body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  display: flex;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

/* ─── Sidebar Navigation ─────────────────────────────── */
.sidebar {
  width: var(--nav-width);
  min-height: 100vh;
  background: var(--color-nav-bg);
  display: flex;
  flex-direction: column;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: 100;
  transition: width var(--transition-slow);
  overflow: hidden;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6) var(--space-5);
  color: #FFFFFF;
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  white-space: nowrap;
}

.nav-logo-icon {
  width: 32px;
  height: 32px;
  background: var(--color-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1rem;
}

.nav-section {
  padding: var(--space-4) var(--space-3);
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.nav-label {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(199,210,254,0.5);
  padding: var(--space-2) var(--space-3) var(--space-1);
  white-space: nowrap;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  color: var(--color-nav-text);
  font-size: 0.875rem;
  font-weight: 500;
  transition: background var(--transition), color var(--transition);
  cursor: pointer;
  white-space: nowrap;
}

.nav-link:hover {
  background: var(--color-nav-hover-bg);
  color: #FFFFFF;
}

.nav-link.active {
  background: var(--color-nav-active-bg);
  color: var(--color-nav-active);
}

.nav-link-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  opacity: 0.8;
}

.nav-link.active .nav-link-icon {
  opacity: 1;
}

.nav-bottom {
  padding: var(--space-4) var(--space-3);
  border-top: 1px solid rgba(255,255,255,0.08);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

/* ─── Main Content ──────────────────────────────────── */
.main-content {
  margin-left: var(--nav-width);
  flex: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: margin-left var(--transition-slow);
}

.page {
  flex: 1;
  padding: var(--space-8);
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  box-sizing: border-box;
}

/* ─── Page Header ────────────────────────────────────── */
.page-header {
  margin-bottom: var(--space-8);
}

.page-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.page-subtitle {
  margin-top: var(--space-2);
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* ─── Grid Layouts ──────────────────────────────────── */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

.grid-auto {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-6);
}

/* ─── Responsive ─────────────────────────────────────── */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --nav-width: 0px; }

  .sidebar {
    width: 100%;
    min-height: auto;
    position: fixed;
    bottom: 0;
    top: auto;
    height: 60px;
    flex-direction: row;
    border-top: 1px solid rgba(255,255,255,0.1);
    z-index: 200;
  }

  .nav-logo,
  .nav-label,
  .nav-bottom { display: none; }

  .nav-section {
    flex-direction: row;
    justify-content: space-around;
    align-items: center;
    padding: var(--space-2);
    flex: 1;
    gap: 0;
  }

  .nav-link {
    flex-direction: column;
    font-size: 0.65rem;
    gap: 2px;
    padding: var(--space-1) var(--space-2);
    text-align: center;
  }

  .main-content {
    margin-left: 0;
    padding-bottom: 70px;
  }

  .page { padding: var(--space-4); }

  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .page { padding: var(--space-3); }
}