.skip-link {
      position: absolute;
      left: -9999px;
      top: auto;
      width: 1px;
      height: 1px;
      overflow: hidden;
      z-index: 9999;
    }

    .skip-link:focus {
      position: fixed;
      left: 12px;
      top: 12px;
      width: auto;
      height: auto;
      overflow: visible;
      padding: 10px 16px;
      background: var(--accent, #8ee66f);
      color: #071016;
      font-weight: 800;
      font-size: 15px;
      border-radius: 10px;
      text-decoration: none;
      box-shadow: 0 4px 20px rgba(0,0,0,.4);
    }

    :root {
      --bg: #0b1020;
      --panel: #141b2f;
      --panel-2: #101729;
      --text: #edf2ff;
      --muted: #9aa8c7;
      --grid: rgba(255,255,255,.095);
      --grid-strong: rgba(255,255,255,.18);
      --trace-a: #41d7ff;
      --trace-b: #ffbe3d;
      --accent: #8ee66f;
      --danger: #ff6878;
      --shadow: 0 24px 70px rgba(0,0,0,.35);
    }

    * { box-sizing: border-box; }

    body {
      margin: 0;
      min-height: 100vh;
      font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      color: var(--text);
      background:
        radial-gradient(circle at top left, rgba(65,215,255,.22), transparent 36rem),
        radial-gradient(circle at bottom right, rgba(255,190,61,.16), transparent 34rem),
        var(--bg);
      display: grid;
      place-items: center;
      padding: 24px;
    }

    .app {
      width: min(1220px, 100%);
      display: grid;
      gap: 16px;
    }

    .topbar,
    .controls,
    .scope-wrap {
      background: linear-gradient(180deg, rgba(255,255,255,.045), rgba(255,255,255,.018));
      border: 1px solid rgba(255,255,255,.1);
      border-radius: 18px;
      box-shadow: var(--shadow);
    }

    .topbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      padding: 16px 18px;
    }

    h1 {
      margin: 0;
      font-size: clamp(20px, 3vw, 30px);
      letter-spacing: -.03em;
    }

    .status {
      color: var(--muted);
      font-size: 14px;
      text-align: right;
      line-height: 1.35;
      min-width: 230px;
    }

    .scope-wrap {
      position: relative;
      overflow: hidden;
      padding: 12px;
      background: rgba(4, 8, 20, .78);
    }

    canvas {
      display: block;
      width: 100%;
      height: min(54vh, 520px);
      min-height: 300px;
      border-radius: 14px;
      background: #050912;
    }

    .legend {
      position: absolute;
      left: 26px;
      top: 24px;
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      font-size: 13px;
      color: var(--muted);
      pointer-events: none;
    }

    .pill {
      display: inline-flex;
      align-items: center;
      gap: 7px;
      padding: 6px 9px;
      background: rgba(0,0,0,.38);
      border: 1px solid rgba(255,255,255,.11);
      border-radius: 999px;
      backdrop-filter: blur(8px);
    }

    .dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      background: currentColor;
      box-shadow: 0 0 14px currentColor;
    }

    .trace-a { color: var(--trace-a); }
    .trace-b { color: var(--trace-b); }

    .controls {
      padding: 16px;
      display: grid;
      gap: 16px;
      background-color: rgba(16, 23, 41, .86);
    }

    .control-grid {
      display: grid;
      grid-template-columns: repeat(4, minmax(190px, 1fr));
      gap: 14px;
    }

    @media (max-width: 1040px) {
      .control-grid { grid-template-columns: repeat(2, minmax(190px, 1fr)); }
      .topbar { align-items: flex-start; flex-direction: column; }
      .status { text-align: left; }
    }

    @media (max-width: 560px) {
      body { padding: 12px; }
      .control-grid { grid-template-columns: 1fr; }
    }

    .group {
      padding: 13px;
      border-radius: 14px;
      background: rgba(0,0,0,.18);
      border: 1px solid rgba(255,255,255,.08);
      display: grid;
      gap: 10px;
      align-content: start;
    }

    .group.is-muted {
      opacity: .58;
    }

    .group h2 {
      margin: 0 0 2px 0;
      font-size: 14px;
      font-weight: 760;
      color: var(--text);
      letter-spacing: .01em;
    }

    label {
      display: grid;
      gap: 6px;
      font-size: 13px;
      color: var(--muted);
    }

    .row {
      display: flex;
      gap: 10px;
      align-items: center;
      justify-content: space-between;
    }

    .check-row {
      display: flex;
      align-items: center;
      justify-content: flex-start;
      gap: 9px;
      color: var(--muted);
      font-size: 13px;
      user-select: none;
    }

    output {
      font-variant-numeric: tabular-nums;
      color: var(--text);
      font-size: 12px;
      padding: 2px 7px;
      background: rgba(255,255,255,.07);
      border-radius: 999px;
    }

    input[type="range"] {
      width: 100%;
      accent-color: var(--accent);
    }

    input[type="checkbox"] {
      accent-color: var(--accent);
    }

    input[type="file"],
    select,
    button {
      border: 1px solid rgba(255,255,255,.12);
      border-radius: 12px;
      background: rgba(255,255,255,.065);
      color: var(--text);
      padding: 10px 12px;
      font: inherit;
    }

    input[type="file"] {
      width: 100%;
      font-size: 13px;
    }

    input[type="file"]::file-selector-button {
      border: 0;
      border-radius: 9px;
      margin-right: 10px;
      padding: 7px 9px;
      background: rgba(142,230,111,.88);
      color: #071016;
      font-weight: 800;
      cursor: pointer;
    }

    select { width: 100%; }

    button {
      cursor: pointer;
      font-weight: 750;
      transition: transform .12s ease, background .12s ease, border-color .12s ease;
    }

    button:hover {
      transform: translateY(-1px);
      background: rgba(255,255,255,.095);
      border-color: rgba(255,255,255,.2);
    }

    button:disabled,
    input:disabled,
    select:disabled {
      opacity: .5;
      cursor: not-allowed;
    }

    .buttons {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
    }

    .primary {
      background: linear-gradient(135deg, rgba(142,230,111,.95), rgba(65,215,255,.92));
      color: #071016;
      border: 0;
    }

    .danger {
      color: white;
      background: rgba(255,104,120,.15);
      border-color: rgba(255,104,120,.33);
    }

    .hint {
      color: var(--muted);
      font-size: 13px;
      line-height: 1.45;
      margin: 0;
    }

    .small-info {
      color: var(--text);
      font-size: 12px;
      line-height: 1.45;
      padding: 8px 9px;
      border-radius: 10px;
      background: rgba(255,255,255,.055);
      border: 1px solid rgba(255,255,255,.075);
      word-break: break-word;
    }

    kbd {
      color: var(--text);
      background: rgba(255,255,255,.08);
      border: 1px solid rgba(255,255,255,.11);
      border-radius: 6px;
      padding: 1px 5px;
      font-size: 12px;
    }