/* MLST Archive Styles
   Based on MLST Brand Guidelines
   Colors: Network navy #232E3F, Cloud white #F4F4F4, Pineapple yellow #FFB52B
   Fonts: Inter (headlines), Merriweather (body)
*/

/* Import fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Merriweather:ital,wght@0,400;0,700;1,400&display=swap');

/* CSS Variables */
:root {
  --color-navy: #232E3F;
  --color-navy-light: #3a4a5f;
  --color-white: #F4F4F4;
  --color-yellow: #FFB52B;
  --color-yellow-hover: #e6a027;
  --color-gray-light: #e8e8e8;
  --color-gray: #6b7280;
  --color-text: #374151;
  --color-border: #d1d5db;

  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Merriweather', Georgia, serif;
  --font-mono: 'SF Mono', Monaco, 'Courier New', monospace;

  --max-width: 1200px;
  --content-width: 800px;
}

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

/* Base */
html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-white);
  line-height: 1.7;
  overflow-x: hidden;
  width: 100%;
  max-width: 100vw;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-navy);
  line-height: 1.3;
  margin-bottom: 0.5em;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: 1rem;
}

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

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

/* Layout */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.content-narrow {
  max-width: var(--content-width);
}

/* Header */
.site-header {
  background: var(--color-navy);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.site-logo img {
  height: 32px;
  width: auto;
}

.site-logo span {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: white;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.site-nav a {
  color: rgba(255, 255, 255, 0.85);
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 500;
}

.site-nav a:hover {
  color: var(--color-yellow);
}

.site-nav .nav-divider {
  width: 1px;
  height: 20px;
  background: rgba(255, 255, 255, 0.3);
  margin: 0 0.5rem;
}

.site-nav .nav-icon {
  width: 16px;
  height: 16px;
  vertical-align: middle;
}

.site-nav .nav-mlst {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.site-nav .nav-mlst .nav-icon {
  height: 14px;
  width: auto;
}

.site-nav .nav-external {
  display: flex;
  align-items: center;
  opacity: 0.7;
}

.site-nav .nav-external:hover {
  opacity: 1;
}

.site-nav .nav-external .nav-icon {
  width: 18px;
  height: 18px;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-navy-light) 100%);
  color: white;
  padding: 4rem 0;
  text-align: center;
}

.hero h1 {
  color: white;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.125rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* Search Box */
.search-box {
  max-width: 600px;
  margin: 2rem auto 0;
  position: relative;
}

.search-box input {
  width: 100%;
  padding: 1rem 1.5rem;
  padding-right: 3.5rem;
  font-family: var(--font-heading);
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  background: white;
  color: var(--color-navy);
}

.search-box input:focus {
  outline: 2px solid var(--color-yellow);
}

.search-box button {
  position: absolute;
  right: 0.5rem;
  top: 50%;
  transform: translateY(-50%);
  background: var(--color-yellow);
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--color-navy);
}

.search-box button:hover {
  background: var(--color-yellow-hover);
}

/* Sections */
.section {
  padding: 3rem 0;
}

.section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--color-navy);
}

.section-title h2 {
  margin-bottom: 0;
}

.section-title a {
  font-family: var(--font-heading);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-gray);
}

/* Article Cards */
.article-grid {
  display: grid;
  gap: 1.5rem;
}

.article-card {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1.5rem;
  transition: box-shadow 0.2s, border-color 0.2s;
}

.article-card:hover {
  border-color: var(--color-yellow);
  box-shadow: 0 4px 12px rgba(35, 46, 63, 0.1);
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
  font-family: var(--font-heading);
  font-size: 0.8rem;
  color: var(--color-gray);
}

.article-card-id {
  background: var(--color-navy);
  color: white;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-weight: 600;
}

.article-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.article-card h3 a {
  color: var(--color-navy);
}

.article-card h3 a:hover {
  color: var(--color-yellow);
}

.article-card-authors {
  font-size: 0.9rem;
  color: var(--color-gray);
  margin-bottom: 0.75rem;
}

.article-card-abstract {
  font-size: 0.9rem;
  color: var(--color-text);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card-actions {
  display: flex;
  gap: 1rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-gray-light);
}

.article-card-actions a {
  font-family: var(--font-heading);
  font-size: 0.8rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* Topics Sidebar */
.topic-tree {
  list-style: none;
}

.topic-tree li {
  margin-bottom: 0.5rem;
}

.topic-tree a {
  font-family: var(--font-heading);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  transition: background 0.2s;
}

.topic-tree a:hover {
  background: var(--color-gray-light);
}

.topic-tree .count {
  font-size: 0.75rem;
  color: var(--color-gray);
  background: var(--color-gray-light);
  padding: 0.125rem 0.5rem;
  border-radius: 10px;
}

.topic-tree ul {
  list-style: none;
  margin-left: 1rem;
  margin-top: 0.25rem;
}

/* Article Page */
.article-header {
  background: var(--color-navy);
  color: white;
  padding: 3rem 0;
}

.article-header h1 {
  color: white;
  max-width: var(--content-width);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 1rem;
  font-family: var(--font-heading);
  font-size: 0.9rem;
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.article-meta-label {
  opacity: 0.7;
}

.article-authors {
  font-size: 1.125rem;
  margin-top: 1rem;
}

.article-authors a {
  color: var(--color-yellow);
}

.article-content {
  padding: 3rem 0;
}

.article-sidebar {
  position: sticky;
  top: 5rem;
}

.article-actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

/* Mobile-only action buttons (shown above abstract on mobile) */
.article-actions-mobile {
  display: none;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 2rem;
  padding: 0 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: 6px;
  text-decoration: none;
  transition: all 0.2s;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: var(--color-yellow);
  color: var(--color-navy);
}

.btn-primary:hover {
  background: var(--color-yellow-hover);
  color: var(--color-navy);
}

.btn-secondary {
  background: var(--color-gray-light);
  color: var(--color-navy);
}

.btn-secondary:hover {
  background: var(--color-border);
  color: var(--color-navy);
}

/* Keywords/Tags */
.keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.keyword {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  background: var(--color-gray-light);
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  color: var(--color-navy);
}

/* Video Embed */
.video-embed {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 */
  height: 0;
  overflow: hidden;
  margin: 2rem 0;
  border-radius: 8px;
  background: var(--color-navy);
}

.video-embed iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

/* Footer */
.site-footer {
  background: var(--color-navy);
  color: rgba(255, 255, 255, 0.7);
  padding: 3rem 0;
  margin-top: 4rem;
}

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

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  font-family: var(--font-heading);
  font-size: 0.9rem;
}

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

.footer-link {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.footer-link svg {
  width: 16px;
  height: 16px;
}

.footer-mlst {
  color: var(--color-yellow) !important;
}

/* Search Results */
.search-results {
  padding: 2rem 0;
}

.search-result-item {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--color-border);
}

.search-result-item:last-child {
  border-bottom: none;
}

mark {
  background: var(--color-yellow);
  padding: 0 0.125rem;
  border-radius: 2px;
}

/* Version History */
.version-history {
  margin-top: 2rem;
}

.version-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-gray-light);
}

.version-number {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.875rem;
  background: var(--color-gray-light);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  white-space: nowrap;
}

.version-info {
  flex: 1;
}

.version-date {
  font-size: 0.8rem;
  color: var(--color-gray);
}

.version-changelog {
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

/* BibTeX */
.bibtex {
  background: var(--color-gray-light);
  padding: 1rem;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
}

/* Responsive */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }

  .container {
    padding: 0 1rem;
  }

  .site-header .container {
    flex-direction: column;
    gap: 1rem;
  }

  .site-nav {
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
  }

  .site-nav .nav-divider {
    display: none;
  }

  .hero {
    padding: 2rem 0;
  }

  .section {
    padding: 2rem 0;
  }

  .article-meta {
    flex-direction: column;
    gap: 0.5rem;
  }

  /* Show mobile buttons above abstract, hide sidebar buttons */
  .article-actions-mobile {
    display: flex;
  }

  .article-sidebar .article-actions {
    display: none;
  }

  .site-footer .container {
    flex-direction: column;
    gap: 1.5rem;
    text-align: center;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
  }
}

/* Layout helpers */
.two-column {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 3rem;
}

@media (max-width: 900px) {
  .two-column {
    grid-template-columns: 1fr;
  }
}

/* Featured badge */
.featured-badge {
  display: inline-flex;
  align-items: center;
  align-self: flex-start; /* Prevent stretching in column flex layout (mobile) */
  background: var(--color-yellow);
  color: var(--color-navy);
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  line-height: 1;
}

/* RSS link */
.rss-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.875rem;
  color: var(--color-gray);
}

.rss-link svg {
  width: 16px;
  height: 16px;
}