:root {
    /* Light Theme */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --bg-color: #ffffff;
    --text-color: #1f2937;
    --text-muted: #6b7280;
    --card-bg: #f9fafb;
    --header-bg: rgba(255, 255, 255, 0.8);
    --border-color: #e5e7eb;
    --gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    --container-width: 1100px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.dark-theme {
    --primary: #818cf8;
    --primary-dark: #6366f1;
    --bg-color: #0f172a;
    --text-color: #f1f5f9;
    --text-muted: #94a3b8;
    --card-bg: #1e293b;
    --header-bg: rgba(15, 23, 42, 0.8);
    --border-color: #334155;
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 100px 0;
}

h1, h2, h3 {
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

/* Header & Nav */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -1px;
}

.logo span {
    color: var(--primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

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

#theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    transition: var(--transition);
}

#theme-toggle:hover {
    background-color: var(--card-bg);
}

.sun-icon { display: none; }
.dark-theme .sun-icon { display: block; }
.dark-theme .moon-icon { display: none; }

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    background: radial-gradient(circle at top right, rgba(99, 102, 241, 0.1), transparent);
}

.hero-content {
    max-width: 800px;
}

.hero h1 {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 2rem;
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 3rem;
    max-width: 600px;
}

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

.btn {
    padding: 12px 32px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: var(--gradient);
    color: white;
    border: none;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.2);
}

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

.btn-secondary:hover {
    background-color: var(--card-bg);
}

/* Features Section */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 4rem;
}

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

.feature-card {
    background-color: var(--card-bg);
    padding: 3rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
}

.feature-card i {
    color: var(--primary);
    width: 40px;
    height: 40px;
    margin-bottom: 1.5rem;
}

/* About Section */
.about-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text .section-title {
    text-align: left;
    margin-bottom: 2rem;
}

.about-list {
    margin-top: 2rem;
}

.about-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.about-list i {
    color: #10b981;
}

.image-placeholder {
    width: 100%;
    aspect-ratio: 4/3;
    background: var(--gradient);
    border-radius: 24px;
    opacity: 0.8;
}

/* Footer */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
    background-color: var(--card-bg);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

/* Scroll Reveal Animations */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

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

/* Mobile Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    .about-container {
        grid-template-columns: 1fr;
    }
    .nav-links {
        gap: 1rem;
    }
    .footer-content {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
}