.donate-card.popular::before {
    content: 'ПОПУЛЯРНЫЙ';
    position: absolute;
    top: 15px;
    right: -34px;
    background: linear-gradient(45deg, #f59e0b, #f97316, #f59e0b);
    background-size: 200% 100%;
    color: white;
    padding: 2px 35px;
    font-size: 12px;
    font-weight: bold;
    transform: rotate(45deg);
    animation: ribbonSlide 3s linear infinite, ribbonGradient 3s linear infinite;
    box-shadow: 0 2px 10px rgba(245, 158, 11, 0.5);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    z-index: 10;
}

@keyframes ribbonSlide {
    0% { right: -34px; }
    25% { right: -30px; }
    50% { right: -34px; }
    75% { right: -38px; }
    100% { right: -34px; }
}

@keyframes ribbonGradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}