:root {
    --bg-color: #0a0a0c;
    --text-color: #e0e0e0;
    --accent-cyan: #00f2ff;
    --accent-purple: #bc13fe;
    --card-bg: #16161a;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

header {
    padding: 1rem 5%;
    background: rgba(10, 10, 12, 0.9);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid #333;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-cyan);
    text-transform: uppercase;
    letter-spacing: 2px;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 2rem;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-color);
    transition: color 0.3s;
}

nav ul li a:hover {
    color: var(--accent-purple);
}

.hero {
    height: 80vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: radial-gradient(circle at center, #1a1a2e 0%, #0a0a0c 100%);
    padding: 0 5%;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    background: linear-gradient(to right, var(--accent-cyan), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.5rem;
    opacity: 0.8;
}

.info-section {
    padding: 100px 10%;
}

.alt-bg {
    background-color: #0f0f13;
}

.content-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.content-grid.reverse {
    grid-template-columns: 1fr 1fr;
}

.text h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--accent-cyan);
}

.text p {
    margin-bottom: 1.2rem;
    font-size: 1.1rem;
}

/* Visuals */
.sphere {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, var(--accent-cyan), #000);
    box-shadow: 0 0 50px rgba(0, 242, 255, 0.3);
    margin: auto;
}

.entanglement-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    height: 150px;
}

.particle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent-purple);
    box-shadow: 0 0 30px var(--accent-purple);
}

.link {
    flex-grow: 1;
    height: 2px;
    background: linear-gradient(to right, var(--accent-purple), var(--accent-cyan));
    opacity: 0.5;
}

/* Demo Section */
.demo-section {
    padding: 100px 10%;
    text-align: center;
}

.demo-box {
    margin-top: 3rem;
    background: var(--card-bg);
    padding: 4rem;
    border-radius: 20px;
    display: inline-block;
}

#demo-qubit {
    font-size: 5rem;
    margin-bottom: 2rem;
    transition: all 0.5s ease;
}

.state-zero { color: var(--accent-cyan); }
.state-one { color: var(--accent-purple); }
.state-superposition { 
    color: white;
    text-shadow: 0 0 20px var(--accent-cyan), 0 0 40px var(--accent-purple);
    animation: flicker 0.1s infinite;
}

@keyframes flicker {
    0% { opacity: 1; }
    50% { opacity: 0.7; }
    100% { opacity: 1; }
}

button {
    padding: 1rem 2.5rem;
    font-size: 1.2rem;
    background: transparent;
    color: var(--accent-cyan);
    border: 2px solid var(--accent-cyan);
    cursor: pointer;
    border-radius: 50px;
    transition: all 0.3s;
}

button:hover {
    background: var(--accent-cyan);
    color: var(--bg-color);
    box-shadow: 0 0 20px var(--accent-cyan);
}

footer {
    padding: 2rem;
    text-align: center;
    border-top: 1px solid #333;
    font-size: 0.9rem;
    opacity: 0.6;
}

@media (max-width: 768px) {
    .content-grid {
        grid-template-columns: 1fr;
    }
    .hero h1 { font-size: 2.5rem; }
    nav ul { display: none; }
}