IntelliJ can't find org.gradle.api libs, but CLI does?

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1

I have a Gradle plugin project that builds on my OSX command line via ./gradlew build for example. I’ve “Import from existing source” the project into IntelliJ and when I build, I get

Error:(3, 22) java: package org.gradle.api does not exist
Error:(4, 28) java: package org.gradle.api.tasks does not exist
Error:(5, 36) java: package org.gradle.api.tasks.options does not exist
Error:(6, 22) java: package org.gradle.api does not exist

and of course because of this I get subsequent Cannot fine symbol errors. This in my build.gradle file.

plugins {
  id 'idea'
  id 'java'
  id 'maven'
  id 'maven-publish'
  id 'java-gradle-plugin'
}
apply plugin: 'idea'
apply plugin: 'java'
apply plugin: 'maven'
apply plugin: 'maven-publish'
apply plugin: 'java-gradle-plugin'

group=project.groupId
version = '0.0.1'

dependencies {
  compile gradleApi()
}

jar {
  manifest {
    attributes 'artifactId': project.artifactId,
               'groupId': project.groupId,
               'version': project.version
  }
  baseName artifactId
  doLast {
    println "artifactId: $project.artifactId\ngroupId: $project.groupId\nversion: $version"
  }
}


jar {
  manifest {
    attributes 'artifactId': project.artifactId,
               'groupId': project.groupId,
               'version': project.version
  }
  baseName artifactId
  doLast {
    println "artifactId: $project.artifactId\ngroupId: $project.groupId\nversion: $version"
  }
}

gradlePlugin {
    plugins {
        simplePlugin {
            id = 'com.zift.utilities.zift-version-plugin'
            implementationClass = 'com.zift.utilities.ZiftVersionPlugin'
        }
    }
}

What am I missing?