/* Intangible Data Platform - Simplified CSS */

/* ========== Base & Variables ========== */
:root {
    --font-serif: 'Merriweather', Georgia, serif;
    --font-sans: 'Roboto', -apple-system, sans-serif;
    --font-mono: 'Roboto Mono', monospace;
    --color-text: #0f172a;
    --color-text-light: #64748b;
    --color-link: #1a56db;
    --color-border: #e2e8f0;
    --color-border-dark: #1e293b;
    --color-bg: #fcfcfc;
    --color-bg-white: #ffffff;
    --color-bg-light: #f8fafc;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

a:hover {
    text-decoration: underline;
}

/* ========== Layout ========== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
    width: 100%;
}

.page-wrapper {
    display: flex;
    gap: 2.5rem;
    padding: 2rem 0 3rem;
    flex: 1;
}

/* ========== Header ========== */
header {
    background: var(--color-bg-white);
    border-bottom: 2px solid var(--color-border-dark);
}

.header-content {
    height: 5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 0;
}

.site-subtitle {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-light);
    margin-top: 0.25rem;
}

/* ========== Sidebar Navigation ========== */
.sidebar {
    width: 14rem;
    flex-shrink: 0;
    border-right: 1px solid var(--color-border);
    padding-right: 1.5rem;
}

.nav-heading {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-light);
    margin-bottom: 0.75rem;
}

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

.nav-list li {
    margin-bottom: 0.25rem;
}

.nav-list a {
    display: block;
    padding: 0.5rem 0 0.5rem 0.75rem;
    font-size: 0.875rem;
    color: var(--color-text-light);
    border-left: 2px solid transparent;
    text-decoration: none;
}

.nav-list a:hover {
    color: var(--color-text);
    text-decoration: underline;
}

.nav-list a.active {
    color: var(--color-text);
    font-weight: 700;
    border-left-color: var(--color-border-dark);
}

/* ========== Main Content ========== */
main {
    flex: 1;
    min-width: 0;
}

.page-header {
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 1.5rem;
    margin-bottom: 2.5rem;
}

.page-title {
    font-family: var(--font-serif);
    font-size: 1.875rem;
    font-weight: 500;
    color: var(--color-text);
    margin: 0 0 0.75rem;
}

.page-description {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.875rem;
    color: var(--color-text-light);
    max-width: 48rem;
    margin: 0;
    line-height: 1.7;
}

.page-description a {
    text-decoration: underline;
}

.page-description p {
    margin: 0;
}

/* ========== Year Sections (Data Index) ========== */
.year-section {
    margin-bottom: 3rem;
}

.year-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 1rem;
    border-bottom: 2px solid var(--color-text);
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

.year-title {
    font-family: var(--font-serif);
    font-size: 1.75rem;
    font-weight: 700;
}

.year-doi {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-light);
    background: var(--color-bg-light);
    padding: 0.25rem 0.5rem;
    border: 1px solid var(--color-border);
    margin-left: 1rem;
}

.year-download {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: underline;
}

/* ========== Dataset Sections ========== */
.dataset-section {
    margin-bottom: 2rem;
}

.dataset-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: #94a3b8;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
    padding-bottom: 0.25rem;
    border-bottom: 1px solid var(--color-border);
}

/* ========== File Entries ========== */
.file-entry {
    padding: 0.75rem 0;
    border-bottom: 1px dotted #cbd5e1;
    display: flex;
    flex-direction: column;
}

@media (min-width: 768px) {
    .file-entry {
        flex-direction: row;
        justify-content: space-between;
        align-items: baseline;
    }
}

.file-details {
    flex: 1;
    padding-right: 2rem;
}

.file-name {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-text);
}

.file-meta {
    font-size: 0.85rem;
    color: var(--color-text-light);
    margin-top: 0.25rem;
}

.file-links {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    white-space: nowrap;
    margin-top: 0.5rem;
}

@media (min-width: 768px) {
    .file-links {
        margin-top: 0;
    }
}

.dl-link {
    color: var(--color-link);
    text-decoration: none;
    font-weight: 500;
    margin-left: 0.625rem;
}

.dl-link:hover {
    text-decoration: underline;
    background: #eff6ff;
}

/* ========== Content Pages (Methodology, Authors) ========== */
.content-article {
    max-width: 48rem;
    font-size: 1rem;
    line-height: 1.8;
}

.content-article p {
    margin-bottom: 1rem;
}

/* Markdown content headings */
.content-article h1,
.content-article h2,
.page-description h1,
.page-description h2 {
    font-family: var(--font-serif);
    color: var(--color-text);
    font-weight: 700;
    font-style: normal;
}

.content-article h1 {
    font-size: 1.75rem;
    margin: 2rem 0 1rem;
}

.content-article h2 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border);
}

.content-article h3 {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 2.5rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border);
}

.content-article ul {
    padding-left: 1.25rem;
    margin-bottom: 1.5rem;
}

.content-article li {
    margin-bottom: 0.5rem;
}

.code-block {
    background: var(--color-bg-light);
    border: 1px solid var(--color-border);
    padding: 1rem;
    margin-bottom: 1.5rem;
}

.code-block-header {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-light);
    margin-bottom: 0.5rem;
    padding-bottom: 0.25rem;
    border-bottom: 1px solid var(--color-border);
}

.code-block code {
    display: block;
    white-space: pre-wrap;
    background: none;
    padding: 0;
}

.callout {
    border-left: 4px solid var(--color-border-dark);
    padding: 0.5rem 1.5rem;
    margin: 2rem 0;
    background: var(--color-bg-white);
}

.callout-title {
    font-weight: 700;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.callout p {
    font-style: italic;
    color: var(--color-text-light);
    font-size: 0.875rem;
    margin: 0;
}

/* Blockquotes - callout style */
.content-article blockquote {
    border-left: 4px solid var(--color-border-dark);
    margin: 1.5rem 0;
    padding: 0.75rem 1.5rem;
    background: var(--color-bg-white);
    font-style: italic;
    color: var(--color-text-light);
}

.content-article blockquote p {
    margin: 0;
}

/* Horizontal rules */
.content-article hr {
    border: none;
    border-top: 2px solid var(--color-border);
    margin: 2.5rem 0;
}

/* Strong emphasis - subtle enhancement */
.content-article strong {
    color: var(--color-text);
    font-weight: 700;
}

/* Links - refined styling */
.content-article a {
    color: var(--color-link);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.content-article a:hover {
    background: #eff6ff;
    text-decoration: underline;
}

/* Code blocks - better visual hierarchy */
.content-article pre {
    background: var(--color-bg-light);
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-text-light);
    padding: 1rem;
    margin: 1.5rem 0;
    overflow-x: auto;
}

.content-article pre code {
    background: none;
    padding: 0;
    font-size: 0.875rem;
    line-height: 1.6;
}

/* Inline code - subtle background */
.content-article code {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    background: var(--color-bg-light);
    padding: 0.125rem 0.375rem;
    border-radius: 3px;
}

/* ========== Author Cards ========== */
.author-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 3rem;
}

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

.author-card {
    background: var(--color-bg-white);
    border: 1px solid var(--color-border);
    padding: 1.5rem;
}

.author-role {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--color-bg-light);
    border: 1px solid var(--color-border);
    padding: 0.25rem 0.5rem;
    margin-bottom: 1rem;
}

.author-name {
    font-family: var(--font-serif);
    font-size: 1.125rem;
    font-weight: 700;
    margin: 0 0 0.25rem;
}

.author-affiliation {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: 1rem;
}

.author-bio {
    font-size: 0.875rem;
    line-height: 1.6;
    margin: 0;
}

/* ========== License Section ========== */
.license-section {
    border-top: 1px solid var(--color-border);
    padding-top: 2.5rem;
    margin-top: 1rem;
}

.license-box {
    background: var(--color-bg-white);
    border: 1px solid var(--color-border);
    padding: 2rem;
}

.license-title {
    font-family: var(--font-serif);
    font-size: 1.125rem;
    font-weight: 700;
    margin: 0 0 1rem;
}

.license-text {
    font-size: 0.875rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.citation-box {
    background: var(--color-bg-light);
    border: 1px solid var(--color-border);
    padding: 1rem;
}

.citation-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-light);
    margin-bottom: 0.5rem;
}

.citation-text {
    font-family: var(--font-serif);
    font-size: 0.875rem;
    margin: 0;
}

/* ========== Footer ========== */
footer {
    background: var(--color-bg-light);
    border-top: 1px solid var(--color-border);
    margin-top: auto;
}

.footer-content {
    padding: 2rem 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-serif);
    font-size: 0.875rem;
    color: var(--color-text-light);
    text-align: center;
}

@media (min-width: 768px) {
    .footer-content {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
    }
}

.footer-links a {
    color: var(--color-text-light);
    margin-left: 1rem;
}

.footer-links a:hover {
    color: var(--color-text);
}

/* ========== Mobile Navigation ========== */
.mobile-nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    flex-direction: column;
    gap: 5px;
}

.mobile-nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: transform 0.2s, opacity 0.2s;
}

.mobile-nav {
    display: none;
    background: var(--color-bg-white);
    border-bottom: 1px solid var(--color-border);
    padding: 1rem 1.5rem;
}

.mobile-nav a {
    display: block;
    padding: 0.75rem 0;
    color: var(--color-text-light);
    border-bottom: 1px solid var(--color-border);
    font-size: 0.9rem;
}

.mobile-nav a:last-child {
    border-bottom: none;
}

.mobile-nav a.active {
    color: var(--color-text);
    font-weight: 700;
}

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

/* Mobile nav toggle animation */
.nav-open .mobile-nav-toggle span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.nav-open .mobile-nav-toggle span:nth-child(2) {
    opacity: 0;
}

.nav-open .mobile-nav-toggle span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

.nav-open .mobile-nav {
    display: block;
}

/* ========== Responsive: Hide sidebar on mobile ========== */
@media (max-width: 767px) {
    .container {
        padding: 0 2rem;
    }

    .sidebar {
        display: none;
    }

    .page-wrapper {
        padding: 1.5rem 0 2rem;
    }

    .mobile-nav {
        padding: 1rem 2rem;
    }

    .mobile-nav-toggle {
        display: flex;
    }

    .page-title {
        font-size: 1.5rem;
    }

    .year-title {
        font-size: 1.35rem;
    }

    .file-entry {
        padding: 1rem 0;
    }

    .file-details {
        padding-right: 0;
    }
}

/* ========== Loading & Error States ========== */
.loading {
    color: var(--color-text-light);
    font-style: italic;
    padding: 1rem 0;
}

.error-message {
    background: #fef2f2;
    border: 1px solid #fecaca;
    color: #991b1b;
    padding: 1rem;
    font-size: 0.875rem;
}