// After Before
@mixin theme-afbf {
    position: absolute;
    content: "";
}

// bg color
@mixin bg-color($color, $opacity) {
    background: rgba($color, $opacity);
}

// Placeholder input
@mixin tp-placeholder {
    &::-webkit-input-placeholder {
        @content;
    }

    &:-moz-placeholder {
        @content;
    }

    &::-moz-placeholder {
        @content;
    }

    &:-ms-input-placeholder {
        @content;
    }
}

// Animate
@mixin animate($animation, $duration, $repeat, $easing) {
    -webkit-animation: $animation $duration $repeat $easing;
    -moz-animation: $animation $duration $repeat $easing;
    -ms-animation: $animation $duration $repeat $easing;
    -o-animation: $animation $duration $repeat $easing;
    animation: $animation $duration $repeat $easing;
}

// Filter
@mixin filter($value) {
    -webkit-filter: $value;
    filter: $value;
}

// Appearance for select
@mixin appearance($value) {
    -webkit-appearance: $value;
    -moz-appearance: $value;
    -ms-appearance: $value;
    -o-appearance: $value;
    appearance: $value;
}

// Keyframes
@mixin keyframes($name) {
    @-webkit-keyframes #{$name} {
        @content;
    }

    @-moz-keyframes #{$name} {
        @content;
    }

    @-ms-keyframes #{$name} {
        @content;
    }

    @keyframes #{$name} {
        @content;
    }
}

// Background
@mixin background($pos: center, $size: cover) {
    background-position: $pos;
    background-size: $size;
    background-repeat: no-repeat;
}

// Transition
@mixin transition($value...) {
    -webkit-transition: $value;
    -moz-transition: $value;
    -ms-transition: $value;
    -o-transition: $value;
    transition: $value;
}

// Transform
@mixin transform($transforms) {
    -webkit-transform: $transforms;
    -moz-transform: $transforms;
    -ms-transform: $transforms;
    -o-transform: $transforms;
    transform: $transforms;
}

// Border radius
@mixin border-radius($value) {
    -webkit-border-radius: $value;
    -moz-border-radius: $value;
    -o-border-radius: $value;
    -ms-border-radius: $value;
    border-radius: $value;
}

// Sentence case
@mixin sentence-case() {
    text-transform: lowercase;

    &:first-letter {
        text-transform: uppercase;
    }
}

// Flexbox display
@mixin flex-column() {
    display: flex;
    flex-direction: column;
}

@mixin flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

@mixin flex-center-column {
    @include flex-center;
    flex-direction: column;
}

@mixin flex-vertical-center {
    display: flex;
    align-items: center;
}

@mixin flex-horizontal-center {
    display: flex;
    justify-content: center;
}

// Box shadows
@mixin box-shadow($shadow) {
    -webkit-box-shadow: $shadow;
    -moz-box-shadow: $shadow;
    -ms-box-shadow: $shadow;
    -o-box-shadow: $shadow;
    box-shadow: $shadow;
}

// Position
@mixin position($pos: center) {
    position: absolute;

    @if $pos ==center {
        left: 50%;
        top: 50%;
        @include transform(translate(-50%, -50%));
    }

    @if $pos ==vertical {
        left: 0;
        top: 50%;
        @include transform(translateY(-50%));
    }

    @if $pos ==right-vertical {
        right: 0;
        top: 50%;
        @include transform(translateY(-50%));
    }

    @if $pos ==horizontal {
        left: 50%;
        top: 0;
        @include transform(translateX(-50%));
    }

    @if $pos ==bottom-horizontal {
        left: 50%;
        bottom: 0;
        @include transform(translateX(-50%));
    }
}

// Font Size
@mixin font-size($size: 12, $base: 16) {
    font-size: $size + px;
    font-size: calc($size / $base) * 1rem;
}

// Fluid Font
@mixin fluid-font($min-width, $max-width, $min-font-size, $max-font-size) {
    $unit1: unit($min-width);
    $unit2: unit($max-width);
    $unit3: unit($min-font-size);
    $unit4: unit($max-font-size);

    @if $unit1 ==$unit2 and $unit1 ==$unit3 and $unit1 ==$unit4 {
        & {
            font-size: $min-font-size;
            line-height: $min-font-size * 1.618;

            @media screen and (min-width: $min-width) {
                font-size: calc(
                    #{$min-font-size} + #{strip-unit($max-font-size - $min-font-size)} *
                        ((100vw - #{$min-width}) / #{strip-unit($max-width - $min-width)})
                );
                line-height: calc(
                    #{$min-font-size} + #{strip-unit($max-font-size - $min-font-size)} * 1.618 *
                        ((100vw - #{$min-width}) / #{strip-unit($max-width - $min-width)})
                );
            }

            @media screen and (min-width: $max-width) {
                font-size: $max-font-size;
                line-height: $max-font-size * 1.618;
            }
        }
    }
}

// Line Height
@mixin line-height($height: 12, $base: 16) {
    line-height: $height + px;
    line-height: calc($height / $base) * 1rem;
}

// Arrow
@mixin arrow($direction: down, $size: 5px, $color: #555) {
    width: 0;
    height: 0;

    @if ($direction ==left) {
        border-top: $size solid transparent;
        border-bottom: $size solid transparent;
        border-right: $size solid $color;
    } @else if ($direction ==right) {
        border-top: $size solid transparent;
        border-bottom: $size solid transparent;
        border-left: $size solid $color;
    } @else if ($direction ==down) {
        border-left: $size solid transparent;
        border-right: $size solid transparent;
        border-top: $size solid $color;
    } @else {
        border-left: $size solid transparent;
        border-right: $size solid transparent;
        border-bottom: $size solid $color;
    }
}