:root {
  color-scheme: dark;
  --bg: #050816;
  --bg-elevated: #0b1020;
  --bg-elevated-soft: #111827;
  --border-subtle: #1f2937;
  --accent: #22c55e;
  --accent-soft: rgba(34, 197, 94, 0.12);
  --accent-strong: rgba(34, 197, 94, 0.25);
  --accent-text: #bbf7d0;
  --text: #f9fafb;
  --text-soft: #9ca3af;
  --danger: #ef4444;
  --radius-lg: 12px;
  --radius-md: 8px;
  --shadow-soft: 0 18px 40px rgba(15, 23, 42, 0.75);
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  background: radial-gradient(circle at top, #111827 0, #020617 45%, #000 100%);
  color: var(--text);
  display: flex;
  flex-direction: column;
}

.app-header {
  padding: 1.75rem 2.5rem 1rem;
}

.app-header h1 {
  margin: 0;
  font-size: 1.9rem;
  letter-spacing: 0.04em;
}

.app-header p {
  margin: 0.3rem 0 0;
  color: var(--text-soft);
  font-size: 0.95rem;
}

.app-main {
  flex: 1;
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 1.5rem;
  padding: 0 2rem 1.5rem;
}

.config-panel,
.preview-panel {
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.98), rgba(17, 24, 39, 0.98));
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-soft);
  padding: 1.25rem 1.4rem;
  display: flex;
  flex-direction: column;
}

.config-panel h2,
.preview-header h2 {
  margin: 0 0 0.9rem;
  font-size: 1.1rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-bottom: 0.9rem;
}

.field-inline {
  gap: 0.5rem;
}

label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-soft);
}

input,
select,
textarea {
  background: #020617;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  color: var(--text);
  font-family: inherit;
  padding: 0.45rem 0.55rem;
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent-soft);
  background: #020617;
}

textarea {
  resize: vertical;
  min-height: 70px;
}

.checkbox {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  color: var(--text-soft);
}

.checkbox input {
  width: 16px;
  height: 16px;
}

.actions {
  display: flex;
  gap: 0.6rem;
  margin-top: 0.4rem;
}

.btn {
  border-radius: 999px;
  border: 1px solid var(--border-subtle);
  background: #020617;
  color: var(--text);
  font-size: 0.85rem;
  padding: 0.5rem 0.9rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  transition: background 0.15s ease, transform 0.1s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.btn.primary {
  background: linear-gradient(135deg, #22c55e, #4ade80);
  color: #052e16;
  border-color: transparent;
  font-weight: 600;
}

.btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.65);
}

.btn.primary:hover:not(:disabled) {
  filter: brightness(1.05);
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  box-shadow: none;
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.6rem;
}

.badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-text);
}

.preview-body {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 0.75rem;
  height: 100%;
  min-height: 260px;
}

.file-tree {
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-elevated-soft);
  padding: 0.4rem 0.35rem;
  font-size: 0.84rem;
  overflow: auto;
}

.file-tree-root {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.1rem 0.4rem 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-soft);
}

.file-tree-folder {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.05rem 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-soft);
}

.file-tree-item {
  padding: 0.1rem 0.4rem;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--text-soft);
}

.file-tree-item span.path {
  white-space: nowrap;
  text-overflow: ellipsis;
  overflow: hidden;
}

.file-tree-item:hover {
  background: rgba(15, 23, 42, 0.9);
  color: var(--text);
}

.file-tree-item.active {
  background: var(--accent-strong);
  color: var(--accent-text);
}

.file-viewer {
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: #020617;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  height: 100%;
}

.file-viewer-header {
  padding: 0.45rem 0.75rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.file-path {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-soft);
}

.code-block {
  margin: 0;
  padding: 0.7rem 0.85rem 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #e5e7eb;
  overflow: auto;
  white-space: pre;
}

.help-code {
  margin: 0;
  padding: 0.5rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: #020617;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  color: var(--text-soft);
  white-space: pre-wrap;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.feature-category {
  margin-top: 0.4rem;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-soft);
}

.feature-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.features-summary {
  font-size: 0.8rem;
  color: var(--text-soft);
}

.modal {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 1.5rem;
  box-sizing: border-box;
  overflow-y: auto;
  z-index: 50;
}

.modal.hidden {
  display: none;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(2px);
  z-index: 50;
}

.modal-dialog {
  position: relative;
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.98), rgba(17, 24, 39, 0.98));
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-soft);
  padding: 1.25rem 1.4rem;
  min-width: 320px;
  width: 100%;
  max-width: 480px;
  z-index: 51;
}

.modal-subtitle {
  margin: 0 0 0.6rem;
  font-size: 0.8rem;
  color: var(--text-soft);
}

.modal-actions {
  margin-top: 1rem;
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
}

.app-footer {
  padding: 0.6rem 2rem 1rem;
  font-size: 0.75rem;
  color: var(--text-soft);
}

@media (max-width: 960px) {
  .app-main {
    grid-template-columns: 1fr;
  }

  .preview-body {
    grid-template-columns: 1fr;
    min-height: 220px;
  }
}