/* ============================================
   LAYOUT — Grid, responsive containers
   ============================================ */

/* ── App Shell ── */
.app {
  display: flex;
  height: 100vh;
  height: 100dvh;
  width: 100vw;
  overflow: hidden;
  background: var(--bg-app);
}

/* ── Sidebar ── */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-4) 0;
  background: var(--bg-surface);
  border-right: 1px solid var(--border-default);
  transition: width var(--transition-slow), min-width var(--transition-slow);
  z-index: var(--z-sticky);
  gap: var(--space-2);
}

/* ── Main Content Area ── */
.main-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  min-width: 0;
  overflow: hidden;
}

/* ── Header ── */
.header {
  height: var(--header-height);
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-6);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-default);
  gap: var(--space-4);
  z-index: var(--z-sticky);
}

/* ── Content + Controls Split ── */
.content-wrapper {
  flex: 1;
  display: flex;
  min-height: 0;
  overflow: hidden;
}

/* ── Main Content (center) ── */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-6);
  overscroll-behavior-y: contain;
  -webkit-overflow-scrolling: touch;
}

/* ── Controls Panel (right) ── */
.controls-panel {
  width: var(--controls-width);
  min-width: var(--controls-width);
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior-y: contain;
  -webkit-overflow-scrolling: touch;
  background: var(--bg-surface);
  border-left: 1px solid var(--border-default);
  padding: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

/* ── View Containers ── */
.view {
  display: none;
  flex-direction: column;
  width: 100%;
  flex: 1;
  min-height: 0;
  animation: fadeIn var(--transition-base) forwards;
}
.view.active {
  display: flex;
}

/* ── Section ── */
.section {
  margin-bottom: var(--space-6);
}
.section__title {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  margin-bottom: var(--space-3);
}

/* ── Grid Layouts ── */
.grid {
  display: grid;
  gap: var(--space-4);
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-auto-fill {
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

/* ── Flex Utilities ── */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.flex-1 { flex: 1; }

/* ── Image Output Area ── */
.output-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 350px;
  border-radius: var(--radius-xl);
  border: 2px dashed var(--border-default);
  background: var(--bg-surface);
  position: relative;
  transition: border-color var(--transition-base);
}
.output-area.has-image {
  border: none;
  align-items: stretch;
  justify-content: flex-start;
}

/* ── Output Images Grid ── */
#output-images {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  width: 100%;
  padding: var(--space-4);
  padding-bottom: var(--space-8);
  margin: 0 auto;
}
#output-images.grid-cols-1 {
  grid-template-columns: 1fr;
  max-width: 600px;
}
#output-images.grid-cols-2 {
  grid-template-columns: repeat(2, 1fr);
}
#output-images.grid-cols-3 {
  grid-template-columns: repeat(3, 1fr);
}
#output-images.grid-cols-4 {
  grid-template-columns: repeat(4, 1fr);
}
#output-images .image-card {
  cursor: pointer;
  width: 100%;
}
#output-images .image-card__img {
  aspect-ratio: auto;
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-lg);
}

@media (max-width: 768px) {
  #output-images {
    padding: var(--space-2);
    gap: var(--space-3);
  }
  #output-images.grid-cols-2,
  #output-images.grid-cols-3,
  #output-images.grid-cols-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  #output-images .image-card__img {
    max-height: 260px;
    object-fit: cover;
  }
}

/* ── Empty State ── */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-12);
  color: var(--text-tertiary);
  text-align: center;
  gap: var(--space-4);
}
.empty-state__icon {
  width: 64px;
  height: 64px;
  opacity: 0.3;
}
.empty-state__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--text-secondary);
}
.empty-state__text {
  font-size: var(--text-sm);
  max-width: 360px;
  line-height: var(--leading-relaxed);
}

/* ── Responsive ── */
@media (max-width: 1024px) {
  .controls-panel {
    position: fixed;
    right: 0;
    top: 0;
    height: 100vh;
    height: 100dvh;
    z-index: var(--z-overlay);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    box-shadow: var(--shadow-2xl);
  }
  .controls-panel.open {
    transform: translateX(0);
  }
  .main-content {
    padding: var(--space-4);
  }
}

@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    min-width: 100%;
    height: auto;
    flex-direction: row;
    justify-content: space-around;
    padding: var(--space-2) 0;
    border-right: none;
    border-top: 1px solid var(--border-default);
    z-index: var(--z-sticky);
    background: var(--bg-surface);
  }
  .app {
    flex-direction: column;
  }
  .main-area {
    height: 100vh;
    height: 100dvh;
  }
  .header {
    padding: 0 var(--space-4);
  }
  .main-content {
    padding: var(--space-3);
    padding-bottom: calc(80px + env(safe-area-inset-bottom, 0px));
  }
  /* Switch views to block layout on mobile so content height
     is NOT constrained by the flex algorithm. This allows
     the scroll container to see the full height of all images. */
  .view.active {
    display: block;
  }
  .view {
    padding-bottom: calc(80px + env(safe-area-inset-bottom, 0px));
  }
  .output-area {
    min-height: calc(100dvh - 180px);
  }
  .output-area.has-image {
    min-height: 0;
  }
  .controls-panel {
    width: 100%;
    min-width: 100%;
    max-height: 70vh;
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    border-left: none;
    border-top: 1px solid var(--border-default);
    bottom: 56px;
    right: 0;
    left: 0;
    top: auto;
    transform: translateY(calc(100% + 72px));
    padding-bottom: calc(120px + env(safe-area-inset-bottom, 0px));
  }
  .controls-panel.open {
    transform: translateY(0);
  }
}

@media (max-width: 480px) {
  .grid-2 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .main-content {
    padding: var(--space-2);
    padding-bottom: calc(160px + env(safe-area-inset-bottom, 0px));
  }
}