/* 星空背景样式 */
.starry-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    overflow: hidden;
    background: linear-gradient(125deg, #000000, #0a0a14 25%, #12121f 50%, #0a0a14 75%, #000000 100%);
}

/* 星星粒子 */
.stars {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.star {
    position: absolute;
    background-color: #ffffff;
    border-radius: 50%;
    animation: twinkle var(--duration) infinite ease-in-out alternate;
    opacity: var(--opacity);
}

/* 流星效果 */
.shooting-star {
    position: absolute;
    width: 100px;
    height: 1px;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0), rgba(255, 255, 255, 1));
    transform: rotate(var(--angle));
    animation: shooting var(--duration) linear infinite;
    animation-delay: var(--delay);
    opacity: 0;
    z-index: -1;
}

/* 星云效果 */
.nebula {
    position: absolute;
    border-radius: 50%;
    filter: blur(30px);
    opacity: 0.1;
    background: radial-gradient(circle at center, var(--color1), var(--color2) 50%, transparent 70%);
    animation: pulse 15s infinite alternate;
}

/* 科技网格 */
.tech-grid {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(0, 195, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 195, 255, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    z-index: -1;
    opacity: 0.3;
}

/* 动画定义 */
@keyframes twinkle {
    0% {
        opacity: var(--min-opacity);
        transform: scale(0.8);
    }
    100% {
        opacity: var(--opacity);
        transform: scale(1);
    }
}

@keyframes shooting {
    0% {
        transform: translateX(-100px) translateY(0) rotate(var(--angle));
        opacity: 1;
    }
    20% {
        opacity: 1;
    }
    30% {
        opacity: 0;
    }
    100% {
        transform: translateX(calc(100vw + 200px)) translateY(calc(100vw * tan(var(--angle)))) rotate(var(--angle));
        opacity: 0;
    }
}

@keyframes pulse {
    0% {
        opacity: 0.05;
        transform: scale(1);
    }
    50% {
        opacity: 0.1;
    }
    100% {
        opacity: 0.05;
        transform: scale(1.1);
    }
}