/* Responsive Layout & Grid System */

.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header Navbar */
.app-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  z-index: 100;
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.brand-wrapper {
  text-decoration: none;
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-sans);
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  background: linear-gradient(135deg, var(--cyan-accent), var(--purple-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-sub {
  font-size: 0.68rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Scroll Reading Progress Bar */
.reading-progress-container {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: transparent;
}

.reading-progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--cyan-accent), var(--purple-accent));
  transition: width 0.1s ease-out;
}

/* Layout Wrapper */
.layout-wrapper {
  display: flex;
  flex: 1;
  margin-top: var(--header-height);
}

/* Collapsible Sidebar (Desktop) */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-primary);
  position: fixed;
  top: var(--header-height);
  bottom: 0;
  left: 0;
  overflow-y: auto;
  padding: 1.5rem 1rem 3rem;
  z-index: 90;
  transition: transform var(--transition-normal), background-color var(--transition-normal), border-color var(--transition-normal);
}

/* Main Area */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 2.25rem 3.5rem 5rem;
  max-width: 1320px;
  width: 100%;
  transition: margin-left var(--transition-normal);
}

/* Mobile Nav Trigger */
.menu-trigger {
  display: flex;
  background: transparent;
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  padding: 0.5rem;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
}

.menu-trigger:hover {
  background-color: var(--bg-tertiary);
}

.menu-trigger svg {
  width: 20px;
  height: 20px;
}

/* Backdrop */
.drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  z-index: 95;
  display: none;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

/* Responsive Overrides */
@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
    z-index: 1000;
    top: 0;
    bottom: 0;
    height: 100%;
    width: var(--sidebar-width);
    box-shadow: var(--shadow-lg);
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
    padding: 2.5rem 2rem 4rem;
  }
  
  .menu-trigger {
    display: flex;
  }
  
  .drawer-backdrop.active {
    display: block;
    opacity: 1;
  }
}

@media (max-width: 640px) {
  .app-header {
    padding: 0 1rem;
  }
  
  .main-content {
    padding: 1.5rem 1rem 3rem;
  }
}

/* Sidebar Collapse (Desktop) */
@media (min-width: 1025px) {
  body.sidebar-collapsed .sidebar {
    transform: translateX(-100%);
  }
  body.sidebar-collapsed .main-content {
    margin-left: 0;
  }
}