/* 粒子动画效果 */
.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 2px;
    height: 2px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.5);
    pointer-events: none;
}