website/_src/assets/css/default/nav.css

body>nav::before,
body::after {
	z-index: -1;
	content: "";
	position: absolute;
	mask-image: url("/assets/img/theme/sundae_sit-lines.png");
	mask-repeat: no-repeat;
	margin: 0;
	width: inherit;
	height: inherit;
	pointer-events: none;
}

body>nav::before {
	bottom: 0;
	left: 0;
	mask-size: 160%;
	-webkit-mask-position-x: -25px;
	-webkit-mask-position-y: 90%;
}

body>nav::after {
	top: 0;
	left: 0;
	width: var(--view);
	content: "";
	position: absolute;
	height: 100%;
	z-index: -2;
	pointer-events: none;
	mask-image: var(--paw-tiled);
	animation: navbg 10s linear infinite;
	mask-size: 128px;
}

body::after {
	content: none;
	mask-size: 100%;
	width: 100%;
	height: 100vw;
	-webkit-mask-position-x: 0;
	-webkit-mask-position-y: bottom;
}

body>nav {
	display: flex;
	flex-direction: column;
	overflow: hidden;
	padding: 1rem;
	position: fixed;
	width: var(--view);
	height: 100%;

	& * svg,
	li img {
		margin: 0 8px 0 8px;
		width: 20px;
		align-self: center;
	}

	& details {
		display: flex;
	}

	& ul {
		margin: var(--pad-sm);
		padding: 0;

		& li,
		button {
			padding: 0;
			align-items: center;
			margin-bottom: inherit;

			& img {
				border-radius: 100%;
			}
		}
	}

	& svg {
		fill: currentColor;
		stroke: currentColor;
		stroke-width: 0;
	}

	& details {
		font-size: 1.4rem;
	}

	& a,
	button {
		display: flex;
		font-size: 1.125rem;
		width: 100%;
		font-weight: bold;
		height: var(--pad-xl);
		line-height: var(--pad-xl);
	}
}

body {
	font-family: "Rubik", sans-serif;

	&>nav {
		gap: var(--pad-m);
		border-right-width: 1px;
		border-right-style: solid;

		& a,
		button {
			align-items: center;
			border-style: solid;
			border-width: 2px;
			border-radius: var(--round);
		}

		& details {
			border-radius: var(--round);
			font-weight: bold;
		}

		& details>summary {
			display: flex;
			justify-content: center;
			padding: 0 var(--pad-lm) 0 0;
			height: var(--pad-xl);

			&>svg {
				transform: rotate(0deg);
				transition: transform var(--trans);
			}
		}

		& details:not([open])>summary {
			border-radius: var(--round);
			border-style: solid;
			border-width: 2px;
		}

		& details[open] {
			border-style: solid;
			border-width: 2px;

			&>summary svg {
				transform: rotate(45deg);
			}
		}
	}
}