/* ============================================
   Regex Tester - Layout & Styles

   Breakpoints:
     Mobile:    < 768px   (single column, compact)
     Tablet:    768-1023px (single column, comfortable)
     Desktop:   1024-1399px (two column panels, no ads)
     Wide:      >= 1400px  (two column panels + ad sidebars)
   ============================================ */

/* ======================
   BASE LAYOUT
   ====================== */

html {
  background-color: #0d9488;
}

body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  background: linear-gradient(135deg, #0d9488 0%, #0f766e 100%);
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 40% 20%, rgba(255, 255, 255, 0.03) 0%, transparent 50%);
  animation: float 20s ease-in-out infinite;
  pointer-events: none;
  z-index: 0;
}

@keyframes float {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(5deg); }
}

/* ======================
   HEADER
   ====================== */

.header {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding: var(--space-3) 0;
  flex-shrink: 0;
  position: relative;
  z-index: 10;
}

.header-content {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.logo-link {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  color: white;
  transition: all var(--transition-base);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(5px);
  flex-shrink: 0;
}

.logo-link:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.logo-text {
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.logo-dot {
  color: #fbbf24;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.2); }
}

.title {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

/* ======================
   REGEX INPUT BAR
   ====================== */

.regex-input-bar {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding: var(--space-3) 0;
  flex-shrink: 0;
  position: relative;
  z-index: 10;
}

.regex-input-content {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.regex-delimiter {
  color: white;
  font-size: var(--text-xl);
  font-family: var(--font-mono);
  font-weight: var(--font-bold);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  flex-shrink: 0;
}

.regex-pattern-input {
  flex: 1;
  min-width: 200px;
  padding: var(--space-2) var(--space-4);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 16px; /* iOS auto-zoom prevention */
  color: var(--color-gray-900);
  transition: all var(--transition-base);
}

.regex-pattern-input:focus {
  outline: none;
  background: white;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.regex-pattern-input::placeholder {
  color: var(--color-gray-400);
}

/* Flag Toggles */
.flag-toggles {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  flex-shrink: 0;
}

.flag-btn {
  min-width: 36px;
  min-height: 36px;
  padding: var(--space-2);
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-sm);
  color: white;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  cursor: pointer;
  transition: all var(--transition-base);
  user-select: none;
}

.flag-btn:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.flag-btn.active {
  background: rgba(59, 130, 246, 0.6);
  border-color: rgba(59, 130, 246, 0.8);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.options-right {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
  flex-shrink: 0;
}

/* Regex Error */
.regex-error {
  padding: var(--space-2) var(--space-4);
  margin-top: var(--space-2);
  background: rgba(239, 68, 68, 0.1);
  border-left: 3px solid #ef4444;
  border-radius: var(--radius-md);
  color: #dc2626;
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  transition: opacity var(--transition-base);
}

.regex-error:empty {
  display: none !important;
}

/* ======================
   TAB NAVIGATION
   ====================== */

.tabs-nav {
  display: flex;
  gap: var(--space-2);
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding: var(--space-2) var(--space-4);
  flex-shrink: 0;
  position: relative;
  z-index: 10;
}

.tab-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-4);
  background: transparent;
  border: none;
  border-bottom: 3px solid transparent;
  color: rgba(255, 255, 255, 0.7);
  font-weight: var(--font-medium);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: all var(--transition-base);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.tab-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.9);
}

.tab-btn.active {
  color: white;
  border-bottom-color: white;
  background: rgba(255, 255, 255, 0.2);
  font-weight: var(--font-semibold);
}

.tab-icon {
  font-size: var(--text-xl);
}

.tab-label {
  font-size: var(--text-sm);
}

/* ======================
   REPLACE OPTIONS
   ====================== */

.replace-options {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding: var(--space-3) 0;
  flex-shrink: 0;
  position: relative;
  z-index: 10;
}

.replace-options-content {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.replace-label {
  color: white;
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  white-space: nowrap;
  flex-shrink: 0;
}

.replace-pattern-input {
  flex: 1;
  min-width: 200px;
  padding: var(--space-2) var(--space-4);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--color-gray-900);
  transition: all var(--transition-base);
}

.replace-pattern-input:focus {
  outline: none;
  background: white;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.replace-pattern-input::placeholder {
  color: var(--color-gray-400);
}

/* ======================
   AUTO-EXECUTE TOGGLE
   ====================== */

.auto-execute-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  cursor: pointer;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all var(--transition-base);
  user-select: none;
  line-height: 1;
}

.auto-execute-toggle:hover {
  background: rgba(255, 255, 255, 0.25);
}

.auto-execute-toggle:has(input:checked) {
  background: rgba(16, 185, 129, 0.3);
  border-color: rgba(16, 185, 129, 0.5);
}

.auto-execute-toggle input[type="checkbox"] {
  width: 14px;
  height: 14px;
  accent-color: #10b981;
  cursor: pointer;
  margin: 0;
}

.auto-execute-label {
  color: white;
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  letter-spacing: 0.02em;
}

/* ======================
   PAGE BODY
   ====================== */

.page-body {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr;
  grid-template-areas: "content";
  min-height: 0;
  overflow: hidden;
  position: relative;
  z-index: 1;
}

/* ======================
   AD SIDEBARS
   ====================== */

.ad-sidebar {
  display: none;
  align-self: center;
  padding: var(--space-4) 0;
}

.ad-sidebar-left {
  grid-area: ad-left;
  justify-self: center;
}

.ad-sidebar-right {
  grid-area: ad-right;
  justify-self: center;
}

.ad-sticky {
  position: sticky;
  top: var(--space-4);
}

.ad-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  width: 160px;
  height: 600px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border: 2px dashed rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-md);
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  line-height: 1.4;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

/* ======================
   MAIN CONTENT
   ====================== */

.main-content {
  grid-area: content;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: var(--space-4) 0;
  min-height: 0;
}

/* ======================
   TAB CONTENT
   ====================== */

/* Prevent tab flicker on load */
body:not(.tabs-initialized) .tab-content {
  visibility: hidden;
}

.tab-content {
  display: none;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.tab-content.active {
  display: flex;
  flex-direction: column;
}

/* Cheatsheet tab specific */
.tab-content[data-tab-content="cheatsheet"] {
  overflow: hidden;
}

.tab-content[data-tab-content="cheatsheet"] > .container {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ======================
   PANELS
   ====================== */

.panels-container {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  min-height: 0;
}

@media (min-width: 1024px) {
  .panels-container {
    grid-template-columns: 1fr 1fr;
  }
}

.panel {
  display: flex;
  flex-direction: column;
  background: rgba(255, 255, 255, 0.95);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255, 255, 255, 0.3);
  overflow: hidden;
  min-height: 0;
  box-shadow:
    0 20px 60px rgba(0, 0, 0, 0.3),
    0 0 0 1px rgba(255, 255, 255, 0.1);
  transition: box-shadow var(--transition-base);
}

.panel:hover {
  box-shadow:
    0 30px 80px rgba(0, 0, 0, 0.4),
    0 0 0 1px rgba(255, 255, 255, 0.2);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-5);
  background: linear-gradient(135deg, rgba(13, 148, 136, 0.1), rgba(15, 118, 110, 0.1));
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.panel-title {
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  color: var(--color-gray-900);
}

.btn-icon {
  background: rgba(13, 148, 136, 0.1);
  border: none;
  cursor: pointer;
  font-size: var(--text-xl);
  padding: var(--space-2);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  color: var(--color-gray-700);
}

.btn-icon:hover {
  background: rgba(13, 148, 136, 0.2);
  transform: scale(1.1);
}

.panel-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.match-count {
  color: var(--color-gray-600);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  padding: var(--space-1) var(--space-3);
  background: rgba(13, 148, 136, 0.1);
  border-radius: var(--radius-md);
}

.panel-body {
  flex: 1;
  padding: var(--space-4);
  overflow: hidden;
  display: flex;
  min-height: 0;
}

.panel-body .textarea {
  flex: 1;
  min-height: 0;
  resize: none;
  font-size: var(--text-sm);
  line-height: 1.6;
  tab-size: 2;
  border: none;
  background: transparent;
  color: var(--color-gray-900);
}

.panel-body .textarea:focus {
  outline: none;
  box-shadow: none;
}

/* ======================
   MATCH RESULTS
   ====================== */

.match-result-container,
.replace-result-container {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  overflow-y: auto;
  height: 100%;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

.match-result-content,
.replace-result-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.empty-state {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--color-gray-500);
  font-size: var(--text-sm);
  text-align: center;
  padding: var(--space-6);
}

.highlighted-section,
.details-section,
.result-section,
.changes-section {
  flex-shrink: 0;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-2);
  border-bottom: 1px solid var(--color-border);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-gray-600);
}

.highlighted-text {
  padding: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-all;
  overflow-x: auto;
}

/* Match Highlighting - 4-color rotation */
.match {
  padding: 0 2px;
  border-radius: 2px;
  transition: all var(--transition-base);
  cursor: pointer;
}

.match.match-0 { background: rgba(59, 130, 246, 0.3); }   /* blue */
.match.match-1 { background: rgba(16, 185, 129, 0.3); }   /* green */
.match.match-2 { background: rgba(245, 158, 11, 0.3); }   /* orange */
.match.match-3 { background: rgba(236, 72, 153, 0.3); }   /* pink */

.match:hover {
  outline: 2px solid currentColor;
  z-index: 1;
}

.match-details {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.match-detail-item {
  padding: var(--space-2) var(--space-3);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  line-height: 1.6;
  transition: all var(--transition-base);
}

.match-detail-item strong {
  display: block;
  margin-bottom: var(--space-1);
  color: var(--color-gray-700);
}

.match-detail-item code {
  background: var(--color-gray-100);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  color: var(--color-primary);
}

.group-info {
  margin-left: var(--space-3);
  color: var(--color-gray-600);
  font-size: var(--text-xs);
}

/* ======================
   REPLACE RESULTS
   ====================== */

.replaced-text {
  padding: var(--space-3);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-all;
  overflow-x: auto;
  margin: 0;
}

.change-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.change-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

.change-old {
  padding: var(--space-1) var(--space-2);
  background: rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-sm);
  text-decoration: line-through;
  color: var(--color-error);
  font-family: var(--font-mono);
}

.change-arrow {
  color: var(--color-gray-400);
  font-weight: var(--font-bold);
}

.change-new {
  padding: var(--space-1) var(--space-2);
  background: rgba(16, 185, 129, 0.2);
  border-radius: var(--radius-sm);
  color: var(--color-success);
  font-weight: var(--font-semibold);
  font-family: var(--font-mono);
}

.change-location {
  margin-left: auto;
  color: var(--color-gray-500);
  font-size: var(--text-xs);
}

/* ======================
   CHEAT SHEET
   ====================== */

.cheatsheet-container {
  padding: var(--space-6);
  overflow-y: auto;
  overflow-x: hidden;
  flex: 1;
  min-height: 0;
  -webkit-overflow-scrolling: touch;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  grid-auto-rows: max-content;
}

.cheatsheet-container::-webkit-scrollbar {
  width: 12px;
}

.cheatsheet-container::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
}

.cheatsheet-container::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.3);
  border-radius: 10px;
}

.cheatsheet-container::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.5);
}

.cheat-category {
  margin-bottom: 0;
}

.cheat-category h3 {
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  color: var(--color-gray-900);
  margin-bottom: var(--space-3);
}

.cheat-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

.cheat-table td {
  padding: var(--space-2) var(--space-3);
  vertical-align: top;
}

.cheat-table td:first-child {
  font-family: var(--font-mono);
  font-weight: var(--font-semibold);
  color: var(--color-primary);
  white-space: nowrap;
  width: 120px;
}

.cheat-table td:last-child {
  color: rgba(255, 255, 255, 0.9);
}

.cheat-table code {
  font-family: var(--font-mono);
  background: rgba(230, 235, 255, 0.85);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(180, 195, 245, 0.6);
  color: #7c66dc;
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
}

/* Presets */
.presets-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.cheat-preset {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  min-height: 44px; /* Mobile touch area */
}

.cheat-preset:hover {
  background: rgba(59, 130, 246, 0.08);
  border-color: rgba(59, 130, 246, 0.3);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.cheat-preset:active {
  background: rgba(59, 130, 246, 0.15);
  transform: translateY(0);
}

.preset-icon {
  font-size: var(--text-xl);
  flex-shrink: 0;
}

.preset-info {
  flex: 1;
  min-width: 0;
}

.preset-name {
  font-weight: var(--font-semibold);
  color: var(--color-gray-900);
  margin-bottom: var(--space-1);
}

.preset-pattern {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-gray-600);
  display: block;
  white-space: pre-wrap;
  word-break: break-all;
  line-height: 1.5;
}

/* 2-column layout (desktop) */
@media (min-width: 1024px) {
  .cheatsheet-container {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ======================
   STATUS BAR
   ====================== */

.status-bar {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  padding: var(--space-2) 0;
  flex-shrink: 0;
  position: relative;
  z-index: 10;
}

.status-content {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  font-size: var(--text-sm);
}

.status-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.status-label {
  color: rgba(255, 255, 255, 0.8);
  font-weight: var(--font-medium);
}

#char-count,
#line-count,
#status-text {
  color: white;
  font-weight: var(--font-semibold);
}

/* ============================================
   RESPONSIVE: Wide Desktop (>= 1400px)
   ============================================ */

@media (min-width: 1400px) {
  .page-body {
    grid-template-columns: 200px 1fr 200px;
    grid-template-areas: "ad-left content ad-right";
  }

  .ad-sidebar {
    display: block;
  }
}

/* ============================================
   RESPONSIVE: Mobile (< 768px)
   ============================================ */

@media (max-width: 767px) {
  /* Mobile viewport: allow scrolling */
  body {
    height: auto;
    min-height: 100vh;
    min-height: 100dvh;
    overflow-y: auto;
  }

  .tab-content.active {
    flex-shrink: 0;
    overflow: visible;
  }

  /* Cheatsheet needs scroll on mobile too */
  .tab-content[data-tab-content="cheatsheet"].active {
    overflow: hidden;
    flex: 1;
    min-height: 0;
  }

  .tab-content[data-tab-content="cheatsheet"] > .container {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }

  .page-body {
    overflow: visible;
    min-height: auto;
  }

  /* Header */
  .header {
    padding: var(--space-2) 0;
  }

  .title {
    font-size: var(--text-sm);
  }

  .logo-link {
    font-size: var(--text-sm);
    padding: var(--space-1) var(--space-2);
  }

  /* Regex Input Bar */
  .regex-input-content {
    gap: var(--space-2);
  }

  /* 플래그를 왼쪽 정렬 */
  .flag-toggles {
    width: 100%;
    justify-content: flex-start;
    gap: var(--space-2);
  }

  .flag-btn {
    min-width: 44px;   /* iOS recommended touch size */
    min-height: 44px;
  }

  .regex-pattern-input,
  .replace-pattern-input {
    font-size: 16px; /* Auto-zoom prevention */
  }

  /* 액션 버튼들을 오른쪽 정렬 */
  .options-right {
    width: 100%;
    margin-left: 0;
    justify-content: flex-end;
    gap: var(--space-2);
  }

  /* Replace Options */
  .replace-options-content {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-2);
  }

  .replace-label {
    width: 100%;
  }

  /* Tabs */
  .tab-btn {
    flex-direction: row;
    font-size: var(--text-xs);
    padding: var(--space-2) var(--space-3);
    gap: var(--space-2);
  }

  .tab-icon {
    font-size: var(--text-base);
  }

  .tab-label {
    font-size: var(--text-xs);
  }

  /* Shorten button text on mobile */
  #btn-example::after {
    content: 'Try';
  }

  #btn-example {
    font-size: 0;
    min-width: auto;
  }

  #btn-example::after {
    font-size: var(--text-sm);
  }

  .btn-sm {
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm);
  }

  .auto-execute-toggle {
    padding: var(--space-2) var(--space-2);
  }

  /* Main Content */
  .main-content {
    padding: var(--space-2) 0;
    overflow: visible;
  }

  .panels-container {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    gap: var(--space-2);
  }

  .panel {
    min-height: 40vh;
  }

  .panel-header {
    padding: var(--space-2) var(--space-3);
  }

  .panel-title {
    font-size: var(--text-sm);
  }

  .panel-body {
    padding: var(--space-2) var(--space-3);
    overflow: auto;
  }

  /* Cheat Sheet */
  .cheatsheet-container {
    padding: var(--space-4);
    grid-template-columns: 1fr;
  }

  .cheat-category h3 {
    font-size: var(--text-base);
  }

  /* Status Bar */
  .status-bar {
    padding: var(--space-1) 0;
  }

  .status-content {
    gap: var(--space-2);
    font-size: var(--text-xs);
  }
}

/* ============================================
   DARK MODE
   ============================================ */

html[data-theme="dark"] {
  background-color: #0f172a;
}

[data-theme="dark"] body {
  background: #0f172a;
}

[data-theme="dark"] .header {
  background: rgba(0, 0, 0, 0.3);
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .regex-input-bar {
  background: rgba(0, 0, 0, 0.2);
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .regex-pattern-input,
[data-theme="dark"] .replace-pattern-input {
  background: var(--color-gray-800);
  color: var(--color-gray-100);
  border-color: var(--color-gray-600);
}

[data-theme="dark"] .regex-pattern-input::placeholder,
[data-theme="dark"] .replace-pattern-input::placeholder {
  color: var(--color-gray-500);
}

[data-theme="dark"] .flag-btn {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.15);
}

[data-theme="dark"] .flag-btn.active {
  background: rgba(96, 165, 250, 0.4);
  border-color: rgba(96, 165, 250, 0.6);
}

[data-theme="dark"] .regex-error {
  background: rgba(239, 68, 68, 0.2);
  border-left-color: #f87171;
  color: #fca5a5;
}

[data-theme="dark"] .tabs-nav {
  background: rgba(0, 0, 0, 0.3);
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .replace-options {
  background: rgba(0, 0, 0, 0.2);
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .panel {
  background: rgba(15, 23, 42, 0.95);
  border-color: rgba(255, 255, 255, 0.1);
  box-shadow:
    0 20px 60px rgba(0, 0, 0, 0.5),
    0 0 0 1px rgba(255, 255, 255, 0.05);
}

[data-theme="dark"] .panel:hover {
  box-shadow:
    0 30px 80px rgba(0, 0, 0, 0.6),
    0 0 0 1px rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .panel-header {
  background: linear-gradient(135deg, rgba(13, 148, 136, 0.15), rgba(15, 118, 110, 0.15));
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .panel-title {
  color: var(--color-gray-100);
}

[data-theme="dark"] .btn-icon {
  background: rgba(13, 148, 136, 0.2);
  color: var(--color-gray-300);
}

[data-theme="dark"] .btn-icon:hover {
  background: rgba(13, 148, 136, 0.3);
}

[data-theme="dark"] .match-count {
  color: var(--color-gray-300);
  background: rgba(13, 148, 136, 0.2);
}

[data-theme="dark"] .panel-body .textarea {
  color: var(--color-gray-100);
}

[data-theme="dark"] .panel-body .textarea::placeholder {
  color: var(--color-gray-500);
}

[data-theme="dark"] .section-header {
  color: var(--color-gray-400);
  border-bottom-color: var(--color-gray-700);
}

[data-theme="dark"] .match-detail-item,
[data-theme="dark"] .replaced-text,
[data-theme="dark"] .change-item {
  background: var(--color-gray-800);
}

[data-theme="dark"] .match.match-0 { background: rgba(96, 165, 250, 0.3); }
[data-theme="dark"] .match.match-1 { background: rgba(52, 211, 153, 0.3); }
[data-theme="dark"] .match.match-2 { background: rgba(251, 191, 36, 0.3); }
[data-theme="dark"] .match.match-3 { background: rgba(244, 114, 182, 0.3); }

[data-theme="dark"] .match-detail-item code {
  background: var(--color-gray-700);
  color: var(--color-primary-light);
}

[data-theme="dark"] .change-old {
  background: rgba(239, 68, 68, 0.3);
}

[data-theme="dark"] .change-new {
  background: rgba(52, 211, 153, 0.3);
}

[data-theme="dark"] .cheat-category h3 {
  color: var(--color-gray-100);
}

[data-theme="dark"] .cheat-table td:first-child {
  color: var(--color-primary-light);
}

[data-theme="dark"] .cheat-table td:last-child {
  color: rgba(255, 255, 255, 0.7);
}

[data-theme="dark"] .cheatsheet-container::-webkit-scrollbar-track {
  background: rgba(0, 0, 0, 0.2);
}

[data-theme="dark"] .cheatsheet-container::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
}

[data-theme="dark"] .cheatsheet-container::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.4);
}

[data-theme="dark"] .cheat-table code {
  background: rgba(13, 148, 136, 0.2);
  border: 1px solid rgba(13, 148, 136, 0.35);
  color: #2dd4bf;
}

[data-theme="dark"] .cheat-preset {
  background: var(--color-gray-800);
  border-color: var(--color-gray-700);
}

[data-theme="dark"] .cheat-preset:hover {
  background: rgba(96, 165, 250, 0.15);
  border-color: var(--color-primary);
}

[data-theme="dark"] .preset-name {
  color: var(--color-gray-100);
}

[data-theme="dark"] .preset-pattern {
  color: var(--color-gray-400);
}

[data-theme="dark"] .status-bar {
  background: rgba(0, 0, 0, 0.3);
  border-top-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .auto-execute-toggle {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.15);
}

[data-theme="dark"] .auto-execute-toggle:has(input:checked) {
  background: rgba(16, 185, 129, 0.25);
  border-color: rgba(16, 185, 129, 0.4);
}

[data-theme="dark"] .ad-placeholder {
  background: rgba(0, 0, 0, 0.2);
  border-color: rgba(255, 255, 255, 0.15);
}

/* ── About/Related fix: allow scrolling past tool UI ─────────────────────── */
.main-content { overflow-y: auto; }
.panels-container { min-height: clamp(350px, 60vh, 800px); }

/* ── Compact header ─────────────────────────────────────────────────────── */
.header { padding: var(--space-1) 0; }
.logo-link { font-size: var(--text-sm); padding: var(--space-1) var(--space-2); }
.title { font-size: var(--text-sm); }

/* ── Mobile: natural page scroll + usable editor height ─────────────────── */
@media (max-width: 767px) {
  body { height: auto; min-height: 100vh; overflow-y: auto; }
  .page-body { overflow: visible; }
  .main-content { overflow: visible !important; padding-bottom: var(--space-8); }
  .panel { min-height: 42vh; }
}