* { box-sizing: border-box; }

:root {
  --bg: #0f1117;
  --panel: #171a23;
  --panel-2: #1d212c;
  --border: #2a2f3c;
  --text: #e6e9ef;
  --muted: #8b93a7;
  --accent: #7c9eff;
  --accent-2: #56d4a0;
  --code-bg: #0b0d13;
}

html, body {
  margin: 0;
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  overflow: hidden;
}

/* Header */
.topbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  height: 56px;
  background: linear-gradient(180deg, #1a1e29, #14171f);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  color: var(--accent);
  font-size: 20px;
  filter: drop-shadow(0 0 6px rgba(124, 158, 255, 0.6));
}

.topbar h1 {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.actions {
  display: flex;
  gap: 8px;
}

.actions button {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 13px;
  font-size: 13px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.05s;
}

.actions button:hover {
  background: #262b38;
  border-color: var(--accent);
}

.actions button:active { transform: translateY(1px); }

/* Workspace */
.workspace {
  flex: 1 1 auto;
  display: flex;
  min-height: 0;
}

.pane {
  flex: 1 1 50%;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.pane-head {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 16px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--muted);
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.meta { font-weight: 400; text-transform: none; letter-spacing: 0; }

.divider {
  flex: 0 0 1px;
  background: var(--border);
}

/* Editor */
#input {
  flex: 1 1 auto;
  width: 100%;
  resize: none;
  border: none;
  outline: none;
  padding: 20px;
  background: var(--code-bg);
  color: var(--text);
  font-family: "SF Mono", ui-monospace, "JetBrains Mono", Menlo, Consolas, monospace;
  font-size: 14px;
  line-height: 1.6;
  overflow: auto;
  tab-size: 2;
}

/* Preview */
.preview-pane { background: var(--panel); }

#preview {
  flex: 1 1 auto;
  overflow: auto;
  padding: 28px 36px;
  line-height: 1.65;
}

/* Scrollbars */
#input::-webkit-scrollbar,
#preview::-webkit-scrollbar { width: 10px; height: 10px; }
#input::-webkit-scrollbar-thumb,
#preview::-webkit-scrollbar-thumb { background: #353b4a; border-radius: 6px; }
#input::-webkit-scrollbar-track,
#preview::-webkit-scrollbar-track { background: transparent; }

/* Markdown body */
.markdown-body { color: var(--text); }
.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  line-height: 1.25;
  margin: 1.4em 0 0.6em;
  font-weight: 600;
}
.markdown-body h1 { font-size: 1.9em; border-bottom: 1px solid var(--border); padding-bottom: 0.3em; }
.markdown-body h2 { font-size: 1.5em; border-bottom: 1px solid var(--border); padding-bottom: 0.25em; }
.markdown-body h3 { font-size: 1.25em; }
.markdown-body h4 { font-size: 1.05em; }
.markdown-body p { margin: 0.8em 0; }
.markdown-body a { color: var(--accent); text-decoration: none; }
.markdown-body a:hover { text-decoration: underline; }
.markdown-body strong { color: #fff; }
.markdown-body em { color: #d9deea; }

.markdown-body code {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 6px;
  font-family: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  font-size: 0.88em;
  color: var(--accent-2);
}

.markdown-body pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  overflow: auto;
  margin: 1em 0;
}
.markdown-body pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--text);
  font-size: 0.86em;
  line-height: 1.55;
}

.markdown-body blockquote {
  margin: 1em 0;
  padding: 4px 18px;
  border-left: 4px solid var(--accent);
  background: rgba(124, 158, 255, 0.08);
  color: var(--muted);
  border-radius: 0 8px 8px 0;
}

.markdown-body ul,
.markdown-body ol { padding-left: 1.6em; margin: 0.8em 0; }
.markdown-body li { margin: 0.3em 0; }

.markdown-body hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.6em 0;
}

.markdown-body table {
  border-collapse: collapse;
  margin: 1em 0;
  width: 100%;
}
.markdown-body th,
.markdown-body td {
  border: 1px solid var(--border);
  padding: 7px 12px;
  text-align: left;
}
.markdown-body th { background: var(--panel-2); }

.markdown-body img { max-width: 100%; border-radius: 8px; }

/* Responsive */
@media (max-width: 720px) {
  .workspace { flex-direction: column; }
  .divider { flex-basis: 1px; }
  .pane { flex: 1 1 50%; }
}