:root {
    --bg: #0a0c0f;
    --surface: #111318;
    --border: #1e2330;
    --accent: #00e5a0;
    --accent2: #00aaff;
    --muted: #3a4255;
    --text: #c8d0e0;
    --text-dim: #5a6478;
    --error: #ff4466;
    --warn: #ffaa00;
    --key-color: #7dd3fc;
    --string-color: #86efac;
    --num-color: #fca5a5;
    --bool-color: #c4b5fd;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; }

  body {
    background: var(--bg);
    color: var(--text);
    font-family: 'IBM Plex Mono', monospace;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 48px 24px;
    position: relative;
    overflow-x: hidden;
  }

  body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
      radial-gradient(ellipse 60% 40% at 20% 10%, rgba(0,229,160,0.04) 0%, transparent 60%),
      radial-gradient(ellipse 50% 50% at 80% 90%, rgba(0,170,255,0.04) 0%, transparent 60%);
    pointer-events: none;
  }

  .scanlines {
    position: fixed;
    inset: 0;
    background: repeating-linear-gradient(
      to bottom,
      transparent,
      transparent 2px,
      rgba(0,0,0,0.12) 2px,
      rgba(0,0,0,0.12) 4px
    );
    pointer-events: none;
    z-index: 0;
  }

  .container {
    width: 100%;
    max-width: 860px;
    position: relative;
    z-index: 1;
  }

  header {
    margin-bottom: 40px;
    display: flex;
    flex-direction: column;
    gap: 8px;
  }

  .tag-line {
    font-size: 10px;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--accent);
    font-weight: 500;
  }

  h1 {
    font-family: 'IBM Plex Mono', monospace;
    font-size: clamp(22px, 4vw, 32px);
    font-weight: 600;
    color: #fff;
    letter-spacing: -0.5px;
  }

  h1 span {
    color: var(--accent);
  }

  .subtitle {
    font-size: 12px;
    color: var(--text-dim);
    margin-top: 4px;
  }

  .input-section {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    position: relative;
    transition: border-color 0.2s;
  }

  .input-section:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px rgba(0,229,160,0.15), 0 0 24px rgba(0,229,160,0.05);
  }

  .input-label {
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-dim);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .input-label::before {
    content: '';
    display: inline-block;
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
  }

  textarea {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: var(--accent2);
    font-family: 'IBM Plex Mono', monospace;
    font-size: 12px;
    line-height: 1.7;
    resize: none;
    min-height: 80px;
    word-break: break-all;
  }

  textarea::placeholder {
    color: var(--muted);
  }

  .controls {
    display: flex;
    gap: 10px;
    margin-top: 14px;
    align-items: center;
  }

  button {
    cursor: pointer;
    border: none;
    font-family: 'IBM Plex Mono', monospace;
    font-size: 11px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    padding: 9px 20px;
    border-radius: 4px;
    transition: all 0.15s;
    font-weight: 500;
  }

  .btn-primary {
    background: var(--accent);
    color: #000;
  }

  .btn-primary:hover {
    background: #00ffb2;
    transform: translateY(-1px);
  }

  .btn-secondary {
    background: transparent;
    color: var(--text-dim);
    border: 1px solid var(--border);
  }

  .btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
  }

  .btn-copy {
    background: transparent;
    color: var(--accent2);
    border: 1px solid var(--border);
    margin-left: auto;
  }

  .btn-copy:hover {
    border-color: var(--accent2);
  }

  .status-bar {
    font-size: 11px;
    color: var(--text-dim);
    display: flex;
    align-items: center;
    gap: 6px;
  }

  .status-bar.error { color: var(--error); }
  .status-bar.success { color: var(--accent); }

  /* Output */
  .output-section {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    display: none;
    animation: fadeIn 0.3s ease;
  }

  .output-section.visible { display: block; }

  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .output-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    border-bottom: 1px solid var(--border);
    background: rgba(0,0,0,0.2);
  }

  .output-title {
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-dim);
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .json-view {
    padding: 20px;
    overflow-x: auto;
  }

  /* JSON renderer */
  .jv-root { font-size: 13px; line-height: 1.8; }

  .jv-obj, .jv-arr { padding-left: 20px; }

.jv-key {
    color: #ffffff;
    font-weight: 500;
}

  .jv-string { color: var(--string-color); }
  .jv-number { color: var(--num-color); }
  .jv-bool { color: var(--bool-color); }
  .jv-null { color: var(--text-dim); font-style: italic; }
  .jv-punct { color: var(--muted); }

  .hex-block {
    display: inline-block;
    background: rgba(0,170,255,0.06);
    border: 1px solid rgba(0,170,255,0.12);
    border-radius: 3px;
    padding: 0 5px;
    font-size: 11px;
    color: var(--accent2);
    word-break: break-all;
    max-width: 100%;
    vertical-align: middle;
  }

  /* Stats row */
  .stats-row {
    display: flex;
    gap: 1px;
    background: var(--border);
    border-top: 1px solid var(--border);
  }

  .stat-cell {
    flex: 1;
    background: var(--surface);
    padding: 12px 16px;
    display: flex;
    flex-direction: column;
    gap: 3px;
  }

  .stat-label {
    font-size: 9px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-dim);
  }

  .stat-value {
    font-size: 16px;
    font-weight: 600;
    color: var(--accent);
  }


  @media (max-width: 600px) {
    .struct-guide { grid-template-columns: 1fr; }
    .stats-row { flex-wrap: wrap; }
  }