less.js/packages/test-data/tests-unit/layer/layer.less

.main {
    @layer {
        &::before {
            color: #f00;
        }
    }
}

@layer legacy {
    @import "./import/layer-import.less";
}

@import url("/import/layer-import-2.css") layer(foo);
@import url("/import/layer-import-3.css") layer(responsive) supports(display: flex) screen and (max-width: 768px);
@import url("/import/layer-import-4.css") layer(print) print;
@import url("/import/layer-import-4.css") layer(print) print, (max-width: 600px);
@import url("/import/layer-import-5.css") layer(features) supports(display: grid);

@layer-name: primevue;

@layer @layer-name {
    .test {
        foo: bar;
    }
}

@layer reset, base, components, utilities;

@layer reset {

    *,
    *::before,
    *::after {
        box-sizing: border-box;
    }
}

@layer base {
    body {
        margin: 0;
        font-family: system-ui, sans-serif;

        header {
            background-color: #f0f0f0;
            padding: 1rem;
        }
    }
}

@layer components {
    .button {
        display: inline-block;
        padding: 0.5rem 1rem;
        background-color: blue;
        color: white;

        &:hover {
            background-color: darkblue;
        }
    }
}

@layer utilities {
    .text-center {
        text-align: center;
    }

    .responsive {
        width: 100%;

        @media (min-width: 768px) {
            width: 50%;
        }
    }
}

.parent {
    color: black;

    .child {
        color: red;
    }

    &:hover {
        background: lightgray;
    }
}

@layer foo.baz {
   .bar {
       font-weight: bold;
   }
}

@layer framework {
    @layer layout {
        .container {
            display: grid;
            gap: 2rem;
        }
    }
}

@layer framework.layout {
    main {
        padding: 2rem;
    }
    p {
        margin-block: 1rem;
        color: #555;
    }
}