:root {
  color-scheme: light;
  --csv-mask-bg: #f3f6f9;
  --csv-mask-panel: #ffffff;
  --csv-mask-panel-soft: #f6f8fa;
  --csv-mask-border: #cbd5e1;
  --csv-mask-text: #172033;
  --csv-mask-muted: #5b677a;
  --csv-mask-primary: #0969da;
  --csv-mask-primary-hover: #0757b8;
  --csv-mask-info-bg: #e8f4ff;
  --csv-mask-info-border: #8cc8ff;
  --csv-mask-success: #137333;
  --csv-mask-warning: #9a6700;
  --csv-mask-danger: #cf222e;
  --csv-mask-highlight: #fff2a8;
  --csv-mask-restored: #fff0f0;
  --csv-mask-code: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace;
  --csv-mask-border-width: 1px;
  --csv-mask-panel-gap: 16px;
  --csv-mask-panel-padding: 18px;
  --csv-mask-panel-padding-mobile: 14px;
  --csv-mask-panel-radius: 10px;
  --csv-mask-grid-gap: 12px;
  --csv-mask-control-height: 42px;
  --csv-mask-control-radius: 7px;
  --csv-mask-button-height: 38px;
  --csv-mask-rule-control-height: 34px;
  --csv-mask-table-radius: 8px;
  --csv-mask-source-height: 180px;
  --csv-mask-preview-height: 520px;
  --csv-mask-preview-height-compact: 380px;
  --csv-mask-column-width: 180px;
  --csv-mask-column-min-width: 80px;
  --csv-mask-column-max-width: 520px;
  --csv-mask-row-number-width: 62px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --csv-mask-bg: #0d1117;
  --csv-mask-panel: #161b22;
  --csv-mask-panel-soft: #21262d;
  --csv-mask-border: #46505f;
  --csv-mask-text: #f0f3f6;
  --csv-mask-muted: #a7b0bf;
  --csv-mask-primary: #2f81f7;
  --csv-mask-primary-hover: #58a6ff;
  --csv-mask-info-bg: #102b46;
  --csv-mask-info-border: #266aa8;
  --csv-mask-success: #56d364;
  --csv-mask-warning: #e3b341;
  --csv-mask-danger: #ff7b72;
  --csv-mask-highlight: #594c00;
  --csv-mask-restored: #4a2028;
}

/* Page shell and headings */
.csv-mask-main,
.csv-mask-main * {
  box-sizing: border-box;
}

body.csv-mask-page {
  margin: 0;
  min-width: 320px;
  background: var(--csv-mask-bg);
  color: var(--csv-mask-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

.csv-mask-main {
  width: min(1480px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 48px;
}

.csv-mask-page-header {
  margin-bottom: var(--csv-mask-panel-gap);
}
.csv-mask-page-header h1 {
  margin: 8px 0 4px;
  font-size: clamp(1.55rem, 3vw, 2rem);
  line-height: 1.35;
}
.csv-mask-page-header p,
.csv-mask-panel-heading p {
  margin: 4px 0 0;
  color: var(--csv-mask-muted);
}
.csv-mask-breadcrumb {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: .9rem;
}
.csv-mask-breadcrumb a {
  color: var(--csv-mask-primary);
}

/* Notices and content panels */
.csv-mask-notice,
.csv-mask-privacy {
  border: var(--csv-mask-border-width) solid var(--csv-mask-info-border);
  background: var(--csv-mask-info-bg);
  color: var(--csv-mask-primary);
}
.csv-mask-notice {
  margin-bottom: var(--csv-mask-panel-gap);
  padding: 12px 14px;
  border-radius: 9px;
}

.csv-mask-panel {
  margin-bottom: var(--csv-mask-panel-gap);
  padding: var(--csv-mask-panel-padding);
  border: var(--csv-mask-border-width) solid var(--csv-mask-border);
  border-radius: var(--csv-mask-panel-radius);
  background: var(--csv-mask-panel);
}
.csv-mask-panel-heading {
  margin-bottom: var(--csv-mask-panel-gap);
}
.csv-mask-panel-heading h2 {
  margin: 0;
  font-size: 1.15rem;
}
.csv-mask-panel-heading--row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
}

/* Form controls and actions */
.csv-mask-field,
.csv-mask-theme {
  display: grid;
  gap: 6px;
  font-weight: 600;
}
.csv-mask-field {
  margin-bottom: 14px;
}
.csv-mask-theme {
  grid-template-columns: auto minmax(110px, 150px);
  align-items: center;
  margin: 0;
}
.csv-mask-control,
.csv-mask-rule-table select,
.csv-mask-rule-table input[type="text"] {
  border: var(--csv-mask-border-width) solid var(--csv-mask-border);
  background: var(--csv-mask-panel-soft);
  color: var(--csv-mask-text);
  font: inherit;
}
.csv-mask-control {
  width: 100%;
  min-height: var(--csv-mask-control-height);
  padding: 9px 11px;
  border-radius: var(--csv-mask-control-radius);
}
.csv-mask-source {
  min-height: var(--csv-mask-source-height);
  max-height: var(--csv-mask-source-height);
  resize: none;
  font-family: var(--csv-mask-code);
  white-space: pre;
  overflow: auto;
}

.csv-mask-control:focus,
.csv-mask-button:focus-visible,
.csv-mask-file-label:focus-within,
.csv-mask-data-table td:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--csv-mask-primary) 42%, transparent);
  outline-offset: 2px;
}

.csv-mask-drop-zone {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-bottom: 14px;
  padding: 18px;
  border: 2px dashed var(--csv-mask-border);
  border-radius: 9px;
  background: var(--csv-mask-panel-soft);
  color: var(--csv-mask-muted);
}
.csv-mask-drop-zone.is-dragging {
  border-color: var(--csv-mask-primary);
  background: var(--csv-mask-info-bg);
}
.csv-mask-file-label,
.csv-mask-button {
  display: inline-flex;
  min-height: var(--csv-mask-button-height);
  align-items: center;
  justify-content: center;
  padding: 8px 13px;
  border: var(--csv-mask-border-width) solid var(--csv-mask-border);
  border-radius: var(--csv-mask-control-radius);
  background: var(--csv-mask-panel-soft);
  color: var(--csv-mask-text);
  font: inherit;
  font-weight: 600;
  line-height: 1.2;
  cursor: pointer;
}
.csv-mask-file-label:hover,
.csv-mask-button:hover:not(:disabled) {
  border-color: var(--csv-mask-primary);
}
.csv-mask-button--primary {
  border-color: var(--csv-mask-primary);
  background: var(--csv-mask-primary);
  color: #fff;
}
.csv-mask-button--primary:hover:not(:disabled) {
  background: var(--csv-mask-primary-hover);
}
.csv-mask-button:disabled {
  cursor: not-allowed;
  opacity: .5;
}
.csv-mask-file-input {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
}

.csv-mask-settings-grid,
.csv-mask-output-grid {
  display: grid;
  grid-template-columns: var(--csv-mask-grid-columns);
  gap: var(--csv-mask-grid-gap);
  align-items: end;
}
.csv-mask-settings-grid {
  --csv-mask-grid-columns: repeat(2, minmax(180px, 260px)) minmax(260px, 1fr);
}
.csv-mask-output-grid {
  --csv-mask-grid-columns: repeat(4, minmax(160px, 1fr));
}
.csv-mask-settings-grid .csv-mask-field,
.csv-mask-output-grid .csv-mask-field {
  margin: 0;
}
.csv-mask-check {
  display: inline-flex;
  min-height: var(--csv-mask-control-height);
  gap: 8px;
  align-items: center;
  color: var(--csv-mask-text);
}
.csv-mask-check input[type="checkbox"],
.csv-mask-rule-table input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--csv-mask-primary);
}
.csv-mask-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-top: 14px;
}
.csv-mask-actions--compact {
  justify-content: flex-end;
  margin-top: 0;
}

.csv-mask-message {
  min-height: 24px;
  margin: 12px 0 0;
  color: var(--csv-mask-muted);
}
.csv-mask-message[data-type="success"] {
  color: var(--csv-mask-success);
}
.csv-mask-message[data-type="warning"] {
  color: var(--csv-mask-warning);
}
.csv-mask-message[data-type="error"] {
  color: var(--csv-mask-danger);
}

/* Rule and preview tables */
.csv-mask-table-wrap {
  overflow: auto;
  border: var(--csv-mask-border-width) solid var(--csv-mask-border);
  border-radius: var(--csv-mask-table-radius);
}
.csv-mask-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: .9rem;
}
.csv-mask-table th,
.csv-mask-table td {
  padding: 9px 10px;
  border-right: var(--csv-mask-border-width) solid var(--csv-mask-border);
  border-bottom: var(--csv-mask-border-width) solid var(--csv-mask-border);
  text-align: left;
  vertical-align: top;
}
.csv-mask-table th:last-child,
.csv-mask-table td:last-child {
  border-right: 0;
}
.csv-mask-table tbody tr:last-child td {
  border-bottom: 0;
}
.csv-mask-table th {
  position: sticky;
  top: 0;
  z-index: 2;
  background: var(--csv-mask-panel-soft);
  white-space: nowrap;
}
.csv-mask-rule-table select,
.csv-mask-rule-table input[type="text"] {
  min-width: 145px;
  min-height: var(--csv-mask-rule-control-height);
  padding: 6px 8px;
  border-radius: 6px;
}
.csv-mask-kind {
  display: inline-flex;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--csv-mask-info-bg);
  color: var(--csv-mask-primary);
  white-space: nowrap;
}

.csv-mask-stats {
  --csv-mask-grid-columns: repeat(4, minmax(120px, 1fr));
  display: grid;
  grid-template-columns: var(--csv-mask-grid-columns);
  gap: 10px;
  margin: 0 0 16px;
}
.csv-mask-stats div {
  padding: 10px 12px;
  border: var(--csv-mask-border-width) solid var(--csv-mask-border);
  border-radius: var(--csv-mask-table-radius);
  background: var(--csv-mask-panel-soft);
}
.csv-mask-stats dt {
  color: var(--csv-mask-muted);
  font-size: .8rem;
}
.csv-mask-stats dd {
  margin: 0;
  font-size: 1.2rem;
  font-weight: 700;
}
.csv-mask-previews {
  --csv-mask-grid-columns: minmax(0, 1fr) minmax(0, 1fr);
  display: grid;
  grid-template-columns: var(--csv-mask-grid-columns);
  gap: var(--csv-mask-grid-gap);
}
.csv-mask-preview {
  min-width: 0;
}
.csv-mask-preview h3 {
  margin: 0 0 8px;
  font-size: 1rem;
}
.csv-mask-data-wrap {
  height: var(--csv-mask-preview-height);
  background: var(--csv-mask-panel);
}
.csv-mask-data-table {
  min-width: max-content;
  font-family: var(--csv-mask-code);
  font-size: .82rem;
  table-layout: fixed;
}
.csv-mask-data-table th,
.csv-mask-data-table td { width: var(--csv-mask-column-width); min-width: var(--csv-mask-column-min-width); max-width: var(--csv-mask-column-max-width); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.csv-mask-data-table .csv-mask-row-number {
  width: var(--csv-mask-row-number-width);
  min-width: var(--csv-mask-row-number-width);
  max-width: var(--csv-mask-row-number-width);
  text-align: right;
  color: var(--csv-mask-muted);
  background: var(--csv-mask-panel-soft);
}
.csv-mask-data-table td.is-masked {
  background: var(--csv-mask-highlight);
}
.csv-mask-data-table td.is-restored {
  background: var(--csv-mask-restored);
  text-decoration: underline;
  font-weight: 700;
}
.csv-mask-resizer {
  position: absolute;
  top: 0;
  right: -4px;
  width: 8px;
  height: 100%;
  cursor: col-resize;
  touch-action: none;
}
.csv-mask-pagination {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  align-items: center;
  margin-top: 14px;
}
.csv-mask-page-size {
  display: flex;
  gap: 7px;
  align-items: center;
  white-space: nowrap;
}
.csv-mask-page-size .csv-mask-control {
  width: 88px;
}

/* Supporting content */
.csv-mask-about h2 {
  margin-top: 0;
}
.csv-mask-about-grid {
  --csv-mask-grid-columns: 1fr 1fr;
  display: grid;
  grid-template-columns: var(--csv-mask-grid-columns);
  gap: 28px;
}
.csv-mask-privacy {
  padding: 12px 14px;
  border-radius: 8px;
}

/* Responsive layout */
@media (max-width: 900px) {
  .csv-mask-panel-heading--row {
    display: grid;
  }
  .csv-mask-theme {
    justify-self: stretch;
  }
  .csv-mask-settings-grid,
  .csv-mask-output-grid {
    --csv-mask-grid-columns: 1fr 1fr;
  }
  .csv-mask-previews {
    --csv-mask-grid-columns: 1fr;
  }
  .csv-mask-data-wrap {
    height: var(--csv-mask-preview-height-compact);
  }
}

@media (max-width: 600px) {
  .csv-mask-main {
    width: min(100% - 20px, 1480px);
    padding-top: 18px;
  }
  .csv-mask-panel {
    padding: var(--csv-mask-panel-padding-mobile);
  }
  .csv-mask-settings-grid,
  .csv-mask-output-grid,
  .csv-mask-stats,
  .csv-mask-about-grid {
    --csv-mask-grid-columns: 1fr;
  }
  .csv-mask-actions .csv-mask-button {
    flex: 1 1 auto;
  }
  .csv-mask-actions--compact {
    justify-content: stretch;
  }
}