diff --git a/css/at-rules.json b/css/at-rules.json
index 732f2cff..d3aaf319 100644
--- a/css/at-rules.json
+++ b/css/at-rules.json
@@ -490,180 +490,5 @@
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@supports"
-  },
-  "@viewport": {
-    "syntax": "@viewport {\n  <group-rule-body>\n}",
-    "interfaces": [
-      "CSSViewportRule"
-    ],
-    "groups": [
-      "CSS Device Adaptation"
-    ],
-    "descriptors": {
-      "height": {
-        "syntax": "<viewport-length>{1,2}",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": [
-          "min-height",
-          "max-height"
-        ],
-        "percentages": [
-          "min-height",
-          "max-height"
-        ],
-        "computed": [
-          "min-height",
-          "max-height"
-        ],
-        "order": "orderOfAppearance",
-        "status": "standard"
-      },
-      "max-height": {
-        "syntax": "<viewport-length>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "referToHeightOfInitialViewport",
-        "computed": "lengthAbsolutePercentageAsSpecifiedOtherwiseAuto",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "max-width": {
-        "syntax": "<viewport-length>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "referToWidthOfInitialViewport",
-        "computed": "lengthAbsolutePercentageAsSpecifiedOtherwiseAuto",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "max-zoom": {
-        "syntax": "auto | <number> | <percentage>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "the zoom factor itself",
-        "computed": "autoNonNegativeOrPercentage",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "min-height": {
-        "syntax": "<viewport-length>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "referToHeightOfInitialViewport",
-        "computed": "lengthAbsolutePercentageAsSpecifiedOtherwiseAuto",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "min-width": {
-        "syntax": "<viewport-length>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "referToWidthOfInitialViewport",
-        "computed": "lengthAbsolutePercentageAsSpecifiedOtherwiseAuto",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "min-zoom": {
-        "syntax": "auto | <number> | <percentage>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "the zoom factor itself",
-        "computed": "autoNonNegativeOrPercentage",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "orientation": {
-        "syntax": "auto | portrait | landscape",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "referToSizeOfBoundingBox",
-        "computed": "asSpecified",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "user-zoom": {
-        "syntax": "zoom | fixed",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "zoom",
-        "percentages": "referToSizeOfBoundingBox",
-        "computed": "asSpecified",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "viewport-fit": {
-        "syntax": "auto | contain | cover",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "no",
-        "computed": "asSpecified",
-        "order": "uniqueOrder",
-        "status": "standard"
-      },
-      "width": {
-        "syntax": "<viewport-length>{1,2}",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": [
-          "min-width",
-          "max-width"
-        ],
-        "percentages": [
-          "min-width",
-          "max-width"
-        ],
-        "computed": [
-          "min-width",
-          "max-width"
-        ],
-        "order": "orderOfAppearance",
-        "status": "standard"
-      },
-      "zoom": {
-        "syntax": "auto | <number> | <percentage>",
-        "media": [
-          "visual",
-          "continuous"
-        ],
-        "initial": "auto",
-        "percentages": "the zoom factor itself",
-        "computed": "autoNonNegativeOrPercentage",
-        "order": "uniqueOrder",
-        "status": "standard"
-      }
-    },
-    "status": "standard",
-    "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@viewport"
   }
 }