.first_part {
    background: 
        radial-gradient(ellipse at bottom, #1a1929 0%, #090a0f 100%);
    position: relative;
    overflow: hidden;
}

.first_part::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        /* 大星星 - 闪烁更明显 */
        radial-gradient(2px 2px at 20px 35px, #fff, rgba(0,0,0,0)),
        radial-gradient(2px 2px at 90px 145px, #fff, rgba(0,0,0,0)),
        radial-gradient(2px 2px at 248px 320px, #fff, rgba(0,0,0,0)),
        
        /* 中等星星 */
        radial-gradient(1.5px 1.5px at 50px 200px, #fff, rgba(0,0,0,0)),
        radial-gradient(1.5px 1.5px at 150px 80px, #fff, rgba(0,0,0,0)),
        radial-gradient(1.5px 1.5px at 280px 250px, #fff, rgba(0,0,0,0)),
        
        /* 小星星 */
        radial-gradient(1px 1px at 120px 300px, #fff, rgba(0,0,0,0)),
        radial-gradient(1px 1px at 200px 150px, #fff, rgba(0,0,0,0)),
        radial-gradient(1px 1px at 320px 400px, #fff, rgba(0,0,0,0));
    
    background-size: 400px 500px;
    animation: 
        stars-move 60s linear infinite,
        stars-twinkle 7s ease-in-out infinite alternate;
}

@keyframes stars-move {
    from { transform: translateY(0) rotate(18deg); }
    to { transform: translateY(-200px) rotate(0deg); }
}

@keyframes stars-twinkle {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 1; }
}




.first_container {
    background: transparent;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 20vw;
    width: 100%;
    flex-wrap: nowrap;
    padding-top: 90vh;
    padding-bottom:20vh;
    position: relative;
    z-index: 2;
    overflow: hidden;

}

.scroll-down {
  position: absolute;
  top:70vh;
  left: 50%;
  transform: translateX(-50%);
  color: #fff;
  font-size: 1rem;
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 2px;
  opacity: 0.8;
}

.arrow {
  display: block;
  width: 24px; 
  height: 24px; 
  margin: 20px auto 0;
  background-image: url('../arrow.png');
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  animation: bounce 2s infinite;
  opacity: 0.8;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}



.gallery {
    width: auto;
    padding: 5rem 0;
    justify-content: center;
    align-items: center;
}

.card {
    width: 12rem;
    height: 8rem;
    margin-left: auto;
    margin-right: auto;
    object-fit: cover;
}

.card:hover {
    transform: scale(1.1);
}

.card img,.card video  {
    width: 100%;
    height: 100%;
    border-radius: 0.8rem;
    object-fit: cover;
    display: block;
}

@media (max-width: 480px) {
    .container {
        height: 250vh;
        gap: 0;
    }

    .card {
        width: 8rem;
        height: 5.5rem;
    }
    
    .first_container {
        gap:15px;
    }
}


svg#lines-svg {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 1;
}
line {
    stroke-linecap: round;
    filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.06));
    mix-blend-mode: screen;
}