Android Studio: Error "Failed to resolve: design"? - android-studio

Question

Hi I receive this error message on gradle project sync.
"Failed to resolve: design"
I can't find what's this.
Is there any friend that can help me with this? Or do you have another icon pack Android Studio project?
It's from CandyBar-Sample-Master android icon pack project.
apply plugin: 'com.android.application'
android {
compileSdkVersion rootProject.ext.CompileSdk
android.applicationVariants.all { variant ->
variant.outputs.all { output ->
def appName = parent.name
def fileName = appName.replace(" ", "_")
outputFileName = "$fileName-v${variant.versionName}.apk"
}
}
defaultConfig {
applicationId "com.grafiman.icons.selero"
minSdkVersion rootProject.ext.MinSdk
targetSdkVersion rootProject.ext.TargetSdk
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
buildToolsVersion '27.0.3'
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.github.danimahardhika.candybar-library:core:3.5.0-b4'
}

Answer 1

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
jcenter()
google()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.3'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
mavenCentral()
jcenter()
google()
maven { url "https://jitpack.io" }
maven { url 'https://maven.google.com' }
}
//NOTE: This is important
rootProject.ext {
BuildTools = "27.0.3"
MinSdk = 15
TargetSdk = 26
CompileSdk = 26
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}