:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --text-main: #1f2937;
    --text-secondary: #4b5563;
    --bg-body: #ffffff;
    --bg-surface: #f9fafb;
    --bg-glass: rgba(255, 255, 255, 0.7);
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* Header & Nav */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(229, 231, 235, 0.5);
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
    margin-right: 2rem;
}

.logo img {
    height: 20px;
    max-height: 20px;
    width: auto;
}

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

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

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

.btn-github {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--text-main);
    color: white !important;
    padding: 0.5rem 1rem;
    border-radius: 9999px;
    font-size: 0.9rem;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-github:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    background-color: #000;
}

/* Hero Section */
.hero {
    position: relative;
    padding: 160px 2rem 100px;
    text-align: center;
    background: radial-gradient(circle at 50% 0%, rgba(37, 99, 235, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 100% 0%, rgba(139, 92, 246, 0.05) 0%, transparent 30%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%239C92AC' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    mask-image: linear-gradient(to bottom, black, transparent);
    z-index: -1;
}

.hero-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(37, 99, 235, 0.2);
}

.hero h1 {
    font-size: 4.5rem;
    line-height: 1.1;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #111827, #4b5563);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: fadeUp 0.8s ease-out;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 2.5rem;
    animation: fadeUp 0.8s ease-out 0.2s backwards;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeUp 0.8s ease-out 0.4s backwards;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.39);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.23);
}

.btn-secondary {
    background-color: white;
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--text-secondary);
    background-color: var(--bg-surface);
}

/* Features Grid */
.features {
    padding: 80px 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

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

.card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(37, 99, 235, 0.3);
}

.card-icon {
    width: 48px;
    height: 48px;
    background: rgba(37, 99, 235, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
}

.card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Footer */
footer {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    padding: 4rem 2rem;
    margin-top: 4rem;
}

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

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

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

/* Animations */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    will-change: opacity, visibility;
}

.fade-in-section.is-visible {
    opacity: 1;
    transform: none;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 3rem;
    }

    .nav-container {
        flex-wrap: wrap;
        justify-content: space-between;
        padding: 1rem;
        gap: 0;
        /* Gap handled by margin in nav-links */
    }

    .logo {
        margin-right: 0;
        order: 1;
    }

    .btn-github {
        display: flex;
        order: 2;
    }

    .nav-links {
        display: flex;
        gap: 1rem;
        margin: 1rem 0 0 0;
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
        order: 3;
    }
}