:root {
  --bg-main: radial-gradient(circle at 10% 10%, #f7efe1 0%, #efe5d4 35%, #ddcbb2 100%);
  --panel-bg: rgba(255, 251, 245, 0.82);
  --panel-border: #c8b59e;
  --ink: #2a2218;
  --ink-soft: #665641;
  --accent: #1f6f62;
  --accent-hover: #19594f;
  --error: #8f2d24;
  --line: #d8c8b4;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg-main);
  color: var(--ink);
  font-family: "Trebuchet MS", "Lucida Sans Unicode", "Lucida Grande", sans-serif;
}

.app-shell {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  padding: 1rem;
  min-height: 100vh;
}

.panel {
  display: flex;
  flex-direction: column;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  backdrop-filter: blur(3px);
  overflow: hidden;
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.65), rgba(255, 255, 255, 0.2));
}

.panel-header h1,
.panel-header h2 {
  margin: 0;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.actions {
  display: flex;
  gap: 0.5rem;
}

button {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0.48rem 0.7rem;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 140ms ease, transform 140ms ease;
}

button:hover {
  background: var(--accent-hover);
}

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

textarea {
  width: 100%;
  flex: 1;
  border: 0;
  border-bottom: 1px solid var(--line);
  padding: 0.85rem 1rem;
  resize: none;
  outline: none;
  background: rgba(255, 255, 255, 0.7);
  color: var(--ink);
  font-family: "Courier New", Courier, monospace;
  font-size: 0.93rem;
  line-height: 1.35;
}

.status {
  margin: 0;
  padding: 0.65rem 1rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.status.error {
  color: var(--error);
  font-weight: 600;
}

.viewer {
  padding: 0.8rem;
  overflow: auto;
  flex: 1;
  font-family: "Courier New", Courier, monospace;
  font-size: 0.92rem;
}

.node {
  line-height: 1.35;
}

.children {
  margin-left: 1.25rem;
  border-left: 1px dashed var(--line);
  padding-left: 0.7rem;
}

.toggle {
  border: 0;
  background: none;
  color: var(--accent);
  cursor: pointer;
  padding: 0;
  margin-right: 0.35rem;
  font-family: inherit;
  font-weight: 700;
}

.toggle:hover {
  color: var(--accent-hover);
  background: none;
}

.key {
  color: #174a6a;
}

.value-string {
  color: #8e3d22;
}

.value-number {
  color: #005b5b;
}

.value-boolean,
.value-null {
  color: #5a336e;
  font-weight: 700;
}

.hidden {
  display: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 860px) {
  .app-shell {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .input-panel,
  .output-panel {
    min-height: 46vh;
  }
}