<?php
header("Content-Type:text/css");
function checkhexcolor($color){
    return preg_match('/^#[a-f0-9]{6}$/i', $color);
}
if (isset($_GET['color']) AND $_GET['color'] != '') {
    $color = "#" . $_GET['color'];
}

if (!$color OR !checkhexcolor($color)) {
    $color = "#336699";
}

function hexToRgb($hex, $alpha = false) {
    $hex      = str_replace('#', '', $hex);
    $length   = strlen($hex);
    $rgb['r'] = hexdec($length == 6 ? substr($hex, 0, 2) : ($length == 3 ? str_repeat(substr($hex, 0, 1), 2) : 0));
    $rgb['g'] = hexdec($length == 6 ? substr($hex, 2, 2) : ($length == 3 ? str_repeat(substr($hex, 1, 1), 2) : 0));
    $rgb['b'] = hexdec($length == 6 ? substr($hex, 4, 2) : ($length == 3 ? str_repeat(substr($hex, 2, 1), 2) : 0));
    if ( $alpha ) {
       $rgb['a'] = $alpha;
    }
    return $rgb;
}


function hexToHsl($hex){
    $hex      = str_replace('#', '', $hex);
    $red = hexdec(substr($hex, 0, 2)) / 255;
    $green = hexdec(substr($hex, 2, 2)) / 255;
    $blue = hexdec(substr($hex, 4, 2)) / 255;

    $cmin = min($red, $green, $blue);
    $cmax = max($red, $green, $blue);
    $delta = $cmax - $cmin;

    if ($delta == 0) {
        $hue = 0;
    } elseif ($cmax === $red) {
        $hue = (($green - $blue) / $delta);
    } elseif ($cmax === $green) {
        $hue = ($blue - $red) / $delta + 2;
    } else {
        $hue = ($red - $green) / $delta + 4;
    }

    $hue = round($hue * 60);
    if ($hue < 0) {
        $hue += 360;
    }


    $lightness = (($cmax + $cmin) / 2);
    $saturation = $delta === 0 ? 0 : ($delta / (1 - abs(2 * $lightness - 1)));
    if ($saturation < 0) {
        $saturation += 1;
    }

    $lightness = round($lightness*100);
    $saturation = round($saturation*100);

    $hsl['h'] = $hue;
    $hsl['s'] = $saturation;
    $hsl['l'] = $lightness;
    return $hsl;

}


?>

:root{
    --base-h: <?php echo hexToHsl($color)['h']; ?>;
    --base-s: <?php echo hexToHsl($color)['s']; ?>%;
    --base-l: <?php echo hexToHsl($color)['l']; ?>%;
}