/* =========================================
   BACKGROUND SYSTEM: Hyper-Network
========================================= */

.fixed-vector-bg {
    position: fixed;
    top: 0; left: 0;
    width: 100vw; height: 100vh;
    z-index: -1;
    /* Deep space background */
    background: radial-gradient(circle at center, #1b1b2f 0%, #000000 100%);
    overflow: hidden;
}

#scroll-svg {
    width: 100%; height: 100%;
}

/* --- 1. Background Grid --- */
.bg-grid {
    /* 网格随滚动缓慢移动，制造视差 */
    transform-origin: center;
    transition: transform 0.1s linear;
}

/* --- 2. Data Cables --- */
.data-cables {
    /* 滤色模式：线条交叠处变亮 */
    mix-blend-mode: screen;
}

.scroll-path {
    stroke-linecap: round;
    /* 关键：JS控制这里的 dashoffset */
    stroke-dasharray: 3000;
    stroke-dashoffset: 3000; 
    transition: stroke-dashoffset 0.1s linear;
}

/* Specific Line Styles */
.cable-cyan {
    stroke: #00f2fe;
    filter: drop-shadow(0 0 8px #00f2fe);
}

.cable-pink {
    stroke: #ff0080;
    filter: drop-shadow(0 0 10px #ff0080);
}

.cable-gold {
    stroke: #ffd200;
    filter: drop-shadow(0 0 6px #ffd200);
}

/* --- 3. Vignette --- */
.vignette-overlay {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    /* 四周压暗，突出中间线条 */
    background: radial-gradient(circle at center, transparent 40%, #000000 130%);
    pointer-events: none;
}