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

:root {
    --primary-color: #6a5acd;
    --secondary-color: #4b0082;
    --accent-color: #00ced1;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --bg-light: #f8f9fa;
    --bg-dark: #1a1a2e;
    --white: #ffffff;
    --gradient-quantum: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
.hero {
    background: var(--gradient-quantum);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    color: var(--white);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(106, 90, 205, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 206, 209, 0.3) 0%, transparent 50%);
    animation: quantumPulse 4s ease-in-out infinite;
}

@keyframes quantumPulse {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.navbar {
    padding: 20px 0;
    position: relative;
    z-index: 10;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
}

.quantum-icon {
    font-size: 2rem;
    margin-right: 10px;
    animation: rotate 3s linear infinite;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-menu a {
    color: var(--white);
    text-decoration: none;
    transition: all 0.3s ease;
    padding: 5px 10px;
    border-radius: 5px;
}

.nav-menu a:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.hero-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 20px;
    position: relative;
    z-index: 5;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 20px;
    font-weight: 300;
    text-shadow: 0 0 20px rgba(255, 255, 255, 0.3);
    animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 40px;
    max-width: 600px;
    opacity: 0.9;
    animation: fadeInUp 1s ease-out 0.3s backwards;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    animation: fadeInUp 1s ease-out 0.6s backwards;
}

.btn-primary, .btn-secondary {
    padding: 15px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: var(--accent-color);
    color: var(--white);
    box-shadow: 0 4px 15px rgba(0, 206, 209, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 206, 209, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-color);
    transform: translateY(-3px);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Sections */
.section {
    padding: 80px 0;
}

.section-alt {
    background: var(--bg-light);
}

.section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
    color: var(--text-dark);
}

/* Overview Grid */
.overview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.overview-card {
    background: var(--white);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    text-align: center;
}

.overview-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(106, 90, 205, 0.2);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.overview-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.overview-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Applications Grid */
.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
    margin-top: 50px;
}

.app-item {
    background: var(--white);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.app-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.app-item h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.app-item ul {
    list-style: none;
    padding-left: 0;
}

.app-item li {
    padding: 8px 0;
    border-bottom: 1px solid #eee;
    color: var(--text-light);
}

.app-item li:last-child {
    border-bottom: none;
}

.app-item li::before {
    content: '✓';
    color: var(--accent-color);
    font-weight: bold;
    margin-right: 10px;
}

/* Concepts Grid */
.concepts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.concept-card {
    background: linear-gradient(135deg, var(--white) 0%, #f0f0f0 100%);
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid var(--primary-color);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.concept-card:hover {
    transform: translateX(10px);
    box-shadow: 0 10px 30px rgba(106, 90, 205, 0.2);
}

.concept-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.concept-card h3 a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
    position: relative;
}

.concept-card h3 a:hover {
    color: var(--secondary-color);
    transform: translateX(3px);
}

.concept-card h3 a::after {
    content: '↗';
    font-size: 0.8rem;
    opacity: 0;
    transition: opacity 0.3s ease, transform 0.3s ease;
    position: absolute;
    right: -20px;
    top: 50%;
    transform: translateY(-50%);
}

.concept-card h3 a:hover::after {
    opacity: 1;
    transform: translateY(-50%) translateX(3px);
}

.concept-card p {
    color: var(--text-light);
    margin-bottom: 15px;
}

.concept-formula {
    background: var(--bg-dark);
    color: var(--accent-color);
    padding: 10px 15px;
    border-radius: 5px;
    font-family: 'Courier New', monospace;
    text-align: center;
    font-style: italic;
}

/* Resources Grid */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.resource-card {
    background: var(--white);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.resource-card h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--secondary-color);
}

.resource-card ul {
    list-style: none;
}

.resource-card li {
    padding: 10px 0;
    border-bottom: 1px solid #eee;
    color: var(--text-light);
    transition: color 0.3s ease;
}

.resource-card li {
    position: relative;
}

.resource-card li a {
    color: inherit;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
}

.resource-card li:hover a {
    color: var(--primary-color);
    transform: translateX(5px);
}

.resource-card li a::after {
    content: '→';
    font-size: 0.9rem;
    opacity: 0;
    transition: opacity 0.3s ease, transform 0.3s ease;
    position: absolute;
    left: -20px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--accent-color);
}

.resource-card li:hover a::after {
    opacity: 1;
    transform: translateY(-50%) translateX(-5px);
}

.resource-card li:hover {
    color: var(--primary-color);
}

.resource-card li:last-child {
    border-bottom: none;
}

/* CTA Section */
.cta-section {
    background: var(--gradient-quantum);
    padding: 80px 0;
    text-align: center;
    color: var(--white);
}

.cta-section h2 {
    color: var(--white);
    margin-bottom: 20px;
}

.cta-section p {
    font-size: 1.2rem;
    margin-bottom: 40px;
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

/* Footer */
footer {
    background: var(--bg-dark);
    color: var(--white);
    text-align: center;
    padding: 30px 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .nav-menu {
        display: none;
    }
    
    .overview-grid,
    .applications-grid,
    .concepts-grid,
    .resources-grid {
        grid-template-columns: 1fr;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .section h2 {
        font-size: 2rem;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Additional animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease-out forwards;
}