Trilium/apps/website/src/components/Header.css

header {
    padding: 1em;
    position: sticky;
    top: 0;
    background: var(--header-background-color);
    box-shadow: 0 0 6px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(20px);    
    z-index: 1000;
    --gap: 1.25em;
    font-size: 0.8em;

    &>.content-wrapper {
        display: flex;
        align-items: center;
        justify-items: center;
        gap: var(--gap);
        min-width: 80vw;
    }

    a.banner {
        display: flex;
        align-items: center;
        justify-items: center;
        text-decoration: none;
        color: inherit;
        
        &:hover { text-decoration: none;}
    }

    img {
        width: 32px;
        height: 32px;
    }

    img+span {
        font-size: 1.3em;
    }

    nav {
        flex-grow: 1;
        display: flex;
        justify-content: flex-end;
        gap: var(--gap);

        a {
            text-decoration: none;
            color: inherit;

            &.active {
                color: var(--brand-1);
            }
        }
    }
}

.repository-button a {
    display: flex;
    color: currentColor;

    &:hover {
        color: var(--brand-1);
        text-decoration: none;
    }

    .counter {
        margin-inline-start: 4px;
    }
}

@media (max-width: 719px) {
    :root {
        --header-height: 60px;
    }

    header {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        min-height: var(--header-height);
        box-sizing: border-box;
        display: flex;

        .content-wrapper {
            display: block;
        }

        .first-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
        }

        .menu-toggle {
            color: inherit;
        }

        nav {
            flex-direction: column;
            max-height: 0;
            overflow: hidden;
            transition: max-height 200ms ease-in;        

            &.mobile-shown {
                display: flex;
                max-height: 100vh;
                padding: 2em 0;
            }
        }
    }

    header + main {
        margin-top: var(--header-height);
    }
    
    header nav a {
        font-size: 1.25em;
        padding: 0.5em 0;
        border-bottom: 1px solid rgba(0, 0, 0, 0.2);
    }

    header .social-buttons {
        justify-content: space-between;
        padding-top: 1em;

        a {
            border-bottom: unset;
            display: flex;
            flex-direction: column;
            align-items: center;
            font-size: 1em;
        }
    }

}

@media (min-width: 720px) {
    header {
        font-size: inherit;

        img {
            width: 48px;
            height: 48px;
        }
    }
}