/* =========================================================
   CSS Custom Properties
   ========================================================= */
:root {
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-border: #d0d0d0;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-danger: #dc2626;
  --color-danger-hover: #b91c1c;
  --color-export: #16a34a;
  --color-export-hover: #15803d;
  --color-text: #111827;
  --color-muted: #6b7280;
  --color-active-col: #2563eb;
  --color-card-bg: #fafafa;
  --color-drop-zone-bg: #eff6ff;
  --color-drop-zone-border: #93c5fd;
  --color-drop-zone-active-bg: #dbeafe;
  --color-error-bg: #fef2f2;
  --color-error-text: #b91c1c;
  --color-error-border: #fca5a5;
  --color-overlay-bg: rgba(0, 0, 0, 0.55);
  --radius: 6px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
  --toolbar-height: 52px;
  --tab-height: 40px;
}

/* =========================================================
   Reset & Base
   ========================================================= */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  height: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 14px;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
}

/* =========================================================
   App Shell
   ========================================================= */
#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* =========================================================
   Toolbar
   ========================================================= */
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 0 16px;
  height: var(--toolbar-height);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
  flex-wrap: wrap;
}

.toolbar-left,
.toolbar-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* =========================================================
   Buttons
   ========================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 6px 14px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
  line-height: 1.4;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
}

.btn-danger {
  background: transparent;
  color: var(--color-danger);
  border-color: var(--color-danger);
}
.btn-danger:hover {
  background: var(--color-danger);
  color: #fff;
}

.btn-export {
  background: var(--color-export);
  color: #fff;
  border-color: var(--color-export);
}
.btn-export:hover {
  background: var(--color-export-hover);
  border-color: var(--color-export-hover);
}

.btn-export:disabled,
.btn-primary:disabled,
.btn-danger:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Column toggle buttons */
.columns-control,
.orientation-control {
  display: flex;
  align-items: center;
  gap: 4px;
}

.columns-label-text {
  font-size: 13px;
  color: var(--color-muted);
  margin-right: 2px;
}

.btn-col {
  padding: 4px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.btn-col:hover {
  border-color: var(--color-active-col);
  color: var(--color-active-col);
}

.btn-col.active {
  background: var(--color-active-col);
  border-color: var(--color-active-col);
  color: #fff;
}

/* =========================================================
   Mobile Tab Switcher
   ========================================================= */
.tab-switcher {
  display: none;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.tab-btn {
  flex: 1;
  height: var(--tab-height);
  border: none;
  background: transparent;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.tab-btn.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* =========================================================
   Panels
   ========================================================= */
.panels {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.panel {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
}

.panel-editor {
  border-right: 1px solid var(--color-border);
  background: var(--color-bg);
}

.panel-preview {
  background: #e5e7eb;
}

/* =========================================================
   Drop Zone
   ========================================================= */
.drop-zone {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 160px;
  border: 2px dashed var(--color-drop-zone-border);
  border-radius: var(--radius);
  background: var(--color-drop-zone-bg);
  color: var(--color-primary);
  font-size: 15px;
  font-weight: 500;
  font-family: inherit;
  text-align: center;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  user-select: none;
  margin-bottom: 12px;
}

.drop-zone:hover,
.drop-zone.drag-over {
  background: var(--color-drop-zone-active-bg);
  border-color: var(--color-primary);
}

.drop-zone.hidden {
  display: none;
}

/* =========================================================
   Error Container
   ========================================================= */
.error-container {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 8px;
}

.error-message {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 12px;
  background: var(--color-error-bg);
  border: 1px solid var(--color-error-border);
  border-radius: var(--radius);
  color: var(--color-error-text);
  font-size: 13px;
}

.error-message button {
  border: none;
  background: none;
  color: var(--color-error-text);
  cursor: pointer;
  font-size: 16px;
  line-height: 1;
  padding: 0 2px;
  flex-shrink: 0;
}

/* =========================================================
   Card List
   ========================================================= */
.card-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* =========================================================
   Image Card
   ========================================================= */
.image-card {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 10px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  cursor: grab;
}

.image-card:active {
  cursor: grabbing;
}

.image-card.sortable-ghost {
  opacity: 0.4;
}

.image-card.sortable-chosen {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.18);
}

.card-thumbnail {
  width: 80px;
  height: 60px;
  object-fit: cover;
  border-radius: 4px;
  flex-shrink: 0;
  background: var(--color-border);
}

.card-fields {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
  min-width: 0;
}

.card-fields input {
  width: 100%;
  padding: 5px 8px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 13px;
  font-family: inherit;
  color: var(--color-text);
  background: var(--color-surface);
  transition: border-color 0.15s;
}

.card-fields input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.card-remove {
  border: none;
  background: none;
  color: var(--color-muted);
  font-size: 18px;
  cursor: pointer;
  padding: 0 4px;
  line-height: 1;
  flex-shrink: 0;
  transition: color 0.15s;
}

.card-remove:hover {
  color: var(--color-danger);
}

/* =========================================================
   Preview Pages
   ========================================================= */
.preview-pages {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  padding-bottom: 24px;
}

/* A4 page wrapper (for scaling) */
.page-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.page-label {
  font-size: 12px;
  color: var(--color-muted);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* A4 page — dimensions set dynamically by JS, scaled to fit the preview panel */
.a4-page {
  background: #fff;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.18);
  flex-shrink: 0;
  position: relative;
  overflow: hidden;
  transform-origin: top center;
}

/* Inner content area — margins and width set dynamically by JS */
.a4-content {
  position: absolute;
  top: 76px;
  left: 76px;
  /* width set inline by JS (contentW()) */
}

/* Cell inside A4 page */
.a4-cell {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  box-sizing: border-box;
  padding: 4px;
}

.a4-cell-title {
  font-family: sans-serif;
  font-size: 14px;
  font-weight: 700;
  text-align: center;
  max-height: calc(14px * 1.3 * 2); /* 2 lines */
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  width: 100%;
  line-height: 1.3;
  margin-bottom: 3px;
}

.a4-cell-img {
  object-fit: contain;
  display: block;
  width: 100%;
}

.a4-cell-subtext {
  font-family: sans-serif;
  font-size: 11px;
  font-weight: 400;
  text-align: center;
  max-height: calc(11px * 1.3 * 2); /* 2 lines */
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  width: 100%;
  line-height: 1.3;
  margin-top: 3px;
}

/* =========================================================
   Preview Panel Scaling
   ========================================================= */
.panel-preview {
  --preview-scale: 1;
}

.preview-pages {
  /* transform applied by JS */
}

/* =========================================================
   Export Overlay
   ========================================================= */
.export-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-overlay-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  gap: 16px;
  color: #fff;
  font-size: 16px;
  font-weight: 500;
}

.export-overlay.hidden {
  display: none;
}

.export-spinner {
  width: 48px;
  height: 48px;
  border: 5px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.85s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* =========================================================
   Responsive — narrow viewport (< 900px)
   ========================================================= */
@media (max-width: 899px) {
  .panels {
    flex-direction: column;
    overflow: visible;
  }

  .panel {
    flex: none;
    overflow: visible;
  }

  .panel-editor {
    border-right: none;
    border-bottom: 1px solid var(--color-border);
  }

  .tab-switcher {
    display: flex;
  }

  /* Hide inactive panel on mobile */
  .panel.hidden-mobile {
    display: none;
  }
}

/* =========================================================
   Print CSS
   ========================================================= */
@media print {
  .toolbar,
  .tab-switcher,
  .panel-editor,
  .export-overlay {
    display: none !important;
  }

  .panels {
    display: block;
  }

  .panel-preview {
    padding: 0;
    background: none;
    overflow: visible;
  }

  .preview-pages {
    gap: 0;
    padding: 0;
  }

  .a4-page {
    transform: none !important;
    box-shadow: none;
    page-break-after: always;
    break-after: page;
  }

  .page-wrapper {
    gap: 0;
  }

  .page-label {
    display: none;
  }
}