/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

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

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-logo i {
    font-size: 2rem;
    color: #667eea;
    animation: robotPulse 2s infinite;
}

.nav-logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(45deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #667eea;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background: linear-gradient(45deg, #667eea, #764ba2);
    transition: width 0.3s ease;
}

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

/* Mobile menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero section */
.hero {
    padding: 120px 20px 80px;
    text-align: center;
    color: white;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-content {
    max-width: 1200px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text h2 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-text p {
    font-size: 1.3rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: linear-gradient(45deg, #ff6b6b, #ffa500);
    color: white;
    padding: 15px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.4);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(255, 107, 107, 0.6);
}

/* Hero animation */
.hero-animation {
    position: relative;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.robot-icon {
    font-size: 8rem;
    color: rgba(255, 255, 255, 0.9);
    animation: robotFloat 3s ease-in-out infinite;
}

.ai-particles {
    position: absolute;
    width: 100%;
    height: 100%;
}

.particle {
    position: absolute;
    width: 8px;
    height: 8px;
    background: #ffa500;
    border-radius: 50%;
    animation: particleFloat 4s ease-in-out infinite;
}

.particle:nth-child(1) { top: 20%; left: 20%; animation-delay: 0s; }
.particle:nth-child(2) { top: 30%; right: 25%; animation-delay: 0.8s; }
.particle:nth-child(3) { bottom: 30%; left: 30%; animation-delay: 1.6s; }
.particle:nth-child(4) { bottom: 25%; right: 20%; animation-delay: 2.4s; }
.particle:nth-child(5) { top: 50%; left: 10%; animation-delay: 3.2s; }

/* Sections */
.notebooks-section, .about-section {
    padding: 80px 20px;
    background: white;
    margin: 40px 20px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #333;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.section-title i {
    color: #667eea;
}

/* Notebooks grid */
.notebooks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.notebook-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.notebook-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
    border-color: #667eea;
}

.notebook-card h3 {
    color: #333;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.notebook-card h3 i {
    color: #667eea;
}

.notebook-card p {
    color: #666;
    margin-bottom: 20px;
}

.notebook-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
}

.notebook-link:hover {
    color: #764ba2;
}

/* About section */
.about-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.about-content p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 40px;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-top: 50px;
}

.feature {
    text-align: center;
    padding: 30px;
    border-radius: 15px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    transition: all 0.3s ease;
}

.feature:hover {
    transform: translateY(-5px);
}

.feature i {
    font-size: 3rem;
    color: #667eea;
    margin-bottom: 20px;
}

.feature h3 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.feature p {
    color: #666;
    font-size: 1rem;
}

/* Footer */
footer {
    background: rgba(0, 0, 0, 0.9);
    color: white;
    text-align: center;
    padding: 40px 20px;
    margin-top: 60px;
}

.footer-links {
    margin-top: 20px;
}

.footer-links a {
    color: white;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
}

.footer-links a:hover {
    color: #667eea;
}

/* Animations */
@keyframes robotPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

@keyframes robotFloat {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

@keyframes particleFloat {
    0%, 100% { transform: translateY(0px) scale(1); opacity: 0.7; }
    50% { transform: translateY(-15px) scale(1.2); opacity: 1; }
}

/* Responsive design */
@media screen and (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 20px 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .hero-text h2 {
        font-size: 2.5rem;
    }
    
    .robot-icon {
        font-size: 5rem;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 2rem;
        flex-direction: column;
        gap: 10px;
    }
}

@media screen and (max-width: 480px) {
    .hero-text h2 {
        font-size: 2rem;
    }
    
    .hero-text p {
        font-size: 1.1rem;
    }
    
    .notebooks-grid {
        grid-template-columns: 1fr;
    }
}

/* Loading animation for notebooks */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 200px;
    font-size: 1.2rem;
    color: #667eea;
}

.loading::after {
    content: '';
    width: 20px;
    height: 20px;
    border: 3px solid #667eea;
    border-top: 3px solid transparent;
    border-radius: 50%;
    margin-left: 10px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Placeholder for when no notebooks exist */
.no-notebooks {
    text-align: center;
    padding: 60px 20px;
    color: #666;
}

.no-notebooks i {
    font-size: 4rem;
    color: #ddd;
    margin-bottom: 20px;
}

.no-notebooks h3 {
    margin-bottom: 15px;
    color: #999;
}