/* ============================================
   水族馆AI企业官网 - 完整样式表
   设计风格：深海蓝主题，参考 Georgia Aquarium
   ============================================ */

/* ---- 1. CSS变量定义 ---- */
:root {
  --bg-primary: #0a1628;
  --bg-secondary: #0d2137;
  --bg-card: #112d4e;
  --accent-primary: #00d4aa;
  --accent-secondary: #00a8e8;
  --text-primary: #ffffff;
  --text-secondary: #b0c4de;
  --gradient-main: linear-gradient(135deg, #0a1628, #1a3a5c);
  --gradient-accent: linear-gradient(135deg, #00d4aa, #00a8e8);
  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 16px 48px rgba(0, 212, 170, 0.15);
  --border-radius: 16px;
  --border-radius-sm: 8px;
  --transition-base: all 0.3s ease;
  --transition-slow: all 0.5s ease;
  --font-main: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-heading: 'Georgia', 'Noto Serif SC', serif;
  --nav-height: 72px;
}

/* ---- 全局重置与基础 ---- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--bg-card) var(--bg-primary);
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; transition: var(--transition-base); }
ul, ol { list-style: none; }
img { max-width: 100%; height: auto; display: block; }
button { cursor: pointer; border: none; outline: none; font-family: inherit; background: none; }
input, textarea, select { font-family: inherit; outline: none; }

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--bg-card); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent-primary); }

::selection { background: rgba(0, 212, 170, 0.3); color: var(--text-primary); }

/* ---- 2. 导航栏 ---- */
.navbar {
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 1000;
  transition: var(--transition-slow);
  background: transparent;
}

.navbar.scrolled {
  background: #0a1628ee;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.nav-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 5%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  z-index: 1001;
}

.nav-logo .logo-icon {
  width: 42px; height: 42px;
  background: var(--gradient-accent);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
}

.nav-logo .logo-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  position: relative;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 4px 0;
  transition: var(--transition-base);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 2px;
  background: var(--gradient-accent);
  border-radius: 1px;
  transition: width 0.3s ease;
}

.nav-link:hover { color: var(--text-primary); }
.nav-link:hover::after { width: 100%; }
.nav-link.active { color: var(--accent-primary); }
.nav-link.active::after { width: 100%; }

/* 汉堡菜单按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 36px; height: 36px;
  cursor: pointer;
  z-index: 1001;
  gap: 6px;
}

.nav-toggle span {
  display: block;
  width: 26px; height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition-base);
  transform-origin: center;
}

.nav-toggle.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-toggle.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

/* ---- 3. Hero区域 ---- */
.hero {
  position: relative;
  width: 100%;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.particle-canvas {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 1;
  pointer-events: none;
}

.hero-bg {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0;
}

.hero-bg-img {
  width: 100%; height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: linear-gradient(
    180deg,
    rgba(10, 22, 40, 0.6) 0%,
    rgba(10, 22, 40, 0.8) 50%,
    rgba(10, 22, 40, 0.95) 100%
  );
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  padding: 0 20px;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #ffffff 0%, #00d4aa 50%, #00a8e8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: fadeInUp 1s ease forwards;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  line-height: 1.8;
  animation: fadeInUp 1s ease 0.3s forwards;
  opacity: 0;
}

.hero-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  animation: fadeInUp 1s ease 0.6s forwards;
  opacity: 0;
}

/* 通用按钮 */
.btn {
  padding: 14px 36px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  transition: var(--transition-base);
  position: relative;
  overflow: hidden;
  display: inline-block;
  text-align: center;
}

.btn-primary {
  background: var(--gradient-accent);
  color: var(--bg-primary);
  box-shadow: 0 0 20px rgba(0, 212, 170, 0.3);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 0 40px rgba(0, 212, 170, 0.5), 0 0 80px rgba(0, 212, 170, 0.2);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 2px solid rgba(0, 212, 170, 0.5);
  box-shadow: 0 0 15px rgba(0, 212, 170, 0.1);
}

.btn-outline:hover {
  transform: translateY(-3px) scale(1.05);
  border-color: var(--accent-primary);
  box-shadow: 0 0 30px rgba(0, 212, 170, 0.3);
  background: rgba(0, 212, 170, 0.1);
}

.btn-block { width: 100%; }

/* 向下滚动指示器 */
.hero-scroll-hint {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  animation: bounce 2s infinite;
  color: var(--text-secondary);
  font-size: 0.8rem;
  letter-spacing: 2px;
}

.scroll-arrow {
  width: 24px; height: 24px;
  border-right: 2px solid var(--accent-primary);
  border-bottom: 2px solid var(--accent-primary);
  transform: rotate(45deg);
  animation: scrollArrow 2s infinite;
}

@keyframes scrollArrow {
  0%, 100% { opacity: 0; transform: rotate(45deg) translate(-5px, -5px); }
  50% { opacity: 1; transform: rotate(45deg) translate(5px, 5px); }
}

/* ---- 4. 通用Section样式 ---- */
.section {
  padding: 100px 5%;
  position: relative;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 5%;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

/* 淡入动画类 */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---- 5. AI功能概览 ---- */
.ai-features {
  background: var(--gradient-main);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  max-width: 1200px;
  margin: 0 auto;
}

.feature-card {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  padding: 40px 30px;
  text-align: center;
  transition: var(--transition-base);
  border: 1px solid rgba(255, 255, 255, 0.05);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 0;
}

.feature-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-hover);
}

.feature-card:hover::before { opacity: 0.03; }
.feature-card > * { position: relative; z-index: 1; }

.feature-icon {
  width: 80px; height: 80px;
  margin: 0 auto 24px;
  background: linear-gradient(135deg, rgba(0, 212, 170, 0.15), rgba(0, 168, 232, 0.15));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-primary);
  transition: var(--transition-base);
}

.feature-card:hover .feature-icon {
  background: linear-gradient(135deg, rgba(0, 212, 170, 0.3), rgba(0, 168, 232, 0.3));
  transform: scale(1.1);
  box-shadow: 0 0 30px rgba(0, 212, 170, 0.2);
}

.feature-title {
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.feature-link {
  color: var(--accent-primary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition-base);
}

.feature-link:hover {
  color: var(--accent-secondary);
  letter-spacing: 1px;
}

/* ---- 6. 鱼类展示区 ---- */
.fish-display {
  background: var(--bg-secondary);
}

.fish-filter {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 10px 24px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: var(--transition-base);
  cursor: pointer;
}

.filter-btn:hover {
  color: var(--text-primary);
  border-color: var(--accent-primary);
  background: rgba(0, 212, 170, 0.1);
}

.filter-btn.active {
  color: var(--bg-primary);
  background: var(--gradient-accent);
  border-color: transparent;
  box-shadow: 0 0 20px rgba(0, 212, 170, 0.3);
}

.fish-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1400px;
  margin: 0 auto;
}

.fish-card {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  overflow: hidden;
  transition: var(--transition-base);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.fish-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(0, 212, 170, 0.3);
}

.fish-card.hidden {
  display: none !important;
}

.fish-img-wrap {
  position: relative;
  width: 100%;
  height: 200px;
  overflow: hidden;
}

.fish-img-wrap img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.fish-card:hover .fish-img-wrap img {
  transform: scale(1.1);
}

.difficulty-tag {
  position: absolute;
  top: 12px; right: 12px;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  color: #fff;
}

.difficulty-tag.easy { background: rgba(76, 175, 80, 0.9); }
.difficulty-tag.medium { background: rgba(255, 193, 7, 0.9); color: #333; }
.difficulty-tag.hard { background: rgba(244, 67, 54, 0.9); }

.fish-info {
  padding: 20px;
}

.fish-name {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.fish-brief {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 12px;
}

.fish-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.fish-type {
  background: rgba(0, 168, 232, 0.15);
  color: var(--accent-secondary);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
}

.fish-temp {
  color: var(--accent-primary);
  font-weight: 500;
}

/* ---- 7. 水质顾问区 ---- */
.water-quality {
  background: var(--gradient-main);
}

.water-quality-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  max-width: 1200px;
  margin: 0 auto;
  align-items: start;
}

.water-quality-img {
  position: relative;
}

.water-quality-img img {
  width: 100%;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-card);
}

.water-quality-tool {
  position: relative;
}

.wq-form {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  padding: 40px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.wq-form .form-group {
  margin-bottom: 20px;
}

.wq-form .form-group label {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  font-weight: 500;
}

.wq-form .form-group input {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: var(--transition-base);
}

.wq-form .form-group input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(0, 212, 170, 0.15);
}

.wq-form .form-group input::placeholder {
  color: rgba(176, 196, 222, 0.5);
}

/* 水质分析结果 */
.wq-result {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  padding: 30px;
  border: 1px solid rgba(0, 212, 170, 0.3);
  position: relative;
  animation: fadeInUp 0.5s ease;
}

.wq-result-title {
  font-size: 1.2rem;
  color: var(--accent-primary);
  margin-bottom: 20px;
  text-align: center;
}

.wq-result-body {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.wq-score {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  min-width: 130px;
}

.wq-score-circle {
  width: 110px; height: 110px;
  border-radius: 50%;
  background: conic-gradient(var(--accent-primary) 0deg, var(--accent-primary) calc(var(--score, 0) * 3.6deg), rgba(255,255,255,0.1) calc(var(--score, 0) * 3.6deg), rgba(255,255,255,0.1) 360deg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  margin-bottom: 10px;
}

.wq-score-circle::after {
  content: '';
  position: absolute;
  width: 86px; height: 86px;
  border-radius: 50%;
  background: var(--bg-card);
}

.wq-score-circle span {
  position: relative;
  z-index: 1;
}

#wq-score-value {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent-primary);
  line-height: 1;
}

.wq-score-label {
  font-size: 0.7rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

.wq-result-right {
  flex: 1;
  min-width: 0;
}

.wq-level-badge {
  display: inline-block;
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
}

.wq-level-badge.excellent { background: rgba(76, 175, 80, 0.2); color: #81c784; }
.wq-level-badge.good { background: rgba(0, 168, 232, 0.2); color: #4fc3f7; }
.wq-level-badge.warning { background: rgba(255, 193, 7, 0.2); color: #ffc107; }
.wq-level-badge.danger { background: rgba(244, 67, 54, 0.2); color: #ef5350; }

.wq-details {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 12px;
}

.wq-detail-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 10px;
  background: var(--bg-secondary);
  border-radius: var(--border-radius-sm);
  font-size: 0.82rem;
}

.wq-detail-status {
  font-weight: 600;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 10px;
}

.wq-detail-status.good { background: rgba(76, 175, 80, 0.2); color: #81c784; }
.wq-detail-status.warning { background: rgba(255, 193, 7, 0.2); color: #ffc107; }
.wq-detail-status.danger { background: rgba(244, 67, 54, 0.2); color: #ef5350; }

.wq-suggestions h5 {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.wq-suggestion-item {
  padding: 8px 12px;
  background: rgba(0, 212, 170, 0.05);
  border-left: 3px solid var(--accent-primary);
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 6px;
}

/* ---- 8. 设备推荐区 ---- */
.equipment {
  background: var(--bg-secondary);
}

.equipment-tabs {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
}

.eq-tab {
  padding: 12px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: var(--transition-base);
  cursor: pointer;
}

.eq-tab:hover {
  color: var(--text-primary);
  border-color: var(--accent-primary);
}

.eq-tab.active {
  color: var(--bg-primary);
  background: var(--gradient-accent);
  border-color: transparent;
  box-shadow: 0 0 20px rgba(0, 212, 170, 0.3);
}

.eq-scene {
  display: none;
  animation: fadeInUp 0.5s ease;
}

.eq-scene.active {
  display: block;
}

.eq-intro {
  text-align: center;
  margin-bottom: 32px;
}

.eq-intro h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.eq-intro p {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.eq-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.eq-card {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  overflow: hidden;
  transition: var(--transition-base);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.eq-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(0, 212, 170, 0.3);
}

.eq-card-img {
  width: 100%;
  height: 200px;
  overflow: hidden;
}

.eq-card-img img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

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

.eq-card-info {
  padding: 20px;
}

.eq-card-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(0, 212, 170, 0.15);
  color: var(--accent-primary);
  margin-bottom: 8px;
}

.eq-card-info h4 {
  font-size: 1.1rem;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.eq-card-info p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.eq-card-price {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent-primary);
}

/* ---- 9. 新闻动态区 ---- */
.news {
  background: var(--gradient-main);
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.news-card {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  overflow: hidden;
  transition: var(--transition-base);
  border: 1px solid rgba(255, 255, 255, 0.05);
  display: grid;
  grid-template-columns: 1fr 1.2fr;
}

.news-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(0, 212, 170, 0.2);
}

.news-img {
  position: relative;
  overflow: hidden;
}

.news-img img {
  width: 100%; height: 100%;
  object-fit: cover;
  min-height: 200px;
  transition: transform 0.5s ease;
}

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

.news-info {
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.news-date {
  font-size: 0.8rem;
  color: var(--accent-primary);
  font-weight: 500;
  margin-bottom: 8px;
}

.news-title {
  font-size: 1.05rem;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: color 0.3s ease;
}

.news-card:hover .news-title {
  color: var(--accent-primary);
}

.news-excerpt {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 12px;
}

.news-link {
  font-size: 0.85rem;
  color: var(--accent-primary);
  font-weight: 500;
  transition: var(--transition-base);
}

.news-link:hover {
  color: var(--accent-secondary);
  letter-spacing: 1px;
}

/* ---- 10. 关于我们区 ---- */
.about {
  background: var(--bg-secondary);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  max-width: 1200px;
  margin: 0 auto;
  align-items: center;
}

.about-img {
  position: relative;
}

.about-img img {
  width: 100%;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-card);
}

.about-text h3 {
  font-family: var(--font-heading);
  font-size: 2rem;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.about-text p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-mission {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 24px;
}

.mission-item {
  padding: 20px;
  background: rgba(0, 212, 170, 0.05);
  border-radius: var(--border-radius-sm);
  border-left: 3px solid var(--accent-primary);
}

.mission-item h4 {
  font-size: 1rem;
  color: var(--accent-primary);
  margin-bottom: 8px;
}

.mission-item p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 60px;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

.stat-item {
  text-align: center;
  padding: 30px 20px;
  background: var(--bg-card);
  border-radius: var(--border-radius);
  border: 1px solid rgba(255, 255, 255, 0.05);
  transition: var(--transition-base);
}

.stat-item:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 212, 170, 0.3);
  box-shadow: var(--shadow-hover);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.stat-suffix {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 8px;
  display: block;
}

/* ---- 11. 联系我们区 ---- */
.contact {
  background: var(--gradient-main);
}

.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  max-width: 1200px;
  margin: 0 auto;
}

.contact-form {
  background: var(--bg-card);
  border-radius: var(--border-radius);
  padding: 40px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.contact-form .form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.contact-form .form-group {
  margin-bottom: 16px;
}

.contact-form .form-group label {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  font-weight: 500;
}

.contact-form .form-group input,
.contact-form .form-group select,
.contact-form .form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: var(--transition-base);
}

.contact-form .form-group input:focus,
.contact-form .form-group select:focus,
.contact-form .form-group textarea:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(0, 212, 170, 0.15);
}

.contact-form .form-group input::placeholder,
.contact-form .form-group textarea::placeholder {
  color: rgba(176, 196, 222, 0.5);
}

.contact-form .form-group select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23b0c4de' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
}

.contact-form .form-group select option {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.contact-form .form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.contact-info {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 24px;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: rgba(0, 212, 170, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-primary);
  flex-shrink: 0;
}

.contact-info-item h4 {
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.contact-info-item p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ---- 12. AI聊天浮窗 ---- */
.ai-chat-widget {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
}

.ai-chat-toggle {
  width: 60px; height: 60px;
  border-radius: 50%;
  background: var(--gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--bg-primary);
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(0, 212, 170, 0.4);
  transition: var(--transition-base);
  position: relative;
}

.ai-chat-toggle::before {
  content: '';
  position: absolute;
  top: -4px; left: -4px; right: -4px; bottom: -4px;
  border-radius: 50%;
  background: var(--gradient-accent);
  opacity: 0;
  animation: pulse 2s infinite;
  z-index: -1;
}

.ai-chat-toggle:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 30px rgba(0, 212, 170, 0.5);
}

.ai-chat-window {
  position: absolute;
  bottom: 72px;
  right: 0;
  width: 380px;
  height: 500px;
  background: var(--bg-primary);
  border-radius: var(--border-radius);
  box-shadow: 0 16px 64px rgba(0, 0, 0, 0.5);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.1);
  animation: fadeInUp 0.3s ease;
}

.ai-chat-header {
  padding: 16px 20px;
  background: var(--bg-card);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  gap: 12px;
}

.ai-chat-avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.ai-chat-title h4 {
  font-size: 0.95rem;
  color: var(--text-primary);
}

.ai-chat-status {
  font-size: 0.75rem;
  color: var(--accent-primary);
}

.ai-chat-close {
  margin-left: auto;
  color: var(--text-secondary);
  transition: var(--transition-base);
  padding: 4px;
}

.ai-chat-close:hover {
  color: var(--text-primary);
}

.ai-chat-messages {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.ai-chat-messages::-webkit-scrollbar { width: 4px; }
.ai-chat-messages::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 2px; }

.chat-message {
  max-width: 85%;
  animation: fadeInUp 0.3s ease;
}

.chat-message.user {
  align-self: flex-end;
}

.chat-message.bot {
  align-self: flex-start;
}

.chat-bubble {
  padding: 10px 14px;
  border-radius: 16px;
  font-size: 0.9rem;
  line-height: 1.5;
}

.chat-message.user .chat-bubble {
  background: var(--accent-secondary);
  color: #fff;
  border-bottom-right-radius: 4px;
}

.chat-message.bot .chat-bubble {
  background: var(--bg-card);
  color: var(--text-primary);
  border-bottom-left-radius: 4px;
}

.ai-chat-quick-replies {
  padding: 8px 16px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  border-top: 1px solid rgba(255,255,255,0.05);
}

.quick-reply {
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--accent-primary);
  background: rgba(0, 212, 170, 0.1);
  border: 1px solid rgba(0, 212, 170, 0.3);
  cursor: pointer;
  transition: var(--transition-base);
  white-space: nowrap;
}

.quick-reply:hover {
  background: rgba(0, 212, 170, 0.2);
  border-color: var(--accent-primary);
}

.ai-chat-input {
  padding: 12px 16px;
  background: var(--bg-card);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  gap: 8px;
}

.ai-chat-input input {
  flex: 1;
  padding: 10px 14px;
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 24px;
  color: var(--text-primary);
  font-size: 0.9rem;
  transition: var(--transition-base);
}

.ai-chat-input input:focus {
  border-color: var(--accent-primary);
}

.ai-chat-input input::placeholder {
  color: rgba(176, 196, 222, 0.5);
}

.ai-chat-send {
  width: 40px; height: 40px;
  border-radius: 50%;
  background: var(--gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--bg-primary);
  transition: var(--transition-base);
  flex-shrink: 0;
}

.ai-chat-send:hover {
  transform: scale(1.1);
  box-shadow: 0 0 15px rgba(0, 212, 170, 0.4);
}

/* ---- 13. 页脚 ---- */
.footer {
  background: #060e1a;
  padding: 80px 5% 0;
}

.footer-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-about {
  padding-right: 40px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.footer-logo .logo-icon {
  width: 36px; height: 36px;
  background: var(--gradient-accent);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.footer-logo .logo-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 20px;
}

.footer-social {
  display: flex;
  gap: 10px;
}

.social-link {
  width: 38px; height: 38px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition-base);
}

.social-link:hover {
  background: var(--accent-primary);
  color: var(--bg-primary);
  transform: translateY(-3px);
}

.footer-links h4 {
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 20px;
  font-weight: 600;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links ul li a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: var(--transition-base);
}

.footer-links ul li a:hover {
  color: var(--accent-primary);
  padding-left: 4px;
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* ---- 14. 动画关键帧 ---- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 0; transform: scale(1.5); }
  100% { opacity: 0; transform: scale(1.5); }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-12px); }
  60% { transform: translateX(-50%) translateY(-6px); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes glow {
  0%, 100% { box-shadow: 0 0 5px rgba(0, 212, 170, 0.2); }
  50% { box-shadow: 0 0 20px rgba(0, 212, 170, 0.4), 0 0 40px rgba(0, 212, 170, 0.2); }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-60px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(60px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes shimmer {
  0% { background-position: -200% center; }
  100% { background-position: 200% center; }
}

/* ---- 15. 响应式断点 ---- */

/* 1200px */
@media (max-width: 1200px) {
  .section { padding: 80px 4%; }
  .hero-title { font-size: 3rem; }
  .features-grid { gap: 24px; }
  .fish-grid { grid-template-columns: repeat(3, 1fr); gap: 20px; }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 30px; }
}

/* 992px */
@media (max-width: 992px) {
  .nav-menu {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(10, 22, 40, 0.95);
    backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 32px;
    z-index: 999;
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-menu .nav-link {
    font-size: 1.5rem;
  }

  .nav-toggle { display: flex; }

  .hero-title { font-size: 2.5rem; }
  .hero-subtitle { font-size: 1.05rem; }
  .section-title { font-size: 2rem; }

  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .fish-grid { grid-template-columns: repeat(2, 1fr); }
  .water-quality-content { grid-template-columns: 1fr; gap: 40px; }
  .eq-grid { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: 1fr; }
  .news-card { grid-template-columns: 1fr 1.2fr; }
  .about-content { grid-template-columns: 1fr; gap: 40px; }
  .contact-content { grid-template-columns: 1fr; gap: 40px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
  .footer-about { grid-column: 1 / -1; padding-right: 0; }
}

/* 768px */
@media (max-width: 768px) {
  :root { --nav-height: 64px; }
  .section { padding: 60px 4%; }
  .section-header { margin-bottom: 40px; }
  .hero-title { font-size: 2rem; }
  .hero-subtitle { font-size: 0.95rem; }
  .hero-buttons { flex-direction: column; gap: 12px; }
  .hero-buttons .btn { width: 100%; max-width: 280px; }

  .features-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .feature-card { padding: 28px 20px; }
  .feature-icon { width: 64px; height: 64px; }

  .fish-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .eq-grid { grid-template-columns: 1fr; }
  .news-card { grid-template-columns: 1fr; }
  .news-img { height: 200px; }

  .about-mission { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: repeat(3, 1fr); gap: 12px; }
  .stat-number { font-size: 2rem; }

  .contact-form .form-row { grid-template-columns: 1fr; }
  .ai-chat-window { width: 340px; height: 460px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}

/* 480px */
@media (max-width: 480px) {
  html { font-size: 14px; }
  .section { padding: 50px 4%; }
  .hero-title { font-size: 1.8rem; }
  .hero-subtitle { font-size: 0.9rem; }
  .section-title { font-size: 1.6rem; }
  .section-subtitle { font-size: 0.95rem; }

  .fish-filter { gap: 8px; }
  .filter-btn { padding: 8px 16px; font-size: 0.8rem; }
  .features-grid { grid-template-columns: 1fr; }
  .fish-grid { grid-template-columns: 1fr; }
  .fish-img-wrap { height: 180px; }

  .wq-form { padding: 24px; }
  .wq-result-body { flex-direction: column; }
  .wq-score { flex-direction: row; gap: 12px; min-width: auto; }
  .wq-score-circle { width: 80px; height: 80px; margin-bottom: 0; }
  .wq-score-circle::after { width: 62px; height: 62px; }
  #wq-score-value { font-size: 1.4rem; }
  .equipment-tabs { flex-direction: column; align-items: center; }
  .eq-tab { width: 100%; max-width: 280px; }

  .about-stats { grid-template-columns: 1fr; gap: 12px; }
  .stat-item { padding: 16px; }
  .stat-number { font-size: 1.8rem; }

  .contact-form { padding: 24px; }
  .ai-chat-window { width: calc(100vw - 32px); height: 420px; right: -8px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-about { padding-right: 0; }
}

/* ---- 辅助工具类 ---- */
.hidden { display: none !important; }
.text-gradient {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}