Sass 101 - A newb's guide: global variables are not scoped

When using global variables, it is important to note that as variables are redefined within the cascade, this will in turn effect the value passed into the preceding variables.

$border-radius: 5px !default;

.block-01 {
  border-radius: $border-radius;
}

.block-02 {
  $border-radius: 10px;
  border-radius: $border-radius;
}

.block-03 {
  border-radius: $border-radius;
}

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