/* ===== LAYOUT — Sidebar + Top Nav + Grid System ===== */

/* App Shell */
.app-shell {
  display: flex;
  min-height: 100vh;
}

/* ===== SIDEBAR ===== */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 40;
  width: 16rem;
  height: 100vh;
  background: var(--surface-container-low);
  display: flex;
  flex-direction: column;
  padding: var(--space-lg);
  overflow-y: auto;
  transition: transform var(--transition-slide);
}

.sidebar__brand {
  margin-bottom: var(--space-2xl);
  padding: 0 var(--space-sm);
}

.sidebar__brand-name {
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: -0.04em;
  color: var(--on-surface);
}

.sidebar__brand-tagline {
  font-size: 0.625rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--on-surface-variant);
  opacity: 0.6;
  margin-top: var(--space-xs);
}

/* Nav Items */
.sidebar__nav {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.sidebar__nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-lg);
  font-size: var(--body-md);
  font-weight: 500;
  color: var(--on-surface-variant);
  opacity: 0.7;
  transition: all var(--transition-base);
  cursor: pointer;
}

.sidebar__nav-item:hover {
  color: var(--on-surface);
  background: var(--surface-container);
  opacity: 1;
}

.sidebar__nav-item:hover .sidebar__nav-icon {
  transform: translateX(2px);
}

.sidebar__nav-item--active {
  color: var(--primary-container);
  background: var(--surface-container-highest);
  opacity: 1;
}

.sidebar__nav-item--active .sidebar__nav-icon {
  font-variation-settings: 'FILL' 1, 'wght' 400, 'GRAD' 0, 'opsz' 24;
}

.sidebar__nav-icon {
  font-size: 1.25rem;
  transition: transform var(--transition-fast);
}

/* Sidebar Footer */
.sidebar__footer {
  padding-top: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.sidebar__footer-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  font-size: var(--body-sm);
  color: var(--on-surface-variant);
  opacity: 0.6;
  transition: opacity var(--transition-fast);
  cursor: pointer;
}

.sidebar__footer-item:hover {
  opacity: 1;
}

/* ===== TOP NAV ===== */
.topnav {
  position: fixed;
  top: 0;
  left: 16rem;
  right: 0;
  z-index: 50;
  height: 4rem;
  background: rgba(18, 19, 27, 0.8);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xl);
  transition: left var(--transition-slide);
}

.topnav__search {
  position: relative;
  width: 16rem;
}

.topnav__search-icon {
  position: absolute;
  left: var(--space-md);
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.125rem;
  color: var(--on-surface-variant);
  opacity: 0.5;
}

.topnav__search-input {
  width: 100%;
  background: var(--surface-container-low);
  border-radius: var(--radius-lg);
  padding: var(--space-sm) var(--space-md) var(--space-sm) 2.5rem;
  font-size: var(--body-sm);
  color: var(--on-surface);
  transition: background var(--transition-fast);
}

.topnav__search-input::placeholder {
  color: var(--on-surface-variant);
  opacity: 0.5;
}

.topnav__search-input:focus {
  background: var(--surface-container);
  box-shadow: 0 0 0 1px rgba(255, 221, 0, 0.2);
}

.topnav__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.topnav__action-btn {
  padding: var(--space-sm);
  color: var(--on-surface-variant);
  opacity: 0.7;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.topnav__action-btn:hover {
  color: var(--primary-container);
  opacity: 1;
}

.topnav__action-btn:active {
  transform: scale(0.95);
}

.topnav__avatar {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  overflow: hidden;
  background: var(--surface-container);
}

.topnav__avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Mobile menu toggle */
.topnav__menu-toggle {
  display: none;
  padding: var(--space-sm);
  color: var(--on-surface);
}

/* ===== MAIN CONTENT ===== */
.main-content {
  flex: 1;
  margin-left: 16rem;
  padding-top: 6rem;
  padding-bottom: var(--space-2xl);
  padding-left: var(--space-xl);
  padding-right: var(--space-xl);
  min-height: 100vh;
  transition: margin-left var(--transition-slide);
}

/* ===== PAGE HEADER ===== */
.page-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: var(--space-2xl);
}

.page-header__overline {
  font-size: var(--body-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--primary-fixed-dim);
  margin-bottom: var(--space-xs);
}

.page-header__title {
  font-size: 3rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--on-surface);
  line-height: 1.1;
}

/* ===== GRID SYSTEM ===== */
.grid {
  display: grid;
  gap: var(--space-lg);
}

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

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.row {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.row--between {
  justify-content: space-between;
}

.row--end {
  justify-content: flex-end;
}

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

@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar--open {
    transform: translateX(0);
  }

  .topnav {
    left: 0;
  }

  .topnav__menu-toggle {
    display: block;
  }

  .topnav__search {
    display: none;
  }

  .main-content {
    margin-left: 0;
    padding-left: var(--space-md);
    padding-right: var(--space-md);
  }

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

  .page-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-md);
  }

  .page-header__title {
    font-size: 2rem;
  }
}

/* Mobile overlay when sidebar is open */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 35;
  background: rgba(0, 0, 0, 0.5);
}

.sidebar-overlay--visible {
  display: block;
}