/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tool-card {
    animation: fadeIn 0.5s ease forwards;
}

/* 级联动画延迟 */
.tool-card:nth-child(2) {
    animation-delay: 0.05s;
}

.tool-card:nth-child(3) {
    animation-delay: 0.1s;
}

.tool-card:nth-child(4) {
    animation-delay: 0.15s;
}

.tool-card:nth-child(5) {
    animation-delay: 0.2s;
}

.tool-card:nth-child(6) {
    animation-delay: 0.25s;
}

.tool-card:nth-child(7) {
    animation-delay: 0.3s;
}

.tool-card:nth-child(8) {
    animation-delay: 0.35s;
}

/* 大屏幕设备 (1200px以上) */
@media (min-width: 1200px) {
    .tools-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* 桌面设备 (992px-1199px) */
@media (max-width: 1199px) and (min-width: 992px) {
    .tools-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .hero h2 {
        font-size: 2.25rem;
    }
}

/* 平板设备 (768px-991px) */
@media (max-width: 991px) and (min-width: 768px) {
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
}

/* 小平板和大手机 (576px-767px) */
@media (max-width: 767px) {
    nav {
        flex-wrap: wrap;
        gap: var(--spacing-md);
    }
    
    .nav-links {
        order: 3;
        width: 100%;
        justify-content: space-between;
        margin-top: var(--spacing-sm);
    }
    
    .search-bar {
        order: 2;
    }
    
    .hero h2 {
        font-size: 1.75rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .footer-links {
        width: 100%;
    }
    
    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* 手机设备 (小于576px) */
@media (max-width: 575px) {
    body {
        padding-bottom: env(safe-area-inset-bottom);
    }
    
    .hero h2 {
        font-size: 1.5rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .category-tabs {
        overflow-x: auto;
        padding-bottom: var(--spacing-sm);
        justify-content: flex-start;
        -webkit-overflow-scrolling: touch;
    }
    
    .category-tabs button {
        white-space: nowrap;
    }
}