// Navigation Functions
@function toggle_collapse($tc, $mc)
    @if $mc <= $tc
        @return $tc
    @else
        @return $mc

@function toggle_visible($tc, $nc)
    @if $tc == $nc
        @return inline-block
    @if $tc != $nc
        @return none

@function max-width($tn, $mn)
    @if $tn < $mn
        @return $mn
    @if $tn > $mn
        @return $tn
    @if $tn == $mn
        @return 100%

@function min-width($tn, $mn)
    @if $tn < $mn
        @return $tn
    @if $tn > $mn
        @return $mn
    @if $tn == $mn
        @return 0

@function yes_or_no($d)
    @if $d == yes
        @return inline-block
    @else
        @return none

@function set-button-color($c)
    @if (lightness($c) > 50)
        @return $black
    @else
        @return $white

@function set-button-shadow($c)
    @if (lightness($c) >= 70)
        @return 8%
    @if (lightness($c) <= 69)
        @return 14%
    @if (lightness($c) <= 30)
        @return 27%


@function sqrt($r)
    $x0: 1
    $x1: $x0
    @for $i from 1 through 10
        $x1: $x0 - ($x0 * $x0 - abs($r)) / (2 * $x0)
        $x0: $x1
    @return $x1