/* Simple Light Theme */
/* A clean, minimal light theme for the HTML5 Layout Demo */

/* ==================== CSS Custom Properties ==================== */
:root {
    /* Colors */
    --color-bg: #ffffff;
    --color-bg-secondary: #f5f5f5;
    --color-text: #333333;
    --color-text-muted: #666666;
    --color-primary: #0066cc;
    --color-primary-hover: #0052a3;
    --color-border: #dddddd;
    --color-header-bg: #f0f0f0;
    --color-footer-bg: #f0f0f0;
    --color-code-bg: #f4f4f4;
    --color-blockquote-border: #0066cc;
    --color-tag-bg: #e8e8e8;
    --color-tag-text: #555555;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Typography */
    --font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --line-height: 1.6;

    /* Layout */
    --nav-width: 200px;
    --aside-width: 250px;
    --header-height: auto;
    --footer-height: auto;
    --border-radius: 4px;
}

/* ==================== Reset & Base ==================== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: var(--line-height);
    color: var(--color-text);
    background-color: var(--color-bg);
}

/* ==================== Typography ==================== */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--color-primary-hover);
    text-decoration: underline;
}

code {
    font-family: var(--font-family-mono);
    background-color: var(--color-code-bg);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    font-size: var(--font-size-sm);
}

blockquote {
    border-left: 4px solid var(--color-blockquote-border);
    padding-left: var(--spacing-md);
    margin: var(--spacing-md) 0;
    font-style: italic;
    color: var(--color-text-muted);
}

ul, ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
}

li {
    margin-bottom: var(--spacing-xs);
}

address {
    font-style: normal;
}

/* ==================== Page Layout ==================== */
.page-layout {
    display: grid;
    grid-template-areas:
        "header header header"
        "nav    main   aside"
        "footer footer footer";
    grid-template-columns: var(--nav-width) 1fr var(--aside-width);
    grid-template-rows: auto 1fr auto;
    min-height: 100vh;
}

/* ==================== Header ==================== */
.site-header {
    grid-area: header;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-xl);
    background-color: var(--color-header-bg);
    border-bottom: 1px solid var(--color-border);
}

.header-brand h1 {
    margin-bottom: 0;
}

.header-tagline {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

/* ==================== Theme Selector ==================== */
.theme-selector {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.theme-selector label {
    font-weight: 500;
}

.theme-selector select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: inherit;
    font-size: inherit;
    cursor: pointer;
}

.theme-selector select:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ==================== Navigation ==================== */
.site-nav {
    grid-area: nav;
    padding: var(--spacing-lg);
    background-color: var(--color-bg-secondary);
    border-right: 1px solid var(--color-border);
}

.site-nav h2 {
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.site-nav ul {
    list-style: none;
    padding-left: 0;
}

.site-nav li {
    margin-bottom: var(--spacing-sm);
}

.site-nav a {
    display: block;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: background-color 0.2s ease;
}

.site-nav a:hover {
    background-color: var(--color-border);
    text-decoration: none;
}

/* ==================== Main Content ==================== */
.site-main {
    grid-area: main;
    padding: var(--spacing-xl);
    overflow-y: auto;
}

.content-section {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--color-border);
}

.content-section:last-child {
    border-bottom: none;
}

.content-section > h2 {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-primary);
}

.content-article {
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-lg);
    background-color: var(--color-bg-secondary);
    border-radius: var(--border-radius);
}

.content-article h3 {
    color: var(--color-primary);
}

.content-article h4 {
    margin-top: var(--spacing-md);
}

/* ==================== Blog Posts ==================== */
.blog-post header {
    margin-bottom: var(--spacing-md);
}

.post-meta {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.post-meta time {
    font-weight: 500;
}

.post-tags {
    font-size: var(--font-size-sm);
}

/* ==================== Tags ==================== */
.tag {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    margin: var(--spacing-xs);
    background-color: var(--color-tag-bg);
    color: var(--color-tag-text);
    border-radius: var(--border-radius);
    font-size: var(--font-size-sm);
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tag-cloud .tag {
    margin: 0;
}

/* ==================== Figures & Images ==================== */
figure {
    margin: var(--spacing-md) 0;
}

.placeholder-image {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 150px;
    background-color: var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-text-muted);
}

figcaption {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    text-align: center;
    margin-top: var(--spacing-sm);
}

/* ==================== Aside ==================== */
.site-aside {
    grid-area: aside;
    padding: var(--spacing-lg);
    background-color: var(--color-bg-secondary);
    border-left: 1px solid var(--color-border);
}

.aside-section {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.aside-section:last-child {
    border-bottom: none;
}

.aside-section h3 {
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

.aside-section ul {
    list-style: none;
    padding-left: 0;
}

.aside-section li {
    margin-bottom: var(--spacing-sm);
}

.recent-posts li {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
}

.recent-posts .date {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

/* ==================== Footer ==================== */
.site-footer {
    grid-area: footer;
    padding: var(--spacing-md) var(--spacing-xl);
    background-color: var(--color-footer-bg);
    border-top: 1px solid var(--color-border);
}

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

.footer-content p {
    margin-bottom: 0;
}

.copyright {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

.built-with {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}