/* ===== 网格布局 ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
    padding: 24px;
    max-width: 1400px;
    margin: 0 auto;
    justify-items: center;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .card-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
        padding: 12px;
    }

    .hero-card {
        width: 100%;
        height: auto;
        aspect-ratio: 3 / 4;
    }

    .app-title {
        font-size: 28px;
        letter-spacing: 4px;
    }

    .filter-btn {
        font-size: 14px;
        padding: 6px 16px;
    }
}

@media (max-width: 480px) {
    .card-grid {
        grid-template-columns: 1fr;
        gap: 16px;
        padding: 16px;
    }

    .hero-card {
        max-width: 320px;
        margin: 0 auto;
    }

    .app-title {
        font-size: 24px;
    }

    .filter-nav {
        gap: 6px;
    }

    .filter-btn {
        font-size: 13px;
        padding: 5px 12px;
    }
}

/* ===== 卡片入场动画 ===== */
@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-card {
    animation: cardFadeIn 0.4s ease-out;
}

/* ===== 卡片隐藏/显示过渡 ===== */
.hero-card.hidden {
    display: none;
}