:root {
  --bg: #0f1115;
  --panel: #171a21;
  --border: #272b35;
  --text: #e6e8ec;
  --muted: #8b92a3;
  --accent: #5b8cff;
  --accent-hover: #7aa0ff;
  --danger: #ff5c5c;
  --warn: #e8b339;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.topbar {
  padding: 2.5rem 1.5rem 1rem;
  text-align: center;
}

.topbar h1 {
  margin: 0 0 0.4rem;
  font-size: 1.8rem;
}

.topbar p {
  margin: 0;
  color: var(--muted);
}

.layout {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem;
  display: grid;
  gap: 1.5rem;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.dropzone:hover,
.dropzone.dragover {
  border-color: var(--accent);
  background: rgba(91, 140, 255, 0.06);
}

.dropzone-text {
  margin: 0;
  color: var(--muted);
}

.file-name {
  margin: 0.6rem 0 0;
  color: var(--text);
  font-weight: 600;
  word-break: break-all;
}

.options {
  margin-top: 1.2rem;
}

.options summary {
  cursor: pointer;
  color: var(--muted);
  user-select: none;
}

.options-grid {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.9rem;
}

.options-grid label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-size: 0.85rem;
  color: var(--muted);
}

.options-grid label.checkbox {
  flex-direction: row;
  align-items: center;
  gap: 0.5rem;
}

.options-grid input[type="number"],
.options-grid select {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 0.4rem 0.5rem;
}

button[type="submit"] {
  margin-top: 1.4rem;
  background: var(--accent);
  color: #0a0c10;
  border: none;
  font-weight: 600;
  padding: 0.7rem 1.4rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
}

button[type="submit"]:hover {
  background: var(--accent-hover);
}

button[type="submit"]:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.error {
  margin-top: 1rem;
  color: var(--danger);
  font-size: 0.9rem;
  white-space: pre-wrap;
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.stats {
  display: flex;
  gap: 1.2rem;
  flex-wrap: wrap;
  font-size: 0.85rem;
  color: var(--muted);
}

.stats b {
  color: var(--text);
}

.downloads {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.downloads button,
.downloads a {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.45rem 0.8rem;
  border-radius: 6px;
  font-size: 0.82rem;
  cursor: pointer;
  text-decoration: none;
}

.downloads button:hover,
.downloads a:hover {
  border-color: var(--accent);
}

.warnings {
  background: rgba(232, 179, 57, 0.08);
  border: 1px solid rgba(232, 179, 57, 0.35);
  border-radius: 8px;
  padding: 0.8rem 1rem;
  margin-bottom: 1rem;
  font-size: 0.85rem;
}

.warnings strong {
  color: var(--warn);
}

.warnings ul {
  margin: 0.4rem 0 0;
  padding-left: 1.2rem;
}

.tabs {
  display: flex;
  gap: 0.4rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1rem;
}

.tab-btn {
  background: none;
  border: none;
  color: var(--muted);
  padding: 0.55rem 0.9rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  font-size: 0.88rem;
}

.tab-btn.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
}

#preview-pane {
  width: 100%;
  height: 600px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
}

#markdown-pane,
#htmlsrc-pane {
  max-height: 600px;
  overflow: auto;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  font-size: 0.82rem;
  line-height: 1.5;
}

.progress-panel {
  text-align: left;
}

.progress-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

#progress-stage {
  color: var(--text);
  font-weight: 600;
}

#progress-percent {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.progress-bar-track {
  height: 10px;
  border-radius: 999px;
  background: var(--bg);
  border: 1px solid var(--border);
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-hover));
  border-radius: 999px;
  transition: width 0.25s ease;
}

.progress-detail {
  margin: 0.6rem 0 0;
  color: var(--muted);
  font-size: 0.82rem;
}

footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.8rem;
  padding: 2rem 1rem;
}

footer a {
  color: var(--accent);
}