/* ===================================
   BrainFusion - Main Stylesheet
   Eine Zusammenarbeit zwischen 
   Christof Bechtiger und Claude
   =================================== */

/* --- CSS Variables --- */
:root {
    --primary-bg: #0a0a0f;
    --secondary-bg: #12121a;
    --accent-color: #00d9ff;
    --accent-glow: rgba(0, 217, 255, 0.3);
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --card-bg: rgba(18, 18, 26, 0.8);
    --card-border: rgba(0, 217, 255, 0.2);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Reset & Base --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--primary-bg);
    color: var(--text-primary);
    line-height: 1.6;
    width: 100%;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    width: 100%;
    box-sizing: border-box;
}

/* --- Particles Background --- */
#particles-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(135deg, #0a0a0f 0%, #1a1a2e 100%);
}

/* --- Navigation --- */
.main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 3rem;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 217, 255, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

.main-nav.scrolled {
    padding: 1rem 3rem;
    box-shadow: 0 4px 20px rgba(0, 217, 255, 0.1);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-color), #00ffaa);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 2px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: var(--transition);
}

.nav-links a:hover {
    color: var(--accent-color);
}

.nav-links a:hover::after {
    width: 100%;
}

/* --- Hero Section --- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
    position: relative;
}

.hero-content {
    max-width: 900px;
    z-index: 10;
}

.hero h1 {
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    letter-spacing: -1px;
    background: linear-gradient(135deg, var(--accent-color), #fff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* --- Glitch Effect --- */
.glitch {
    position: relative;
    color: var(--text-primary);
    animation: glitch-subtle 5s infinite;
}

@keyframes glitch-subtle {
    0%, 96%, 100% {
        text-shadow: 
            0 0 20px var(--accent-glow),
            2px 2px 0 rgba(0, 217, 255, 0.2),
            -2px -2px 0 rgba(255, 0, 255, 0.2);
    }
    97% {
        text-shadow: 
            0 0 30px var(--accent-glow),
            3px 0 0 rgba(0, 217, 255, 0.4),
            -3px 0 0 rgba(255, 0, 255, 0.4);
    }
    98% {
        text-shadow: 
            0 0 25px var(--accent-glow),
            -3px 0 0 rgba(0, 217, 255, 0.4),
            3px 0 0 rgba(255, 0, 255, 0.4);
    }
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

/* --- Buttons --- */
.cta-button,
.cta-button-large {
    background: linear-gradient(135deg, var(--accent-color), #00ffaa);
    color: var(--primary-bg);
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 20px var(--accent-glow);
    text-transform: uppercase;
    letter-spacing: 1px;
    text-decoration: none;
    display: inline-block;
}

.cta-button-large {
    padding: 1.25rem 3rem;
    font-size: 1.125rem;
}

.cta-button:hover,
.cta-button-large:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px var(--accent-glow);
}

.cta-button:active,
.cta-button-large:active {
    transform: translateY(0);
}

/* --- Interactive Section --- */
.interactive-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 4rem 2rem;
    background: rgba(26, 26, 46, 0.3);
}

.interactive-section h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    background: linear-gradient(135deg, var(--accent-color), #00ffaa);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

#atom-visualization {
    width: 100%;
    height: 400px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.explanation {
    text-align: center;
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
}

/* --- Introduction Section --- */
.introduction {
    padding: 6rem 2rem;
    background: rgba(26, 26, 46, 0.3);
}

.introduction h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
}

.intro-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.intro-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 2.5rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.intro-card:hover {
    transform: translateY(-10px);
    border-color: var(--accent-color);
    box-shadow: 0 8px 32px var(--accent-glow);
}

.intro-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.intro-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* --- Books Section --- */
.books-preview {
    padding: 6rem 2rem;
    background: rgba(26, 26, 46, 0.3);
}

.books-preview h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
}

.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.book-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 2rem;
    transition: var(--transition);
    text-align: center;
}

.book-card:hover {
    transform: translateY(-10px);
    border-color: var(--accent-color);
    box-shadow: 0 12px 40px var(--accent-glow);
}

.book-card img {
    width: 100%;
    height: 400px;
    object-fit: contain;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #1a1a2e, #2a2a3e);
}

.book-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.book-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.book-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.book-link:hover {
    color: #00ffaa;
}

/* --- CTA Section --- */
.cta-section {
    padding: 6rem 2rem;
    background: rgba(26, 26, 46, 0.3);
    text-align: center;
}

.cta-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.cta-section p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

/* --- Footer --- */
footer {
    padding: 3rem 2rem;
    background: rgba(26, 26, 46, 0.3);
    border-top: 1px solid var(--card-border);
    text-align: center;
}

footer p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.footer-quote {
    font-style: italic;
    color: var(--accent-color);
    margin-top: 1rem;
}

/* --- Hamburger Menu --- */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--accent-color);
    transition: var(--transition);
    border-radius: 3px;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* --- Responsive Design --- */
@media (max-width: 968px) {
    .main-nav {
        padding: 1rem 1.5rem;
    }
    
    .hamburger {
        display: flex;
    }
    
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(10, 10, 15, 0.98);
        backdrop-filter: blur(20px);
        padding: 2rem;
        gap: 1.5rem;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        border-bottom: 1px solid var(--card-border);
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    }
    
    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-links a {
        font-size: 1.25rem;
        text-align: center;
        padding: 0.75rem;
        border-bottom: 1px solid rgba(0, 217, 255, 0.1);
    }
    
    .nav-links a:last-child {
        border-bottom: none;
    }
    
    body.menu-open {
        overflow: hidden;
    }
}

@media (max-width: 768px) {
    .hero {
        padding-top: 6rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .intro-grid,
    .books-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .container {
        padding: 0 1rem;
    }
    
    .book-card img {
        height: 300px;
    }
    
    .cta-button,
    .cta-button-large {
        padding: 0.875rem 2rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .main-nav {
        padding: 0.75rem 1rem;
    }
    
    .logo {
        font-size: 1.25rem;
    }
    
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .subtitle {
        font-size: 0.9rem;
    }
    
    .intro-card,
    .book-card {
        padding: 1.5rem;
    }
    
    section h2 {
        font-size: 1.75rem !important;
    }
    
    #atom-visualization {
        height: 300px;
    }
}

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

.fade-in-up {
    animation: fadeInUp 0.8s ease-out;
}

/* --- Nav Highlight (Salon) --- */
.nav-highlight {
    background: linear-gradient(135deg, var(--accent-color), #00ffaa);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 600 !important;
    position: relative;
}

.nav-highlight::before {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-color), #00ffaa);
    opacity: 0.5;
}

/* --- Nav Special (Unendlichkeit) --- */
.nav-special {
    color: var(--accent-color) !important;
    font-weight: 600 !important;
    position: relative;
    text-shadow: 0 0 10px var(--accent-glow);
}

.nav-special::before {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--accent-color);
    opacity: 0.7;
    animation: pulse-line 2s ease-in-out infinite;
}

@keyframes pulse-line {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 1; }
}

/* --- Utility Classes --- */
.text-gradient {
    background: linear-gradient(135deg, var(--accent-color), #00ffaa);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* --- Mobile Hard-Protection --- */
@media (max-width: 480px) {
    html, body {
        width: 100%;
        max-width: 100%;
    }
    
    section, .container {
        max-width: 100%;
        width: 100%;
    }
}