.stats-card {
            background: linear-gradient(135deg, #1f2937 0%, #111827 100%);
            transition: all 0.3s ease;
        }
        .stats-card:hover {
            background: linear-gradient(135deg, #374151 0%, #1f2937 100%);
            transform: translateY(-2px);
        }
        .gradient-text {
            background: linear-gradient(45deg, #60a5fa, #a78bfa);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .metric-card {
            background: linear-gradient(135deg, #374151 0%, #1f2937 100%);
            border: 1px solid #4b5563;
            transition: all 0.3s ease;
        }
        .metric-card:hover {
            border-color: #60a5fa;
            box-shadow: 0 0 20px rgba(96, 165, 250, 0.1);
        }
        .progress-bar {
            background: linear-gradient(90deg, #3b82f6, #8b5cf6);
            transition: width 0.8s ease;
        }
        .rating-star {
            transition: all 0.2s ease;
            cursor: pointer;
        }
        .rating-star:hover {
            transform: scale(1.2);
        }
        .rating-star.filled {
            color: #fbbf24;
            filter: drop-shadow(0 0 4px #fbbf24);
        }
        .chart-container {
            position: relative;
            height: 300px;
        }
        .chart-container.large {
            height: 400px;
        }
        .social-icon {
            transition: all 0.3s ease;
        }
        .social-icon:hover {
            transform: scale(1.1);
        }
        .country-flag {
            width: 24px;
            height: 16px;
            border-radius: 2px;
            display: inline-block;
        }
        .flag-jp { background: linear-gradient(to bottom, #ffffff 33%, #bc002d 33%, #bc002d 66%, #ffffff 66%); }
        .flag-us { background: linear-gradient(to bottom, #b22234 0%, #b22234 7.7%, #ffffff 7.7%, #ffffff 15.4%, #b22234 15.4%); }
        .flag-kr { background: linear-gradient(to bottom, #ffffff 25%, #cd2e3a 25%, #cd2e3a 50%, #0047a0 50%, #0047a0 75%, #ffffff 75%); }
        .flag-cn { background: #de2910; }
        .age-bar {
            transition: all 0.5s ease;
        }
        .trend-arrow {
            transition: all 0.3s ease;
        }
        .trend-up { color: #10b981; }
        .trend-down { color: #ef4444; }
        .trend-neutral { color: #6b7280; }
        .floating-stats {
            position: fixed;
            top: 50%;
            right: 2rem;
            transform: translateY(-50%);
            z-index: 40;
        }
        .tab-button {
            transition: all 0.3s ease;
        }
        .tab-button.active {
            background: linear-gradient(45deg, #3b82f6, #8b5cf6);
            color: white;
        }
        .comparison-card {
            background: linear-gradient(135deg, #065f46 0%, #047857 100%);
        }
        .warning-card {
            background: linear-gradient(135deg, #92400e 0%, #b45309 100%);
        }
        .pulse-animation {
            animation: pulse 2s infinite;
        }
        @keyframes pulse {
            0%, 100% { opacity: 1; }
            50% { opacity: 0.7; }
        }
        .loading-skeleton {
            background: linear-gradient(90deg, #374151 25%, #4b5563 50%, #374151 75%);
            background-size: 200% 100%;
            animation: loading 1.5s infinite;
        }
        @keyframes loading {
            0% { background-position: 200% 0; }
            100% { background-position: -200% 0; }
        }