/* === Variables === */
:root {
  --font-mono: 'SF Mono', 'Fira Code', 'JetBrains Mono', 'Cascadia Code', Consolas, monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --radius: 8px;
  --transition: 0.2s ease;
}

[data-theme="dark"] {
  --bg: #0d1117;
  --bg2: #161b22;
  --bg3: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --text2: #8b949e;
  --accent: #58a6ff;
  --accent2: #1f6feb;
  --match-bg: rgba(88,166,255,0.25);
  --match-border: rgba(88,166,255,0.5);
  --group1: rgba(255,123,114,0.25);
  --group2: rgba(126,231,135,0.25);
  --group3: rgba(210,153,255,0.25);
  --error-bg: rgba(248,81,73,0.15);
  --error-text: #f85149;
}

[data-theme="light"] {
  --bg: #ffffff;
  --bg2: #f6f8fa;
  --bg3: #eaeef2;
  --border: #d0d7de;
  --text: #1f2328;
  --text2: #656d76;
  --accent: #0969da;
  --accent2: #0550ae;
  --match-bg: rgba(9,105,218,0.15);
  --match-border: rgba(9,105,218,0.4);
  --group1: rgba(207,34,46,0.15);
  --group2: rgba(26,127,55,0.15);
  --group3: rgba(130,80,223,0.15);
  --error-bg: rgba(207,34,46,0.1);
  --error-text: #cf222e;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

/* === Header === */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  border-bottom: 1px solid var(--border);
  background: var(--bg2);
}

h1 { font-size: 1.4rem; font-weight: 700; }
.accent { color: var(--accent); }
.tagline { color: var(--text2); font-size: 0.85rem; margin-left: 12px; }
.header-right { display: flex; gap: 8px; }

.btn {
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.85rem;
  transition: all var(--transition);
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { padding: 4px 10px; font-size: 0.8rem; }

/* === Main === */
main { max-width: 1400px; margin: 0 auto; padding: 16px 24px; }

/* === Pattern Bar === */
.pattern-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.pattern-input-wrap {
  display: flex;
  align-items: center;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0 12px;
  flex: 1;
  min-width: 300px;
}

.regex-delim { color: var(--accent); font-family: var(--font-mono); font-size: 1.1rem; font-weight: 600; }

.pattern-input-wrap input {
  background: transparent;
  border: none;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 1rem;
  padding: 10px 8px;
  outline: none;
  width: 100%;
}

.flags-input { width: 60px !important; text-align: center; }

.flag-toggles { display: flex; gap: 4px; }

.flag-chip {
  display: flex;
  align-items: center;
  cursor: pointer;
}
.flag-chip input { display: none; }
.flag-chip span {
  display: block;
  padding: 6px 10px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text2);
  transition: all var(--transition);
}
.flag-chip input:checked + span {
  background: var(--accent2);
  color: #fff;
  border-color: var(--accent);
}

.mode-toggle { display: flex; gap: 4px; }
.mode-chip { display: flex; cursor: pointer; }
.mode-chip input { display: none; }
.mode-chip span {
  padding: 6px 14px;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text2);
  transition: all var(--transition);
}
.mode-chip input:checked + span {
  background: var(--accent2);
  color: #fff;
  border-color: var(--accent);
}

/* === Replace Bar === */
.replace-bar {
  margin-bottom: 12px;
}
.replace-bar input {
  width: 100%;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 1rem;
  padding: 10px 14px;
  outline: none;
}
.replace-bar input:focus { border-color: var(--accent); }

/* === Error === */
.error-bar {
  background: var(--error-bg);
  color: var(--error-text);
  padding: 8px 14px;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  margin-bottom: 12px;
}

/* === Split Pane === */
.split-pane {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}

.pane {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.pane-header {
  padding: 8px 14px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text2);
  background: var(--bg3);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.match-count {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 0.8rem;
}

.test-area, .result-area {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.6;
  padding: 14px;
  min-height: 200px;
  white-space: pre-wrap;
  word-break: break-word;
  outline: none;
}

.test-area:empty::before {
  content: attr(data-placeholder);
  color: var(--text2);
}

.result-area { color: var(--text); }

/* Match highlighting */
.match { background: var(--match-bg); border-bottom: 2px solid var(--match-border); border-radius: 2px; }
.group-1 { background: var(--group1); }
.group-2 { background: var(--group2); }
.group-3 { background: var(--group3); }

/* === Match Details Table === */
.match-details {
  padding: 0 14px 14px;
  overflow-x: auto;
}

#matchTable {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

#matchTable th, #matchTable td {
  text-align: left;
  padding: 6px 10px;
  border-bottom: 1px solid var(--border);
}

#matchTable th { color: var(--text2); font-weight: 600; }
#matchTable td { color: var(--text); }
#matchTable .group-label { color: var(--accent); font-weight: 600; }

/* === Library === */
.library { margin-bottom: 32px; }
.library h2 { font-size: 1.1rem; margin-bottom: 12px; }

.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 8px;
}

.library-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  cursor: pointer;
  transition: all var(--transition);
}
.library-card:hover { border-color: var(--accent); }
.library-card .lib-name { font-weight: 600; font-size: 0.9rem; margin-bottom: 4px; }
.library-card .lib-pattern { font-family: var(--font-mono); font-size: 0.8rem; color: var(--accent); word-break: break-all; }

/* === Cheat Sheet === */
.cheatsheet {
  position: fixed;
  top: 0;
  right: 0;
  width: 380px;
  max-width: 90vw;
  height: 100vh;
  background: var(--bg2);
  border-left: 1px solid var(--border);
  z-index: 100;
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform 0.3s ease;
}
.cheatsheet.open { transform: translateX(0); }

.cheatsheet-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg2);
}
.cheatsheet-header h2 { font-size: 1.1rem; }

.cheatsheet-body { padding: 16px; }

.cheat-section { margin-bottom: 20px; }
.cheat-section h3 { font-size: 0.9rem; color: var(--accent); margin-bottom: 8px; }

.cheat-row {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  font-size: 0.85rem;
  border-bottom: 1px solid var(--border);
}
.cheat-token { font-family: var(--font-mono); font-weight: 600; color: var(--text); }
.cheat-desc { color: var(--text2); text-align: right; }

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 99;
}

/* === Toast === */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent2);
  color: #fff;
  padding: 10px 20px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  z-index: 200;
  transition: opacity 0.3s;
}

/* === Footer === */
footer {
  border-top: 1px solid var(--border);
  padding: 16px 24px;
  text-align: center;
  color: var(--text2);
  font-size: 0.85rem;
}

.footer-tools { margin-bottom: 8px; display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.footer-tools a { color: var(--accent); text-decoration: none; }
.footer-tools a:hover { text-decoration: underline; }

.hidden { display: none !important; }

/* === Responsive === */
@media (max-width: 768px) {
  .split-pane { grid-template-columns: 1fr; }
  .pattern-bar { flex-direction: column; align-items: stretch; }
  .pattern-input-wrap { min-width: auto; }
  .flag-toggles { flex-wrap: wrap; }
  header { flex-direction: column; gap: 8px; }
}