/* =========================================
   1. Design tokens
========================================= */

:root {
    /* Colors */
    --color-page-bg: #f7f8fa;
    --color-surface: #ffffff;
    --color-surface-muted: #f1f3f6;

    --color-text: #1f2933;
    --color-text-muted: #5f6b7a;
    --color-heading: #111827;

    --color-border: #d9dee7;
    --color-border-muted: #e7ebf1;

    --color-link: #245a8d;
    --color-link-hover: #173f66;
    --color-focus: #bf7a00;

    /* Typography */
    --font-family-base: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

    --font-size-base: 1rem;
    --font-size-sm: 0.9375rem;
    --font-size-lg: 1.125rem;

    --font-size-h1: clamp(2rem, 4vw, 3.25rem);
    --font-size-h2: clamp(1.5rem, 3vw, 2.25rem);
    --font-size-h3: clamp(1.25rem, 2vw, 1.5rem);

    --line-height-base: 1.65;
    --line-height-content: 1.75;
    --line-height-compact: 1.35;
    --line-height-heading: 1.15;

    /* Layout */
    --layout-site-max-width: 90rem;
    --layout-wide-max-width: 72rem;
    --layout-content-max-width: 48rem;
    --layout-padding-inline: clamp(1rem, 4vw, 3rem);

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.5rem;
    --space-6: 2rem;
    --space-7: 3rem;
    --space-8: 4rem;
    --space-9: 6rem;

    /* Shape */
    --radius-sm: 0.375rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;

    /* Effects */
    --shadow-sm: 0 0.25rem 1rem rgb(15 23 42 / 0.06);
    --shadow-md: 0 1rem 2.5rem rgb(15 23 42 / 0.08);
}


/* =========================================
   2. Reset / base
========================================= */

html {
    font-size: 100%;
    box-sizing: border-box;
}

*,
*::before,
*::after {
    box-sizing: inherit;
}

body {
    margin: 0;
    min-width: 20rem;
    color: var(--color-text);
    background: var(--color-page-bg);
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    text-rendering: optimizeLegibility;
}

img,
svg {
    display: block;
    max-width: 100%;
}

img {
    height: auto;
}

a {
    color: var(--color-link);
    text-decoration-thickness: 0.08em;
    text-underline-offset: 0.18em;
}

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

:focus-visible {
    outline: 0.1875rem solid var(--color-focus);
    outline-offset: 0.1875rem;
}

::selection {
    color: var(--color-surface);
    background: var(--color-link);
}


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

.visually-hidden {
    position: absolute;
    width: 0.0625rem;
    height: 0.0625rem;
    padding: 0;
    overflow: hidden;
    white-space: nowrap;
    border: 0;
    clip-path: inset(50%);
}


/* =========================================
   4. Layout
========================================= */

.site {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.site-header-inner,
.site-main-inner,
.site-footer-inner {
    width: min(100% - (2 * var(--layout-padding-inline)), var(--layout-site-max-width));
    margin-inline: auto;
}

.site-main {
    flex: 1;
    padding-block: var(--space-7);
}


/* =========================================
   5. Header
========================================= */

.site-header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border-muted);
}

.site-header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-6);
    padding-block: var(--space-4);
}

.site-brand {
    margin: 0;
    color: var(--color-heading);
    font-size: var(--font-size-lg);
    font-weight: 700;
    line-height: var(--line-height-compact);
}

.site-brand a {
    color: inherit;
    text-decoration: none;
}

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

.site-nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    min-height: 2.75rem;
    padding: var(--space-2) var(--space-4);
    color: var(--color-heading);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font: inherit;
    font-size: var(--font-size-sm);
    font-weight: 700;
    line-height: var(--line-height-compact);
    cursor: pointer;
}

.site-nav-toggle:hover {
    color: var(--color-link);
    background: var(--color-surface-muted);
}

.site-nav-toggle-icon {
    width: 0.55rem;
    height: 0.55rem;
    border-right: 0.125rem solid currentColor;
    border-bottom: 0.125rem solid currentColor;
    transform: translateY(-0.125rem) rotate(45deg);
}

.site-nav-toggle[aria-expanded="true"] .site-nav-toggle-icon {
    transform: translateY(0.125rem) rotate(225deg);
}

/* =========================================
   6. Navigation
========================================= */

.site-nav {
    font-size: var(--font-size-sm);
}

.nav-tree-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-tree li + li {
    margin-top: 0;
}

.nav-tree-list-root {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-2) var(--space-4);
}

.nav-tree-item {
    position: relative;
}

.nav-tree-link-row {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.nav-tree-link {
    display: inline-flex;
    align-items: center;
    min-height: 2.5rem;
    color: var(--color-text);
    font-weight: 600;
    line-height: var(--line-height-compact);
    text-decoration: none;
}

.nav-tree-link:hover {
    color: var(--color-link);
}

.nav-tree-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    padding: 0;
    color: var(--color-text-muted);
    background: transparent;
    border: 0;
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.nav-tree-toggle:hover {
    color: var(--color-link);
    background: var(--color-surface-muted);
}

.nav-tree-toggle-icon {
    width: 0.5rem;
    height: 0.5rem;
    border-right: 0.125rem solid currentColor;
    border-bottom: 0.125rem solid currentColor;
    transform: translateY(-0.125rem) rotate(45deg);
}

.nav-tree-toggle[aria-expanded="true"] .nav-tree-toggle-icon {
    transform: translateY(0.125rem) rotate(225deg);
}

.nav-tree-list-sub {
    margin-top: var(--space-1);
    padding-left: var(--space-4);
}

.nav-tree-list-sub .nav-tree-link {
    min-height: 2rem;
    color: var(--color-text-muted);
    font-weight: 500;
}

.nav-tree-list-sub .nav-tree-link:hover {
    color: var(--color-link);
}

.nav-tree.is-enhanced .nav-tree-list-sub[hidden] {
    display: none;
}


/* =========================================
   7. Navigation - desktop dropdown
========================================= */

@media (min-width: 48.001rem) {
    .nav-tree-list-root > .nav-tree-item > .nav-tree-list-sub {
        position: absolute;
        z-index: 20;
        top: calc(100% + var(--space-2));
        left: 0;
        min-width: 16rem;
        max-width: min(24rem, calc(100vw - 2rem));
        margin-top: 0;
        padding: var(--space-3);
        background: var(--color-surface);
        border: 1px solid var(--color-border-muted);
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-md);
    }

    .nav-tree-list-root > .nav-tree-item:last-child > .nav-tree-list-sub {
        right: 0;
        left: auto;
    }

    .nav-tree-list-sub .nav-tree-link-row {
        justify-content: space-between;
    }

    .nav-tree-list-sub .nav-tree-list-sub {
        margin-top: var(--space-1);
        margin-bottom: var(--space-2);
        padding-left: var(--space-4);
        border-left: 1px solid var(--color-border-muted);
    }

    .nav-tree-list-sub .nav-tree-item + .nav-tree-item {
        margin-top: var(--space-1);
    }
}


/* =========================================
   8. Typography
========================================= */

h1,
h2,
h3 {
    color: var(--color-heading);
    line-height: var(--line-height-heading);
    text-wrap: balance;
}

h1 {
    max-width: var(--layout-wide-max-width);
    margin: 0 0 var(--space-5);
    font-size: var(--font-size-h1);
    letter-spacing: -0.035em;
}

h2 {
    margin: var(--space-7) 0 var(--space-4);
    font-size: var(--font-size-h2);
    letter-spacing: -0.025em;
}

h3 {
    margin: var(--space-5) 0 var(--space-3);
    font-size: var(--font-size-h3);
    letter-spacing: -0.015em;
}

p {
    margin: 0 0 var(--space-4);
}

ul,
ol {
    padding-left: 1.4em;
}

li + li {
    margin-top: var(--space-1);
}

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


/* =========================================
   9. Rich text content
========================================= */

.page-content,
.article-content,
.article-section-description,
.homepage-article-section-description {
    max-width: var(--layout-content-max-width);
}

.page-content > *:first-child,
.article-content > *:first-child,
.article-section-description > *:first-child,
.homepage-article-section-description > *:first-child {
    margin-top: 0;
}

.page-content > *:last-child,
.article-content > *:last-child,
.article-section-description > *:last-child,
.homepage-article-section-description > *:last-child {
    margin-bottom: 0;
}

.page-content,
.article-content {
    color: var(--color-text);
    font-size: var(--font-size-base);
    line-height: var(--line-height-content);
}

.page-content h2,
.article-content h2,
.page-content h3,
.article-content h3 {
    max-width: var(--layout-content-max-width);
}

.page-content h2,
.article-content h2 {
    margin-top: var(--space-7);
}

.page-content h3,
.article-content h3 {
    margin-top: var(--space-6);
}

.page-content p,
.article-content p,
.page-content ul,
.article-content ul,
.page-content ol,
.article-content ol {
    max-width: var(--layout-content-max-width);
}

.page-content p,
.article-content p {
    margin-top: 0;
    margin-bottom: var(--space-5);
}

.page-content ul,
.article-content ul,
.page-content ol,
.article-content ol {
    margin-top: 0;
    margin-bottom: var(--space-5);
}

.page-content li + li,
.article-content li + li {
    margin-top: var(--space-2);
}

.page-content strong,
.article-content strong {
    color: var(--color-heading);
    font-weight: 700;
}

.page-content figure,
.article-content figure {
    max-width: var(--layout-wide-max-width);
    margin: var(--space-6) 0 var(--space-7);
}

.page-content figure img,
.article-content figure img {
    width: auto;
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
}

.page-content > img,
.article-content > img {
    width: 100%;
    max-width: var(--layout-content-max-width);
    height: auto;
    border-radius: var(--radius-lg);
}

.page-content figcaption,
.article-content figcaption {
    max-width: var(--layout-content-max-width);
    margin-top: var(--space-2);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-compact);
}

.page-content table,
.article-content table {
    display: block;
    width: fit-content;
    max-width: 100%;
    margin: var(--space-6) 0 var(--space-7);
    overflow-x: auto;
    border-collapse: collapse;
    font-size: var(--font-size-sm);
    background: var(--color-surface);
    border: 1px solid var(--color-border-muted);
    border-radius: var(--radius-md);
}

.page-content th,
.article-content th,
.page-content td,
.article-content td {
    padding: var(--space-3) var(--space-4);
    text-align: left;
    vertical-align: top;
    border-bottom: 1px solid var(--color-border-muted);
}

.page-content th,
.article-content th {
    color: var(--color-heading);
    font-weight: 700;
    background: var(--color-surface-muted);
}

.page-content th + th,
.article-content th + th,
.page-content td + td,
.article-content td + td {
    border-left: 1px solid var(--color-border-muted);
}

.page-content tr:last-child td,
.article-content tr:last-child td {
    border-bottom: 0;
}

.page-content blockquote,
.article-content blockquote {
    max-width: var(--layout-content-max-width);
    margin: var(--space-6) 0;
    padding: var(--space-4) var(--space-5);
    color: var(--color-text-muted);
    background: var(--color-surface);
    border-left: 0.25rem solid var(--color-border);
    border-radius: var(--radius-md);
}

.page-content blockquote > *:last-child,
.article-content blockquote > *:last-child {
    margin-bottom: 0;
}


/* =========================================
   10. Content detail
========================================= */

.content-detail,
.page-detail,
.article-detail {
    max-width: var(--layout-site-max-width);
}

.content-detail-header {
    max-width: var(--layout-wide-max-width);
    margin-bottom: var(--space-5);
}

.content-detail-title {
    margin-bottom: var(--space-4);
}

.content-detail-meta {
    margin-bottom: var(--space-3);
}

.content-detail-perex,
.page-perex,
.article-perex {
    max-width: var(--layout-content-max-width);
    margin-bottom: var(--space-5);
    color: var(--color-text-muted);
    font-size: var(--font-size-lg);
    line-height: 1.55;
}

.content-detail-perex strong {
    color: inherit;
    font-weight: 700;
}

.content-detail > .media-main-image,
.content-detail > .page-main-image,
.content-detail > .article-main-image {
    margin-top: var(--space-5);
}


/* =========================================
   11. Homepage
========================================= */

.page-homepage {
    max-width: none;
}

.homepage-article-section {
    margin-top: var(--space-8);
}

.homepage-article-section > h2 {
    max-width: var(--layout-wide-max-width);
}

.homepage-article-section-description {
    margin-bottom: var(--space-5);
    color: var(--color-text-muted);
}

.homepage-article-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
    align-items: start;
    gap: var(--space-5);
}


/* =========================================
   12. Article section and list
========================================= */

.article-section {
    max-width: var(--layout-site-max-width);
}

.article-section-description {
    margin-bottom: var(--space-6);
    color: var(--color-text-muted);
}

.article-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 18rem), 1fr));
    align-items: start;
    gap: var(--space-5);
}


/* =========================================
   13. Article card
========================================= */

.article-card,
.homepage-article-item,
.article-list-item {
    display: flex;
    flex-direction: column;
    padding: var(--space-5);
    background: var(--color-surface);
    border: 1px solid var(--color-border-muted);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.article-card-image,
.homepage-article-item-image,
.article-list-image {
    margin: calc(-1 * var(--space-5)) calc(-1 * var(--space-5)) var(--space-4);
}

.article-card-image-link {
    display: block;
}

.article-card-image img,
.homepage-article-item-image img,
.article-list-image img {
    width: 100%;
    aspect-ratio: 4 / 3;
    object-fit: cover;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.article-card-body {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.article-card-title,
.homepage-article-item h3,
.article-list-item h2 {
    margin-top: 0;
    margin-bottom: var(--space-3);
    font-size: var(--font-size-h3);
}

.article-card-date {
    margin-bottom: var(--space-3);
}

.article-card-perex {
    color: var(--color-text);
}

.article-card-more {
    margin-top: auto;
    margin-bottom: 0;
}


/* =========================================
   14. Article detail
========================================= */

.article-detail {
    max-width: var(--layout-site-max-width);
}

.content-detail-back {
    margin-bottom: var(--space-5);
}

.content-detail-back a {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-decoration: none;
}

.content-detail-back a:hover {
    color: var(--color-link);
}

/* =========================================
   15. Media - main image, gallery, files
========================================= */

.media-main-image,
.page-main-image,
.article-main-image {
    max-width: var(--layout-wide-max-width);
    margin: 0 0 var(--space-6);
}

.media-main-image img,
.page-main-image img,
.article-main-image img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.media-main-image-caption,
.media-gallery-caption {
    margin-top: var(--space-2);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-compact);
}

.media-gallery,
.page-gallery,
.article-gallery {
    margin-top: var(--space-8);
}

.media-gallery-title,
.media-files-title,
.page-gallery h2,
.article-gallery h2,
.page-files h2,
.article-files h2 {
    margin-top: 0;
}

.media-gallery-items,
.page-gallery-items,
.article-gallery-items {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(100%, 14rem), 18rem));
    justify-content: start;
    gap: var(--space-4);
}

.media-gallery-item,
.page-gallery-item,
.article-gallery-item {
    margin: 0;
}

.media-gallery-link,
.page-gallery-item a,
.article-gallery-item a {
    display: block;
}

.media-gallery-image,
.page-gallery-item img,
.article-gallery-item img {
    width: 100%;
    aspect-ratio: 4 / 3;
    object-fit: cover;
    border-radius: var(--radius-md);
}

.media-files,
.page-files,
.article-files {
    max-width: var(--layout-content-max-width);
    margin-top: var(--space-8);
    padding: var(--space-5);
    background: var(--color-surface);
    border: 1px solid var(--color-border-muted);
    border-radius: var(--radius-lg);
}

.media-files-list,
.page-files ul,
.article-files ul {
    display: grid;
    gap: var(--space-3);
    margin: 0;
    padding-left: 1.2em;
}

.media-files-item {
    margin: 0;
}

.media-files-link {
    font-weight: 600;
}

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

.media-files-size::before {
    content: " (";
}

.media-files-size::after {
    content: ")";
}

.media-files-description {
    display: block;
    margin-top: var(--space-1);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-compact);
}


/* =========================================
   16. Footer
========================================= */

.site-footer {
    color: var(--color-text-muted);
    background: var(--color-surface);
    border-top: 1px solid var(--color-border-muted);
}

.site-footer-inner {
    padding-block: var(--space-5);
}

.site-footer-brand {
    display: grid;
    gap: var(--space-1);
}

.site-footer-title {
    margin: 0;
    color: var(--color-heading);
    font-size: var(--font-size-sm);
    font-weight: 700;
    line-height: var(--line-height-compact);
}

.site-footer-meta {
    margin: 0;
    font-size: var(--font-size-sm);
    line-height: var(--line-height-compact);
}

/* =========================================
   17. Responsive
========================================= */

@media (max-width: 48rem) {
    .site-header-inner {
        display: grid;
        grid-template-columns: minmax(0, 1fr) auto;
        align-items: center;
        gap: var(--space-3);
    }

    .site-header.is-enhanced .site-nav-toggle {
        display: inline-flex;
    }

    .site-nav {
        grid-column: 1 / -1;
        width: 100%;
    }

    .site-header.is-enhanced .site-nav[hidden] {
        display: none;
    }

    .nav-tree-list-root {
        align-items: flex-start;
        flex-direction: column;
        gap: var(--space-1);
        padding-top: var(--space-2);
    }

    .nav-tree-link-row {
        width: 100%;
    }

    .nav-tree-toggle {
        margin-left: -0.25rem;
    }

    .nav-tree-link {
        min-height: 2.25rem;
    }

    .nav-tree-list-sub {
        width: 100%;
        margin-top: 0;
        padding-left: var(--space-4);
        border-left: 1px solid var(--color-border-muted);
    }

    .site-main {
        padding-block: var(--space-6);
    }

    .homepage-article-section {
        margin-top: var(--space-7);
    }
}


/* =========================================
   18. User preferences
========================================= */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
    }
}