@header-image-px: 60px;
@header-link-margin: 14px;
@header-icon-px: 40px;

.header {
    --header-image-px: @header-image-px;
    --header-link-margin: @header-link-margin;
    --header-background-mask-image: linear-gradient(180deg, @background-colour 0, transparent 100%);
    --header-background-mask-image: linear-gradient(180deg, var(--background-colour) 0, transparent 100%);

    flex: 0 0 auto;

    &__background {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: @background-pattern;
        background-color: @header-accent-colour;
        background: var(--background-pattern);
        background-color: var(--header-accent-colour);
        background-blend-mode: multiply;
        mask-image: var(--header-background-mask-image);
        -webkit-mask-image: var(--header-background-mask-image); // fuck chrome
    }

    &__desktop {
        margin: 0 auto;
        display: flex;
        align-items: flex-start;
        padding: 4px;
        max-width: @site-max-width;
        height: @header-height-desktop;
        max-width: var(--site-max-width);
        height: var(--header-height-desktop);

        @media (max-width: @site-mobile-width) {
            display: none;
        }

        &__logo {
            flex: 0 0 auto;
            color: inherit;
            text-decoration: none;
            cursor: pointer;
            display: block;
            background: no-repeat center / cover;
            background-image: @site-logo;
            width: @header-image-px;
            height: @header-image-px;
            background-image: var(--site-logo);
            width: var(--header-image-px);
            height: var(--header-image-px);
            font-size: 0;
            transition: width .1s, height .1s;
        }

        &__menus {
            display: flex;
            flex: 0 0 auto;
            height: 100%;
        }

        &__link {
            color: inherit;
            text-decoration: none;
            display: block;
            min-width: 100px;
            cursor: pointer;
            border-radius: 2px;
            padding: 4px 10px;
            transition: background-color .2s;

            &:hover,
            &:focus {
                background-color: fade(#fff, 20%);
            }

            &:active {
                background-color: fade(#fff, 10%);
            }
        }

        &__menu {
            margin: 0 5px;

            &__link {
                margin: @header-link-margin 0;
                margin: var(--header-link-margin) 0;
                font-size: 1.2em;
                padding: 6px 10px;
                text-align: center;
            }
        }

        &__submenu {
            position: absolute;
            z-index: 100;
            overflow: hidden;
            max-height: 0;
            transition: max-height .2s;
            left: -5px;
            top: 50px;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);

            &__link {
                margin: 5px;
            }

            &__background {
                background: @header-accent-colour;
                background: var(--header-accent-colour);
                position: absolute;
                top: 0;
                left: 0;
                right: 0;
                bottom: 0;
            }

            &__content {
                background: @background-colour-translucent-9;
                background: var(--background-colour-translucent-9);
                overflow: hidden;
            }
        }

        &__menu:hover &__submenu,
        &__menu:focus &__submenu,
        &__menu:focus-within &__submenu,
        &__menu:active &__submenu {
            max-height: 200px;
        }

        &__user {
            flex: 0 0 auto;
            display: flex;
            align-items: center;
            margin-left: auto;

            &__avatar {
                width: @header-image-px;
                height: @header-image-px;
                width: var(--header-image-px);
                height: var(--header-image-px);
                margin-left: 5px;
                transition: width .1s, height .1s;
                box-shadow: 0 0 4px #111;

                &:hover,
                &:focus,
                &:active {
                    box-shadow: inset 0 0 0 1px @user-colour, 0 0 4px #111;
                    box-shadow: inset 0 0 0 1px var(--user-colour), 0 0 4px #111;
                }
            }

            &__button {
                margin: 2px;
                color: inherit;
                text-decoration: none;
                font-size: 1.5em;
                line-height: 32px;
                width: 32px;
                height: 32px;
                transition: background-color .2s;
                border-radius: 4px;
                text-align: center;

                &:hover,
                &:focus {
                    background-color: fade(#fff, 20%);
                }

                &:active {
                    background-color: fade(#fff, 10%);
                }

                &__count {
                    position: absolute;
                    bottom: 1px;
                    right: 1px;
                    font-size: 10px;
                    background-color: @header-accent-colour;
                    background-color: var(--header-accent-colour);
                    opacity: .9;
                    border-radius: 4px;
                    line-height: 12px;
                    padding: 2px 4px;
                }
            }
        }
    }

    &__mobile {
        --header-icon-px: @header-icon-px;
        display: block;

        @media (min-width: @site-mobile-width) {
            display: none;
        }

        &__icons {
            display: flex;
            justify-content: space-between;
            height: @header-height-mobile;
            height: var(--header-height-mobile);
            padding: 5px;
            z-index: 100;

            -webkit-touch-callout: none !important;
            -webkit-user-select: none !important;
            -khtml-user-select: none !important;
            -moz-user-select: none !important;
            -ms-user-select: none !important;
            user-select: none !important;
        }

        &__icon {
            flex: 0 0 auto;
            cursor: pointer;
            font-size: 32px;
            width: @header-icon-px;
            height: @header-icon-px;
            width: var(--header-icon-px);
            height: var(--header-icon-px);
            display: flex;
            justify-content: center;
            align-items: center;

            -webkit-touch-callout: none !important;
            -webkit-user-select: none !important;
            -khtml-user-select: none !important;
            -moz-user-select: none !important;
            -ms-user-select: none !important;
            user-select: none !important;
        }

        &__logo {
            color: inherit;
            text-decoration: none;
            background: no-repeat center / cover;
            background-image: @site-logo;
            background-image: var(--site-logo);
            font-size: 0;
        }

        &__avatar {
            transition: box-shadow .2s;
            box-shadow: 0 0 4px #111;
        }

        &__toggle {
            display: none;
        }

        &__menu {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            z-index: 99;
            background: @background-pattern;
            background-color: @header-accent-colour;
            background: var(--background-pattern);
            background-color: var(--header-accent-colour);
            background-blend-mode: multiply;
            transition: max-height .2s;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
            text-shadow: 0 1px 4px #000;
            max-height: 0;
            overflow: hidden;

            &__spacer {
                height: @header-height-mobile;
                height: var(--header-height-mobile);
            }
        }

        &__toggle:checked ~ &__menu {
            max-height: 600px;
        }

        &__user {
            display: grid;
            grid-template-columns: 1fr 1fr;
            border-bottom: 1px solid #fff;
            padding: 5px 5px 3px; // extra 2px is provided by the buttons
        }

        &__navigation {
            padding: 5px;
        }

        &__link {
            color: inherit;
            text-decoration: none;
            display: block;
            padding: 8px;
            padding-left: 20px;
            cursor: pointer;
            border-radius: 2px;
            transition: background-color .2s, margin .1s, opacity .1s;
            font-size: 1.2em;

            &:not(:last-child) {
                margin-bottom: 2px;
            }

            &--primary {
                font-size: 1.5em;
                padding: 10px;
            }

            &--user {
                margin: 2px;
                font-size: 1.5em;
                padding: 10px;
            }

            &:hover,
            &:focus {
                background-color: fade(#fff, 20%);
            }

            &:active {
                background-color: fade(#fff, 10%);
            }
        }
    }
}