:root {
  --c-base: #ffffff;
  --c-text: #3c4043;
  --c-strong: #202124;
  --c-subtle: #5f6368;
  --c-surface: #f8fafd;
  --c-canvas: #eef2f7;
  --c-hover: #f1f3f4;
  --c-border: #dadce0;
  --c-focus: #1a73e8;
  --c-primary: #1a73e8;
  --c-primary-hover: #185abc;
  --c-primary-surface: #e8f0fe;
  --font-family: "Google Sans", "Noto Sans JP", "Hiragino Sans", "Yu Gothic UI", Arial, system-ui, sans-serif;
  --font-size-body: 13px;
  --font-size-small: 11px;
  --font-size-label: 12px;
  --line-height: 1.5;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --touch-target: 44px;
  --header-height: 72px;
  --left-width: 240px;
  --right-width: 304px;
  font-family: var(--font-family);
  color: var(--c-text);
  background: var(--c-surface);
  font-synthesis: none;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

html,
body { height: 100%; }

body {
  margin: 0;
  min-width: 320px;
  overflow: hidden;
  background: var(--c-canvas);
  font-size: var(--font-size-body);
  line-height: var(--line-height);
}

button,
input,
select,
textarea { font: inherit; }

button,
.button { -webkit-tap-highlight-color: transparent; }

button:focus-visible,
.button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--c-focus) 30%, transparent);
  outline-offset: 2px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 8px;
  left: 8px;
  padding: 12px 16px;
  color: var(--c-base);
  background: var(--c-strong);
  transform: translateY(-160%);
}

.skip-link:focus { transform: translateY(0); }

.app-header {
  position: relative;
  z-index: 20;
  height: var(--header-height);
  min-height: var(--header-height);
  display: grid;
  grid-template-columns: minmax(190px, 1fr) auto minmax(190px, 1fr);
  align-items: center;
  gap: var(--space-4);
  padding: 10px 20px;
  background: var(--c-base);
  border-bottom: 1px solid var(--c-border);
}

.brand-block {
  min-width: 0;
  display: flex;
  align-items: center;
  white-space: nowrap;
}

.brand-copy { min-width: 0; display: grid; }
.brand-block strong { color: var(--c-strong); font-size: 15px; line-height: 1.25; }

.brand-copy span {
  overflow: hidden;
  color: var(--c-subtle);
  font-size: var(--font-size-label);
  line-height: 1.25;
  text-overflow: ellipsis;
}

.file-actions,
.history-actions,
.mobile-panel-actions,
.selection-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.history-actions { justify-self: end; }

.button,
button {
  min-height: var(--touch-target);
  border: 1px solid transparent;
  border-radius: 22px;
  cursor: pointer;
  font-weight: 700;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease, opacity 150ms ease;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  text-decoration: none;
}

.button-primary {
  color: var(--c-base);
  background: var(--c-primary);
  border-color: var(--c-primary);
}

.button-primary:hover { background: var(--c-primary-hover); border-color: var(--c-primary-hover); }

.button-quiet {
  color: var(--c-strong);
  background: var(--c-base);
  border-color: transparent;
}

.button-quiet:hover { background: var(--c-hover); border-color: var(--c-hover); }

.icon-button {
  width: 44px;
  padding: 0;
  color: var(--c-strong);
  background: var(--c-base);
  border-color: transparent;
  font-weight: 400;
}

.icon-button:hover { background: var(--c-hover); }
.icon-button svg { width: 20px; height: 20px; fill: currentColor; }

button:disabled {
  cursor: not-allowed;
  opacity: .38;
}

.save-status {
  min-width: 64px;
  color: var(--c-subtle);
  font-size: var(--font-size-label);
  text-align: right;
}

.workspace {
  height: calc(100vh - var(--header-height));
  display: grid;
  grid-template-columns: var(--left-width) minmax(0, 1fr) var(--right-width);
}

.sidebar {
  position: relative;
  z-index: 10;
  min-width: 0;
  overflow: auto;
  background: var(--c-surface);
}

.sidebar-left { border-right: 1px solid var(--c-border); }
.sidebar-right { border-left: 1px solid var(--c-border); }

.sidebar-header {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--c-border);
}

.sidebar-header h1,
.sidebar-section h2,
.sidebar-header p { margin: 0; }
.sidebar-header > div { min-width: 0; }
.sidebar-header h1 { color: var(--c-strong); font-size: 13px; letter-spacing: -.01em; }
.sidebar-header p {
  margin-top: 2px;
  overflow: hidden;
  color: var(--c-subtle);
  font-size: var(--font-size-label);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.close-drawer {
  display: none;
  padding: 0 12px;
  color: var(--c-strong);
  background: var(--c-base);
  border-color: transparent;
  white-space: nowrap;
}

.sidebar-section {
  padding: 20px;
  border-bottom: 1px solid var(--c-border);
}

.sidebar-section h2,
.inspector-form legend {
  color: var(--c-subtle);
  font-size: var(--font-size-label);
  font-weight: 700;
  letter-spacing: .04em;
}

.add-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin-top: 12px;
}

.add-grid button {
  padding: 4px 8px;
  color: var(--c-strong);
  background: var(--c-base);
  border-color: var(--c-border);
  border-radius: 12px;
  font-size: 13px;
}

.add-grid button:hover { color: var(--c-primary-hover); background: var(--c-primary-surface); border-color: var(--c-primary-surface); }

.section-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.section-title-row span {
  color: var(--c-subtle);
  font-size: var(--font-size-label);
}

.layer-section { padding-inline: 0; }
.layer-section .section-title-row { padding-inline: 20px; }
.layer-section .section-title-row span {
  min-width: 24px;
  padding: 2px 6px;
  color: var(--c-subtle);
  background: var(--c-hover);
  border-radius: 10px;
  font-size: 11px;
  text-align: center;
}
.layer-tree { margin-top: 8px; padding: 0 8px 12px; }

.layer-item {
  --layer-indent: 8px;
  width: 100%;
  min-height: 44px;
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px 4px var(--layer-indent);
  color: var(--c-text);
  background: transparent;
  border: 0;
  border-radius: 8px;
  font-size: var(--font-size-label);
  font-weight: 400;
  text-align: left;
}

.layer-item:hover { background: var(--c-hover); }
.layer-item.is-nested::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: var(--layer-guide);
  border-left: 1px solid var(--c-border);
  pointer-events: none;
}
.layer-item::before {
  content: "";
  width: 10px;
  height: 10px;
  flex: 0 0 10px;
}
.layer-item.has-children::before {
  width: 6px;
  height: 6px;
  margin-inline: 2px;
  border-right: 1.5px solid var(--c-subtle);
  border-bottom: 1.5px solid var(--c-subtle);
  transform: rotate(45deg) translate(-1px, -1px);
}
.layer-item.is-selected {
  color: var(--c-primary-hover);
  background: var(--c-primary-surface);
  box-shadow: inset 3px 0 0 var(--c-primary);
  font-weight: 700;
}

.layer-item .tag {
  min-width: 30px;
  padding: 1px 5px;
  color: var(--c-subtle);
  background: var(--c-base);
  border: 1px solid var(--c-border);
  border-radius: 5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 10px;
  line-height: 16px;
  text-align: center;
  text-transform: uppercase;
}

.layer-item.is-selected .tag {
  color: var(--c-primary-hover);
  border-color: color-mix(in srgb, var(--c-primary) 28%, var(--c-border));
}

.layer-item .name {
  min-width: 0;
  overflow: hidden;
  color: var(--c-strong);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.canvas-region {
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: 56px minmax(0, 1fr) 48px;
  background: var(--c-canvas);
}

.canvas-toolbar {
  position: relative;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 6px 16px;
  background: var(--c-base);
  border-bottom: 1px solid var(--c-border);
}

.mode-switcher,
.viewport-switcher,
.segmented {
  display: inline-flex;
  padding: 3px;
  background: var(--c-hover);
  border: 1px solid transparent;
  border-radius: 24px;
}

.mode-switcher button,
.viewport-switcher button,
.segmented button {
  min-width: 44px;
  min-height: 44px;
  padding: 0 12px;
  color: var(--c-subtle);
  background: transparent;
  border: 0;
  border-radius: 20px;
  font-size: 13px;
}

.mode-switcher button.is-active,
.viewport-switcher button.is-active,
.segmented button.is-active {
  color: var(--c-primary-hover);
  background: var(--c-primary-surface);
  border: 1px solid transparent;
}

.mode-switcher button:hover,
.viewport-switcher button:hover,
.segmented button:hover { color: var(--c-strong); background: color-mix(in srgb, var(--c-primary-surface) 55%, var(--c-base)); }

.selection-actions button {
  min-height: 44px;
  padding: 0 12px;
  color: var(--c-strong);
  background: var(--c-base);
  border-color: transparent;
  border-radius: 22px;
  font-size: 13px;
}

.selection-actions button:hover:not(:disabled) { background: var(--c-hover); }

.selection-actions #delete-element { color: var(--c-subtle); }
.mobile-panel-actions { display: none; }

.editor-stage {
  min-width: 0;
  min-height: 0;
  position: relative;
}

.canvas-scroll {
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  overflow: auto;
  padding: 28px;
}

.canvas-shell {
  position: relative;
  width: min(1200px, 100%);
  height: max(680px, calc(100vh - 216px));
  margin: 0 auto;
  background: var(--c-base);
  border: 1px solid color-mix(in srgb, var(--c-border) 72%, transparent);
  border-radius: 4px;
  box-shadow: 0 1px 3px rgb(60 64 67 / 22%);
  overflow: hidden;
  transition: width 180ms ease, box-shadow 180ms ease;
}

.canvas-shell[data-viewport="tablet"] { width: min(768px, 100%); }
.canvas-shell[data-viewport="mobile"] { width: min(390px, 100%); }

#page-frame {
  width: 100%;
  height: 100%;
  display: block;
  background: var(--c-base);
  border: 0;
}

.selection-box {
  position: absolute;
  z-index: 3;
  pointer-events: none;
  border: 2px solid var(--c-primary);
}

.selection-box.is-locked { border-style: dashed; }
.selection-box.is-locked .resize-handle { display: none; }

.selection-label {
  position: absolute;
  bottom: calc(100% + 4px);
  left: -2px;
  max-width: 100%;
  padding: 2px 6px;
  overflow: hidden;
  color: var(--c-base);
  background: var(--c-primary);
  font-size: var(--font-size-small);
  line-height: 24px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.resize-handle {
  position: absolute;
  width: 24px;
  min-height: 24px;
  padding: 0;
  pointer-events: auto;
  background: var(--c-base);
  border: 2px solid var(--c-primary);
  border-radius: 50%;
}

.resize-nw { top: -12px; left: -12px; cursor: nwse-resize; }
.resize-ne { top: -12px; right: -12px; cursor: nesw-resize; }
.resize-sw { bottom: -12px; left: -12px; cursor: nesw-resize; }
.resize-se { right: -12px; bottom: -12px; cursor: nwse-resize; }

.code-view {
  width: 100%;
  height: 100%;
  min-height: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  padding: 20px;
  background: var(--c-canvas);
}

.code-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 16px;
  background: var(--c-base);
  border: 1px solid var(--c-border);
  border-bottom: 0;
  border-radius: 12px 12px 0 0;
}

.code-toolbar h2,
.code-toolbar p { margin: 0; }
.code-toolbar h2 { color: var(--c-strong); font-size: 13px; }
.code-toolbar p { margin-top: 2px; color: var(--c-subtle); font-size: var(--font-size-label); }

.code-editor {
  width: 100%;
  min-height: 0;
  padding: 20px;
  resize: none;
  color: var(--c-strong);
  background: var(--c-base);
  border: 1px solid var(--c-border);
  border-radius: 0 0 12px 12px;
  font: 400 13px/1.6 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  tab-size: 2;
  white-space: pre;
  overflow: auto;
}

.canvas-footer {
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-left: 16px;
  background: var(--c-base);
  border-top: 1px solid var(--c-border);
}

.canvas-hint {
  min-width: 0;
  margin: 0;
  overflow: hidden;
  color: var(--c-subtle);
  font-size: var(--font-size-label);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.zoom-controls {
  flex: 0 0 auto;
  display: flex;
  align-self: stretch;
  border-left: 1px solid var(--c-border);
}

.zoom-controls button {
  min-width: 44px;
  min-height: 44px;
  padding: 0 10px;
  color: var(--c-subtle);
  background: var(--c-base);
  border: 0;
  border-left: 1px solid var(--c-border);
  border-radius: 0;
  font-size: 13px;
}

.zoom-controls button:hover:not(:disabled) { color: var(--c-primary-hover); background: var(--c-primary-surface); }

.zoom-controls button:first-child { border-left: 0; }
#zoom-reset { min-width: 64px; }

.empty-inspector { padding: 24px 16px; color: var(--c-subtle); font-size: 13px; }
.empty-inspector p { margin: 0; }

.inspector-form { padding-bottom: 32px; }

.inspector-form fieldset {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 16px;
  border: 0;
  border-bottom: 1px solid var(--c-border);
}

.inspector-form legend { padding: 0 0 12px; }
.inspector-form label { color: var(--c-subtle); font-size: var(--font-size-label); font-weight: 700; }

.field-label {
  color: var(--c-subtle);
  font-size: var(--font-size-label);
  font-weight: 700;
}

.inspector-action,
.arrange-grid button {
  min-height: 44px;
  padding: 0 8px;
  color: var(--c-strong);
  background: var(--c-base);
  border-color: var(--c-border);
  border-radius: 12px;
  font-size: 13px;
}

.inspector-action:hover,
.arrange-grid button:hover { color: var(--c-primary-hover); background: var(--c-primary-surface); border-color: var(--c-primary-surface); }

.inspector-action[aria-pressed="true"] {
  color: var(--c-base);
  background: var(--c-primary);
  border-color: var(--c-primary);
}

.arrange-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.arrange-grid-align { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.inspector-form input,
.inspector-form select,
.inspector-form textarea {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  color: var(--c-strong);
  background: var(--c-base);
  border: 1px solid var(--c-border);
  border-radius: 8px;
}

.inspector-form input:hover,
.inspector-form select:hover,
.inspector-form textarea:hover { border-color: #bdc1c6; }

.inspector-form input:focus,
.inspector-form select:focus,
.inspector-form textarea:focus { border-color: var(--c-primary); }

.inspector-form textarea { resize: vertical; }

.inspector-form input[type="color"] {
  padding: 4px;
  cursor: pointer;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.field-grid > div { display: grid; gap: 6px; }

.unit-input { position: relative; }
.unit-input input { padding-right: 36px; }
.unit-input span {
  position: absolute;
  top: 50%;
  right: 10px;
  color: var(--c-subtle);
  font-size: var(--font-size-small);
  transform: translateY(-50%);
  pointer-events: none;
}

.full-width { width: 100%; }

.toast {
  position: fixed;
  z-index: 80;
  right: 20px;
  bottom: 20px;
  max-width: min(360px, calc(100vw - 40px));
  padding: 12px 16px;
  color: var(--c-base);
  background: var(--c-strong);
  border: 1px solid var(--c-strong);
  border-radius: 8px;
  box-shadow: 0 4px 12px rgb(60 64 67 / 28%);
  font-size: 13px;
}

.toast[data-kind="error"] {
  color: var(--c-primary-hover);
  background: var(--c-base);
  border-color: var(--c-border);
}

.drawer-backdrop {
  position: fixed;
  z-index: 30;
  inset: var(--header-height) 0 0;
  background: rgb(17 17 17 / 24%);
}

@media (max-width: 1100px) {
  :root { --left-width: 208px; --right-width: 264px; }
  .brand-copy span { display: none; }
  .canvas-scroll { padding: 20px; }
}

@media (max-width: 900px) {
  .app-header {
    grid-template-columns: 1fr auto;
    gap: 8px;
  }

  .file-actions { order: 3; grid-column: 1 / -1; }
  .history-actions { grid-column: 2; grid-row: 1; }
  .app-header { --header-height: 112px; }
  :root { --header-height: 112px; }

  .workspace { grid-template-columns: minmax(0, 1fr); }

  .sidebar {
    position: fixed;
    z-index: 40;
    top: var(--header-height);
    bottom: 0;
    width: min(360px, calc(100vw - 16px));
    transition: transform 180ms ease;
  }

  .sidebar-left { left: 0; transform: translateX(-105%); }
  .sidebar-right { right: 0; transform: translateX(105%); }
  .sidebar.is-open { transform: translateX(0); }
  .close-drawer { display: inline-flex; align-items: center; }
  .mobile-panel-actions { display: flex; }
  .canvas-region { grid-column: 1; }
  .selection-actions { display: none; }
}

@media (max-width: 560px) {
  :root { --header-height: 112px; }
  .app-header { grid-template-columns: minmax(0, 1fr) auto; }
  .brand-block strong { font-size: 15px; }
  .file-actions {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .file-actions .button { padding: 0 8px; font-size: 13px; }
  .open-prefix,
  .export-prefix { display: none; }
  .save-status { display: none; }
  .canvas-toolbar { align-items: stretch; flex-wrap: wrap; }
  .canvas-region { grid-template-rows: auto minmax(0, 1fr) 48px; }
  .mobile-panel-actions,
  .mode-switcher,
  .viewport-switcher { flex: 1 1 auto; }
  .mode-switcher { justify-content: stretch; }
  .mode-switcher button { flex: 1; white-space: nowrap; }
  .viewport-switcher { justify-content: stretch; }
  .viewport-switcher button { flex: 1; padding-inline: 8px; }
  .viewport-switcher button { padding-inline: 2px; font-size: 13px; white-space: nowrap; }
  .canvas-scroll { padding: 12px; }
  .canvas-shell { min-width: 280px; height: max(560px, calc(100vh - 260px)); }
  .code-view { padding: 12px; }
  .code-toolbar { padding: 8px 12px; }
  .code-toolbar .button { padding-inline: 12px; white-space: nowrap; }
  .code-editor { padding: 16px; font-size: 13px; }
  .canvas-footer { padding-left: 12px; }
  .canvas-hint { display: none; }
  .canvas-footer { justify-content: flex-end; }
  .canvas-footer.is-code-mode { justify-content: flex-start; }
  .canvas-footer.is-code-mode .canvas-hint { display: block; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}