margins.css

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --ui-background: #ffffff;
  --ui-foreground: #000000;
}

body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 10pt;
  background: var(--ui-background);
  color: var(--ui-foreground);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

#top-bar {
  flex-shrink: 0;
  display: flex;
  align-items: flex-start;
  border-bottom: 1px solid var(--ui-foreground);
}

#top-bar-title {
  width: 220px;
  min-width: 220px;
  padding: 12px 14px 10px;
  border-right: 1px solid var(--ui-foreground);
  font-weight: normal;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

#top-bar-main {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  height: 100%;
}

#menu-bar {
  display: flex;
  align-self: stretch;
  align-items: stretch;
}

#app-shell {
  flex: 1;
  min-height: 0;
  display: flex;
}

#sidebar {
  width: 220px;
  min-width: 220px;
  border-right: 1px solid var(--ui-foreground);
  padding: 16px 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 0;
  overflow-y: auto;
}

.menu-dropdown {
  position: relative;
  display: flex;
  align-items: stretch;
  padding: 10px 14px 8px;
  cursor: pointer;
}

.menu-dropdown > summary {
  list-style: none;
  display: flex;
  align-items: flex-start;
  height: 100%;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.08em;
  text-transform: none;
  cursor: inherit;
  user-select: none;
  color: inherit;
  pointer-events: none;
}

.menu-dropdown > summary::-webkit-details-marker {
  display: none;
}

.menu-dropdown[open] {
  background: var(--ui-foreground);
  color: var(--ui-background);
}

.menu-dropdown:hover {
  background: var(--ui-foreground);
  color: var(--ui-background);
}

.menu-panel {
  position: absolute;
  left: 0;
  top: 100%;
  min-width: 180px;
  padding: 4px 0;
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  z-index: 50;
}

.menu-action,
.menu-check,
.menu-submenu-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  font: inherit;
  line-height: 1.2;
  color: var(--ui-foreground);
  background: none;
  border: none;
  border-radius: 0;
  text-align: left;
  cursor: pointer;
}

.menu-submenu {
  position: relative;
  display: block;
  width: 100%;
  margin: 0;
  padding: 0;
}

.menu-submenu-trigger {
  list-style: none;
  font-variant-caps: normal;
  letter-spacing: normal;
  text-transform: none;
  justify-content: space-between;
  box-sizing: border-box;
  min-height: 27px;
  padding-left: 10px;
  padding-right: 12px;
}

.menu-submenu-trigger::after {
  content: ">";
  flex: 0 0 auto;
  margin-left: 12px;
}

.menu-submenu-trigger::-webkit-details-marker {
  display: none;
}

.menu-submenu-panel {
  position: absolute;
  left: 100%;
  top: -5px;
  box-sizing: border-box;
  min-width: 170px;
  padding: 4px 0;
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  z-index: 60;
}

.menu-list {
  padding: 0;
}

.menu-list-item {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-sizing: border-box;
  min-height: 27px;
  font: inherit;
  color: var(--ui-foreground);
  background: none;
  border: none;
  border-radius: 0;
  padding: 6px 10px;
  text-align: left;
  cursor: pointer;
}

.menu-list-item.active {
  background: var(--ui-foreground);
  color: var(--ui-background);
}

.menu-list-item::after {
  content: "";
  width: 12px;
  margin-left: 12px;
  text-align: right;
}

.menu-list-item.active::after {
  content: "x";
}

.menu-action.active {
  background: var(--ui-foreground);
  color: var(--ui-background);
}

.menu-action:hover,
.menu-check:hover,
.menu-submenu[open] > .menu-submenu-trigger,
.menu-submenu-trigger:hover,
.menu-list-item:hover {
  background: var(--ui-foreground);
  color: var(--ui-background);
}

.menu-file-action {
  position: relative;
  overflow: hidden;
}

.menu-file-action input[type="file"] {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  font: inherit;
  cursor: pointer;
}

.menu-action:disabled,
.menu-check input:disabled + span {
  color: var(--ui-foreground);
  opacity: 0.45;
  cursor: default;
}

.menu-check input {
  margin: 0;
}

#export-status {
  font-size: 10px;
  color: var(--ui-foreground);
  opacity: 0.65;
  min-width: 220px;
  padding-top: 2px;
}

#export-status-text {
  min-height: 12px;
}

#export-progress {
  height: 6px;
  margin-top: 6px;
  border: 1px solid var(--ui-foreground);
}

#export-progress-fill {
  height: 100%;
  width: 0;
  background: var(--ui-foreground);
}

#busy-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--ui-background);
  color: var(--ui-foreground);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  z-index: 1000;
}

#busy-overlay[hidden] {
  display: none;
}

body[data-exporting="true"] {
  cursor: progress !important;
}

.app-modal {
  margin: auto;
  padding: 0;
  border: none;
  background: transparent;
  color: var(--ui-foreground);
}

.app-modal::backdrop {
  background: color-mix(in srgb, var(--ui-background) 28%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.modal-card {
  width: min(420px, calc(100vw - 32px));
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  color: var(--ui-foreground);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  border-bottom: 1px solid var(--ui-foreground);
}

.modal-title {
  font-size: 9px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.modal-close-btn,
.modal-action-btn {
  font: inherit;
  color: var(--ui-foreground);
  background: none;
  border: 1px solid var(--ui-foreground);
  border-radius: 0;
  padding: 4px 8px;
  cursor: pointer;
}

.modal-content {
  padding: 12px;
}

.modal-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.modal-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.modal-section-label {
  font-size: 9px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.modal-check {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.modal-inline-field {
  display: grid;
  grid-template-columns: 1fr minmax(0, 120px);
  align-items: center;
  gap: 10px;
}

.modal-stat-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  font-size: 11px;
}

.modal-stat-row span:last-child {
  text-align: right;
}

.modal-color-row {
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 10px;
}

.modal-color-input {
  width: 34px;
  height: 24px;
  padding: 0;
}

.modal-color-value {
  min-width: 72px;
  text-align: right;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding-top: 2px;
}

/* ── Toolbar (swappable region) ─────────────────────────────────────────────── */

#toolbar {
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* ── Layout mode sections ───────────────────────────────────────────────────── */

.section {
  padding: 12px 0;
  border-bottom: 1px dotted var(--ui-foreground);
}

.section-label {
  font-size: 9px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

select, input[type="number"] {
  width: 100%;
  padding: 3px 4px;
  border: 1px solid var(--ui-foreground);
  border-radius: 0;
  font-family: inherit;
  font-size: 11px;
  background: var(--ui-background);
  color: var(--ui-foreground);
  appearance: none;
  -webkit-appearance: none;
}

input[type="number"] {
  padding-right: 0;
  -moz-appearance: textfield;
}

input, textarea, select {
  user-select: text;
  -webkit-user-select: text;
}

input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border: 1px solid var(--ui-foreground);
  border-radius: 0;
  background: var(--ui-background);
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
}

input[type="checkbox"]:checked::after {
  content: "\2713";
  position: absolute;
  left: 1px;
  top: -3px;
  font-size: 13px;
  line-height: 1;
  color: var(--ui-foreground);
}

select { cursor: pointer; }

input[type="color"] {
  width: 32px;
  height: 22px;
  padding: 1px 2px;
  border: 1px solid var(--ui-foreground);
  border-radius: 0;
  background: none;
  cursor: pointer;
  flex-shrink: 0;
  -webkit-appearance: none;
}

input[type="number"]:focus, select:focus {
  outline: none;
  border-style: solid;
}

.dim-row {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 5px;
}

.dim-row label {
  width: 52px;
  flex-shrink: 0;
}

.dim-row input { flex: 1; }
.dim-row input[type="range"] { flex: 1 1 auto; }
.dim-row .number-input-wrap { flex: 1; }
.dim-row .value-input {
  flex: 0 0 68px;
  width: 68px;
}

.number-input-wrap {
  display: inline-flex;
  align-items: stretch;
  min-width: 0;
  width: 100%;
  min-height: 21px;
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  overflow: hidden;
}

.number-input-wrap input[type="number"] {
  flex: 1;
  min-width: 0;
  border: none;
}

.number-input-wrap:focus-within {
  outline: 1px solid var(--ui-foreground);
  outline-offset: 0;
}

.number-stepper-btn {
  --pm-minus-left: 5px;
  --pm-minus-top: 10px;
  --pm-plus-left: 9px;
  --pm-plus-top: 6px;
  appearance: none;
  -webkit-appearance: none;
  flex: 0 0 19px;
  width: 19px;
  align-self: stretch;
  padding: 0;
  color: var(--ui-foreground);
  background: var(--ui-background);
  border: none;
  border-radius: 0;
  position: relative;
  font-size: 0;
  line-height: 1;
  cursor: pointer;
}

.number-stepper-btn::after,
.number-stepper-up::before,
.custom-slider-nudge::after,
.custom-slider-nudge-plus::before,
#canvas-zoom-controls button::after,
#canvas-zoom-in::before {
  content: "";
  position: absolute;
  background: currentColor;
}

.number-stepper-btn::after,
.custom-slider-nudge::after,
#canvas-zoom-controls button::after {
  left: var(--pm-minus-left);
  top: var(--pm-minus-top);
  width: 9px;
  height: 1px;
}

.number-stepper-up::before,
.custom-slider-nudge-plus::before,
#canvas-zoom-in::before {
  left: var(--pm-plus-left);
  top: var(--pm-plus-top);
  width: 1px;
  height: 9px;
}

.number-input-wrap > .number-stepper-btn:first-child {
  border-right: 1px solid var(--ui-foreground);
}

.number-input-wrap > input[type="number"] + .number-stepper-btn {
  border-left: 1px solid var(--ui-foreground);
}

.custom-slider-source {
  display: none;
}

.custom-slider-control {
  --slider-percent: 0.5;
  --slider-node-size: 17px;
  --slider-node-center: calc((var(--slider-node-size) - 1px) / 2);
  --slider-range-box-size: 13px;
  --slider-range-offset: calc((var(--slider-node-size) - var(--slider-range-box-size)) / 2);
  position: relative;
  display: grid;
  grid-template-columns: var(--slider-node-size) 1fr var(--slider-node-size);
  column-gap: 0;
  align-items: start;
  width: 100%;
}

.custom-slider-control::before {
  content: "";
  position: absolute;
  left: var(--slider-node-center);
  right: var(--slider-node-center);
  top: var(--slider-node-center);
  height: 1px;
  background: var(--ui-foreground);
  pointer-events: none;
}

.custom-slider-control.disabled {
  opacity: 0.45;
}

.custom-slider-main {
  grid-column: 2;
  min-width: 0;
  position: relative;
  z-index: 1;
}

.custom-slider-nudge {
  --pm-minus-left: 3px;
  --pm-minus-top: 7px;
  --pm-plus-left: 7px;
  --pm-plus-top: 3px;
  width: var(--slider-node-size);
  height: var(--slider-node-size);
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  color: var(--ui-foreground);
  position: relative;
  font-size: 0;
  cursor: pointer;
  padding: 0;
  z-index: 1;
}

.custom-slider-nudge-minus {
  grid-column: 1;
}

.custom-slider-nudge-plus {
  grid-column: 3;
}

.custom-slider-range {
  width: 100%;
  height: var(--slider-range-box-size);
  position: relative;
  top: var(--slider-range-offset);
  z-index: 1;
}

.custom-slider-range::-webkit-slider-thumb {
  height: var(--slider-node-size);
  box-sizing: border-box;
  margin-top: calc((1px - var(--slider-node-size)) / 2);
}

.custom-slider-range::-moz-range-thumb {
  height: var(--slider-node-size);
  box-sizing: border-box;
}

.custom-slider-value-row {
  position: relative;
  height: 22px;
  margin-top: 6px;
}

.custom-slider-value,
.custom-slider-value-editor {
  position: absolute;
  left: calc(var(--slider-percent) * 100%);
  transform: translateX(-50%);
  min-width: 48px;
  text-align: center;
  font: inherit;
  font-size: 10px;
  line-height: 1.2;
}

.custom-slider-value {
  border: none;
  background: none;
  color: var(--ui-foreground);
  cursor: text;
  padding: 0;
}

.custom-slider-value-editor {
  width: 56px;
  padding: 2px 4px;
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  color: var(--ui-foreground);
}

.dim-row .unit { color: var(--ui-foreground); opacity: 0.65; font-size: 10px; }

#measure-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
}

#measure-status {
  font-size: 10px;
  color: var(--ui-foreground);
  opacity: 0.65;
}

#measure-row {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 6px;
}

#measure-color {
  width: 34px;
  height: 34px;
  border: 1px solid var(--ui-foreground);
  flex-shrink: 0;
  padding: 0;
  background: none;
}

#measure-summary {
  min-width: 0;
  font-size: 11px;
}

#measure-hex {
  font-size: 12px;
}

#measure-rgb {
  color: var(--ui-foreground);
  opacity: 0.65;
  margin-top: 2px;
}

.measure-grid {
  margin-bottom: 10px;
}

/* slider */
#slider-header, #trim-header, #selection-header, #neutralize-header, #levels-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
}

#trim-header .section-label { margin: 0; }
#trim-val, #neutralize-val { font-size: 10px; color: var(--ui-foreground); opacity: 0.65; }

input[type="range"] {
  width: 100%;
  cursor: pointer;
  height: 14px;
  position: relative;
  z-index: 0;
  appearance: none;
  -webkit-appearance: none;
  background: transparent;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 1px;
  background: transparent;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  -webkit-appearance: none;
  width: 5px;
  height: 24px;
  border: 1px solid var(--ui-foreground);
  border-radius: 0;
  background:
    repeating-linear-gradient(
      90deg,
      var(--ui-background) 0,
      var(--ui-background) 1px,
      var(--ui-foreground) 1px,
      var(--ui-foreground) 2px
    );
  margin-top: -12px;
}

input[type="range"]::-moz-range-track {
  height: 1px;
  background: transparent;
}

input[type="range"]::-moz-range-thumb {
  width: 5px;
  height: 24px;
  border: 1px solid var(--ui-foreground);
  border-radius: 0;
  background:
    repeating-linear-gradient(
      90deg,
      var(--ui-background) 0,
      var(--ui-background) 1px,
      var(--ui-foreground) 1px,
      var(--ui-foreground) 2px
    );
  box-sizing: border-box;
}

input[type="range"]::-moz-range-progress {
  background: transparent;
  height: 1px;
}

.slider-ends {
  display: flex;
  justify-content: space-between;
  font-size: 9px;
  color: var(--ui-foreground);
  opacity: 0.65;
  margin-top: 2px;
  pointer-events: none;
}

.content-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  margin-top: 18px;
  padding-top: 6px;
  position: relative;
  z-index: 2;
}

.content-toggle input {
  position: relative;
  z-index: 2;
  flex-shrink: 0;
}

/* computed */
.computed-row {
  display: flex;
  justify-content: space-between;
  padding: 2px 0;
  border-bottom: 1px dotted var(--ui-foreground);
}

.computed-row:last-child { border-bottom: none; }
.computed-row.warn * { color: var(--ui-foreground); text-decoration: underline; }

/* ── Content mode ───────────────────────────────────────────────────────────── */

#drop-target {
  border: 1px dashed var(--ui-foreground);
  padding: 18px 8px;
  text-align: center;
  font-size: 10px;
  color: var(--ui-foreground);
  opacity: 0.65;
  line-height: 1.8;
  cursor: default;
  transition: border-color 0.1s, color 0.1s;
}

#drop-target.drag-over {
  border-color: var(--ui-foreground);
  border-style: solid;
  color: var(--ui-foreground);
  opacity: 1;
}

#page-list {
  display: flex;
  flex-direction: column;
  gap: 3px;
  max-height: 200px;
  overflow-y: auto;
}

.page-thumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 3px;
  cursor: pointer;
  border: 1px solid transparent;
}

.page-thumb.active {
  border-color: var(--ui-foreground);
}

.page-thumb canvas {
  width: 40px;
  height: auto;
  display: block;
  border: 1px solid var(--ui-foreground);
  flex-shrink: 0;
}

.page-thumb span {
  font-size: 10px;
  letter-spacing: 0.05em;
  color: var(--ui-foreground);
  opacity: 0.65;
}

.page-thumb.active span { color: var(--ui-foreground); }

/* ── Canvas area ────────────────────────────────────────────────────────────── */

#canvas-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--ui-background);
  overflow: hidden;
  min-width: 0;
  position: relative;
}

#canvas-area {
  flex: 1;
  min-height: 0;
  position: relative;
  overflow: auto;
  scrollbar-gutter: stable both-edges;
}

#canvas-area-inner {
  min-width: 100%;
  min-height: 100%;
  width: max-content;
  height: max-content;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  box-sizing: border-box;
}

#canvas-stage {
  position: relative;
  flex: none;
}

#spread-canvas,
#overlay-canvas {
  display: block;
  width: 100%;
  height: 100%;
  max-width: none;
  max-height: none;
}

/* The book's shadow. drop-shadow traces the canvas's alpha, so it follows the
   page silhouette — including the curl of a turning leaf — where a box-shadow
   on the stage would draw a rectangle around the whole viewport box.
   Deliberately NOT on the shared rule above: the overlay canvas and the edit
   layers occupy the same stage box, and a filter there embosses every margin
   guide, arrow and crop handle as well. */
#spread-canvas {
  filter: drop-shadow(gray 0 11px 10px);
}

#content-edit-layer,
#layout-preview-layer,
#overlay-canvas {
  position: absolute;
  left: 0;
  top: 0;
  pointer-events: none;
}

#content-edit-layer {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

#layout-preview-layer {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

#content-edit-layer[hidden],
#layout-preview-layer[hidden] {
  display: none;
}

.content-edit-frame,
.layout-preview-page,
.layout-preview-clip {
  position: absolute;
  left: 0;
  top: 0;
  overflow: hidden;
}

.content-edit-frame,
.layout-preview-page {
  contain: layout paint style;
  will-change: transform, width, height;
}

.layout-preview-clip {
  will-change: transform, width, height;
}

.content-edit-image,
.layout-preview-image {
  position: absolute;
  left: 0;
  top: 0;
  display: block;
  max-width: none;
  max-height: none;
  transform-origin: 0 0;
  will-change: transform;
}

#canvas-controls {
  position: absolute;
  padding: 8px 16px 0;
}

#canvas-zoom-controls {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

#canvas-zoom-controls button {
  --pm-minus-left: 5px;
  --pm-minus-top: 9px;
  --pm-plus-left: 9px;
  --pm-plus-top: 5px;
  width: 21px;
  height: 21px;
  border: 1px solid var(--ui-foreground);
  background: var(--ui-background);
  color: var(--ui-foreground);
  position: relative;
  font-size: 0;
  cursor: pointer;
  padding: 0;
}

#canvas-zoom-controls button:disabled {
  color: var(--ui-foreground);
  border-color: var(--ui-foreground);
  opacity: 0.45;
  cursor: default;
}

/* ── Page strip ─────────────────────────────────────────────────────────────── */

#page-strip {
  flex-shrink: 0;
  display: flex;
  flex-direction: row;
  align-items: flex-end;
  justify-content: safe center;
  gap: 6px;
  padding: 10px 16px;
  border-top: 1px dotted var(--ui-foreground);
  overflow-x: auto;
  min-height: 24px;
}

.strip-thumb {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  cursor: pointer;
  flex-shrink: 0;
  padding: 3px;
  border: 1px solid transparent;
}

.strip-thumb.in-spread { border-color: var(--ui-foreground); }
.strip-thumb.selected  { background: var(--ui-foreground); border-color: var(--ui-foreground); }
.strip-thumb.active    { border-color: var(--ui-foreground); background: var(--ui-foreground); }

.strip-thumb canvas {
  display: block;
  /* border: 1px solid var(--ui-foreground); */
}

.strip-thumb span {
  font-size: 9px;
  letter-spacing: 0.05em;
  color: var(--ui-foreground);
  opacity: 0.65;
}

.strip-thumb.in-spread span,
.strip-thumb.selected span,
.strip-thumb.active span { color: var(--ui-foreground); opacity: 1; }

.toolbar-mini-btn {
  font: inherit;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ui-foreground);
  background: none;
  border: 1px solid var(--ui-foreground);
  padding: 2px 6px;
  cursor: pointer;
}