(--app-border); }
.app-btn-secondary:hover { background: var(--app-border); }

.app-btn-danger { background: var(--app-danger); color: #fff; }
.app-btn-danger:hover { background: #dc2626; }

.app-btn-sm { padding: .4rem .75rem; font-size: .82rem; }

/* Badges */
.app-badge {
  display: inline-flex;
  align-items: center;
  padding: .25rem .6rem;
  border-radius: 999px;
  font-size: .75rem;
  font-weight: 600;
}

.app-badge-success { background: rgba(16, 185, 129, .12); color: var(--app-success); }
.app-badge-warning { background: rgba(245, 158, 11, .12); color: #b45309; }
.app-badge-danger { background: rgba(239, 68, 68, .12); color: var(--app-danger); }
.app-badge-info { background: rgba(59, 130, 246, .12); color: var(--app-info); }

html[data-theme="dark"] .app-badge-warning { color: #fbbf24; }

/* Forms */
.app-form-label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  margin-bottom: .35rem;
  color: var(--app-text);
}

.app-form-control {
  width: 100%;
  padding: .55rem .8rem;
  border: 1px solid var(--app-border);
  border-radius: .7rem;
  background: var(--app-bg);
  color: var(--app-text);
  font-size: .9rem;
}
.app-form-control:focus {
  outline: 0;
  border-color: var(--app-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, .12);
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--app-muted);
}

.empty-state svg {
  width: 64px;
  height: 64px;
  margin-bottom: 1rem;
  opacity: .35;
}

/* Toast */
.app-toast {
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  z-index: 100;
  background: var(--app-card);
  border: 1px solid var(--app-border);
  border-radius: .85rem;
  padding: .9rem 1.1rem;
  box-shadow: var(--app-shadow);
  display: flex;
  align-items: center;
  gap: .75rem;
  transform: translateY(120%);
  transition: transform .25s ease;
}
.app-toast.show { transform: translateY(0); }

/* Skeleton */
.skeleton {
  background: linear-gradient(90deg, var(--app-border) 25%, var(--app-bg) 50%, var(--app-border) 75%);
  background-size: 200% 100%;
  animation: skeleton 1.2s infinite;
  border-radius: .5rem;
}
@keyframes skeleton { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* Mobile helpers */
@media (max-width: 1023px) {
  .app-sidebar { top: var(--app-topbar); }
  .app-sidebar.open { transform: translateX(0); }
}

/* Utility helpers */
.d-grid { display: grid; }
.w-100 { width: 100%; }