.gradient-text {
            background: linear-gradient(90deg, #3b82f6, #8b5cf6);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }
        
        .glass-card {
            background: rgba(39, 39, 42, 0.5);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border: 1px solid rgba(255, 255, 255, 0.08);
        }
        
        .challenge-card {
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.1);
            transform-style: preserve-3d;
        }
        
        .challenge-card:hover {
            transform: translateY(-8px) scale(1.02);
            box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
        }
        
        .challenge-image {
            height: 180px;
            object-fit: cover;
            transition: all 0.4s ease;
        }
        
        .challenge-card:hover .challenge-image {
            transform: scale(1.05);
        }
        
        .difficulty-indicator {
            width: 100%;
            height: 4px;
            position: relative;
            overflow: hidden;
        }
        
        .difficulty-indicator::after {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            height: 100%;
            background: linear-gradient(90deg, #10b981, #34d399);
            transition: width 0.6s ease;
        }
        
        .difficulty-indicator.easy::after { width: 33%; }
        .difficulty-indicator.medium::after { width: 66%; }
        .difficulty-indicator.hard::after { width: 100%; }
        
        .completed-ribbon {
            position: absolute;
            top: 30px;
            right: -50px;
            width: 190px;
            padding: 4px 0;
            background: #10b981;
            color: white;
            text-align: center;
            font-size: 15px;
            transform: rotate(45deg);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
        }
        
        .tag {
            display: inline-block;
            background: rgba(59, 130, 246, 0.15);
            color: #3b82f6;
            padding: 0.25rem 0.75rem;
            border-radius: 9999px;
            font-size: 0.75rem;
            margin-right: 0.5rem;
            margin-bottom: 0.5rem;
            border: 1px solid rgba(59, 130, 246, 0.3);
            transition: all 0.2s ease;
        }
        
        .tag:hover {
            background: rgba(59, 130, 246, 0.3);
            transform: translateY(-1px);
        }
        
        .modal-overlay {
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
        }
        
        .modal-overlay.active {
            opacity: 1;
            visibility: visible;
        }
        
        .modal-content {
            transform: translateY(20px) scale(0.95);
            transition: all 0.3s ease;
            opacity: 0;
        }
        
        .modal-overlay.active .modal-content {
            transform: translateY(0) scale(1);
            opacity: 1;
        }
        
        @keyframes float {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-10px); }
        }
        
        .floating-icon {
            animation: float 6s ease-in-out infinite;
        }
        
        .search-box {
            background: rgba(31, 41, 55, 0.6);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
        }

        /* Animaciones de éxito */
        @keyframes confetti {
            0% { transform: translateY(0) rotate(0deg); opacity: 1; }
            100% { transform: translateY(-100vh) rotate(360deg); opacity: 0; }
        }

        .confetti {
            position: fixed;
            width: 10px;
            height: 10px;
            background-color: #3b82f6;
            opacity: 0;
            z-index: 1000;
            animation: confetti 2s ease-out forwards;
        }

        .checkmark {
            width: 80px;
            height: 80px;
            border-radius: 50%;
            display: block;
            stroke-width: 5;
            stroke: #fff;
            stroke-miterlimit: 10;
            margin: 0 auto;
            box-shadow: 0 0 0 rgba(16, 185, 129, 0.4);
            animation: fill .4s ease-in-out .4s forwards, scale .3s ease-in-out .9s both;
        }

        .checkmark__circle {
            stroke-dasharray: 166;
            stroke-dashoffset: 166;
            stroke-width: 5;
            stroke-miterlimit: 10;
            stroke: #10b981;
            fill: none;
            animation: stroke .6s cubic-bezier(0.65, 0, 0.45, 1) forwards;
        }

        .checkmark__check {
            transform-origin: 50% 50%;
            stroke-dasharray: 48;
            stroke-dashoffset: 48;
            animation: stroke .3s cubic-bezier(0.65, 0, 0.45, 1) .8s forwards;
        }

        @keyframes stroke {
            100% { stroke-dashoffset: 0; }
        }

        @keyframes scale {
            0%, 100% { transform: none; }
            50% { transform: scale3d(1.1, 1.1, 1); }
        }

        @keyframes fill {
            100% { box-shadow: inset 0 0 0 40px #10b981; }
        }

          /* Nuevo estilo para el badge de dificultad en cards */
        .difficulty-badge {
            font-size: 0.75rem;
            font-weight: 600;
            padding: 0.25rem 0.75rem;
            border-radius: 9999px;
            display: inline-flex;
            align-items: center;
            gap: 0.25rem;
        }
        
        .difficulty-badge.easy {
            background-color: #10b98120;
            color: #10b981;
        }
        
        .difficulty-badge.medium {
            background-color: #f59e0b20;
            color: #f59e0b;
        }
        
        .difficulty-badge.hard {
            background-color: #ef444420;
            color: #ef4444;
        }