:root {
    --bg: #050508;
    --surface: #0d0d14;
    --surface2: #13131e;
    --border: rgba(255,255,255,0.07);
    --border-bright: rgba(255,255,255,0.15);
    --accent: #7c5cff;
    --accent2: #ff5ca8;
    --accent3: #00e5ff;
    --text: #e8e8f0;
    --muted: #666680;
    --font-mono: 'JetBrains Mono', monospace;
    --font-display: 'Syne', sans-serif;
    --error: #ff4d6d;
    --success: #00e5a0;
  }

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

  html, body {
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-mono);
    overflow: hidden;
  }

  /* ── LAYOUT ── */
  .app {
    display: grid;
    grid-template-rows: 52px 1fr;
    grid-template-columns: 1fr 420px;
    height: 100vh;
    width: 100vw;
  }

  /* ── HEADER ── */
  header {
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
    backdrop-filter: blur(12px);
    z-index: 10;
  }

  .logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 17px;
    font-weight: 800;
    letter-spacing: -0.3px;
  }

  .logo-icon {
    width: 28px; height: 28px;
    background: conic-gradient(from 0deg, var(--accent), var(--accent2), var(--accent3), var(--accent));
    border-radius: 7px;
    animation: spin 8s linear infinite;
  }

  @keyframes spin { to { transform: rotate(360deg); } }

  .logo span { color: var(--accent); }

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

  .badge {
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 1.5px;
    padding: 3px 8px;
    border-radius: 3px;
    background: rgba(124,92,255,0.15);
    color: var(--accent);
    border: 1px solid rgba(124,92,255,0.3);
    text-transform: uppercase;
  }

  .fps-counter {
    font-size: 11px;
    color: var(--muted);
    min-width: 56px;
    text-align: right;
  }

  /* ── CANVAS PANEL ── */
  .canvas-panel {
    position: relative;
    overflow: hidden;
    background: #000;
  }

  #glCanvas {
    display: block;
    width: 100%;
    height: 100%;
  }

  .canvas-overlay {
    position: absolute;
    bottom: 16px;
    left: 16px;
    display: flex;
    gap: 8px;
    align-items: center;
  }

  .ctrl-btn {
    width: 36px; height: 36px;
    border-radius: 8px;
    background: rgba(13,13,20,0.85);
    border: 1px solid var(--border-bright);
    color: var(--text);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    font-size: 14px;
    backdrop-filter: blur(8px);
    transition: background 0.15s, border-color 0.15s;
  }

  .ctrl-btn:hover { background: rgba(124,92,255,0.25); border-color: var(--accent); }
  .ctrl-btn.active { background: rgba(124,92,255,0.35); border-color: var(--accent); color: var(--accent); }

  .time-display {
    font-size: 11px;
    color: var(--muted);
    padding: 6px 10px;
    background: rgba(13,13,20,0.85);
    border: 1px solid var(--border);
    border-radius: 6px;
    backdrop-filter: blur(8px);
    font-family: var(--font-mono);
  }

  .error-overlay {
    position: absolute;
    inset: 0;
    background: rgba(5,5,8,0.92);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
    display: none;
    backdrop-filter: blur(4px);
  }

  .error-box {
    background: rgba(255,77,109,0.08);
    border: 1px solid rgba(255,77,109,0.3);
    border-radius: 10px;
    padding: 20px 24px;
    max-width: 520px;
    width: 100%;
  }

  .error-box h4 {
    font-family: var(--font-display);
    font-size: 13px;
    color: var(--error);
    margin-bottom: 10px;
    letter-spacing: 1px;
    text-transform: uppercase;
  }

  .error-box pre {
    font-size: 11px;
    color: #ff9aaa;
    white-space: pre-wrap;
    word-break: break-word;
    line-height: 1.6;
  }

  /* ── RIGHT PANEL ── */
  .right-panel {
    display: flex;
    flex-direction: column;
    border-left: 1px solid var(--border);
    background: var(--surface);
    overflow: hidden;
  }

  /* ── AI PROMPT AREA ── */
  .prompt-area {
    padding: 16px;
    border-bottom: 1px solid var(--border);
  }

  .section-label {
    font-size: 9px;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .section-label::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
  }

  .prompt-input-wrap {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 8px;
  }

  textarea#promptInput {
    width: 100%;
    min-height: 76px;
    max-height: 140px;
    resize: vertical;
    background: var(--surface2);
    border: 1px solid var(--border-bright);
    border-radius: 8px;
    color: var(--text);
    font-family: var(--font-mono);
    font-size: 12px;
    line-height: 1.6;
    padding: 10px 12px;
    outline: none;
    transition: border-color 0.2s;
  }

  textarea#promptInput:focus { border-color: var(--accent); }
  textarea#promptInput::placeholder { color: var(--muted); }

  .prompt-actions {
    display: flex;
    gap: 8px;
    align-items: center;
  }

  .btn-generate {
    flex: 1;
    padding: 9px 14px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 7px;
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
    transition: opacity 0.15s, transform 0.1s;
    position: relative;
    overflow: hidden;
  }

  .btn-generate:hover { opacity: 0.88; transform: translateY(-1px); }
  .btn-generate:active { transform: translateY(0); }
  .btn-generate:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }

  .btn-generate .spinner {
    width: 13px; height: 13px;
    border: 2px solid rgba(255,255,255,0.4);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
    display: none;
  }

  .btn-generate.loading .spinner { display: block; }
  .btn-generate.loading .btn-text { display: none; }

  .btn-random {
    padding: 9px 11px;
    background: var(--surface2);
    border: 1px solid var(--border-bright);
    border-radius: 7px;
    color: var(--muted);
    font-size: 14px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
  }
  .btn-random:hover { color: var(--text); border-color: var(--border-bright); }

  /* ── QUICK PRESETS ── */
  .presets-wrap {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-top: 8px;
  }

  .preset-chip {
    font-size: 10px;
    padding: 3px 8px;
    border-radius: 99px;
    background: var(--surface2);
    border: 1px solid var(--border);
    color: var(--muted);
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
    font-family: var(--font-mono);
  }

  .preset-chip:hover { color: var(--text); border-color: var(--border-bright); }

  /* ── CODE EDITOR ── */
  .code-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    padding: 16px;
    gap: 10px;
  }

  .code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .code-actions {
    display: flex;
    gap: 6px;
  }

  .btn-sm {
    font-size: 10px;
    padding: 4px 9px;
    border-radius: 5px;
    background: var(--surface2);
    border: 1px solid var(--border);
    color: var(--muted);
    cursor: pointer;
    font-family: var(--font-mono);
    transition: color 0.15s, border-color 0.15s;
  }
  .btn-sm:hover { color: var(--text); border-color: var(--border-bright); }
  .btn-sm.primary { color: var(--accent3); border-color: rgba(0,229,255,0.3); background: rgba(0,229,255,0.05); }
  .btn-sm.primary:hover { background: rgba(0,229,255,0.12); }

  #codeEditor {
    flex: 1;
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: #a8c4d8;
    font-family: var(--font-mono);
    font-size: 11.5px;
    line-height: 1.7;
    padding: 12px;
    resize: none;
    outline: none;
    overflow-y: auto;
    transition: border-color 0.2s;
    tab-size: 2;
    white-space: pre;
    overflow-x: auto;
  }

  #codeEditor:focus { border-color: rgba(124,92,255,0.4); }

  /* ── STATUS BAR ── */
  .status-bar {
    height: 26px;
    display: flex;
    align-items: center;
    padding: 0 16px;
    border-top: 1px solid var(--border);
    gap: 12px;
    font-size: 10px;
    color: var(--muted);
  }

  .status-dot {
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 6px var(--success);
  }

  .status-dot.error { background: var(--error); box-shadow: 0 0 6px var(--error); }
  .status-dot.pending { background: var(--accent); box-shadow: 0 0 6px var(--accent); animation: pulse 1s ease-in-out infinite; }

  @keyframes pulse { 0%,100%{opacity:1} 50%{opacity:0.4} }

  /* ── SCROLLBAR ── */
  ::-webkit-scrollbar { width: 5px; height: 5px; }
  ::-webkit-scrollbar-track { background: transparent; }
  ::-webkit-scrollbar-thumb { background: var(--border-bright); border-radius: 99px; }

  /* ── TOAST ── */
  .toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--surface2);
    border: 1px solid var(--border-bright);
    border-radius: 8px;
    padding: 8px 16px;
    font-size: 12px;
    color: var(--text);
    opacity: 0;
    transition: opacity 0.2s, transform 0.2s;
    pointer-events: none;
    z-index: 999;
    backdrop-filter: blur(8px);
  }

  .toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

  /* ── GRID LINES BG on canvas placeholder ── */
  .canvas-panel::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
      linear-gradient(rgba(124,92,255,0.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(124,92,255,0.04) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    z-index: 0;
  }

  #glCanvas { position: relative; z-index: 1; }