/* ============================================
   The Observatory — 天文台
   明亮高端 × 星座式布局 × 国家地理 × 未来科学馆
   ============================================ */

/* ===== Reset ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

/* ===== CSS Variables ===== */
:root {
  /* 明亮色调 */
  --obs-bg: #fafbfc;
  --obs-bg-deep: #f4f7fa;
  --obs-bg-card: #ffffff;
  --obs-bg-hero: linear-gradient(135deg, #f8fafb 0%, #eef3f7 100%);
  
  /* 文字颜色 */
  --obs-text-primary: #1a2a3a;
  --obs-text-secondary: #4a5a6a;
  --obs-text-muted: #7a8a9a;
  --obs-text-light: #a0b0c0;
  
  /* 天文台主题色 - 深蓝星空 */
  --obs-accent: #1e3a5f;
  --obs-accent-light: #3a5a8f;
  --obs-accent-subtle: rgba(30, 58, 95, 0.08);
  --obs-accent-glow: rgba(30, 58, 95, 0.15);
  
  /* 星座金色 */
  --obs-star: #d4af37;
  --obs-star-light: #f0d878;
  --obs-star-glow: rgba(212, 175, 55, 0.3);
  
  /* 边框和阴影 */
  --obs-border: rgba(30, 58, 95, 0.08);
  --obs-border-strong: rgba(30, 58, 95, 0.15);
  --obs-shadow-sm: 0 2px 8px rgba(26, 42, 58, 0.04);
  --obs-shadow-md: 0 4px 16px rgba(26, 42, 58, 0.06);
  --obs-shadow-lg: 0 8px 32px rgba(26, 42, 58, 0.08);
  --obs-shadow-star: 0 0 20px rgba(212, 175, 55, 0.2);
  
  /* 圆角 */
  --obs-radius: 8px;
  --obs-radius-lg: 12px;
  
  /* 字体 */
  --obs-font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --obs-font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  /* 布局 */
  --obs-max-width: 1400px;
  --obs-section-gap: 80px;
}

/* ===== Body — 明亮背景 ===== */
body {
  font-family: var(--obs-font-body);
  background: var(--obs-bg);
  color: var(--obs-text-primary);
  line-height: 1.7;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

/* ===== 星空点缀背景 ===== */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: 
    radial-gradient(circle at 20% 30%, rgba(212, 175, 55, 0.03) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(30, 58, 95, 0.02) 0%, transparent 50%),
    radial-gradient(circle at 50% 50%, rgba(212, 175, 55, 0.02) 0%, transparent 60%);
  opacity: 1;
}

/* ===== Navigation — 天文台导航 ===== */
.obs-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--obs-border);
  box-shadow: var(--obs-shadow-sm);
}

.obs-nav-inner {
  max-width: var(--obs-max-width);
  margin: 0 auto;
  height: 70px;
  display: flex;
  align-items: center;
  padding: 0 48px;
  gap: 40px;
  position: relative;
  z-index: 1;
}

.obs-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  flex-shrink: 0;
}

.obs-logo-mark {
  width: 40px;
  height: 40px;
  border: 2px solid var(--obs-accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--obs-star);
  font-size: 18px;
  position: relative;
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.8), transparent);
  box-shadow: var(--obs-shadow-star);
}

.obs-logo-mark::before {
  content: '';
  position: absolute;
  width: 8px;
  height: 8px;
  background: var(--obs-star);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 10px var(--obs-star-glow);
}

.obs-logo-text {
  font-size: 18px;
  font-weight: 600;
  color: var(--obs-text-primary);
  letter-spacing: -0.3px;
}

.obs-nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.obs-nav-links a {
  text-decoration: none;
  color: var(--obs-text-secondary);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.5px;
  transition: all 0.3s ease;
  position: relative;
  padding: 6px 0;
}

.obs-nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--obs-star), var(--obs-accent));
  transform: scaleX(0);
  transition: transform 0.3s ease;
  transform-origin: left;
}

.obs-nav-links a:hover { 
  color: var(--obs-accent); 
}

.obs-nav-links a:hover::after { 
  transform: scaleX(1); 
}

.obs-nav-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 16px;
}

.obs-search-btn {
  width: 40px;
  height: 40px;
  border: 1px solid var(--obs-border);
  border-radius: 50%;
  background: var(--obs-bg-card);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.obs-search-btn:hover {
  border-color: var(--obs-accent);
  box-shadow: var(--obs-shadow-md);
}

.obs-search-btn svg {
  width: 18px;
  height: 18px;
  color: var(--obs-text-secondary);
}

/* ===== Hero Section — 今日星座 ===== */
.obs-hero {
  position: relative;
  z-index: 1;
  padding: 80px 48px;
  background: var(--obs-bg-hero);
  overflow: hidden;
}

.obs-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(212, 175, 55, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 90% 80%, rgba(30, 58, 95, 0.05) 0%, transparent 40%);
  pointer-events: none;
}

.obs-hero-inner {
  max-width: var(--obs-max-width);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.obs-hero-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(212, 175, 55, 0.1);
  border: 1px solid rgba(212, 175, 55, 0.3);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  color: var(--obs-accent);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 24px;
}

.obs-hero-label::before {
  content: '★';
  color: var(--obs-star);
  font-size: 14px;
}

.obs-hero-card {
  display: block;
  background: var(--obs-bg-card);
  border-radius: var(--obs-radius-lg);
  overflow: hidden;
  box-shadow: var(--obs-shadow-lg);
  transition: all 0.4s ease;
  text-decoration: none;
  border: 1px solid var(--obs-border);
}

.obs-hero-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--obs-shadow-lg), var(--obs-shadow-star);
}

.obs-hero-card-inner {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 0;
}

.obs-hero-card-img {
  position: relative;
  overflow: hidden;
  background: var(--obs-bg-deep);
  aspect-ratio: 16/9;
}

.obs-hero-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease;
}

.obs-hero-card:hover .obs-hero-card-img img {
  transform: scale(1.05);
}

.obs-hero-card-body {
  padding: 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.obs-hero-card-tag {
  display: inline-block;
  padding: 6px 14px;
  background: var(--obs-accent-subtle);
  border: 1px solid var(--obs-border-strong);
  border-radius: 16px;
  font-size: 11px;
  font-weight: 600;
  color: var(--obs-accent);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 20px;
  width: fit-content;
}

.obs-hero-card-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--obs-text-primary);
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.obs-hero-card-excerpt {
  font-size: 16px;
  color: var(--obs-text-secondary);
  line-height: 1.7;
  margin-bottom: 24px;
}

.obs-hero-card-meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--obs-accent);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.obs-hero-card-meta svg {
  width: 16px;
  height: 16px;
}

/* ===== Section — 星系区域 ===== */
.obs-section {
  position: relative;
  z-index: 1;
  padding: 80px 48px;
}

.obs-section-inner {
  max-width: var(--obs-max-width);
  margin: 0 auto;
}

.obs-section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 48px;
  padding-bottom: 24px;
  border-bottom: 2px solid var(--obs-border);
  position: relative;
}

.obs-section-header::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 120px;
  height: 2px;
  background: linear-gradient(90deg, var(--obs-star), var(--obs-accent));
}

.obs-section-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--obs-star);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 8px;
}

.obs-section-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--obs-text-primary);
  letter-spacing: -0.5px;
}

.obs-section-id {
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 11px;
  font-weight: 600;
  color: var(--obs-text-light);
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 6px 12px;
  background: var(--obs-bg-deep);
  border-radius: 4px;
  border: 1px solid var(--obs-border);
}

/* ===== 星座网格布局 ===== */
.obs-constellation {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 32px;
}

.obs-card {
  display: block;
  background: var(--obs-bg-card);
  border-radius: var(--obs-radius);
  overflow: hidden;
  box-shadow: var(--obs-shadow-sm);
  transition: all 0.4s ease;
  text-decoration: none;
  border: 1px solid var(--obs-border);
  position: relative;
}

.obs-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--obs-star), var(--obs-accent));
  transform: scaleX(0);
  transition: transform 0.4s ease;
}

.obs-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--obs-shadow-lg);
  border-color: var(--obs-border-strong);
}

.obs-card:hover::before {
  transform: scaleX(1);
}

.obs-card-img {
  position: relative;
  overflow: hidden;
  background: var(--obs-bg-deep);
  aspect-ratio: 16/10;
  min-height: 200px;
}

.obs-card-img::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--obs-bg-deep) 0%, rgba(212, 175, 55, 0.05) 100%);
  z-index: 1;
}

.obs-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease, opacity 0.4s ease;
  position: relative;
  z-index: 2;
}

.obs-card:hover .obs-card-img img {
  transform: scale(1.08);
}

.obs-card-body {
  padding: 24px;
}

.obs-card-tag {
  display: inline-block;
  padding: 4px 10px;
  background: var(--obs-accent-subtle);
  border-radius: 12px;
  font-size: 10px;
  font-weight: 600;
  color: var(--obs-accent);
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 12px;
}

.obs-card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--obs-text-primary);
  line-height: 1.4;
  margin-bottom: 12px;
  letter-spacing: -0.2px;
}

.obs-card-excerpt {
  font-size: 14px;
  color: var(--obs-text-secondary);
  line-height: 1.6;
}

/* ===== Divider — 星际分隔 ===== */
.obs-divider {
  position: relative;
  z-index: 1;
  padding: 0 48px;
  margin: 0;
}

.obs-divider-line {
  max-width: var(--obs-max-width);
  margin: 0 auto;
  height: 1px;
  background: linear-gradient(90deg, 
    transparent 0%, 
    var(--obs-border-strong) 20%, 
    var(--obs-star) 50%, 
    var(--obs-border-strong) 80%, 
    transparent 100%
  );
  opacity: 0.5;
}

/* ===== Search Overlay ===== */
.obs-search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 200;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 120px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.obs-search-overlay.active {
  opacity: 1;
  visibility: visible;
}

.obs-search-overlay-inner {
  width: 100%;
  max-width: 700px;
  padding: 0 48px;
}

.obs-search-close {
  position: absolute;
  top: 40px;
  right: 48px;
  width: 48px;
  height: 48px;
  border: none;
  background: var(--obs-bg-card);
  border-radius: 50%;
  font-size: 32px;
  cursor: pointer;
  color: var(--obs-text-secondary);
  transition: all 0.3s ease;
  box-shadow: var(--obs-shadow-md);
}

.obs-search-close:hover {
  background: var(--obs-bg-deep);
  color: var(--obs-accent);
}

.obs-search-box {
  position: relative;
  margin-bottom: 32px;
}

.obs-search-box svg {
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  width: 24px;
  height: 24px;
  color: var(--obs-text-muted);
}

.obs-search-input {
  width: 100%;
  padding: 20px 20px 20px 60px;
  font-size: 18px;
  border: 2px solid var(--obs-border);
  border-radius: var(--obs-radius-lg);
  background: var(--obs-bg-card);
  color: var(--obs-text-primary);
  transition: all 0.3s ease;
}

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

.obs-search-results {
  max-height: 400px;
  overflow-y: auto;
}

/* ===== Footer ===== */
.obs-footer {
  position: relative;
  z-index: 1;
  padding: 64px 48px;
  background: var(--obs-bg-deep);
  border-top: 1px solid var(--obs-border);
}

.obs-footer-inner {
  max-width: var(--obs-max-width);
  margin: 0 auto;
  text-align: center;
}

.obs-footer-text {
  font-size: 14px;
  color: var(--obs-text-muted);
  margin-bottom: 16px;
}

.obs-footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.obs-footer-links a {
  color: var(--obs-text-secondary);
  text-decoration: none;
  font-size: 13px;
  transition: color 0.3s ease;
}

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

/* ===== Mobile Menu Button ===== */
.obs-mobile-menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--obs-border);
  border-radius: var(--obs-radius);
  background: var(--obs-bg-card);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.obs-mobile-menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--obs-text-primary);
  transition: all 0.3s ease;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .obs-nav-inner {
    padding: 0 32px;
  }
  
  .obs-hero {
    padding: 60px 32px;
  }
  
  .obs-section {
    padding: 60px 32px;
  }
  
  .obs-hero-card-inner {
    grid-template-columns: 1fr;
  }
  
  .obs-hero-card-img {
    aspect-ratio: 16/9;
  }
  
  .obs-hero-card-title {
    font-size: 28px;
  }
  
  .obs-constellation {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
  }
}

@media (max-width: 768px) {
  .obs-nav-links {
    display: none;
  }
  
  .obs-mobile-menu-btn {
    display: flex;
  }
  
  .obs-nav-inner {
    padding: 0 24px;
  }
  
  .obs-hero {
    padding: 40px 24px;
  }
  
  .obs-section {
    padding: 40px 24px;
  }
  
  .obs-hero-card-body {
    padding: 32px 24px;
  }
  
  .obs-hero-card-title {
    font-size: 24px;
  }
  
  .obs-section-title {
    font-size: 24px;
  }
  
  .obs-constellation {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .obs-divider {
    padding: 0 24px;
  }
  
  .obs-footer {
    padding: 40px 24px;
  }
}

/* ===== Animation ===== */
.obs-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.8s ease;
}

.obs-reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 星星装饰 ===== */
.obs-star-decoration {
  position: absolute;
  width: 4px;
  height: 4px;
  background: var(--obs-star);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--obs-star-glow);
  animation: twinkle 3s ease-in-out infinite;
}

@keyframes twinkle {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 1; }
}