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

:root {
    /* Light theme colors */
    --bg-color: #ffffff;
    --text-color: #1a1a1a;
    --text-secondary: #666666;
    --accent-color: #2563eb;
    --border-color: #e5e7eb;
    --card-bg: #f9fafb;
    --hover-bg: #f3f4f6;
    
    /* Typography */
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Layout */
    --max-width: 768px;
    --border-radius: 0.5rem;
}

[data-theme="dark"] {
    --bg-color: #0f0f0f;
    --text-color: #e5e5e5;
    --text-secondary: #a3a3a3;
    --accent-color: #3b82f6;
    --border-color: #262626;
    --card-bg: #1a1a1a;
    --hover-bg: #262626;
}

/* Base Styles */
html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    font-size: 16px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* Header */
header {
    padding: var(--space-2xl) 0 var(--space-xl) 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--space-2xl);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-lg);
}

h1 {
    font-size: 2rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.theme-toggle {
    display: flex;
    align-items: center;
}

#theme-toggle-btn {
    background: none;
    border: 1px solid var(--border-color);
    padding: var(--space-sm);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.2s ease;
}

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

/* Navigation */
nav {
    display: flex;
    gap: var(--space-lg);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
    padding: var(--space-sm) 0;
}

.nav-link:hover {
    color: var(--accent-color);
}

/* Main Content */
main {
    margin-bottom: var(--space-3xl);
}

.section {
    margin-bottom: var(--space-3xl);
}

.section h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    letter-spacing: -0.01em;
}

/* About Section */
.intro {
    max-width: 600px;
}

.lead {
    font-size: 1.125rem;
    font-weight: 400;
    color: var(--text-color);
    margin-bottom: var(--space-lg);
    line-height: 1.7;
}

.intro p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

/* Writing Section */
.posts-container {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.post-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

.post-preview {
    padding: var(--space-lg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: all 0.2s ease;
    cursor: pointer;
}

.post-link:hover .post-preview {
    border-color: var(--accent-color);
    background-color: var(--hover-bg);
    transform: translateY(-2px);
}

.post-date {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--text-secondary);
    display: block;
    margin-bottom: var(--space-sm);
}

.post-preview h3 {
    margin-bottom: var(--space-sm);
    font-size: 1.125rem;
    font-weight: 600;
}

.post-preview h3 {
    color: var(--text-color);
    transition: color 0.2s ease;
}

.post-link:hover .post-preview h3 {
    color: var(--accent-color);
}

.post-excerpt {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.5;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.project-card {
    padding: var(--space-lg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--card-bg);
    transition: all 0.2s ease;
}

.project-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-2px);
}

.project-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.project-card p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    font-size: 0.95rem;
}

.project-links {
    display: flex;
    gap: var(--space-md);
}

.project-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.875rem;
    transition: opacity 0.2s ease;
}

.project-link:hover {
    opacity: 0.8;
}

/* Contact Section */
#contact a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.2s ease;
}

#contact a:hover {
    opacity: 0.8;
}

/* Footer */
footer {
    padding: var(--space-2xl) 0;
    border-top: 1px solid var(--border-color);
    margin-top: var(--space-3xl);
}

footer p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--space-md);
    }
    
    .header-content {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }
    
    nav {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    h1 {
        font-size: 1.75rem;
    }
    
    .section h2 {
        font-size: 1.25rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-sm);
    }
    
    .post-preview,
    .project-card {
        padding: var(--space-md);
    }
    
    .nav-link {
        font-size: 0.95rem;
    }
}

/* Focus styles for accessibility */
button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Smooth transitions */
* {
    transition: border-color 0.2s ease, background-color 0.2s ease, color 0.2s ease;
}