:root {
  color-scheme: dark;
  --tools-bg: #1d2a3e;
  --tools-panel: #1f2c40;
  --tools-panel-strong: #203047;
  --tools-line: #34465d;
  --tools-text: #f0f3fa;
  --tools-muted: #9aaac0;
  --tools-accent: #58e0d3;
  --tools-accent-ink: #06373c;
  --tools-accent-soft: #173c48;
  --tools-danger: #ffb9c0;
  --tools-danger-soft: #49303c;
  --tools-shadow: none;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--tools-bg);
  color: var(--tools-text);
}

body {
  min-height: 100vh;
  overflow-x: hidden;
}

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

.tools-page {
  width: min(914px, calc(100% - 8px));
  margin: 0 auto;
  padding: 4px 0 16px;
}

.tools-toolbar {
  display: flex;
  align-items: center;
  min-height: 36px;
  margin-bottom: 12px;
}

.tools-back-link {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 14px;
  border: 1px solid var(--tools-line);
  border-radius: 8px;
  background: transparent;
  color: var(--tools-muted);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
  transition: color 0.12s ease, background 0.12s ease, border-color 0.12s ease;
}

.tools-back-link:hover {
  border-color: var(--tools-accent);
  background: var(--tools-accent-soft);
  color: var(--tools-text);
}

.tools-layout {
  display: grid;
  gap: 16px;
}

.primary-btn,
.secondary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.08s ease, background 0.12s ease, border-color 0.12s ease;
}

.primary-btn:disabled,
.secondary-btn:disabled {
  cursor: not-allowed;
  opacity: 0.52;
  transform: none;
}

.primary-btn {
  background: var(--tools-accent);
  color: var(--tools-accent-ink);
  font-weight: 650;
}

.secondary-btn {
  background: transparent;
  color: var(--tools-text);
  border: 1px solid var(--tools-line);
  font-weight: 600;
}

.primary-btn:active,
.secondary-btn:active,
.tool-card-action:active {
  transform: scale(0.98);
}

#toolStatus {
  margin: 0;
  padding: 10px 14px;
  border: 1px solid var(--tools-line);
  border-radius: 10px;
  background: var(--tools-panel);
  color: var(--tools-muted);
  box-shadow: var(--tools-shadow);
}

#toolCards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.tool-card {
  min-width: 0;
  min-height: 192px;
  padding: 16px 18px 18px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
  background: var(--tools-panel);
  border: 1px solid var(--tools-line);
  border-radius: 11px;
  box-shadow: var(--tools-shadow);
}

.tool-card.is-active {
  border-color: var(--tools-line);
}

.tool-card-header {
  display: flex;
  align-items: center;
  gap: 11px;
  min-height: 40px;
}

.tool-card-icon {
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid rgba(42, 107, 119, 0.36);
  border-radius: 9px;
  background: #183d49;
  font-size: 24px;
  line-height: 1;
}

.tool-card-icon-symbol {
  color: var(--tools-accent);
  font-size: 29px;
}

.tool-card-title {
  margin: 0;
  font-size: 18px;
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.tool-card-description {
  margin: 14px 0 7px;
  color: var(--tools-muted);
  font-size: 15px;
  line-height: 1.72;
  letter-spacing: -0.02px;
  white-space: pre-line;
}

.tool-card-action {
  min-height: 44px;
  margin-top: auto;
  padding: 0 18px;
  border: 0;
  border-radius: 8px;
  background: var(--tools-accent);
  color: var(--tools-accent-ink);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.08s ease, filter 0.12s ease;
}

.tool-card-action:hover {
  filter: brightness(1.04);
}

.tool-card-action:focus-visible,
.tools-back-link:focus-visible,
.primary-btn:focus-visible,
.secondary-btn:focus-visible,
.tool-text-input:focus-visible,
select:focus-visible {
  outline: 2px solid var(--tools-accent);
  outline-offset: 2px;
}

#toolWorkspace {
  min-height: 320px;
}

#toolWorkspace[hidden],
#toolStatus[hidden] {
  display: none;
}

.tool-workspace-panel {
  padding: 22px;
  border: 1px solid var(--tools-line);
  border-radius: 24px;
  background: var(--tools-panel);
  box-shadow: var(--tools-shadow);
}

.tool-workspace-header {
  margin-bottom: 20px;
}

.tool-workspace-title {
  margin: 0 0 8px;
  font-size: 28px;
  letter-spacing: -0.03em;
}

.tool-workspace-description {
  margin: 0;
  color: var(--tools-muted);
  line-height: 1.6;
}

.tool-file-chooser {
  display: grid;
  gap: 12px;
}

.tool-file-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tool-file-hint {
  margin: 0;
  color: var(--tools-muted);
}

.tool-drop-zone {
  width: 100%;
  min-height: 128px;
  padding: 22px;
  display: grid;
  place-items: center;
  gap: 6px;
  border: 1px dashed rgba(88, 224, 211, 0.45);
  border-radius: 18px;
  background: var(--tools-accent-soft);
  color: var(--tools-text);
  cursor: pointer;
  text-align: center;
}

.tool-drop-zone.is-dragover {
  border-style: solid;
  border-color: var(--tools-accent);
}

.tool-drop-zone-title {
  font-size: 18px;
  font-weight: 700;
}

.tool-drop-zone-copy {
  color: var(--tools-muted);
}

.tool-workspace-info {
  display: grid;
  gap: 8px;
  margin: 18px 0 16px;
}

.tool-file-summary,
.tool-progress-text {
  margin: 0;
  color: var(--tools-muted);
}

.tool-error {
  margin-bottom: 16px;
  padding: 12px 14px;
  border-radius: 14px;
  background: var(--tools-danger-soft);
  color: var(--tools-danger);
}

.tool-file-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.tool-action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.tool-text-input {
  width: 100%;
  min-height: 44px;
  padding: 9px 12px;
  border: 1px solid var(--tools-line);
  border-radius: 12px;
  background: var(--tools-panel-strong);
  color: var(--tools-text);
}

.tool-text-input:focus,
.merge-file-item:focus-visible,
.merge-drag-handle:focus-visible,
.tool-icon-btn:focus-visible {
  outline: 3px solid rgba(88, 224, 211, 0.34);
  outline-offset: 2px;
}

.merge-output-field,
.split-range-field {
  display: grid;
  gap: 8px;
  margin-top: 18px;
  color: var(--tools-text);
  font-weight: 700;
}

.tool-field-hint {
  margin: 8px 0 0;
  color: var(--tools-muted);
  font-size: 13px;
  line-height: 1.5;
}

.merge-file-list {
  gap: 10px;
  counter-reset: merge-file;
}

.merge-file-item {
  display: grid;
  grid-template-columns: auto auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  touch-action: manipulation;
  user-select: none;
}

.merge-file-item.is-dragging {
  border-color: var(--tools-accent);
  background: var(--tools-accent-soft);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.16);
}

.merge-drag-handle {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 1px solid var(--tools-line);
  border-radius: 10px;
  background: var(--tools-panel-strong);
  color: var(--tools-muted);
  cursor: grab;
  font-size: 20px;
  line-height: 1;
  touch-action: none;
}

.merge-drag-handle:active {
  cursor: grabbing;
}

.merge-file-position {
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--tools-accent-soft);
  color: var(--tools-accent);
  font-size: 13px;
  font-weight: 800;
}

.merge-file-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
}

.tool-icon-btn {
  min-width: 38px;
  min-height: 38px;
  padding: 0 10px;
}

.split-page-count {
  min-height: 20px;
}

.split-range-error {
  margin: 12px 0 0;
}

.merge-workspace .tool-file-summary,
.split-workspace .tool-file-summary,
.tool-progress-text {
  line-height: 1.5;
}

.page-tool-file-picker {
  display: grid;
  gap: 12px;
}

.image-file-list {
  counter-reset: image-file;
}

.image-file-item {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) auto;
  align-items: center;
}

.image-file-preview {
  width: 64px;
  height: 64px;
  object-fit: contain;
  border: 1px solid var(--tools-line);
  border-radius: 10px;
  background: var(--tools-panel-strong);
}

.image-settings {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 180px));
  gap: 12px;
  margin-top: 18px;
}

.image-setting {
  display: grid;
  gap: 8px;
  color: var(--tools-text);
  font-weight: 700;
}

.image-setting select {
  appearance: auto;
  cursor: pointer;
}

.page-tool-workspace {
  display: grid;
  gap: 0;
}

.page-tool-options {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 18px;
}

.page-tool-fieldset {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.page-tool-fieldset legend {
  width: 100%;
  margin-bottom: 4px;
  color: var(--tools-text);
  font-weight: 700;
}

.page-tool-radio {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 38px;
  padding: 0 10px;
  border: 1px solid var(--tools-line);
  border-radius: 999px;
  background: var(--tools-panel-strong);
  color: var(--tools-text);
  cursor: pointer;
}

.page-tool-radio input {
  accent-color: var(--tools-accent);
}

.page-tool-grid-wrap {
  margin-top: 18px;
}

.page-tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
  gap: 14px;
  align-items: start;
}

.page-tool-card {
  min-width: 0;
  padding: 10px;
  border: 1px solid var(--tools-line);
  border-radius: 16px;
  background: var(--tools-panel-strong);
  transition: border-color 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
}

.page-tool-card.is-selected {
  border-color: rgba(88, 224, 211, 0.72);
  background: var(--tools-accent-soft);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.14);
}

.page-tool-card.is-dragging {
  opacity: 0.58;
}

.page-tool-card.is-drop-target {
  border-top: 4px solid var(--tools-accent);
}

.page-tool-card-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  min-height: 28px;
  margin-bottom: 8px;
}

.page-tool-position {
  display: inline-grid;
  place-items: center;
  min-width: 26px;
  height: 26px;
  padding: 0 6px;
  border-radius: 50%;
  background: var(--tools-accent-soft);
  color: var(--tools-accent);
  font-size: 12px;
  font-weight: 800;
}

.page-tool-number {
  color: var(--tools-muted);
  font-size: 13px;
  font-weight: 700;
}

.page-tool-thumb-shell {
  display: grid;
  place-items: center;
  min-height: 190px;
  overflow: hidden;
  border-radius: 10px;
  background: linear-gradient(135deg, #26364b, #1a2739);
}

.page-tool-thumb-shell::before {
  content: '正在載入預覽…';
  color: var(--tools-muted);
  font-size: 12px;
}

.page-tool-thumb-shell[data-ready="true"]::before,
.page-tool-thumb-shell[data-error="true"]::before {
  display: none;
}

.page-tool-thumb-shell canvas {
  display: block;
  max-width: 100%;
  height: auto;
  background: #ffffff;
  box-shadow: 0 3px 8px rgba(14, 28, 46, 0.14);
}

.page-tool-card-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
  margin-top: 10px;
}

.page-tool-select,
.page-tool-drag-handle {
  min-height: 36px;
  padding: 0 10px;
}

.page-tool-drag-handle {
  border: 1px solid var(--tools-line);
  border-radius: 10px;
  background: var(--tools-panel-strong);
  color: var(--tools-muted);
  cursor: grab;
  font-size: 18px;
  touch-action: none;
}

.page-tool-drag-handle:active {
  cursor: grabbing;
}

.page-selection-actions {
  margin-top: 14px;
}

.tool-file-item,
.tool-file-empty {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border: 1px solid var(--tools-line);
  border-radius: 16px;
  background: var(--tools-panel-strong);
}

.tool-file-meta {
  min-width: 0;
}

.tool-file-name {
  font-weight: 650;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tool-file-details,
.tool-file-empty {
  color: var(--tools-muted);
}

.tool-file-remove {
  flex: 0 0 auto;
}

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

@media (max-width: 768px) {
  .tools-page {
    width: min(100%, calc(100% - 20px));
    padding-top: 18px;
  }

  .tools-header {
    flex-direction: column;
    align-items: stretch;
  }

  #toolCards {
    grid-template-columns: minmax(0, 1fr);
  }

  .tool-card,
  .tool-workspace-panel {
    padding: 18px;
  }

  .tool-file-item,
  .tool-file-empty {
    flex-direction: column;
    align-items: stretch;
  }

  .image-file-item {
    display: grid;
    grid-template-columns: 64px minmax(0, 1fr);
  }

  .image-file-item .tool-file-remove {
    grid-column: 1 / -1;
  }

  .image-settings {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .tool-file-remove {
    width: 100%;
  }

  .merge-file-item {
    grid-template-columns: auto auto minmax(0, 1fr);
  }

  .merge-file-actions {
    grid-column: 1 / -1;
    justify-content: stretch;
  }

  .merge-file-actions .secondary-btn {
    flex: 1 1 0;
  }

  .page-tool-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .page-tool-card {
    padding: 8px;
  }

  .page-tool-thumb-shell {
    min-height: 150px;
  }

  .page-tool-card-actions > * {
    flex: 1 1 auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
    scroll-behavior: auto !important;
  }
}