/* CSS Variables */
:root {
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-text-muted: #666666;
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-border: #e5e5e5;
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, monospace;
    --max-width: 65ch;
    --spacing: clamp(1rem, 3vw, 2rem);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; }

/* Base */
html {
    font-size: clamp(16px, 1vw + 14px, 20px);
    line-height: 1.6;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Typography */
h1, h2, h3 { line-height: 1.2; margin: 0 0 1rem; }
h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }

p { margin: 0 0 1rem; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Header */
.site-header {
    border-bottom: 1px solid var(--color-border);
    padding: 1rem var(--spacing);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-logo {
    font-weight: 700;
    color: var(--color-text);
}

.nav-links {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 1.5rem;
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing);
    width: 100%;
}

/* Hero */
.hero {
    text-align: center;
    padding: 3rem 0;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-muted);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    font-weight: 500;
    transition: background-color 0.2s;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

.btn-primary:hover {
    background: var(--color-primary-hover);
    text-decoration: none;
}

/* Sections */
.content-section {
    padding: 2rem 0;
    border-top: 1px solid var(--color-border);
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border);
}

/* Article */
.article-header {
    margin-bottom: 2rem;
}

.article-header time,
.article-header .author {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.article-image img {
    width: 100%;
    height: auto;
    border-radius: 0.5rem;
}

.article-content { margin: 2rem 0; }
.article-content img { max-width: 100%; height: auto; }
.article-content pre {
    background: #f5f5f5;
    padding: 1rem;
    overflow-x: auto;
    border-radius: 0.375rem;
    font-family: var(--font-mono);
}

.tags {
    list-style: none;
    padding: 0;
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    background: var(--color-border);
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.85rem;
}

.article-nav {
    margin-top: 3rem;
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: 2rem var(--spacing);
    text-align: center;
    color: var(--color-text-muted);
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
}