:root {
  --bg: #0b0c0f;
  --panel: #12141a;
  --panel-elev: #171a22;
  --text: #e6e9ef;
  --muted: #9aa3b2;
  --border: #242a35;
  --accent: #3b82f6;
  --danger: #ef4444;
  --good: #22c55e;
  --radius: 12px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f8fb;
    --panel: #ffffff;
    --panel-elev: #f3f5f9;
    --text: #0f172a;
    --muted: #5b677a;
    --border: #e5e7eb;
    --accent: #2563eb;
  }
}

* {
  box-sizing: border-box;
}
html,
body,
#app {
  height: 100%;
}
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto,
    Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background: var(--bg);
  color: var(--text);
}

.app {
  display: grid;
  grid-template-columns: 280px 1fr;
  grid-template-rows: 100%;
  height: 100vh;
}

.sidebar {
  border-right: 1px solid var(--border);
  background: var(--panel);
  display: flex;
  flex-direction: column;
  min-width: 240px;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 14px;
  border-bottom: 1px solid var(--border);
}

.sidebar-title {
  font-weight: 600;
  letter-spacing: 0.2px;
}

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

.history-list {
  padding: 12px;
  overflow: auto;
  display: grid;
  grid-auto-rows: min-content;
  gap: 10px;
}

.history-item {
  position: relative;
  display: grid;
  grid-template-columns: 8px 1fr auto;
  align-items: center;
  gap: 16px;
  background: var(--panel-elev);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 10px 10px 0;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.2s ease, border-color 0.2s ease;
}

.history-item:hover {
  transform: translateY(-1px);
  border-color: color-mix(in oklab, var(--accent) 30%, var(--border));
}
.history-item:active {
  transform: translateY(0);
}

.color-bar {
  width: 10px;
  height: calc(100% + 22px);
  border-radius: 10px 0 0 10px;
  margin-left: -1px;
}
.history-text {
  font-size: 13px;
  color: var(--text);
  opacity: 0.95;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.history-meta {
  font-size: 11px;
  color: var(--muted);
}
.history-right {
  display: flex;
  align-items: center;
  gap: 6px;
  padding-left: 6px;
}
.history-del {
  border: 0;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  padding: 4px;
  border-radius: 6px;
}
.history-del:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.06);
}

.main {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.controls-left,
.controls-right {
  display: flex;
  align-items: center;
  gap: 8px;
}
.muted {
  color: var(--muted);
  font-size: 12px;
}

.btn {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--panel-elev);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 500;
  font-size: 13px;
}
.btn:hover {
  border-color: color-mix(in oklab, var(--accent) 35%, var(--border));
}
.btn:active {
  transform: translateY(1px);
}
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-ghost {
  background: transparent;
}

.checkbox {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text);
}
.checkbox input {
  width: 16px;
  height: 16px;
}

.panes {
  display: grid;
  grid-template-columns: 0.4fr 8px 0.6fr;
  gap: 12px;
  padding: 12px;
  overflow: hidden;
  height: calc(100vh - 54px);
  background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.02));
}

.resizer {
  background: transparent;
  cursor: col-resize;
  position: relative;
}
.resizer::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
  transform: translateX(-1px);
  border-radius: 2px;
}

.pane {
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.pane-header {
  padding: 10px 12px;
  font-size: 12px;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  background: var(--panel-elev);
}

textarea#input {
  flex: 1;
  width: 100%;
  border: 0;
  outline: none;
  background: transparent;
  color: var(--text);
  padding: 12px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
  font-size: 13px;
  line-height: 1.6;
}

.input-pane {
  position: relative;
}
.input-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.error-highlight {
  position: absolute;
  background: color-mix(in oklab, var(--danger) 16%, transparent);
  border-left: 2px solid var(--danger);
  pointer-events: auto; /* allow hover */
}
.error-highlight::after {
  content: attr(data-tooltip);
  position: absolute;
  left: 10px;
  top: 100%;
  margin-top: 6px;
  background: var(--panel-elev);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 8px;
  font-size: 12px;
  white-space: pre-wrap;
  max-width: 60ch;
  opacity: 0;
  transform: translateY(-2px);
  transition: opacity 0.12s ease, transform 0.12s ease;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
  pointer-events: none;
}
.error-highlight:hover::after {
  opacity: 1;
  transform: translateY(0);
}

.error {
  padding: 8px 12px;
  font-size: 12px;
  color: var(--danger);
  border-top: 1px dashed var(--border);
  background: transparent;
  min-height: 0;
  display: none;
}
.error.show {
  display: block;
  background: color-mix(in oklab, var(--danger) 7%, transparent);
  min-height: 20px;
}

.output {
  flex: 1;
  margin: 0;
  padding: 12px;
  overflow: auto;
  background: var(--panel);
}
.output code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
  font-size: 13px;
  line-height: 1.6;
  white-space: pre;
}

/* Active doc item */
.history-item.active {
  border-color: color-mix(in oklab, var(--accent) 60%, var(--border));
  background: color-mix(in oklab, var(--accent) 12%, var(--panel-elev));
}

/* Syntax highlighting */
.token.string {
  color: #22c55e;
}
.token.number {
  color: #eab308;
}
.token.boolean {
  color: #60a5fa;
}
.token.null {
  color: #f472b6;
}
.token.key {
  color: #93c5fd;
}

/* Responsive */
@media (max-width: 1100px) {
  .app {
    grid-template-columns: 220px 1fr;
  }
}
@media (max-width: 900px) {
  .app {
    grid-template-columns: 1fr;
  }
  .sidebar {
    display: none;
  }
  .panes {
    grid-template-columns: 1fr;
    height: calc(100vh - 54px);
  }
}