/* LoomSci.com — main.css v1.0
   Design: Minimal, Georgia serif headings, responsive 3→1 col
   Based on hand-crafted index.html design
*/

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

:root {
  --hero-bg: #ffffff;
  --hero-text: #1a1a1a;
  --body-bg: #ffffff;
  --card-bg: #fafafa;
  --card-border: #eeeeee;
  --card-hover-border: #1a1a1a;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.03);
  --text: #1a1a1a;
  --text-secondary: #666666;
  --text-muted: #aaaaaa;
  --accent: #1a1a1a;
  --tag-bg: #f5f5f5;
  --tag-text: #777777;
  --nav-bg: #ffffff;
  --nav-text: #1a1a1a;
  --heading-font: "Georgia", "Noto Serif SC", serif;
  --radius: 8px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--body-bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* === NAV === */
.nav {
  background: var(--nav-bg);
  border-bottom: 1px solid rgba(0,0,0,0.08);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--nav-text);
}

.nav-logo {
  width: 24px;
  height: 24px;
  image-rendering: pixelated;
  flex-shrink: 0;
}

.nav-name {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav-links-desktop {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  font-size: 0.88rem;
  color: var(--nav-text);
  text-decoration: none;
  opacity: 0.75;
  transition: opacity 0.2s;
}

.nav-link:hover, .nav-link.active { opacity: 1; }

/* About dropdown */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-toggle {
  font-size: 0.88rem;
  color: var(--nav-text);
  text-decoration: none;
  opacity: 0.75;
  transition: opacity 0.2s;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  background: none;
  border: none;
  padding: 0;
  font-family: inherit;
}

.nav-dropdown-toggle:hover { opacity: 1; }

.nav-dropdown-toggle::after {
  content: "▾";
  font-size: 0.7em;
}

.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  right: 0;
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: 0 4px 16px rgba(0,0,0,0.1);
  min-width: 140px;
  z-index: 200;
  padding: 6px 0;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown.open .nav-dropdown-menu {
  display: block;
}

.nav-dropdown-item {
  display: block;
  padding: 8px 18px;
  font-size: 0.88rem;
  color: var(--nav-text);
  text-decoration: none;
  opacity: 0.75;
  transition: opacity 0.15s, background 0.15s;
}

.nav-dropdown-item:hover {
  opacity: 1;
  background: var(--tag-bg);
}

/* RSS icon */
.nav-rss {
  font-size: 1.1rem;
  text-decoration: none;
  opacity: 0.6;
  transition: opacity 0.2s;
}
.nav-rss:hover { opacity: 1; }

/* === HERO === */
.hero {
  background: var(--hero-bg);
  color: var(--hero-text);
  padding: 80px 0 64px;
  text-align: center;
}

.hero-inner {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 32px;
}

.hero-slogan {
  font-family: var(--heading-font);
  font-size: clamp(1.25rem, 5.5vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  text-wrap: balance;
}

.hero-tagline {
  font-size: clamp(0.85rem, 3vw, 1.15rem);
  opacity: 0.65;
  font-weight: 300;
  margin: 0;
  text-wrap: balance;
}

/* Test Banner */
.test-banner {
  background: #fff8e1;
  border-bottom: 1px solid #ffe082;
  text-align: center;
  padding: 12px 24px;
  font-size: 0.92rem;
  color: #6d4c00;
}
.test-banner strong { color: #e65100; }

/* === CONTENT === */
.content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 32px;
}

.section-label {
  font-size: 0.88rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.section-label a {
  font-size: 0.82rem;
  text-decoration: none;
  color: var(--text-muted);
  opacity: 0.7;
}
.section-label a:hover { opacity: 1; }

/* === CARDS === */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-shadow: var(--card-shadow);
}

.card:hover {
  border-color: var(--card-hover-border);
  box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}

.card-visual {
  height: 140px;
  width: 100%;
  position: relative;
  overflow: hidden;
  background: #1a1a1a;
}

.card-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.card-body {
  flex: 1;
  padding: 20px 22px;
}

.card-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 3px 8px;
  border-radius: 4px;
  margin-bottom: 8px;
}

.card-title {
  font-family: var(--heading-font);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.45;
  margin-bottom: 10px;
  color: var(--text);
}

.card-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  display: -webkit-box;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-meta {
  display: flex;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 0 22px 18px;
}

/* Hero card (featured) */
.card.hero-card {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.card.hero-card .card-visual {
  aspect-ratio: 16 / 9;
  height: auto;
  min-height: 200px;
}

.card.hero-card .card-body {
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.card.hero-card .card-title {
  font-size: 1.6rem;
  margin-bottom: 14px;
}

.card.hero-card .card-desc {
  -webkit-line-clamp: 5;
}

/* === CATEGORY PAGE === */
.cat-header {
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--card-border);
  margin-bottom: 36px;
}

.cat-header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

.cat-title {
  font-family: var(--heading-font);
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
}

.cat-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* === ARTICLE PAGE === */
.article {
  max-width: 720px;
  margin: 0 auto;
  padding: 56px 32px;
}

/* 标题：唯一H1，在题图上方 */
.article-title {
  font-family: var(--heading-font);
  font-size: 2.4rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.03em;
  line-height: 1.3;
}

.article-meta {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 36px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* 题图：figure 语义化 */
.article-hero {
  margin: 0 0 40px 0;
  width: calc(100% + 64px);
  margin-left: -32px;
}

.article-hero-img {
  width: 100%;
  max-height: 480px;
  object-fit: cover;
  display: block;
  border-radius: 6px 6px 0 0;
}

.article-hero-caption {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
  padding: 10px 16px;
  background: var(--tag-bg);
  border-radius: 0 0 6px 6px;
  font-style: italic;
}

.article-headline {
  margin: 0 0 32px 0;
  padding: 16px 20px;
  border-left: 3px solid var(--accent);
  background: var(--tag-bg);
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--text-secondary);
  font-style: italic;
}

/* 安全网：万一去重失败，CSS隐藏重复内容 */
.article-body h1 {
  display: none;
}

.article-body img[alt="heading"] {
  display: none;
}

.article-body {
  font-size: 1.08rem;
  line-height: 1.85;
  color: #333333;            /* P0: #666666 → #333333, 对比度5.5:1→11.3:1 (AAA) */
}

.article-body p {
  margin-bottom: 20px;
}

/* 正文插图：响应式，参考Discourse实现 */
.article-body img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 24px auto;
  border-radius: 6px;
}

/* 正文 blockquote 紧跟 img 时，作为图注样式 */
.article-body img + blockquote {
  border-left: none;
  padding-left: 0;
  font-style: normal;
  font-size: 0.88rem;
  color: var(--text-muted);
  text-align: center;
  margin: -16px auto 24px;
  max-width: 90%;
}

.article-body h2 {
  font-family: var(--heading-font);
  font-size: 1.5rem;
  font-weight: 600;
  margin: 40px 0 16px;
  color: var(--text);
}

.article-body h3 {
  font-family: var(--heading-font);
  font-size: 1.25rem;
  font-weight: 600;
  margin: 32px 0 12px;
  color: var(--text);
}

.article-body blockquote {
  border-left: 3px solid var(--card-border);
  padding-left: 20px;
  margin: 24px 0;
  font-style: italic;
  color: var(--text-muted);
}

.article-body strong { color: var(--text); }

.article-body em { font-style: italic; }

.article-body hr {
  border: none;
  border-top: 1px solid var(--card-border);
  margin: 32px 0;
}

.article-body ul, .article-body ol {
  padding-left: 24px;
  margin-bottom: 20px;
}

.article-body li { margin-bottom: 6px; }

.article-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.article-body code {
  background: var(--tag-bg);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.9em;
}

.article-copyright {
  margin-top: 48px;
  padding: 16px 20px;
  background: var(--tag-bg);
  border-radius: var(--radius);
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  font-style: italic;
}

/* === PAGE (About/Policy) === */
.page {
  max-width: 720px;
  margin: 0 auto;
  padding: 56px 32px;
}

.page h1 {
  font-family: var(--heading-font);
  font-size: 2.4rem;
  font-weight: 700;
  margin-bottom: 32px;
  letter-spacing: -0.03em;
}

.page h2 {
  font-family: var(--heading-font);
  font-size: 1.4rem;
  font-weight: 600;
  margin: 36px 0 16px;
}

.page p, .page ul {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 18px;
}

.page ul { padding-left: 20px; }
.page li { margin-bottom: 6px; }
.page strong { color: var(--text); }

.page a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* Page body (MD-driven pages) */
.page-body table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 20px;
  font-size: 0.95rem;
}

.page-body table td,
.page-body table th {
  padding: 8px 12px;
  border-bottom: 1px solid var(--card-border);
  text-align: left;
}

.page-body table th {
  font-weight: 600;
  color: var(--text);
}

/* === FOOTER === */
.footer {
  border-top: 1px solid var(--card-border);
  padding: 28px 0;
  margin-top: 48px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-left {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-sep { opacity: 0.4; }

.footer-right {
  display: flex;
  gap: 20px;
}

.footer-link {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-decoration: none;
}

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

/* === PAGINATION === */
.pagination {
  display: flex;
  gap: 12px;
  justify-content: center;
  align-items: center;
  margin-top: 40px;
}

.pagination .pagination-nav {
  padding: 8px 16px;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  font-size: 0.88rem;
  text-decoration: none;
  color: var(--text-secondary);
  transition: border-color 0.2s;
  white-space: nowrap;
}

.pagination .pagination-nav:hover {
  border-color: var(--card-hover-border);
}

.pagination .pagination-info {
  font-size: 0.85rem;
  color: var(--text-muted);
  white-space: nowrap;
}

/* === 404 === */
.not-found {
  text-align: center;
  padding: 120px 32px;
}

.not-found h1 {
  font-family: var(--heading-font);
  font-size: 6rem;
  font-weight: 700;
  color: var(--card-border);
  margin-bottom: 16px;
}

.not-found p {
  font-size: 1.2rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.not-found a {
  color: var(--accent);
  text-decoration: underline;
}

/* === RESPONSIVE === */
@media (max-width: 1024px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
  .card.hero-card { grid-template-columns: 1fr; }
  .card.hero-card .card-visual { min-height: 200px; }
}

@media (max-width: 768px) {
  .nav-inner { padding: 0 18px; }
  .nav-links-desktop { display: none !important; }
  .footer-inner { padding: 0 18px; flex-direction: column; align-items: flex-start; }
  .footer-left { flex-direction: column; align-items: flex-start; gap: 2px; }
  .footer-sep { display: none; }
}

@media (max-width: 640px) {
  .hero { padding: 40px 0 32px; }
  .hero-inner { padding: 0 20px; }
  .content { padding: 32px 18px; }
  .cards { grid-template-columns: 1fr; gap: 14px; }
  .card.hero-card .card-title { font-size: 1.3rem; }
  .page { padding: 36px 18px; }
  .page h1 { font-size: 1.8rem; }
  .article { padding: 36px 18px; }
  .article-title { font-size: 1.8rem; }
  .article-hero {
    width: calc(100% + 36px);
    margin-left: -18px;
  }
  .article-hero-img {
    max-height: 280px;
  }
}

/* === MOBILE DRAWER NAV === */
.nav-hamburger { display: none; }
.nav-drawer { display: none; }

@media (max-width: 768px) {
  .nav-name { display: inline !important; font-size: 1.05rem; }

  .nav-hamburger {
    display: flex; flex-direction: column; gap: 5px;
    background: none; border: none; cursor: pointer; padding: 8px;
  }
  .nav-hamburger span {
    display: block; width: 22px; height: 2px;
    background: var(--nav-text); border-radius: 1px;
    transition: transform 0.3s, opacity 0.3s;
  }
  .nav-hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
  .nav-hamburger.active span:nth-child(2) { opacity: 0; }
  .nav-hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

  .nav-drawer {
    display: block; position: fixed; inset: 0; z-index: 2000;
    pointer-events: none; visibility: hidden;
  }
  .nav-drawer.open { pointer-events: auto; visibility: visible; }

  .nav-drawer-overlay {
    position: absolute; inset: 0;
    background: rgba(0,0,0,0.4); opacity: 0; transition: opacity 0.3s;
  }
  .nav-drawer.open .nav-drawer-overlay { opacity: 1; }

  .nav-drawer-content {
    position: absolute; top: 0; right: 0;
    width: min(280px, 80vw); height: 100%;
    background: var(--nav-bg, #fff);
    box-shadow: -2px 0 8px rgba(0,0,0,0.15);
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4,0,0.2,1);
    display: flex; flex-direction: column; overflow-y: auto;
  }
  .nav-drawer.open .nav-drawer-content { transform: translateX(0); }

  .nav-drawer-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 20px; border-bottom: 1px solid var(--card-border);
  }
  .nav-drawer-close {
    background: none; border: none; font-size: 1.4rem;
    color: var(--nav-text); cursor: pointer; padding: 4px 8px;
  }
  .nav-drawer-link {
    display: block; padding: 10px 20px; color: var(--nav-text);
    text-decoration: none; font-size: 0.95rem;
    border-bottom: 1px solid var(--card-border);
  }
  .nav-drawer-collapsible-toggle {
    display: flex; justify-content: space-between; align-items: center;
    width: 100%; padding: 10px 20px; background: none; border: none;
    border-bottom: 1px solid var(--card-border);
    color: var(--nav-text); font-size: 0.95rem; cursor: pointer;
  }
  .nav-drawer-collapsible-toggle span {
    transition: transform 0.3s; display: inline-block;
  }
  .nav-drawer-collapsible.open .nav-drawer-collapsible-toggle span {
    transform: rotate(90deg);
  }
  .nav-drawer-collapsible-content {
    max-height: 0; overflow: hidden; transition: max-height 0.3s;
  }
  .nav-drawer-collapsible.open .nav-drawer-collapsible-content { max-height: 200px; }
  .nav-drawer-sublink { padding-left: 36px; font-size: 0.88rem; opacity: 0.85; }

  body.drawer-open { overflow: hidden; }
}