:root {
    --text-primary: #1a1a1a;
    --text-secondary: #666;
    --text-tertiary: #999;
    --accent: #0066cc;
    --border: #e8e8e8;
    --bg: #ffffff;
}

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

html {
    font-size: 18px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Crimson Pro', Georgia, serif;
    color: var(--text-primary);
    background: var(--bg);
    line-height: 1.7;
    max-width: 640px;
    margin: 0 auto;
    padding: 80px 32px 120px;
}

/* Header */
header {
    margin-bottom: 80px;
    border-bottom: 1px solid var(--border);
    padding-bottom: 40px;
}

.site-title {
    font-family: 'IBM Plex Sans', -apple-system, system-ui, sans-serif;
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: -0.01em;
    margin-bottom: 12px;
}

.site-title a {
    color: var(--text-primary);
    text-decoration: none;
}

.bio {
    font-size: 0.94rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 520px;
}

/* Navigation */
nav {
    margin-top: 20px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 24px;
}

nav a,
.back-link a,
.post-navigation a,
.pagination a {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.83rem;
    color: var(--text-tertiary);
    text-decoration: none;
    transition: color 0.2s;
}

nav a:hover,
.back-link a:hover,
.post-navigation a:hover,
.pagination a:hover {
    color: var(--accent);
}

/* Featured Post */
.featured {
    margin-bottom: 60px;
    padding-bottom: 60px;
    border-bottom: 1px solid var(--border);
}

.featured-label {
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 20px;
    font-weight: 400;
}

/* Article Listings */
article {
    margin-bottom: 56px;
}

article.featured-post {
    margin-bottom: 0;
}

.post-date {
    margin-bottom: 8px;
    letter-spacing: 0.02em;
}

h1 {
    font-size: 2rem;
    line-height: 1.25;
    font-weight: 600;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

h1 a,
h2 a {
    color: var(--text-primary);
    text-decoration: none;
}

h1 a:hover,
h2 a:hover {
    color: var(--accent);
}

h2 {
    font-size: 1.5rem;
    line-height: 1.3;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: -0.015em;
}

.excerpt {
    font-size: 1rem;
    line-height: 1.65;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.continue-reading {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.83rem;
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.2s;
}

.continue-reading:hover {
    opacity: 0.7;
}

.continue-reading::after {
    content: ' →';
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 80px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.83rem;
}

.page-numbers {
    display: flex;
    gap: 16px;
}

.page-numbers a,
.page-numbers span {
    color: var(--text-tertiary);
    text-decoration: none;
}

.page-numbers .current {
    color: var(--text-primary);
    font-weight: 500;
}

.page-numbers a:hover {
    color: var(--accent);
}

/* Footer */
footer {
    margin-top: 120px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
}

.footer-links {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.83rem;
}

.footer-links ul {
    list-style: none;
    display: flex;
    gap: 20px;
    margin-bottom: 16px;
}

.footer-links a {
    color: var(--text-tertiary);
    text-decoration: none;
    transition: color 0.2s;
}

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

.copyright,
.post-date,
.featured-label {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.72rem;
    color: var(--text-tertiary);
}

/* Post Content Styles */
article.post-content {
    margin-top: 40px;
}

article.post-content p {
    margin-bottom: 1.4em;
}

article.post-content h2 {
    font-size: 1.5rem;
    line-height: 1.3;
    font-weight: 600;
    margin: 2.5em 0 0.75em;
    letter-spacing: -0.015em;
}

article.post-content h3 {
    font-size: 1.25rem;
    line-height: 1.35;
    font-weight: 600;
    margin: 2em 0 0.75em;
    letter-spacing: -0.01em;
}

article.post-content h4 {
    font-size: 1.1rem;
    line-height: 1.4;
    font-weight: 600;
    margin: 1.75em 0 0.5em;
}

article.post-content blockquote {
    border-left: 3px solid var(--border);
    padding-left: 1.5em;
    margin: 1.5em 0;
    color: var(--text-secondary);
    font-style: italic;
}

article.post-content ul,
article.post-content ol {
    margin-bottom: 1.4em;
    padding-left: 1.5em;
}

article.post-content li {
    margin-bottom: 0.5em;
}

article.post-content code {
    font-family: 'IBM Plex Mono', 'Consolas', 'Monaco', monospace;
    font-size: 0.9em;
    background: #f5f5f5;
    padding: 0.2em 0.4em;
    border-radius: 3px;
}

article.post-content pre {
    background: #f5f5f5;
    padding: 1.5em;
    overflow-x: auto;
    border-radius: 4px;
    margin: 1.5em 0;
}

article.post-content pre code {
    background: none;
    padding: 0;
}

article.post-content a {
    color: var(--accent);
    text-decoration: none;
    border-bottom: 1px solid var(--accent);
    transition: opacity 0.2s;
}

article.post-content a:hover {
    opacity: 0.7;
}

article.post-content img {
    max-width: 100%;
    height: auto;
    margin: 2em 0;
    border-radius: 4px;
}

article.post-content hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 3em 0;
}

/* Post Header */
.post-header {
    margin-bottom: 40px;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--border);
}

.post-header h1 {
    font-size: 2.25rem;
    line-height: 1.2;
    margin-bottom: 16px;
}

.post-meta {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.83rem;
    color: var(--text-tertiary);
}

.post-meta time {
    margin-right: 16px;
}

/* Post Navigation */
.post-navigation {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
}

.post-navigation .prev::before {
    content: '← ';
}

.post-navigation .next::after {
    content: ' →';
}

/* Back to Home Link */
.back-link {
    margin-bottom: 40px;
}

.back-link a::before {
    content: '← ';
}

/* Archive Page */
.archive-section {
    margin-bottom: 60px;
}

.archive-year {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.archive-list {
    list-style: none;
}

.archive-list li {
    margin-bottom: 24px;
}

/* Responsive */
@media (max-width: 640px) {
    html {
        font-size: 17px;
    }

    body {
        padding: 48px 24px 80px;
    }

    header {
        margin-bottom: 56px;
        padding-bottom: 32px;
    }

    h1 {
        font-size: 1.65rem;
    }

    h2 {
        font-size: 1.35rem;
    }

    .featured {
        margin-bottom: 48px;
        padding-bottom: 48px;
    }

    article {
        margin-bottom: 48px;
    }

    nav ul {
        gap: 20px;
    }

    .page-numbers {
        gap: 12px;
    }

    .post-header h1 {
        font-size: 1.75rem;
    }
}