Background

{
  "type": "object",
  "description": "Theme-controlled PowerPoint slide background. The slot is resolved through the active color scheme and remains theme-aware.",
  "required": [
    "type",
    "slot"
  ],
  "properties": {
    "type": {
      "type": "string",
      "const": "theme",
      "description": "Theme-controlled background fill."
    },
    "slot": {
      "$ref": "#/$defs/ThemeBackgroundSlot"
    }
  }
}

{
  "type": "object",
  "description": "Fixed solid slide background fill.",
  "required": [
    "type",
    "color"
  ],
  "properties": {
    "type": {
      "type": "string",
      "const": "solid",
      "description": "Fixed solid background fill."
    },
    "color": {
      "$ref": "#/$defs/ColorRef",
      "description": "Fixed solid fill color: a hex string, a color-scheme slot or role name, or a var:<id> variable reference (a ColorRef, resolved against the effective color scheme and the deck variables). Use { type: 'theme', slot: ... } for PowerPoint's four theme-controlled background choices.",
      "examples": [
        "#FFFFFF",
        "#0F172A",
        "#F8FAFC"
      ]
    },
    "opacity": {
      "type": "number",
      "minimum": 0,
      "maximum": 1,
      "description": "Background opacity from 0 (fully transparent) to 1 (fully opaque)."
    }
  }
}

{
  "type": "object",
  "description": "Fixed gradient slide background fill.",
  "required": [
    "type",
    "gradient"
  ],
  "properties": {
    "tone": {
      "type": "string",
      "enum": [
        "dark",
        "light"
      ],
      "description": "Whether the background is dark or light, which picks the color map (dark1 or light1) so text, lines and neutrals read on it. Without a tone a picture or gradient takes the deck's variant, else counts as light."
    },
    "type": {
      "type": "string",
      "const": "gradient",
      "description": "Fixed gradient background fill."
    },
    "gradient": {
      "type": "object",
      "description": "Gradient fill definition.",
      "properties": {
        "angle": {
          "type": "number",
          "description": "Gradient angle in degrees (0 = left-to-right, 90 = top-to-bottom)."
        },
        "stops": {
          "type": "array",
          "minItems": 2,
          "description": "Ordered list of color stops along the gradient. A gradient needs at least two stops.",
          "items": {
            "type": "object",
            "description": "Color stop along the gradient.",
            "required": [
              "color",
              "position"
            ],
            "properties": {
              "color": {
                "$ref": "#/$defs/ColorRef",
                "description": "Stop color: a hex string, a color-scheme slot or role name, or a var:<id> variable reference (a ColorRef).",
                "examples": [
                  "#1E40AF",
                  "#22D3EE"
                ]
              },
              "position": {
                "type": "number",
                "minimum": 0,
                "maximum": 1,
                "description": "Stop position along the gradient, from 0 (start) to 1 (end)."
              }
            }
          }
        }
      }
    },
    "opacity": {
      "type": "number",
      "minimum": 0,
      "maximum": 1,
      "description": "Background opacity from 0 (fully transparent) to 1 (fully opaque)."
    }
  }
}

{
  "type": "object",
  "additionalProperties": false,
  "description": "Picture background: the image fills the whole canvas behind everything and never moves content (to push content aside, use an image block with placement). The string shorthand 'asset:x' (or any image source) is { type: 'image', src: 'asset:x' }, a cover image. Paint order: the colour scheme's default slide background, the picture, then the overlay, then furniture and content.",
  "required": [
    "type",
    "src"
  ],
  "properties": {
    "tone": {
      "type": "string",
      "enum": [
        "dark",
        "light"
      ],
      "description": "Whether the background is dark or light, which picks the color map (dark1 or light1) so text, lines and neutrals read on it. Without a tone a picture or gradient takes the deck's variant, else counts as light."
    },
    "type": {
      "type": "string",
      "const": "image",
      "description": "Picture background."
    },
    "src": {
      "type": "string",
      "description": "Source for the background image: an 'asset:<id>' reference, HTTPS URL, data URI, or a relative path resolved against the OPF file location.",
      "examples": [
        "https://cdn.acme.com/backgrounds/cover.jpg",
        "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAA...",
        "./backgrounds/cover.jpg",
        "asset:bg-cover"
      ]
    },
    "alt": {
      "type": "string",
      "description": "Alternative text. A background with alt is meaningful: PowerPoint export draws it as a full-slide picture at the back that carries the text, so screen readers see it. Without alt it is decorative and exports as the native slide background; the alt text of a referenced asset does not count, so a background is decorative unless it says otherwise."
    },
    "fit": {
      "type": "string",
      "enum": [
        "cover",
        "contain",
        "stretch",
        "tile"
      ],
      "description": "How the picture fills the canvas: 'cover' fills it and crops what overflows around focus; 'contain' shows the whole picture centered over the colour scheme's default background; 'stretch' scales it to the canvas exactly; 'tile' repeats it at its own size from the top-left corner. Default 'cover'."
    },
    "focus": {
      "$ref": "#/$defs/ImageFocus",
      "description": "Point of the picture to keep in view when 'cover' crops it. Ignored by the other fits."
    },
    "opacity": {
      "type": "number",
      "minimum": 0,
      "maximum": 1,
      "description": "Picture opacity from 0 (fully transparent) to 1 (fully opaque); the overlay keeps its own opacity. Default 1."
    },
    "recolor": {
      "$ref": "#/$defs/ImageRecolor",
      "description": "Grayscale or duotone treatment of the picture's pixels, as on an image block: recolor and opacity apply to the pixels, then the overlay is drawn above."
    },
    "overlay": {
      "$ref": "#/$defs/Overlay",
      "description": "Scrim over the whole picture or a band along one edge (edge, size), beneath furniture and content, for example to keep a title readable over a busy photo."
    }
  },
  "examples": [
    {
      "type": "image",
      "src": "asset:cover-photo"
    },
    {
      "type": "image",
      "src": "./images/harbour.jpg",
      "alt": "Container ships at dawn",
      "focus": {
        "x": 0.5,
        "y": 0.7
      },
      "overlay": {
        "color": "dark1",
        "opacity": 0.4
      }
    }
  ]
}

{
  "type": "object",
  "description": "Fixed pattern slide background fill.",
  "required": [
    "type",
    "pattern"
  ],
  "properties": {
    "type": {
      "type": "string",
      "const": "pattern",
      "description": "Fixed pattern background fill."
    },
    "pattern": {
      "type": "object",
      "description": "Pattern fill definition.",
      "required": [
        "preset"
      ],
      "properties": {
        "preset": {
          "type": "string",
          "description": "Pattern preset or engine-defined pattern id. DrawingML preset names (ECMA-376 ST_PresetPatternVal, for example pct5, ltHorz, wdUpDiag) are portable: PPTX export writes them as native pattern fills and import returns the same name. Engine-defined ids are renderer-specific; the legacy preview id diagStripe remains accepted and exports as wdUpDiag.",
          "examples": [
            "pct5",
            "ltHorz",
            "wdUpDiag"
          ]
        },
        "foregroundColor": {
          "$ref": "#/$defs/ColorRef",
          "description": "Foreground color for the pattern: a hex string, a color-scheme slot or role name, or a var:<id> variable reference (a ColorRef).",
          "examples": [
            "#0F172A"
          ]
        },
        "backgroundColor": {
          "$ref": "#/$defs/ColorRef",
          "description": "Background color behind the pattern: a hex string, a color-scheme slot or role name, or a var:<id> variable reference (a ColorRef).",
          "examples": [
            "#FFFFFF"
          ]
        }
      }
    },
    "opacity": {
      "type": "number",
      "minimum": 0,
      "maximum": 1,
      "description": "Background opacity from 0 (fully transparent) to 1 (fully opaque)."
    }
  }
}