/**
 * ============================================
 * Back to Top Button - Professional Design
 * ============================================
 * 
 * Smooth scroll to top button with modern design
 * Features:
 * - Appears after scrolling down
 * - Smooth animations
 * - Accessible
 * - Responsive
 */

.ep-back-to-top {
    position: fixed;
    bottom: 2rem;
    left: 2rem;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #9333ea 0%, #ec4899 100%);
    color: #ffffff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: 0 4px 16px rgba(147, 51, 234, 0.3), 0 2px 8px rgba(236, 72, 153, 0.2);
    z-index: 9998;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px) scale(0.8);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(10px);
}

.ep-back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

.ep-back-to-top:hover {
    background: linear-gradient(135deg, #7e22ce 0%, #db2777 100%);
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 8px 24px rgba(147, 51, 234, 0.4), 0 4px 12px rgba(236, 72, 153, 0.3);
}

.ep-back-to-top:active {
    transform: translateY(-2px) scale(1);
}

.ep-back-to-top:focus {
    outline: none;
    box-shadow: 0 0 0 4px rgba(147, 51, 234, 0.2), 0 4px 16px rgba(147, 51, 234, 0.3);
}

.ep-back-to-top i {
    transition: transform 0.3s ease;
}

.ep-back-to-top:hover i {
    transform: translateY(-2px);
}

@media (max-width: 768px) {
    .ep-back-to-top {
        bottom: 1.5rem;
        left: 1.5rem;
        width: 44px;
        height: 44px;
        font-size: 1.125rem;
    }
}

@media (max-width: 480px) {
    .ep-back-to-top {
        bottom: 1rem;
        left: 1rem;
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    .ep-back-to-top {
        transition: opacity 0.2s ease, visibility 0.2s ease;
    }
    
    .ep-back-to-top:hover {
        transform: none;
    }
    
    .ep-back-to-top i {
        transition: none;
    }
}