zulip/web/styles/image_upload_widget.css

/* common CSS for all image upload widget's */
.image_upload_widget {
    position: relative;
    border-radius: 5px;
    box-shadow: 0 0 10px hsl(0deg 0% 0% / 10%);
    overflow: hidden;

    transition: all 0.3s ease;

    .image-block {
        background-size: contain;
        height: 100%;
    }

    .image-hover-background {
        content: "";
        background-color: hsl(0deg 0% 0% / 60%);
        height: 100%;
        width: 100%;
        z-index: 99;
        position: absolute;
        display: none;
        cursor: pointer;
    }

    .image_upload_button {
        position: absolute;
        width: 100%;
        height: 100%;
        display: flex;
        align-items: center;
        text-align: center;
        justify-content: center;
        box-shadow: 0 0 10px hsl(0deg 0% 0% / 10%);
        z-index: 99;
    }

    .image-delete-button {
        background: none;
        border: none;
        cursor: pointer;
        color: hsl(0deg 0% 75%);
        opacity: 0;
        padding: 0;
        position: absolute;
        font-size: 2rem;
        top: 10px;
        right: 10px;
        z-index: 99;
        line-height: 20px;
    }

    .image-disabled-text {
        color: hsl(0deg 0% 100%);
        cursor: not-allowed;
        position: absolute;
        text-align: center;
        visibility: hidden;
        z-index: 99;
    }

    .image-delete-text,
    .image-upload-text,
    .image-disabled-text {
        box-sizing: border-box;
        width: 100%;
        padding: 0 10px;
    }

    .image-delete-button:focus,
    .image-delete-button:hover {
        color: hsl(0deg 0% 100%);
    }

    .image-delete-button:hover ~ .image-upload-text {
        visibility: hidden;
    }

    .image-delete-button:hover ~ .image-delete-text {
        visibility: visible;
    }

    .image-delete-text {
        color: hsl(0deg 0% 100%);
        font-size: 0.85rem;
        position: absolute;
        visibility: hidden;
        z-index: 99;
    }

    .image-upload-text {
        cursor: pointer;
        font-size: 0.85rem;
        color: hsl(0deg 0% 85%);
        position: absolute;
        z-index: 99;
        visibility: hidden;
    }

    .image-upload-text:hover {
        color: hsl(0deg 0% 100%);
    }

    .upload-spinner-background {
        display: flex;
        justify-content: center;
        align-items: center;
        background-color: hsl(0deg 0% 10%);
        font-size: 0.8rem;
        width: 100%;
        opacity: 0.8;
        height: 100%;
        position: absolute;
        visibility: hidden;
        z-index: 99;
        cursor: pointer;
        border-radius: 5px;
    }

    .hide {
        display: none;
    }

    &:hover {
        .image-upload-text {
            visibility: visible;
        }

        .image-delete-button {
            opacity: 1;
        }

        .image-disabled-text {
            visibility: visible;
        }

        .image-hover-background {
            display: block;
        }
    }
}

.user-avatar-section,
.realm-logo-section,
.realm-icon-section {
    margin: 20px 0;
}

/* CSS related to settings page user avatar upload widget only */
#user-avatar-upload-widget {
    .image-block {
        width: 200px;
        height: 200px;
    }
}

#user-avatar-source {
    font-size: 1em;
    z-index: 99;
    margin-top: 10px;
}

/* CSS related to settings page realm icon upload widget only */
#realm-icon-upload-widget {
    width: 100px;
    height: 100px;
    box-shadow: 0 0 10px hsl(0deg 0% 0% / 10%);

    .image-delete-button {
        top: 5px;
        right: 5px;
    }
}

/* CSS related to settings page realm day/night logo upload widget only */
#realm-day-logo-upload-widget,
#realm-night-logo-upload-widget {
    width: 220px;
    height: 55px;
    text-align: center;

    .image-delete-button {
        top: 5px;
        right: 5px;
    }
}

#realm-day-logo-upload-widget {
    background-color: hsl(0deg 100% 100%);
}

#realm-night-logo-upload-widget {
    background-color: hsl(212deg 28% 18%);
}

.realm-logo-block {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 0 20px;
}

.realm-logo-group {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
}

/* CSS  related to upload widget's preview image */
.upload_widget_image_preview {
    object-fit: cover;
}