vars:
  - name: title
    required: true
  - name: subtitle
    required: false
    default: ""
  - name: author
    required: false
    default: ""
  - name: date
    required: false
    default: ""

elements:
  # 标题
  - type: shape
    box: [0, 0, 10, 5.625]
    shape: rectangle
    fill: "#4a90e2"

  # 标题文本
  - type: text
    box: [1, 1.5, 8, 1]
    content: "{title}"
    font:
      size: 44
      bold: true
      color: "#ffffff"
      align: center

  # 副标题（条件显示）
  - type: text
    box: [1, 2.8, 8, 0.6]
    content: "{subtitle}"
    visible: "{subtitle != ''}"
    font:
      size: 24
      color: "#ffffff"
      align: center

  # 作者
  - type: text
    box: [1, 4, 8, 0.5]
    content: "{author}"
    visible: "{author != ''}"
    font:
      size: 18
      color: "#e0e0e0"
      align: center

  # 日期
  - type: text
    box: [1, 4.8, 8, 0.4]
    content: "{date}"
    visible: "{date != ''}"
    font:
      size: 14
      color: "#cccccc"
      align: center