:root {
  --bg-color: #0d1117;
  --panel-bg: #161b22;
  --card-bg: #1c2128;
  --border-color: #30363d;
  --text-primary: #c9d1d9;
  --text-secondary: #8b949e;
  --accent-color: #58a6ff;
  --success-color: #3fb950;
  --error-color: #f85149;
  
  --font-sans: 'Inter', -apple-system, sans-serif;
  --font-mono: 'Fira Code', ui-monospace, SFMono-Regular, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

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

.code-font { font-family: var(--font-mono); font-size: 14px; }

header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  border-bottom: 1px solid var(--border-color);
  padding: 1.5rem 2rem;
}

.header-left h1 { font-size: 1.5rem; font-weight: 600; margin-top: 0.5rem; }

.back-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.2s;
  display: inline-block;
  margin-bottom: 0.5rem;
}
.back-link:hover { color: var(--accent-color); }
.header-right p { color: var(--text-secondary); font-size: 0.875rem; }

.main-content {
  padding: 2rem;
  max-width: 1400px;
  margin: 0 auto;
}

.card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
}

.toolbar {
  display: flex;
  justify-content: space-between;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.tool-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.tool-group label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
  text-transform: uppercase;
}

.btn-group {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.divider {
  width: 1px;
  height: 24px;
  background-color: var(--border-color);
  margin: 0 0.5rem;
}

button {
  cursor: pointer;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 6px;
  padding: 0.5rem 1rem;
  transition: 0.2s;
}

.primary-btn {
  background-color: #238636;
  color: #fff;
  border: 1px solid rgba(240, 246, 252, 0.1);
}
.primary-btn:hover { background-color: #2ea043; }

.secondary-btn {
  background-color: var(--panel-bg);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}
.secondary-btn:hover { background-color: #30363d; border-color: #8b949e; }
.secondary-btn.danger { color: var(--error-color); }
.secondary-btn.danger:hover { background-color: rgba(248, 81, 73, 0.1); border-color: var(--error-color); }

.split-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

@media (max-width: 1024px) {
  .split-layout { grid-template-columns: 1fr; }
}

.editor-section h2, .output-section h2 {
  font-size: 1.125rem;
  margin-bottom: 1rem;
  color: #fff;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.section-header h2 { margin-bottom: 0; }

.table-container {
  overflow-x: auto;
  padding-bottom: 1rem;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  border: 1px solid var(--border-color);
  padding: 0;
  min-width: 150px;
}

th {
  background-color: var(--panel-bg);
}

.cell-input {
  width: 100%;
  height: 100%;
  background: transparent;
  border: none;
  color: var(--text-primary);
  padding: 0.75rem;
  outline: none;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  transition: background-color 0.2s;
}

th .cell-input {
  font-weight: 600;
  color: var(--accent-color);
}

.cell-input:focus {
  background-color: rgba(88, 166, 255, 0.1);
}

.flex-column {
  display: flex;
  flex-direction: column;
}

#markdown-output {
  flex-grow: 1;
  min-height: 400px;
  background-color: var(--panel-bg);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: var(--text-primary);
  padding: 1rem;
  resize: none;
  outline: none;
  line-height: 1.5;
  white-space: pre; /* Important for tables */
}
#markdown-output:focus { border-color: var(--accent-color); }