loader.js

// JS

Beast.decl({
    Loader: {
        mix: 'typo_text',
        expand: function () {
            this.append(
                (this.text() + '...').replace(/ /, ' ').split('').map(
                    letter => <letter>{letter}</letter>
                )
            )
        }
    },
    Loader__letter: {
        mod: {
            state: 'release',
        },
        domInit: function () {
            let interval = 1000
            let act = () => {
                this.toggleMod('state', 'active', 'release')
            }

            setTimeout(
                () => {
                    act()
                    setInterval(act, interval)
                },
                this.index() * 100
            )
        }
    }
})

// CSS

.Loader
    color gray-300

    &__letter
        display inline-block
        transition color 500ms
        &_state_active
            color black