body > header .avatar {
    margin: 0 0 0 auto;
    padding: 0 1em 0 0;
    height: 100%;
    text-align: right;
    display: flex;
    flex-flow: row;
    align-items: center;
    position: relative;
}
header .avatar img[src] {
    max-width: 100%;
    max-height: 100%;
    aspect-ratio: 1;
    border-radius: 50%;
    border: 0.5rem solid var(--header-background-color);
    object-fit: cover;
}
body > header .avatar::after {
    content: "▼";
}

header .avatar ul {
    display: none;
    position: absolute;
    flex-flow: column nowrap;
    gap: 0;
    z-index: 10;
    top: 2.85em;
    right: -0.4em;
    align-items: stretch;
}
header .avatar li.user {
    background-color: hsl(from var(--header-background-color) h calc(s - 30) calc(l + 40) / 1);
    padding: 0.5rem 1rem;
}
header .avatar ul a {
    color: var(--header-link-color);
    background-color: var(--header-background-color);
    padding: 0.5rem 1rem;
    display: block;
    white-space: nowrap;
}
header .avatar ul a:hover {
    background-color: hsl(from var(--header-background-color) h s calc(l + 10) / 1);
    filter: brightness(1.1);
}
header .avatar li:first-child a::before {
    content: "";
    background-color: inherit;
    position: absolute;
    top: -0.25em;
    right: 0.5em;
    width: 0.5em;
    height: 0.5em;
    transform: rotate(45deg);
}

/* form .logo, */
form .avatar {
    display: flex;
    flex-flow: column nowrap;
    gap: 0.5rem;
    max-width: 10rem;
}
/* form .logo img, */
form .avatar img {
    width: 100%;
    border-radius: 0.25rem;
    aspect-ratio: 1 / 1;
    object-fit: cover;
}
/* form .logo input[type="file"], */
form .avatar input[type="file"] {
    display: none;
}
form .logo .preview-notice,
form .avatar .preview-notice {
    position: absolute;
    padding: 0.5rem;
    background-color: var(--warn-color);
    color: var(--warn-color-bg);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 3px;
}