/* ========================================
   APP SHELL LAYOUT
   Three-zone layout: Sidebar + Banner + Main
   ======================================== */

/* Viewport lock - no page scroll */
html,
body {
  margin: 0;
  padding: 0;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  background: var(--color-bg-darkest);
}

/* App shell container */
#app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: 1fr;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
}

#app-shell.hidden {
  display: none;
}

/* ========================================
   ZONE 1: SIDEBAR
   ======================================== */

.sidebar {
  grid-column: 1;
  grid-row: 1;
  display: flex;
  flex-direction: column;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--panel-bg);
  border-right: var(--border-width) solid var(--color-border);
  z-index: var(--z-sidebar);
  overflow: hidden;
}

/* ========================================
   ZONE 2 & 3: MAIN AREA (Banner + Content)
   ======================================== */

.main-area {
  grid-column: 2;
  grid-row: 1;
  display: flex;
  flex-direction: column;
  width: var(--main-content-width);
  height: 100vh;
  overflow: hidden;
}

/* Banner at top of main area */
.banner {
  flex-shrink: 0;
  height: var(--banner-height);
  z-index: var(--z-banner);
}

/* Main content fills remaining space */
.main-content {
  flex: 1;
  min-height: 0;
  overflow: hidden;
}