/* Design tokens */
:root {
  color-scheme: light;
  --regex-background: #f4f6f8;
  --regex-surface: #ffffff;
  --regex-surface-subtle: #f6f8fa;
  --regex-border: #d0d7de;
  --regex-text: #1f2328;
  --regex-muted: #57606a;
  --regex-accent: #0969da;
  --regex-accent-hover: #0757b5;
  --regex-success: #1a7f37;
  --regex-warning: #9a6700;
  --regex-danger: #cf222e;
  --regex-mark: #fff1a8;
  --regex-font-family: "Cascadia Code", "Consolas", monospace;
  --regex-font-size: 14px;
  --regex-border-width: 1px;
  --regex-surface-radius: 10px;
  --regex-control-radius: 7px;
  --regex-control-height: 36px;
  --regex-text-input-height: 42px;
  --regex-content-spacing: 14px;
  --regex-panel-padding: 16px;
  --regex-focus-width: 2px;
  --regex-focus-offset: 1px;
  --regex-editor-min-height: 240px;
  --regex-replacement-min-height: 180px;
  --regex-table-min-width: 760px;
  --regex-surface-shadow: 0 1px 2px rgba(31, 35, 40, 0.06);
}

/* Page foundation */
* {
  box-sizing: border-box;
}

body.regex-tester-page {
  margin: 0;
  min-height: 100vh;
  color: var(--regex-text);
  background: var(--regex-background);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

.regex-tester-page main {
  width: min(1200px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0;
}

/* Page-owned classes stay namespaced so the injected site shell is not restyled. */
.regex-tester-page .regex-page-header {
  margin-bottom: 16px;
}

.regex-tester-page h1 {
  margin: 8px 0 0;
  font-size: clamp(1.7rem, 3vw, 2.2rem);
}

.regex-tester-page .regex-page-header p {
  margin: 8px 0 0;
  color: var(--regex-muted);
  line-height: 1.7;
}

.regex-tester-page .regex-breadcrumb {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: 0.9rem;
}

.regex-tester-page .regex-breadcrumb a {
  color: var(--regex-accent);
  font-weight: 700;
  text-decoration: none;
}

.regex-tester-page .regex-breadcrumb a:hover,
.regex-tester-page .regex-breadcrumb a:focus-visible {
  text-decoration: underline;
}

/* Shared surfaces */
.regex-notice,
.regex-workspace,
.regex-panel {
  border: var(--regex-border-width) solid var(--regex-border);
  border-radius: var(--regex-surface-radius);
  background: var(--regex-surface);
  box-shadow: var(--regex-surface-shadow);
}

.regex-notice {
  margin: 0 0 16px;
  padding: 12px 14px;
  color: #0550ae;
  background: #ddf4ff;
  border-color: #b6e3ff;
  line-height: 1.6;
}

/* Workspace theme */
.regex-workspace {
  --workspace-surface: var(--regex-surface);
  --workspace-surface-subtle: var(--regex-surface-subtle);
  --workspace-border: var(--regex-border);
  --workspace-text: var(--regex-text);
  --workspace-muted: var(--regex-muted);
  --workspace-input: var(--regex-surface);
  --workspace-mark: var(--regex-mark);
  overflow: hidden;
  color: var(--workspace-text);
  background: var(--workspace-surface);
}

.regex-workspace[data-theme="dark"] {
  color-scheme: dark;
  --workspace-surface: #161b22;
  --workspace-surface-subtle: #21262d;
  --workspace-border: #3d444d;
  --workspace-text: #f0f6fc;
  --workspace-muted: #9da7b3;
  --workspace-input: #0d1117;
  --workspace-mark: #6e5f16;
}

/* Workspace chrome */
.regex-toolbar,
.regex-settings,
.regex-pattern-row,
.regex-panel-heading,
.regex-summary {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.regex-toolbar,
.regex-settings {
  padding: 12px 14px;
  background: var(--workspace-surface-subtle);
  border-bottom: var(--regex-border-width) solid var(--workspace-border);
}

.regex-toolbar {
  justify-content: space-between;
}

.regex-toolbar-group {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* Form controls */
.regex-workspace button,
.regex-workspace select,
.regex-workspace input,
.regex-workspace textarea {
  color: var(--workspace-text);
  border: var(--regex-border-width) solid var(--workspace-border);
  border-radius: var(--regex-control-radius);
  background: var(--workspace-input);
  font: inherit;
}

.regex-workspace button,
.regex-workspace select {
  min-height: var(--regex-control-height);
}

.regex-workspace button {
  padding: 0 12px;
  background: var(--workspace-surface-subtle);
  font-weight: 700;
  cursor: pointer;
}

.regex-workspace button:hover,
.regex-workspace button:focus-visible,
.regex-workspace select:hover,
.regex-workspace select:focus-visible,
.regex-workspace input:focus-visible,
.regex-workspace textarea:focus-visible {
  border-color: var(--regex-accent);
  outline: var(--regex-focus-width) solid color-mix(in srgb, var(--regex-accent) 24%, transparent);
  outline-offset: var(--regex-focus-offset);
}

.regex-workspace button.regex-primary-button {
  color: #ffffff;
  background: var(--regex-accent);
  border-color: var(--regex-accent);
}

.regex-workspace button.regex-primary-button:hover,
.regex-workspace button.regex-primary-button:focus-visible {
  background: var(--regex-accent-hover);
}

.regex-workspace button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.regex-settings label,
.regex-toolbar label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--workspace-muted);
  font-weight: 700;
}

.regex-settings select,
.regex-toolbar select {
  padding: 0 30px 0 10px;
}

.regex-pattern-input,
.regex-editor,
.regex-output,
.regex-replacement-input,
.regex-table .regex-code-cell {
  font-family: var(--regex-font-family);
  font-size: var(--regex-font-size);
}

/* Content and panels */
.regex-content {
  display: grid;
  gap: var(--regex-content-spacing);
  padding: var(--regex-content-spacing);
}

.regex-panel {
  min-width: 0;
  padding: var(--regex-panel-padding);
  color: var(--workspace-text);
  background: var(--workspace-surface);
  border-color: var(--workspace-border);
  box-shadow: none;
}

.regex-panel-title {
  margin: 0;
  font-size: 1.05rem;
}

.regex-panel-heading {
  justify-content: space-between;
  margin-bottom: 12px;
}

.regex-field-label {
  display: block;
  margin: 10px 0 6px;
  color: var(--workspace-muted);
  font-weight: 700;
}

.regex-panel-heading + .regex-field-label {
  margin-top: 0;
}

/* Pattern and flags */
.regex-pattern-row {
  align-items: stretch;
}

.regex-delimiter {
  align-self: center;
  color: var(--workspace-muted);
  font: 700 1.25rem/1 var(--regex-font-family);
}

.regex-pattern-input {
  flex: 1 1 480px;
  min-width: 0;
  height: var(--regex-text-input-height);
  padding: 0 12px;
}

.regex-flags {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  margin: 12px 0 0;
  padding: 0;
  border: 0;
}

.regex-flags legend {
  float: left;
  margin-right: 8px;
  color: var(--workspace-muted);
  font-weight: 700;
}

.regex-flags label {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  min-height: 34px;
  gap: 5px;
  padding: 4px 8px;
  color: var(--workspace-text);
  border: var(--regex-border-width) solid var(--workspace-border);
  border-radius: var(--regex-control-radius);
  background: var(--workspace-surface-subtle);
  font: 700 0.9rem/1 var(--regex-font-family);
}

.regex-flags label.regex-unsupported {
  opacity: 0.45;
}

.regex-flags input {
  margin: 0;
  accent-color: var(--regex-accent);
}

/* Editors and highlighted output */
.regex-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--regex-content-spacing);
}

.regex-drop-zone {
  transition: border-color 0.15s ease, background 0.15s ease;
}

.regex-drop-zone.regex-dragging {
  border-color: var(--regex-accent);
  background: color-mix(in srgb, var(--regex-accent) 8%, var(--workspace-surface));
}

.regex-editor,
.regex-output {
  display: block;
  width: 100%;
  min-height: var(--regex-editor-min-height);
  resize: vertical;
  padding: 12px;
  color: var(--workspace-text);
  background: var(--workspace-input);
  line-height: 1.6;
  tab-size: 4;
  white-space: pre;
  overflow: auto;
}

.regex-output {
  margin: 0;
  border: var(--regex-border-width) solid var(--workspace-border);
  border-radius: var(--regex-control-radius);
}

.regex-output mark {
  padding: 0;
  color: inherit;
  background: var(--workspace-mark);
  border-radius: 2px;
}

.regex-output .regex-zero-width-match {
  color: var(--regex-danger);
  background: transparent;
  font-weight: 900;
}

.regex-meta {
  display: flex;
  gap: 10px;
  justify-content: space-between;
  margin-top: 8px;
  color: var(--workspace-muted);
  font-size: 0.82rem;
}

.regex-replacement-input {
  width: 100%;
  min-height: var(--regex-text-input-height);
  padding: 9px 12px;
}

.regex-replacement-output {
  min-height: var(--regex-replacement-min-height);
  resize: vertical;
}

/* Status and messages */
.regex-summary {
  padding: 10px 14px;
  color: var(--workspace-muted);
  background: var(--workspace-surface-subtle);
  border-top: var(--regex-border-width) solid var(--workspace-border);
  border-bottom: var(--regex-border-width) solid var(--workspace-border);
}

.regex-summary strong {
  color: var(--workspace-text);
}

.regex-status-text[data-state="success"] {
  color: var(--regex-success);
}

.regex-status-text[data-state="warning"] {
  color: var(--regex-warning);
}

.regex-status-text[data-state="error"] {
  color: var(--regex-danger);
}

.regex-message {
  margin: 0 0 12px;
  padding: 10px 12px;
  border: var(--regex-border-width) solid;
  border-radius: var(--regex-control-radius);
  line-height: 1.5;
}

.regex-error {
  color: var(--regex-danger);
  background: color-mix(in srgb, var(--regex-danger) 9%, var(--workspace-surface));
  border-color: color-mix(in srgb, var(--regex-danger) 35%, var(--workspace-border));
}

.regex-risk {
  color: var(--regex-warning);
  background: color-mix(in srgb, #bf8700 10%, var(--workspace-surface));
  border-color: color-mix(in srgb, #bf8700 40%, var(--workspace-border));
}

.regex-risk strong {
  display: block;
  margin-bottom: 5px;
}

.regex-risk ul,
.regex-explanation ul {
  margin: 0;
  padding-left: 1.3rem;
}

/* Match table and explanation */
.regex-table-wrap {
  overflow: auto;
  border: var(--regex-border-width) solid var(--workspace-border);
  border-radius: var(--regex-control-radius);
}

.regex-table {
  width: 100%;
  min-width: var(--regex-table-min-width);
  border-collapse: collapse;
}

.regex-table th,
.regex-table td {
  padding: 9px 10px;
  text-align: left;
  vertical-align: top;
  border-right: var(--regex-border-width) solid var(--workspace-border);
  border-bottom: var(--regex-border-width) solid var(--workspace-border);
}

.regex-table th {
  position: sticky;
  top: 0;
  z-index: 1;
  background: var(--workspace-surface-subtle);
  white-space: nowrap;
}

.regex-table td:first-child,
.regex-table td:nth-child(3),
.regex-table td:nth-child(4) {
  white-space: nowrap;
}

.regex-table .regex-code-cell {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.regex-empty {
  padding: 24px;
  color: var(--workspace-muted);
  text-align: center;
}

.regex-explanation {
  line-height: 1.7;
}

.regex-explanation p {
  color: var(--workspace-muted);
}

/* Visibility utilities */
[hidden] {
  display: none !important;
}

/* Responsive layout */
@media (max-width: 800px) {
  .regex-tester-page main {
    width: min(100% - 20px, 1200px);
    padding: 20px 0;
  }

  .regex-grid {
    grid-template-columns: 1fr;
  }

  .regex-toolbar,
  .regex-settings {
    align-items: stretch;
  }

  .regex-toolbar-group {
    width: 100%;
  }

  .regex-toolbar-group > * {
    flex: 1 1 auto;
  }
}