/*
 * AI News Daily - Main Stylesheet
 * Version: 1.0
 * Author: Senior Web Designer
 * Palette: Steel/Blue
 */

/* ---------------------------------- */
/*      1. VARIABLES & BASE           */
/* ---------------------------------- */

:root {
    /* Light Theme */
    --color-bg: #f8f9fa;
    --color-surface: #ffffff;
    --color-text: #212529;
    --color-heading: #111827;
    --color-muted: #6c757d;
    --color-border: #dee2e6;
    
    --color-primary: #005a9c; /* Steel Blue */
    --color-primary-light: #0077cc;
    
    --color-tag-construction-bg: #e0f2fe;
    --color-tag-construction-text: #0c4a6e;
    --color-tag-admin-bg: #e0e7ff;
    --color-tag-admin-text: #3730a3;
    --color-tag-transition-bg: #d1fae5;
    --color-tag-transition-text: #065f46;
    --color-tag-market-bg: #fef3c7;
    --color-tag-market-text: #92400e;

    /* Typography & Layout */
    --font-body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-heading: "Georgia", "Times New Roman", serif;
    --spacing-unit: 1rem;
    --container-width: 70rem;
    --border-radius: 4px;
}

@media (prefers-color-scheme: dark) {
    :root {
        /* Dark Theme */
        --color-bg: #111827;
        --color-surface: #1f2937;
        --color-text: #e5e7eb;
        --color-heading: #ffffff;
        --color-muted: #9ca3af;
        --color-border: #374151;

        --color-primary: #38bdf8; /* Lighter blue for contrast */
        --color-primary-light: #7dd3fc;
        
        --color-tag-construction-bg: #0c4a6e;
        --color-tag-construction-text: #e0f2fe;
        --color-tag-admin-bg: #3730a3;
        --color-tag-admin-text: #e0e7ff;
        --color-tag-transition-bg: #065f46;
        --color-tag-transition-text: #d1fae5;
        --color-tag-market-bg: #92400e;
        --color-tag-market-text: #fef3c7;
    }
}

/* Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--font-body);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    font-size: 1.125rem;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Accessibility: Visible Focus */
:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}

/* ---------------------------------- */
/*      2. TYPOGRAPHY & UTILITIES     */
/* ---------------------------------- */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--color-heading);
    line-height: 1.2;
    margin: 0 0 calc(var(--spacing-unit) * 1.5);
    font-weight: 700;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
p { margin: 0 0 var(--spacing-unit); }

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s ease-in-out;
}
a:hover {
    color: var(--color-primary-light);
    text-decoration: underline;
}

.container {
    max-width: var(--container-width);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--spacing-unit);
    padding-right: var(--spacing-unit);
}

/* ---------------------------------- */
/*      3. LAYOUT & COMPONENTS        */
/* ---------------------------------- */

/* Header & Navigation */
.site-header {
    padding: calc(var(--spacing-unit) * 1.5) 0;
    border-bottom: 1px solid var(--color-border);
    background-color: var(--color-bg);
}
.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-unit);
}
.site-title {
    margin: 0;
}
.site-title a {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: bold;
    color: var(--color-heading);
    text-decoration: none;
}
.main-nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    gap: calc(var(--spacing-unit) * 1.5);
}

/* Hero Section */
.hero {
    background-color: var(--color-surface);
    text-align: center;
    padding: calc(var(--spacing-unit) * 4) var(--spacing-unit);
    border-bottom: 1px solid var(--color-border);
}
.hero h1 {
    max-width: 30ch;
    margin-left: auto;
    margin-right: auto;
}
.hero p {
    font-size: 1.25rem;
    color: var(--color-muted);
    max-width: 60ch;
    margin-left: auto;
    margin-right: auto;
    margin-top: var(--spacing-unit);
    margin-bottom: 0;
}

/* Latest Posts Section */
.latest-posts {
    padding: calc(var(--spacing-unit) * 4) 0;
}
.post-list {
    display: grid;
    gap: calc(var(--spacing-unit) * 2);
}
.post-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 1.5);
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}
.post-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
}
.post-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-unit);
    font-size: 0.9rem;
    color: var(--color-muted);
}
.post-card-category {
    font-weight: bold;
    padding: 0.25em 0.75em;
    border-radius: 999px;
    font-size: 0.8rem;
}
.post-card-category.construction { background-color: var(--color-tag-construction-bg); color: var(--color-tag-construction-text); }
.post-card-category.admin { background-color: var(--color-tag-admin-bg); color: var(--color-tag-admin-text); }
.post-card-category.transition { background-color: var(--color-tag-transition-bg); color: var(--color-tag-transition-text); }
.post-card-category.market { background-color: var(--color-tag-market-bg); color: var(--color-tag-market-text); }

.post-card-title {
    margin-bottom: calc(var(--spacing-unit) * 0.5);
}
.post-card-title a {
    color: var(--color-heading);
    text-decoration: none;
}
.post-card-title a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}
.post-card-excerpt {
    color: var(--color-muted);
    margin-bottom: 0;
}

/* Sticky CTA */
.cta-sticky {
    position: fixed;
    bottom: var(--spacing-unit);
    right: var(--spacing-unit);
    background-color: var(--color-primary);
    color: #fff;
    padding: 0.75em 1.25em;
    border-radius: var(--border-radius);
    font-weight: bold;
    text-decoration: none;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: background-color 0.2s ease-in-out, transform 0.2s ease-in-out;
}
.cta-sticky:hover {
    background-color: var(--color-primary-light);
    color: #fff;
    text-decoration: none;
    transform: translateY(-2px);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: calc(var(--spacing-unit) * 2) 0;
    margin-top: calc(var(--spacing-unit) * 4);
    font-size: 0.9rem;
    color: var(--color-muted);
}
.site-footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-unit);
}
.site-footer p {
    margin: 0;
}
.site-footer a {
    color: var(--color-muted);
}
.site-footer a:hover {
    color: var(--color-primary);
}

/* Jekyll Post Layout */
.post-shell {
    padding-top: calc(var(--spacing-unit) * 3);
    padding-bottom: calc(var(--spacing-unit) * 2);
    max-width: 48rem;
}

.post-header {
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.post-date {
    margin-bottom: calc(var(--spacing-unit) * 0.5);
    color: var(--color-muted);
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

.post-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem 1rem;
    align-items: center;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.post-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.post-content {
    width: 100%;
    min-width: 0;
    overflow-x: hidden;
}

.prose {
    width: 100%;
    max-width: 100%;
}

.prose > * {
    max-width: 100%;
}

.prose > * + * {
    margin-top: 1rem;
}

.prose ul,
.prose ol {
    padding-left: 1.5rem;
}

.prose li + li {
    margin-top: 0.35rem;
}

.prose img {
    display: block;
    max-width: 100%;
    width: auto;
    height: auto;
    margin: 1.5rem auto;
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
}

.prose p,
.prose li,
.prose blockquote,
.prose pre {
    overflow-wrap: anywhere;
}

.prose iframe,
.prose video,
.prose table,
.prose canvas,
.prose svg,
.prose embed,
.prose object {
    max-width: 100%;
}

.prose iframe,
.prose video,
.prose embed,
.prose object {
    display: block;
    width: 100%;
    margin: 1.5rem auto;
}

.prose iframe {
    aspect-ratio: 16 / 9;
    min-height: 320px;
    border: 0;
}

.prose table {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.prose blockquote {
    margin: 1.5rem 0;
    padding: 1rem 1.25rem;
    border-left: 4px solid var(--color-primary);
    background-color: var(--color-surface);
    color: var(--color-muted);
}

.prose pre,
.prose code {
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.prose code {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 3px;
    padding: 0.15em 0.35em;
    font-size: 0.92em;
}

.prose pre {
    overflow-x: auto;
    padding: 1rem;
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
}

.prose pre code {
    padding: 0;
    border: 0;
    background: transparent;
}

.post-nav {
    margin-top: calc(var(--spacing-unit) * 2.5);
    padding-top: calc(var(--spacing-unit) * 1.5);
    border-top: 1px solid var(--color-border);
}


/* ---------------------------------- */
/*      4. RESPONSIVE DESIGN          */
/* ---------------------------------- */

@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    .hero { padding: calc(var(--spacing-unit) * 3) var(--spacing-unit); }
    .site-header .container { flex-direction: column; }
}

@media (max-width: 480px) {
    body { font-size: 1rem; }
    .main-nav ul { gap: var(--spacing-unit); }
    .cta-sticky {
        width: calc(100% - 2 * var(--spacing-unit));
        text-align: center;
        bottom: var(--spacing-unit);
        left: var(--spacing-unit);
        right: var(--spacing-unit);
    }
}