html, body {
  height: 100%;
  overflow: hidden;
}

.site-header { flex-shrink: 0; }

.tool-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.toolbar-left { display: flex; align-items: baseline; gap: 12px; }
.toolbar-left strong { font-size: 15px; }
.toolbar-left .hint { color: var(--muted); font-size: 12px; }

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.field {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
}

.field select {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  padding: 6px 26px 6px 10px;
  font-size: 13px;
  color: var(--text);
  cursor: pointer;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3e%3cpath fill='none' stroke='%236b7280' stroke-width='1.5' d='M3 4.5l3 3 3-3'/%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 8px center;
}

.editor {
  display: grid;
  grid-template-columns: 1fr 1fr;
  height: calc(100vh - 55px - 53px);
  border-top: 1px solid var(--border);
}

.pane {
  display: flex;
  flex-direction: column;
  min-width: 0;
  border-right: 1px solid var(--border);
  background: var(--surface);
}

.pane:last-child { border-right: none; }

.pane-title {
  flex-shrink: 0;
  padding: 8px 16px;
  font-size: 12px;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  background: #fafbff;
}

.editor-pane textarea {
  flex: 1;
  width: 100%;
  resize: none;
  border: none;
  outline: none;
  padding: 18px 20px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "PingFang SC", monospace;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text);
  background: #fff;
}

.preview-pane {
  background: #ecedf3;
}

.preview-scroll {
  flex: 1;
  overflow: auto;
  padding: 28px 24px;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

#previewWrap {
  background: #fff;
  border-radius: 6px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  overflow: hidden;
  transition: width 0.2s ease;
}

.markdown-body {
  padding: 32px 28px;
  font-size: 15px;
  line-height: 1.75;
  word-wrap: break-word;
}

.markdown-body > *:first-child { margin-top: 0; }
.markdown-body > *:last-child { margin-bottom: 0; }

.toast {
  position: fixed;
  left: 50%;
  bottom: 36px;
  transform: translate(-50%, 20px);
  background: rgba(31, 35, 48, 0.92);
  color: #fff;
  padding: 8px 18px;
  border-radius: 999px;
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 999;
}
.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 800px) {
  .editor { grid-template-columns: 1fr; height: auto; }
  .pane { border-right: none; border-bottom: 1px solid var(--border); }
  .editor-pane textarea { min-height: 280px; }
  .preview-scroll { padding: 16px; }
  html, body { overflow: auto; }
}