:root {
    --bg: #010810;
    --nexus-cyan: #00f3ff;
    --nexus-purple: #9d00ff;
    --glass: rgba(0, 243, 255, 0.03);
    --border: rgba(0, 243, 255, 0.15);
    --text: #e0e6ed;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Outfit', 'Inter', sans-serif;
    height: 100vh;
    overflow: hidden;
    background-image: 
        linear-gradient(rgba(0, 243, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 243, 255, 0.05) 1px, transparent 1px);
    background-size: 50px 50px;
}

.back-btn {
    position: fixed; top: 20px; left: 20px; padding: 8px 20px;
    background: var(--glass); border: 1px solid var(--border);
    border-radius: 4px; color: var(--nexus-cyan);
    text-decoration: none; font-size: 0.75rem; letter-spacing: 2px;
    backdrop-filter: blur(15px); z-index: 1000; transition: 0.3s;
}
.back-btn:hover { background: var(--nexus-cyan); color: #000; box-shadow: 0 0 20px var(--nexus-cyan); }

/* NEXUS CONTAINER */
.nexus-wrapper {
    display: grid;
    grid-template-columns: 350px 1fr 350px;
    height: 100vh;
    padding: 80px 40px 40px;
    gap: 30px;
}

.panel {
    background: var(--glass); border: 1px solid var(--border);
    border-radius: 12px; backdrop-filter: blur(25px);
    display: flex; flex-direction: column; padding: 25px;
    position: relative; overflow: hidden;
}

.panel h2 {
    font-size: 0.75rem; letter-spacing: 4px; color: var(--nexus-cyan);
    margin-bottom: 25px; text-transform: uppercase;
    display: flex; align-items: center; gap: 10px;
}

.panel h2::before {
    content: ''; width: 8px; height: 8px; background: var(--nexus-cyan);
    box-shadow: 0 0 10px var(--nexus-cyan); border-radius: 2px;
}

/* NODE GRID */
.node-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 15px; flex-grow: 1; align-content: start;
}

.node {
    aspect-ratio: 1; border: 1px solid var(--border);
    border-radius: 8px; display: flex; flex-direction: column;
    align-items: center; justify-content: center; font-size: 0.65rem;
    color: #444; transition: 0.3s; position: relative;
}

.node.active { 
    color: var(--nexus-cyan); border-color: var(--nexus-cyan);
    background: rgba(0, 243, 255, 0.05);
}

.node.purified::after {
    content: 'P'; position: absolute; top: 2px; right: 4px;
    font-size: 0.5rem; color: var(--nexus-cyan); font-weight: bold;
}

/* DATA FLOW LOG */
.log-stream {
    flex-grow: 1; overflow-y: auto; font-family: monospace;
    font-size: 0.7rem; color: #555;
}

.log-entry { margin-bottom: 8px; line-height: 1.4; }
.log-entry span { color: var(--nexus-cyan); }

/* CENTRAL VISUAL */
.central-core {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    position: relative;
}

.core-circle {
    width: 300px; height: 300px; border: 2px solid var(--border);
    border-radius: 50%; position: relative;
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.core-inner {
    position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
    text-align: center;
}

.nexus-logo {
    font-size: 1.5rem; font-weight: 200; letter-spacing: 15px;
    color: #fff; text-shadow: 0 0 20px var(--nexus-cyan);
}

/* SCANLINE */
.scanline {
    position: absolute; top: 0; left: 0; width: 100%; height: 4px;
    background: linear-gradient(to right, transparent, var(--nexus-cyan), transparent);
    opacity: 0.3; animation: scan 4s infinite linear;
}

@keyframes scan {
    from { top: -10%; }
    to { top: 110%; }
}

@media (max-width: 1000px) {
    body { overflow-y: auto; height: auto; }
    .nexus-wrapper { 
        grid-template-columns: 1fr; height: auto; padding: 100px 20px 40px; gap: 40px;
    }
    .core-circle { width: 200px; height: 200px; }
    .central-core { order: -1; margin-bottom: 20px; }
    .nexus-logo { font-size: 1.1rem; letter-spacing: 5px; }
}