.scroll-to-top-button {
    position: fixed;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
    cursor: pointer;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.scroll-to-top-button:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.scroll-to-top-button.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top-button.stt-style-circle {
    border-radius: 50%;
}

.scroll-to-top-button.stt-style-arrow,
.scroll-to-top-button.stt-style-text {
    border-radius: 4px;
}

.scroll-to-top-button.stt-size-small {
    width: 40px;
    height: 40px;
    font-size: 16px;
}

.scroll-to-top-button.stt-size-medium {
    width: 50px;
    height: 50px;
    font-size: 20px;
}

.scroll-to-top-button.stt-size-large {
    width: 60px;
    height: 60px;
    font-size: 24px;
}

.scroll-to-top-button.stt-position-bottom-right {
    right: 20px;
    bottom: 20px;
    left: auto;
}

.scroll-to-top-button.stt-position-bottom-left {
    left: 20px;
    bottom: 20px;
    right: auto;
}

.stt-button-content {
    pointer-events: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.stt-style-circle .stt-button-content::before {
    content: '↑';
}

.stt-style-arrow .stt-button-content::before {
    content: '↑';
}

.stt-style-text .stt-button-content::before {
    content: 'Top';
    font-weight: bold;
}

.scroll-to-top-button.stt-hide-mobile {
    display: none;
}

@media screen and (max-width: 768px) {
    .scroll-to-top-button.stt-size-small {
        width: 35px;
        height: 35px;
        font-size: 14px;
    }
    
    .scroll-to-top-button.stt-size-medium {
        width: 45px;
        height: 45px;
        font-size: 18px;
    }
    
    .scroll-to-top-button.stt-size-large {
        width: 50px;
        height: 50px;
        font-size: 20px;
    }
    
    .scroll-to-top-button.stt-position-bottom-right {
        right: 15px;
        bottom: 15px;
    }
    
    .scroll-to-top-button.stt-position-bottom-left {
        left: 15px;
        bottom: 15px;
    }
}

@media screen and (min-width: 769px) {
    .scroll-to-top-button.stt-hide-mobile {
        display: flex;
    }
}