/* Layout Structure — Sidebar, Header, Mobile Nav — ProblemX */

.app-container {
  display: flex;
  min-height: 100vh;
  width: 100vw;
  background-color: var(--color-bg-secondary);
}

/* Sidebar (Desktop) */
.sidebar {
  width: 260px;
  min-width: 260px;
  background-color: var(--color-card);
  border-right: 1px solid var(--color-border);
  padding: var(--space-6) 0;
  display: flex;
  flex-direction: column;
  position: sticky;
  top: 0;
  height: 100vh;
  z-index: 100;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.sidebar-logo {
  padding: 0 var(--space-6) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.sidebar-logo .brand-mark {
  font-family: var(--font-secondary);
  font-size: var(--fs-h3);
  font-weight: var(--fw-bold);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.sidebar-logo .brand-version {
  font-size: var(--fs-caption);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: var(--space-1);
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  overflow-y: auto;
}

.nav-section-title {
  padding: var(--space-4) var(--space-6) var(--space-2);
  font-size: var(--fs-caption);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-6);
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  border-left: 3px solid transparent;
  transition: all 0.2s ease;
}

.nav-item:hover {
  color: var(--color-text-primary);
  background-color: var(--color-bg-secondary);
}

.nav-item.active {
  color: var(--color-primary);
  background-color: var(--color-primary-light);
  border-left-color: var(--color-primary);
  font-weight: var(--fw-semibold);
}

.nav-item i, .nav-item svg {
  width: 20px;
  height: 20px;
  stroke-width: 2px;
}

/* Header (Top Nav) */
.main-content {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  min-width: 0;
  padding-bottom: 0;
}

.app-header {
  height: 70px;
  background-color: var(--color-card);
  border-bottom: 1px solid var(--color-border);
  padding: 0 var(--space-8);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 90;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-title-area {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.user-profile-menu {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  cursor: pointer;
}

.user-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background-color: var(--color-border);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--color-primary);
}

/* Main Area Container */
.page-container {
  flex-grow: 1;
  padding: var(--space-8);
  overflow-y: auto;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
}

/* Mobile Nav Bar (Bottom Navigation) */
.mobile-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 64px;
  background-color: var(--color-card);
  border-top: 1px solid var(--color-border);
  z-index: 110;
  justify-content: space-around;
  align-items: center;
  padding: 0 var(--space-4);
}

.mobile-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  font-size: 10px;
  font-weight: var(--fw-medium);
  gap: var(--space-1);
  flex: 1;
  height: 100%;
  transition: color 0.2s ease;
}

.mobile-nav-item i, .mobile-nav-item svg {
  width: 22px;
  height: 22px;
  stroke-width: 2px;
}

.mobile-nav-item.active {
  color: var(--color-primary);
  font-weight: var(--fw-semibold);
}

/* Responsiveness */
@media (max-width: 768px) {
  .sidebar {
    display: none; /* Hide sidebar on mobile */
  }

  .mobile-nav {
    display: flex; /* Show bottom nav on mobile */
  }

  .app-header {
    padding: 0 var(--space-4);
  }

  .page-container {
    padding: var(--space-4);
    /* Extra padding to prevent bottom nav overlay */
    padding-bottom: calc(64px + var(--space-4));
  }
}