:root {
  --bg: #faf8f5;
  --bg-elevated: #ffffff;
  --text: #1a1a2e;
  --text-secondary: #6a6a8a;
  --text-muted: #9a9aaa;
  --border: #e8e8f0;
  --border-light: #f0eef5;
  --accent: #4a4a6a;
  --accent-hover: #2d2d44;
  --tag-bg: #f0eef5;
  --tag-text: #5a5a7a;
  --card-shadow: 0 2px 12px rgba(0,0,0,0.04);
  --card-shadow-hover: 0 4px 24px rgba(0,0,0,0.08);
  --radius: 12px;
  --radius-sm: 8px;
  --max-width: 960px;
  --nav-height: 64px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-size: 16px;
}

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

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

/* Header & Nav */
header {
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-brand {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text);
  letter-spacing: -0.02em;
}

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

.nav-links {
  display: flex;
  gap: 1.75rem;
  align-items: center;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  transition: 0.3s;
}

/* Main */
main {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
  width: 100%;
}

/* Hero */
.hero {
  padding: 4rem 0 3rem;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  max-width: 680px;
}

.hero .subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 560px;
  line-height: 1.7;
}

.hero .tagline {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-top: 1.5rem;
  font-style: italic;
}

/* Section */
.section {
  padding: 2.5rem 0;
}

.section-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title a {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-muted);
}

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

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  transition: box-shadow 0.25s, transform 0.25s;
}

.card:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-2px);
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--text);
}

.card .meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
}

.card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.card .tags {
  margin-top: 0.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

/* Tags */
.tag {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.2rem 0.55rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: var(--radius-sm);
  font-weight: 500;
}

.tag.active {
  background: var(--accent);
  color: #fff;
}

/* Lists */
.list-item {
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--border-light);
}

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

.list-item h4 {
  font-size: 0.95rem;
  font-weight: 500;
  margin-bottom: 0.2rem;
}

.list-item p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Focus items */
.focus-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
}

.focus-item {
  padding: 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.focus-item h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
}

.focus-item p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Filter buttons */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.filter-btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.filter-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.filter-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* Page header */
.page-header {
  padding: 2rem 0 1.5rem;
}

.page-header h1 {
  font-size: 1.6rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.page-header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  max-width: 600px;
}

/* Columns */
.columns {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 2rem;
}

.column h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.column ul {
  list-style: none;
}

.column li {
  padding: 0.4rem 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

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

/* Contact */
.contact {
  padding: 2rem 0;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 0.75rem;
}

.contact-links a {
  font-size: 0.9rem;
}

/* Footer */
footer {
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
  margin-top: auto;
}

footer p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0.25rem 0;
}

/* Project detail page */
.project-detail {
  max-width: 720px;
}

.project-detail .back-link {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  display: inline-block;
}

.project-detail .back-link:hover {
  color: var(--accent);
}

.project-detail h1 {
  font-size: 1.8rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  letter-spacing: -0.02em;
}

.project-detail .project-meta {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.project-detail .project-summary {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  line-height: 1.7;
  max-width: 640px;
}

.detail-section {
  margin-bottom: 2.5rem;
}

.detail-section h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.detail-section p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.75rem;
  max-width: 640px;
}

.detail-section ul {
  margin-left: 1.25rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.detail-section li {
  margin-bottom: 0.3rem;
}

.detail-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 0.5rem;
}

.detail-links a {
  font-size: 0.9rem;
}

/* Card link overlay */
.card-link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.card-link:hover {
  color: inherit;
}

.card-link .card {
  height: 100%;
}

/* Utility */
.text-secondary {
  color: var(--text-secondary);
}

.text-muted {
  color: var(--text-muted);
}

.mb-2 {
  margin-bottom: 2rem;
}

/* Search */
.search-box {
  margin-bottom: 1.5rem;
}

.search-box input {
  width: 100%;
  max-width: 560px;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  color: var(--text);
  font-family: inherit;
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent);
}

/* Tags cloud */
.tags-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.tag-btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.tag-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Discovery links */
.discovery-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 0.75rem;
}

.discovery-links a {
  font-size: 0.9rem;
  padding: 0.5rem 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: all 0.2s;
}

.discovery-links a:hover {
  border-color: var(--accent);
  background: var(--tag-bg);
}

/* Relation cards */
.relation-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 0.75rem;
}

.relation-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.relation-card .relation-title {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
}

.relation-card .relation-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.relation-card .relation-reason {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  line-height: 1.6;
}

.relation-pair {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.relation-arrow {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.relation-pill {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: var(--radius-sm);
  margin-top: 0.4rem;
}

/* Knowledge map overview */
.map-overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 1rem;
}

.map-stat {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-align: center;
}

.map-stat-number {
  display: block;
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--text);
}

.map-stat-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

/* Hero actions */
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2rem;
}

.btn-primary {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 0.95rem;
  transition: background 0.2s;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
}

.btn-secondary {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 0.95rem;
  transition: all 0.2s;
}

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

/* Hero eyebrow */
.hero-eyebrow {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

/* Workbench grid */
.workbench-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 1rem;
}

.workbench-item {
  display: block;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-align: center;
  transition: box-shadow 0.25s, transform 0.25s;
}

.workbench-item:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-2px);
}

.workbench-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.workbench-item p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Featured cards */
.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.featured-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
}

.featured-card:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-2px);
}

.featured-media {
  aspect-ratio: 1200 / 630;
  background: var(--bg);
  overflow: hidden;
}

.featured-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.featured-content {
  padding: 1rem;
}

.featured-content h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
  color: var(--text);
}

.featured-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.featured-summary {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.featured-link {
  font-size: 0.85rem;
  font-weight: 500;
}

/* Relation preview */
.relation-preview {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.relation-preview-item {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.relation-from,
.relation-to {
  font-weight: 600;
  font-size: 0.9rem;
}

.relation-type {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: var(--radius-sm);
  margin: 0 0.25rem;
}

.relation-reason {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  line-height: 1.6;
}

/* Focus list */
.focus-list {
  list-style: none;
  padding: 0;
}

.focus-list li {
  padding: 0.5rem 0;
  font-size: 0.95rem;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-light);
}

.focus-list li:last-child {
  border-bottom: none;
}

.focus-list li::before {
  content: "→";
  margin-right: 0.5rem;
  color: var(--text-muted);
}

/* Status grid */
.status-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.status-item {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  text-align: center;
}

.status-number {
  display: block;
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--text);
}

.status-label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.status-details {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.status-details a {
  color: var(--accent);
}

/* Discovery links */
.discovery-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.discovery-link {
  display: flex;
  flex-direction: column;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  min-width: 200px;
  transition: box-shadow 0.25s, transform 0.25s;
}

.discovery-link:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-2px);
  border-color: var(--accent);
}

.discovery-link strong {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.25rem;
}

.discovery-link span {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Media section */
.media-section {
  margin: 1.5rem 0;
  padding: 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.media-frame {
  aspect-ratio: 1200 / 630;
  background: var(--bg);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 0.75rem;
}

.preview-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media-caption {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.screenshots-placeholder {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-style: italic;
}

/* Screenshot grid */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}

.screenshot-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
}

.screenshot-card:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-2px);
}

.screenshot-frame {
  aspect-ratio: 1440 / 900;
  background: var(--bg);
  overflow: hidden;
}

.screenshot-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.screenshot-caption {
  padding: 0.75rem 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
}

/* Media gallery */
.media-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.media-gallery-item {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.media-gallery-item img {
  width: 100%;
  height: auto;
  display: block;
}

.media-gallery-item p {
  padding: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
}

/* Responsive */
@media (max-width: 640px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 1rem 1.5rem;
    gap: 1rem;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  .hero h1 {
    font-size: 1.5rem;
  }

  .hero .subtitle {
    font-size: 0.95rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    text-align: center;
  }

  .cards {
    grid-template-columns: 1fr;
  }

  .featured-grid {
    grid-template-columns: 1fr;
  }

  .workbench-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .focus-grid {
    grid-template-columns: 1fr;
  }

  .columns {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .status-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .screenshot-grid {
    grid-template-columns: 1fr;
  }

  main {
    padding: 1.5rem 1rem;
  }
}