.app {
  display: grid;
  grid-template-areas:
    "header header"
    "panel  terminal"
    "footer footer";
  grid-template-columns: var(--panel-w) 1fr;
  grid-template-rows: var(--header-h) 1fr var(--footer-h);
  height: 100vh;
  width: 100vw;
}

.app-header  { grid-area: header; }
.app-panel   { grid-area: panel; }
.app-terminal{ grid-area: terminal; }
.app-footer  { grid-area: footer; }

.app-header {
  background: var(--color-navy);
  color: #fff;
  display: flex;
  align-items: center;
  padding: 0 var(--space-5);
  gap: var(--space-5);
  border-bottom: 1px solid var(--color-navy-soft);
}

.brand {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}
.brand-title {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.brand-sub {
  font-size: 11px;
  color: #b9c8d8;
  margin-top: 2px;
}

.header-spacer { flex: 1; }

.header-progress {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: #cbd6e2;
  font-size: var(--fs-small);
}
.chapter-label { color: #fff; font-weight: 600; }

.progress-dots { display: flex; align-items: center; gap: 6px; }
.progress-dot {
  width: 12px; height: 12px;
  border: 1.5px solid #6c8aab;
  border-radius: 50%;
  background: transparent;
}
.progress-dot.done   { background: var(--color-action); border-color: var(--color-action); }
.progress-dot.active { background: #fff; border-color: #fff; }
.progress-sep { width: 14px; height: 1.5px; background: #6c8aab; }
.progress-sep.done { background: var(--color-action); }

.progress-count { font-variant-numeric: tabular-nums; }

.header-actions { display: flex; gap: var(--space-2); }
.btn-ghost {
  background: transparent;
  color: #fff;
  border: 1px solid #3a5a82;
}
.btn-ghost:hover { background: rgba(255,255,255,0.08); }

.app-footer {
  background: var(--color-bg-sub);
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  padding: 0 var(--space-5);
  font-size: var(--fs-small);
  color: var(--color-text-mute);
  gap: var(--space-3);
}
.footer-hint { flex: 1; }
.footer-meta { color: #999; }

@media (max-width: 900px) {
  .app {
    grid-template-areas:
      "header"
      "panel"
      "terminal"
      "footer";
    grid-template-columns: 1fr;
    grid-template-rows: var(--header-h) auto 1fr var(--footer-h);
  }
}