/* Back to Top Button Responsive Styles */
#backToTopBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    background: linear-gradient(135deg, #3b82f6, #06b6d4);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
    cursor: pointer;
    align-items: center;
    justify-content: center;
    transition: opacity 0.3s ease, transform 0.3s ease;
    opacity: 0;
    font-size: 18px;
}

#backToTopBtn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

#backToTopBtn:active {
    transform: scale(0.95);
}

/* Mobile Responsive - Small screens (smartphones) */
@media (max-width: 576px) {
    #backToTopBtn {
        width: 45px;
        height: 45px;
        bottom: 15px;
        right: 15px;
        font-size: 16px;
        box-shadow: 0 3px 12px rgba(59, 130, 246, 0.3);
    }
    
    #backToTopBtn:hover {
        transform: scale(1.05); /* Smaller scale on mobile for better UX */
    }
}

/* Tablet Portrait */
@media (min-width: 577px) and (max-width: 768px) {
    #backToTopBtn {
        width: 48px;
        height: 48px;
        bottom: 18px;
        right: 18px;
        font-size: 17px;
    }
}

/* Large screens */
@media (min-width: 1200px) {
    #backToTopBtn {
        width: 55px;
        height: 55px;
        bottom: 25px;
        right: 25px;
        font-size: 20px;
        box-shadow: 0 5px 18px rgba(59, 130, 246, 0.3);
    }
}

/* Extra large screens */
@media (min-width: 1400px) {
    #backToTopBtn {
        width: 60px;
        height: 60px;
        bottom: 30px;
        right: 30px;
        font-size: 22px;
    }
}

/* High DPI screens */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 2dppx) {
    #backToTopBtn {
        box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    #backToTopBtn {
        /* Larger touch target for mobile */
        min-width: 44px;
        min-height: 44px;
    }
    
    #backToTopBtn:hover {
        transform: none; /* Disable hover effects on touch devices */
    }
    
    #backToTopBtn:active {
        transform: scale(0.9);
        background: linear-gradient(135deg, #2563eb, #0891b2);
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    #backToTopBtn {
        box-shadow: 0 4px 15px rgba(59, 130, 246, 0.5);
    }
}

/* Reduced motion for accessibility */
@media (prefers-reduced-motion: reduce) {
    #backToTopBtn {
        transition: opacity 0.3s ease;
    }
    
    #backToTopBtn:hover {
        transform: none;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    #backToTopBtn {
        border: 2px solid white;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    }
}