:root {
    /* Refined Light Theme - Modern, Clean, Minimal */
    --bg-color: #fafafa;
    --card-bg: #ffffff;
    --text-primary: #111111;
    --text-secondary: #666666;
    --accent: #2563eb; /* Modern Blue */
    --accent-hover: #1d4ed8;
    --border-color: #eaeaea;
    --nav-bg: rgba(250, 250, 250, 0.8);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    --font-mono: 'JetBrains Mono', SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
}

[data-theme="dark"] {
    /* Refined Dark Theme - Deep, Professional, Easy on eyes */
    --bg-color: #050505;
    --card-bg: #0f0f0f;
    --text-primary: #f5f5f5;
    --text-secondary: #a1a1aa;
    --accent: #60a5fa;
    --accent-hover: #93c5fd;
    --border-color: #262626;
    --nav-bg: rgba(5, 5, 5, 0.8);
    --shadow: 0 10px 15px -3px rgb(0 0 0 / 0.5);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.4s cubic-bezier(0.4, 0, 0.2, 1), color 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 1rem 2rem;
}

/* Navigation */
header {
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
}

.logo-icon {
    width: 32px;
    height: 32px;
    fill: var(--accent);
}

.logo-text {
    font-family: var(--font-mono);
    font-weight: 800;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

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

/* Theme Toggle Button */
.theme-toggle {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 36px;
    height: 36px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    box-shadow: var(--shadow);
}

.theme-toggle:hover {
    border-color: var(--accent);
    transform: translateY(-1px);
}

/* Hero Section */
.hero {
    padding: 6rem 0 4rem;
}

.hero h1 {
    font-size: clamp(2.5rem, 8vw, 4rem);
    line-height: 1.05;
    margin-bottom: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin-bottom: 2rem;
}

.badge {
    display: inline-block;
    background-color: var(--card-bg);
    color: var(--accent);
    padding: 0.4rem 1rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-family: var(--font-mono);
    font-weight: 600;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

/* Projects & Sections */
.section-title {
    font-size: 1.75rem;
    margin: 4rem 0 2rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow);
}

.project-card:hover {
    transform: translateY(-6px);
    border-color: var(--accent);
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

.project-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    font-weight: 700;
}

.project-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.tech-stack {
    margin-top: auto;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 4px 10px;
    border-radius: 6px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Footer */
footer {
    border-top: 1px solid var(--border-color);
    padding: 4rem 2rem;
    margin-top: 6rem;
    background-color: var(--card-bg);
}

.footer-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
    text-align: center;
}

.social-links {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.social-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.2s ease;
}

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

/* Responsive Utilities */
@media (max-width: 640px) {
    .hero {
        padding: 4rem 0 2rem;
    }
    .nav-links {
        display: none; /* Simplification for mobile, can add a hamburger if needed */
    }
    .nav-container {
        padding: 1rem;
    }
    .container {
        padding: 1rem;
    }
    .footer-container {
        gap: 1.5rem;
    }
}

/* Blog List */
ul.posts {
    list-style: none;
}

ul.posts li {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: border-color 0.2s ease;
}

ul.posts li:hover {
    border-color: var(--accent);
}

ul.posts a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 700;
    display: block;
    margin-bottom: 0.5rem;
}

ul.posts span {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-family: var(--font-mono);
}