/* ── Workspace layout ── */
    .workspace {
      display: grid;
      grid-template-columns: 1fr 300px;
      gap: 20px;
      align-items: start;
    }

    /* ── Preview panel ── */
    .preview-panel {
      border: 1px solid var(--border); background: var(--card);
      display: flex; flex-direction: column;
    }
    .panel-header {
      display: flex; align-items: center; justify-content: space-between;
      padding: 10px 16px; border-bottom: 1px solid var(--border); background: var(--bg);
    }
    .panel-header-left { display: flex; align-items: center; gap: 8px; }
    .panel-label { font-size: 10px; letter-spacing: 0.2em; color: var(--ink-light); text-transform: uppercase; }
    .live-badge  { font-size: 9px; letter-spacing: 0.15em; background: var(--green-bg); color: var(--green); padding: 2px 8px; border: 1px solid var(--green); }
    .frame-info  { font-size: 10px; color: var(--ink-light); font-family: var(--mono); }

    .preview-canvas-wrap {
      flex: 1; min-height: 400px;
      display: flex; align-items: center; justify-content: center;
      padding: 40px;
      background: repeating-conic-gradient(#E8EAED 0% 25%, #F8F9FA 0% 50%) 0 0 / 16px 16px;
      overflow: hidden;
    }
    #previewCanvas {
      display: block;
      max-width: 100%; max-height: 480px;
      object-fit: contain;
      box-shadow: 0 4px 20px rgba(0,0,0,0.12);
    }
    .panel-footer {
      padding: 10px 16px; border-top: 1px solid var(--border); background: var(--bg);
      display: flex; align-items: center; justify-content: space-between;
    }

    /* ── Sidebar ── */
    .sidebar {
      display: flex; flex-direction: column; gap: 1px;
      background: var(--border); border: 1px solid var(--border);
    }
    .sidebar-section { background: var(--card); padding: 16px; }
    .sidebar-title {
      font-size: 9px; letter-spacing: 0.25em;
      color: var(--ink-light); text-transform: uppercase; margin-bottom: 14px;
    }

    /* Thickness slider */
    .slider-wrap { display: flex; align-items: center; gap: 10px; }
    .slider-num  { font-size: 20px; color: var(--ink); min-width: 40px; text-align: right; line-height: 1; }
    .slider-unit { font-size: 10px; color: var(--ink-light); }

    /* Color picker */
    .color-wrap { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }


    /* Option buttons */
    .fmt-row { display: flex; }
    .fmt-btn, .corner-btn {
      flex: 1;
      font-size: 10px;
      letter-spacing: 0.08em;
      padding: 8px 14px;
      border: 1px solid var(--border);
      background: transparent;
      color: var(--ink-light);
      cursor: pointer;
      transition: all 0.15s;
      margin-left: -1px;
      white-space: nowrap;
      min-height: 38px;
    }
    .fmt-btn:first-child, .corner-btn:first-child { margin-left: 0; }
    .fmt-btn:hover:not(.active), .corner-btn:hover:not(.active) {
      border-color: var(--blue);
      color: var(--blue);
      z-index: 1;
      position: relative;
    }
    .fmt-btn.active, .corner-btn.active {
      background: var(--blue);
      color: #fff;
      border-color: var(--blue);
      z-index: 1;
      position: relative;
    }

    /* Preset colors */
    .preset-color {
      width: 20px; height: 20px; border: 1px solid transparent;
      cursor: pointer; transition: all 0.12s; flex-shrink: 0;
    }
    .preset-color:hover { transform: scale(1.15); border-color: var(--ink); }
    .preset-color.active { border: 2px solid var(--ink); }

    /* ── Action section ── */
    .action-section {
      background: var(--card); padding: 14px 16px;
      display: flex; flex-direction: column; gap: 8px;
    }

    @media (max-width: 800px) {
      .workspace { grid-template-columns: 1fr; }
    }