.subtitle { font-size: 12px; color: var(--ink-light); font-weight: 300; letter-spacing: 0.1em; border-left: 2px solid var(--accent); padding-left: 10px; }
.panel-header { padding:10px 16px; border-bottom:1px solid var(--border); background:var(--bg); display:flex; justify-content:space-between; align-items:center; gap:12px; }
    .panel-label { font-size:10px; letter-spacing:.2em; color:var(--ink-light); text-transform:uppercase; }
    .panel-body { padding:18px; }
.hidden { display:none !important; }
    @media (max-width:900px) {
}

    /* ── Size input field match watermark style ── */
    #widthInput,
    #heightInput {
      width: 100%;
      border: 1px solid var(--border);
      background: #fff;
      color: var(--ink);
      font: inherit;
      font-size: 13px;
      padding: 10px 12px;
      border-radius: 6px;
      outline: none;
      box-sizing: border-box;
      line-height: 1.4;
    }
    #widthInput:focus,
    #heightInput:focus {
      border-color: var(--blue);
      background: #fff;
      box-shadow: none;
    }
    #widthInput::placeholder,
    #heightInput::placeholder {
      color: var(--ink-light);
    }

    /* PNG warning note */
    .png-warning {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      background: #EFF6FF;
      border: 1px solid #BFDBFE;
      border-left: 3px solid var(--blue);
      border-radius: 6px;
      padding: 12px 16px;
      margin-top: 12px;
    }
    .png-warning-icon {
      font-size: 15px;
      flex-shrink: 0;
      margin-top: 1px;
      line-height: 1.5;
    }
    .png-warning-body {
      display: flex;
      flex-direction: column;
      gap: 3px;
    }
    .png-warning-title {
      font-size: 10px;
      font-weight: 700;
      letter-spacing: 0.15em;
      color: var(--blue);
      text-transform: uppercase;
    }
    .png-warning-text {
      font-size: 12.5px;
      color: var(--ink-mid);
      font-weight: 400;
      line-height: 1.75;
    }
    .png-warning-text strong {
      font-weight: 700;
      color: var(--ink);
    }