:root {
    --bg-color: #050505;
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    --primary-color: #06b6d4;
    --accent-color: #a855f7;
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.08);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

html {
    scroll-behavior: smooth;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

/* Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.6rem 1.5rem;
    border-radius: 9999px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    color: white;
    border: none;
    box-shadow: 0 4px 14px 0 rgba(10, 182, 212, 0.39);
}

.btn-primary:hover {
    box-shadow: 0 6px 20px rgba(10, 182, 212, 0.6);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
}

.btn-outline:hover {
    border-color: var(--primary-color);
    background: rgba(6, 182, 212, 0.1);
}

.btn-large {
    padding: 0.8rem 2rem;
    font-size: 1.1rem;
}

.btn-sm {
    padding: 0.4rem 1rem;
    font-size: 0.875rem;
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    background: rgba(255,255,255,0.1);
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.badge-primary { background: rgba(6, 182, 212, 0.2); color: var(--primary-color); }
.badge-accent { background: rgba(168, 85, 247, 0.2); color: var(--accent-color); }

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    border-bottom: 1px solid var(--glass-border);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

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

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
}

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

/* Hero Section */
.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px; 
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 10;
    max-width: 600px;
    padding-left: 10%;
    margin-top: -5vh; /* Center optical offset */
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -0.03em;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 90%;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.hero-spline {
    position: absolute;
    top: 0;
    right: 0;
    width: 60%;
    height: 100%;
    z-index: 0;
    mask-image: linear-gradient(to right, transparent, black 15%);
    -webkit-mask-image: linear-gradient(to right, transparent, black 15%);
}

spline-viewer {
    width: 100%;
    height: 100%;
}

@media (max-width: 992px) {
    .hero-spline {
        width: 100%;
        mask-image: none;
        -webkit-mask-image: none;
        opacity: 0.5;
    }
    .hero-content {
        padding-left: 5%;
        max-width: 100%;
        text-align: center;
        display: flex;
        flex-direction: column;
        align-items: center;
        margin-top: 0;
    }
    .hero-buttons {
        justify-content: center;
    }
}

/* Typography Colors for utility */
.text-primary { color: var(--primary-color); }

/* Sections */
.section {
    padding: 8rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 5rem;
}

.section-header h2 {
    font-size: 3rem;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.section-header p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    padding: 3rem 2rem;
    border-radius: 24px;
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: rgba(6, 182, 212, 0.4);
}

.feature-icon {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    background: rgba(6, 182, 212, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--text-secondary);
}

/* Courses Grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2.5rem;
}

.course-card {
    border-radius: 20px;
    overflow: hidden;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.course-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.05);
}

.course-image {
    height: 200px;
    background-size: cover;
    background-position: center;
    background-color: #1a1a24;
    position: relative;
    border-bottom: 1px solid var(--glass-border);
}
.course-image.ai-intro-bg {
    background-image: linear-gradient(to bottom, transparent, #1a1a24), url('https://images.unsplash.com/photo-1620712943543-bcc4688e7485?q=80&w=800&auto=format&fit=crop');
}
.course-image.nlp-bg {
    background-image: linear-gradient(to bottom, transparent, #1a1a24), url('https://images.unsplash.com/photo-1555949963-aa79dcee981c?q=80&w=800&auto=format&fit=crop');
}
.course-image.cv-bg {
    background-image: linear-gradient(to bottom, transparent, #1a1a24), url('https://images.unsplash.com/photo-1526374965328-7f61d4dc18c5?q=80&w=800&auto=format&fit=crop');
}

.course-content {
    padding: 2rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.course-content h3 {
    font-size: 1.4rem;
    margin-bottom: 0.75rem;
}

.course-content p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    flex-grow: 1;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1.5rem;
    border-top: 1px solid var(--glass-border);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.course-meta span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Footer Element */
.footer {
    padding: 5rem 0 2rem;
    border-top: 1px solid var(--glass-border);
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 3rem;
    margin-bottom: 4rem;
}

.footer-brand {
    max-width: 300px;
}

.footer-brand .logo {
    margin-bottom: 1rem;
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links h4 {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.8rem;
}

.footer-links a {
    color: var(--text-secondary);
}

.footer-links a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--glass-border);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Animations */
.animate-fade-in {
    animation: fadeIn 1s ease forwards;
}

.animate-fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

/* Scroll reveal classes */
.reveal {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}