*, *::before, *::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Poppins', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 14px;
  line-height: 1.5;
}

#app {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr var(--preview-width);
  height: 100vh;
  overflow: hidden;
}

#sidebar {
  background: var(--color-sidebar-bg);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  padding: 0;
}

#main {
  display: grid;
  grid-template-rows: auto 1fr;
  overflow: hidden;
}

#topbar {
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: 10px 20px;
  flex-shrink: 0;
}

#content {
  padding: 20px;
  overflow-y: auto;
  padding-bottom: 72px;
}

#preview-panel {
  background: var(--color-white);
  border-left: 1px solid var(--color-border);
  padding: 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#action-bar {
  position: fixed;
  bottom: 0;
  left: var(--sidebar-width);
  right: var(--preview-width);
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  align-items: center;
  padding: 10px 20px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  border-top: 1px solid var(--color-border);
  z-index: 100;
}

@media print {
  #sidebar, #topbar, #action-bar, #content { display: none !important; }
  #app { display: block; }
  #preview-panel {
    border: none;
    width: 100%;
    padding: 40px;
  }
}