/* Base64 转图片：预览用棋盘格底，方便看透明背景 */
.b64-preview{display:flex;align-items:center;justify-content:center;padding:1rem;border:1px solid #eef1f5;border-radius:.6rem;
  background:linear-gradient(45deg,#f7f8fa 25%,transparent 25%,transparent 75%,#f7f8fa 75%),
             linear-gradient(45deg,#f7f8fa 25%,#fff 25%,#fff 75%,#f7f8fa 75%);
  background-size:16px 16px;background-position:0 0,8px 8px}
.b64-preview img{display:block;max-width:100%;height:auto;max-height:20rem}

.b64-kv{border:1px solid #eef1f5;border-radius:.5rem;overflow:hidden}
.b64-kv-row{display:flex;align-items:center;gap:1rem;padding:.5rem .75rem;border-bottom:1px solid #f2f4f7;font-size:.875rem}
.b64-kv-row:last-child{border-bottom:0}
.b64-kv-row span{flex:none;width:5rem;color:#8a9199;font-size:.8125rem}
.b64-kv-row b{color:#3f4650;word-break:break-all}