:root {
    /* Nordic Light Theme */
    --bg-color: #fafafa;
    --surface-color: #ffffff;
    --text-primary: #111111;
    --text-secondary: #666666;
    --border-color: #e5e5e5;
    --accent-color: #000000;
    
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-serif: 'Georgia', serif;
    
    --radius-sm: 4px;
    --transition-fast: 0.15s ease-out;
}

[data-theme="dark"] {
    /* Nordic Dark Theme */
    --bg-color: #121212;
    --surface-color: #1a1a1a;
    --text-primary: #f0f0f0;
    --text-secondary: #a0a0a0;
    --border-color: #333333;
    --accent-color: #ffffff;
}

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

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 var(--transition-fast), color var(--transition-fast);
}

.container {
    max-width: 800px; /* Narrower reading width for minimalism */
    margin: 0 auto;
    padding: 0 2rem;
}

/* Typography */
h1, h2, h3, h4, .font-serif {
    font-family: var(--font-serif);
    font-weight: 400; /* Minimalist weights */
    color: var(--text-primary);
}

p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    line-height: 1.8;
}

a {
    color: var(--text-primary);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-fast);
}

a:hover {
    border-bottom-color: var(--text-primary);
}

/* Navbar */
nav {
    padding: 2rem 0;
    margin-bottom: 4rem;
    border-bottom: 1px solid var(--border-color);
}

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

.logo {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 700;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
    align-items: center;
}

.nav-links a {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    border-bottom: none;
}

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

.toggles {
    display: flex;
    gap: 1rem;
}

.toggle-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    padding: 0.5rem;
    transition: color var(--transition-fast);
}

.toggle-btn:hover {
    color: var(--text-primary);
}

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

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: 2rem;
    line-height: 1.1;
}

.hero p {
    font-size: 1.25rem;
    max-width: 600px;
}

/* Minimalist List for Posts */
.post-list {
    list-style: none;
    margin: 4rem 0;
}

.post-item {
    display: block;
    padding: 2rem 0;
    border-bottom: 1px solid var(--border-color);
    border-bottom-color: transparent; /* No underlines on items themselves */
    transition: transform var(--transition-fast);
}

.post-item:not(:last-child) {
    border-bottom: 1px solid var(--border-color);
}

.post-item:hover {
    transform: translateX(10px);
    border-bottom-color: transparent; /* Disable the a:hover border */
}

.post-meta {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.post-title {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.post-desc {
    font-size: 1rem;
    margin-bottom: 0;
}

/* Markdown Post Content */
#post-content {
    margin-top: 4rem;
}

#post-content h1 { font-size: 3rem; margin-bottom: 1rem; line-height: 1.1; }
#post-content h2 { font-size: 2rem; margin: 3rem 0 1rem 0; }
#post-content h3 { font-size: 1.5rem; margin: 2rem 0 1rem 0; }
#post-content p { color: var(--text-primary); }

#post-content img {
    max-width: 100%;
    margin: 2rem 0;
}

#post-content pre {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 2rem 0;
    font-family: monospace;
    font-size: 0.9rem;
}

#post-content blockquote {
    border-left: 2px solid var(--text-primary);
    padding-left: 1.5rem;
    margin: 2rem 0;
    font-style: italic;
}

/* Footer & Socials */
footer {
    margin-top: 8rem;
    padding: 3rem 0 2rem 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.social-links a {
    color: var(--text-secondary);
    font-size: 1.25rem;
    transition: color var(--transition-fast), transform var(--transition-fast);
    border-bottom: none;
}

.social-links a:hover {
    color: var(--text-primary);
    transform: translateY(-2px);
    border-bottom: none;
}

/* i18n hiding classes */
.lang-zh [data-lang="en"] { display: none !important; }
.lang-en [data-lang="zh"] { display: none !important; }