/* ==========================================================================
   null-island-theme — Null Island Dispatch
   Modern editorial design for a GeoAI newsletter
   ========================================================================== */

/* ==========================================================================
   0. Fonts — self-hosted woff2
   ========================================================================== */

@font-face {
    font-family: 'Inter';
    src: url('../fonts/Inter.woff2') format('woff2');
    font-weight: 400 800;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'JetBrains Mono';
    src: url('../fonts/JetBrainsMono-Regular.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}


/* ==========================================================================
   1. Design Tokens
   ========================================================================== */

:root {
    /* Colors */
    --color-text:           #111111;
    --color-bg:             #FFFFFF;
    --color-accent:         #2563EB;
    --color-accent-hover:   #1D4ED8;
    --color-muted:          #6B7280;
    --color-subtle:         #F3F4F6;
    --color-border:         #E5E7EB;
    --color-border-strong:  #D1D5DB;

    /* Functional aliases */
    --color-link:           var(--color-accent);
    --color-link-hover:     var(--color-accent-hover);

    /* Typography */
    --font-display:    'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-body:       'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono:       'JetBrains Mono', 'Courier New', monospace;

    /* Type scale */
    --size-xs:    0.75rem;
    --size-sm:    0.875rem;
    --size-base:  1rem;
    --size-md:    1.125rem;
    --size-lg:    1.25rem;
    --size-xl:    1.75rem;
    --size-2xl:   2.25rem;
    --size-hero:  3rem;

    /* Line heights */
    --leading-tight:   1.2;
    --leading-normal:  1.6;
    --leading-relaxed: 1.7;

    /* Letter spacing */
    --tracking-tight:    -0.02em;
    --tracking-normal:    0;
    --tracking-wide:      0.02em;

    /* Spacing */
    --space-xs:   0.25rem;
    --space-sm:   0.5rem;
    --space-md:   1rem;
    --space-lg:   1.5rem;
    --space-xl:   2rem;
    --space-2xl:  3rem;
    --space-3xl:  4rem;
    --space-4xl:  6rem;

    /* Layout */
    --width-content:  680px;
    --width-wide:     960px;
    --width-full:     1200px;

    /* Borders & Effects */
    --border-thin:    1px solid var(--color-border);
    --border-accent:  2px solid var(--color-accent);
    --radius-sm:      6px;
    --radius-md:      8px;
    --shadow-sm:      0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md:      0 4px 12px rgba(0, 0, 0, 0.08);
}


/* ==========================================================================
   2. Reset & Base
   ========================================================================== */

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

html {
    font-size: 100%;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--gh-font-body, var(--font-body));
    font-size: var(--size-base);
    line-height: var(--leading-normal);
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-link);
    text-decoration: none;
    transition: color 0.15s ease;
}

a:hover {
    color: var(--color-link-hover);
}

a:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}


/* ==========================================================================
   3. Accessibility
   ========================================================================== */

.skip-link {
    position: absolute;
    top: -100%;
    left: var(--space-md);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-accent);
    color: var(--color-bg);
    font-size: var(--size-sm);
    font-weight: 500;
    border-radius: var(--radius-sm);
    z-index: 1000;
    text-decoration: none;
}

.skip-link:focus {
    top: var(--space-sm);
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}


/* ==========================================================================
   4. Typography
   ========================================================================== */

h1, h2, h3 {
    font-family: var(--gh-font-heading, var(--font-display));
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-tight);
    color: var(--color-text);
}

h1 { font-size: var(--size-2xl); font-weight: 800; }
h2 { font-size: var(--size-xl);  font-weight: 700; }
h3 { font-size: var(--size-lg);  font-weight: 600; }


/* ==========================================================================
   5. Layout — Site Header
   ========================================================================== */

.site-header {
    border-bottom: var(--border-thin);
    padding: var(--space-lg) var(--space-xl);
    position: relative;
}

.site-header__inner {
    max-width: var(--width-full);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
}

.site-header__logo {
    text-decoration: none;
    display: flex;
    align-items: center;
}

.site-header__logo-img {
    height: 28px;
    width: auto;
}

.site-header__title {
    font-family: var(--font-display);
    font-size: var(--size-lg);
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: var(--tracking-tight);
}


/* ==========================================================================
   6. Layout — Navigation
   ========================================================================== */

.site-nav__list {
    display: none;
    gap: var(--space-xl);
    list-style: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: var(--border-thin);
    padding: var(--space-md) var(--space-xl);
    box-shadow: var(--shadow-md);
    flex-direction: column;
    gap: var(--space-md);
}

.site-nav__list--open {
    display: flex;
}

.site-nav__link {
    font-family: var(--font-body);
    font-size: var(--size-sm);
    font-weight: 500;
    color: var(--color-muted);
    text-decoration: none;
    transition: color 0.15s ease;
}

.site-nav__link:hover,
.site-nav__link--active {
    color: var(--color-text);
}

.site-nav__toggle {
    display: block;
    background: none;
    border: none;
    padding: var(--space-sm);
    cursor: pointer;
}

.site-nav__hamburger {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-text);
    position: relative;
}

.site-nav__hamburger::before,
.site-nav__hamburger::after {
    content: '';
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-text);
    position: absolute;
    left: 0;
}

.site-nav__hamburger::before { top: -6px; }
.site-nav__hamburger::after  { top: 6px; }

.site-header__subscribe,
.site-header__account {
    font-family: var(--font-body);
    font-size: var(--size-sm);
    font-weight: 600;
    background: var(--color-accent);
    color: var(--color-bg);
    border: none;
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    text-decoration: none;
    transition: background 0.15s ease;
}

.site-header__subscribe:hover,
.site-header__account:hover {
    background: var(--color-accent-hover);
}


/* ==========================================================================
   7. Layout — Hero
   ========================================================================== */

.hero {
    max-width: var(--width-content);
    margin: var(--space-2xl) auto var(--space-2xl);
    padding: 0 var(--space-xl);
}

.hero__tag {
    font-size: var(--size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    color: var(--color-accent);
}

.hero__title {
    font-size: var(--size-2xl);
    font-weight: 800;
    letter-spacing: var(--tracking-tight);
    margin: var(--space-sm) 0 var(--space-md);
}

.hero__title a {
    color: var(--color-text);
    text-decoration: none;
}

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

.hero__excerpt {
    font-size: var(--size-md);
    color: var(--color-muted);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--space-md);
}

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

.hero__link {
    display: inline-block;
    margin-top: var(--space-lg);
    font-size: var(--size-sm);
    font-weight: 600;
    color: var(--color-accent);
}

.hero__link:hover {
    color: var(--color-accent-hover);
}


/* ==========================================================================
   8. Layout — Archive Grid
   ========================================================================== */

.archive {
    max-width: var(--width-full);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

.archive__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

@media (min-width: 768px) {
    .archive__grid {
        grid-template-columns: 1fr 1fr;
    }
}


/* ==========================================================================
   9. Components — Post Card
   ========================================================================== */

.post-card {
    border: var(--border-thin);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.post-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-border-strong);
}

.post-card--featured {
    border-color: var(--color-accent);
}

.post-card__image {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

.post-card__body {
    padding: var(--space-lg);
}

.post-card__tag {
    font-size: var(--size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    color: var(--color-accent);
}

.post-card__title {
    font-size: var(--size-lg);
    font-weight: 700;
    margin: var(--space-sm) 0;
    letter-spacing: var(--tracking-tight);
}

.post-card__title a {
    color: var(--color-text);
    text-decoration: none;
}

.post-card__title a:hover {
    color: var(--color-accent);
}

.post-card__excerpt {
    font-size: var(--size-sm);
    color: var(--color-muted);
    line-height: var(--leading-normal);
    margin-bottom: var(--space-md);
}

.post-card__meta {
    font-size: var(--size-xs);
    color: var(--color-muted);
}


/* ==========================================================================
   10. Layout — Post / Page Content
   ========================================================================== */

.post__header,
.page__header {
    max-width: var(--width-content);
    margin: var(--space-2xl) auto var(--space-xl);
    padding: 0 var(--space-xl);
}

.post__tag {
    font-size: var(--size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    color: var(--color-accent);
}

.post__title,
.page__title {
    font-size: var(--size-xl);
    font-weight: 800;
    letter-spacing: var(--tracking-tight);
    margin: var(--space-sm) 0;
}

.post__meta {
    font-size: var(--size-sm);
    color: var(--color-muted);
    margin-top: var(--space-sm);
}

.post__feature-image {
    max-width: var(--width-wide);
    margin: 0 auto var(--space-2xl);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.post__feature-caption {
    font-size: var(--size-sm);
    color: var(--color-muted);
    text-align: center;
    margin-top: var(--space-sm);
    padding: 0 var(--space-xl);
}

.post__content,
.page__content {
    max-width: var(--width-content);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

.post__content p,
.page__content p {
    margin-bottom: var(--space-lg);
    line-height: var(--leading-relaxed);
}

.post__content h2 {
    margin-top: var(--space-3xl);
    margin-bottom: var(--space-md);
}

.post__content h3 {
    margin-top: var(--space-2xl);
    margin-bottom: var(--space-md);
}

/* Blockquotes */
.post__content blockquote {
    border-left: var(--border-accent);
    padding-left: var(--space-lg);
    margin: var(--space-xl) 0;
    color: var(--color-muted);
}

.post__content blockquote p {
    font-size: var(--size-md);
}

/* Code blocks */
.post__content pre {
    background: var(--color-subtle);
    border: var(--border-thin);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    overflow-x: auto;
    margin: var(--space-xl) 0;
    font-family: var(--font-mono);
    font-size: var(--size-sm);
    line-height: var(--leading-normal);
}

.post__content code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--color-subtle);
    padding: 0.15em 0.4em;
    border-radius: var(--radius-sm);
}

.post__content pre code {
    background: none;
    padding: 0;
    font-size: inherit;
}

/* Ghost width classes — wide and full-bleed content */
.kg-width-wide {
    max-width: var(--width-wide);
    margin-left: 50%;
    transform: translateX(-50%);
}

.kg-width-full {
    max-width: none;
    margin-left: 50%;
    transform: translateX(-50%);
    width: 100vw;
}

/* Images — contained on mobile, break to wide width on desktop (see section 17) */
.post__content img {
    max-width: 100%;
    border-radius: var(--radius-md);
}

/* Ghost card: callout */
.post__content .kg-callout-card {
    background: var(--color-subtle);
    border: var(--border-thin);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    margin: var(--space-xl) 0;
}

/* Ghost card: bookmark */
.post__content .kg-bookmark-card {
    border: var(--border-thin);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: box-shadow 0.2s ease;
}

.post__content .kg-bookmark-card:hover {
    box-shadow: var(--shadow-sm);
}

/* Ghost card: toggle */
.post__content .kg-toggle-card {
    border: var(--border-thin);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    margin: var(--space-md) 0;
}


/* ==========================================================================
   11. Components — Author Card
   ========================================================================== */

.author-card {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    max-width: var(--width-content);
    margin: var(--space-2xl) auto;
    padding: var(--space-xl) var(--space-xl);
    border-top: var(--border-thin);
}

.author-card__avatar {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    flex-shrink: 0;
}

.author-card__name {
    font-family: var(--font-display);
    font-size: var(--size-base);
    font-weight: 600;
    display: block;
}

.author-card__bio {
    font-size: var(--size-sm);
    color: var(--color-muted);
    margin-top: var(--space-xs);
    line-height: var(--leading-normal);
}


/* ==========================================================================
   12. Components — Newsletter CTA
   ========================================================================== */

.newsletter-cta {
    max-width: var(--width-content);
    margin: var(--space-3xl) auto;
    padding: var(--space-2xl) var(--space-xl);
    text-align: center;
    border: var(--border-thin);
    border-radius: var(--radius-md);
    background: var(--color-subtle);
}

.newsletter-cta__title {
    font-size: var(--size-xl);
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.newsletter-cta__description {
    font-size: var(--size-base);
    color: var(--color-muted);
    margin-bottom: var(--space-lg);
}

.newsletter-cta__button {
    font-family: var(--font-body);
    font-size: var(--size-base);
    font-weight: 600;
    background: var(--color-accent);
    color: var(--color-bg);
    border: none;
    padding: var(--space-sm) var(--space-xl);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background 0.15s ease;
}

.newsletter-cta__button:hover {
    background: var(--color-accent-hover);
}

.newsletter-cta__button:focus-visible {
    outline: 2px solid var(--color-text);
    outline-offset: 2px;
}


/* ==========================================================================
   13. Components — Divider
   ========================================================================== */

.divider {
    max-width: var(--width-content);
    margin: var(--space-3xl) auto;
    height: 1px;
    background: var(--color-border);
}


/* ==========================================================================
   14. Components — Pagination
   ========================================================================== */

.pagination {
    max-width: var(--width-content);
    margin: var(--space-2xl) auto;
    padding: 0 var(--space-xl);
}

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

.pagination__link {
    font-size: var(--size-sm);
    font-weight: 500;
    color: var(--color-accent);
}

.pagination__link:hover {
    color: var(--color-accent-hover);
}

.pagination__count {
    font-size: var(--size-xs);
    color: var(--color-muted);
}


/* ==========================================================================
   15. Layout — Footer
   ========================================================================== */

.site-footer {
    border-top: var(--border-thin);
    padding: var(--space-2xl) var(--space-xl);
    margin-top: var(--space-4xl);
}

.site-footer__inner {
    max-width: var(--width-full);
    margin: 0 auto;
    text-align: center;
}

.site-footer__nav {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.site-footer__link {
    font-size: var(--size-sm);
    font-weight: 500;
    color: var(--color-muted);
    text-decoration: none;
    transition: color 0.15s ease;
}

.site-footer__link:hover {
    color: var(--color-text);
}

.site-footer__meta {
    font-size: var(--size-sm);
    color: var(--color-muted);
    margin-bottom: var(--space-md);
}

.site-footer__coordinates {
    font-family: var(--font-mono);
    font-size: var(--size-xs);
    color: var(--color-border-strong);
    letter-spacing: var(--tracking-wide);
    margin-top: var(--space-md);
}


/* ==========================================================================
   16. Layout — Tag & Author Archives
   ========================================================================== */

.tag-archive__header,
.author-archive__header {
    max-width: var(--width-content);
    margin: var(--space-3xl) auto var(--space-2xl);
    padding: 0 var(--space-xl);
}

.tag-archive__title,
.author-archive__name {
    font-size: var(--size-2xl);
    font-weight: 800;
}

.tag-archive__description,
.author-archive__bio {
    font-size: var(--size-base);
    color: var(--color-muted);
    margin-top: var(--space-sm);
}

.author-archive__avatar {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    margin-bottom: var(--space-md);
}

.author-archive__location {
    font-size: var(--size-sm);
    color: var(--color-muted);
    display: block;
    margin-top: var(--space-xs);
}


/* ==========================================================================
   17. Responsive — Mobile-first overrides
   ========================================================================== */

/*
 * Base styles (above) are mobile. The mobile nav toggle is visible by default,
 * and the nav list is hidden until toggled open. Desktop overrides below
 * promote to full layout at 768px+.
 */

@media (min-width: 768px) {
    .hero {
        margin-top: var(--space-4xl);
    }

    .hero__title {
        font-size: var(--size-hero);
    }

    .post__title,
    .page__title {
        font-size: var(--size-2xl);
    }

    .post__header,
    .page__header {
        margin-top: var(--space-4xl);
    }

    .post__content img {
        max-width: var(--width-wide);
        margin-left: 50%;
        transform: translateX(-50%);
    }

    .site-nav__toggle {
        display: none;
    }

    .site-nav__list {
        display: flex;
        position: static;
        flex-direction: row;
        background: none;
        border-bottom: none;
        padding: 0;
        box-shadow: none;
        gap: var(--space-xl);
    }

    .site-header {
        position: static;
    }
}