/* ===== 全局重置 & 基础变量 ===== */
:root {
  --primary: #ff8c00;
  --primary-light: #ffb347;
  --primary-dark: #e67a00;
  --accent: #ffc107;
  --bg-light: #f5f9fe;
  --bg-dark: #0b1421;
  --text-light: #1a2a3a;
  --text-dark: #e0e8f0;
  --card-bg-light: rgba(255, 255, 255, 0.75);
  --card-bg-dark: rgba(20, 34, 54, 0.8);
  --header-bg: rgba(11, 26, 46, 0.9);
  --header-bg-dark: rgba(7, 17, 30, 0.95);
  --footer-bg: #0b1a2e;
  --footer-bg-dark: #050d1a;
  --border-light: rgba(255, 255, 255, 0.3);
  --border-dark: #2a3f5a;
  --shadow-sm: 0 8px 30px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 20px 40px rgba(0, 0, 0, 0.1);
  --shadow-btn: 0 8px 20px rgba(255, 140, 0, 0.25);
  --shadow-btn-hover: 0 12px 28px rgba(255, 140, 0, 0.4);
  --radius-card: 28px;
  --radius-btn: 50px;
  --radius-sm: 30px;
  --transition-fast: 0.2s;
  --transition-normal: 0.3s;
  --transition-slow: 0.7s;
  --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-light);
  color: var(--text-light);
  line-height: 1.6;
  transition: background var(--transition-normal), color var(--transition-normal);
}

body.dark-mode {
  background: var(--bg-dark);
  color: var(--text-dark);
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ===== 容器 & 布局工具 ===== */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

.flex {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.grid-2 {
  display: grid;
  gap: 28px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-3 {
  display: grid;
  gap: 28px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.grid-4 {
  display: grid;
  gap: 28px;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.text-center {
  text-align: center;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary-light), var(--primary));
  color: #0b1a2e;
  font-weight: 600;
  padding: 12px 28px;
  border-radius: var(--radius-btn);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  border: none;
  cursor: pointer;
  box-shadow: var(--shadow-btn);
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-btn-hover);
}

.dark-mode .btn {
  background: #f0b34b;
  color: #0b1421;
}

/* ===== 标题装饰 ===== */
.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 20px;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--primary);
  border-radius: 4px;
  margin-top: 6px;
}

/* ===== 卡片通用 ===== */
.card {
  background: var(--card-bg-light);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: var(--radius-card);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-normal);
  border: 1px solid var(--border-light);
}

.dark-mode .card {
  background: var(--card-bg-dark);
  border-color: var(--border-dark);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

/* ===== Header ===== */
.global-header {
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 12px 24px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
  transition: background var(--transition-normal);
}

.dark-mode .global-header {
  background: var(--header-bg-dark);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  max-width: 1280px;
  margin: 0 auto;
}

.logo svg {
  width: 140px;
  height: auto;
  display: block;
}

.nav-menu {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.nav-menu a {
  color: #f0f4fa;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), color var(--transition-fast);
  font-size: 0.95rem;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: rgba(255, 255, 255, 0.15);
  color: var(--accent);
}

.dark-mode .nav-menu a {
  color: #cfddee;
}

.menu-toggle,
.dark-toggle {
  background: none;
  border: none;
  color: #fff;
  font-size: 1.6rem;
  cursor: pointer;
  padding: 4px 8px;
}

.dark-toggle {
  font-size: 1.3rem;
}

.mobile-nav {
  display: none;
  width: 100%;
  background: rgba(0, 0, 0, 0.3);
  padding: 12px 0;
  border-radius: 20px;
  margin-top: 10px;
}

.mobile-nav.open {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.mobile-nav a {
  color: #f0f4fa;
  padding: 8px 16px;
  border-radius: 40px;
}

/* ===== Hero Banner ===== */
.hero-banner {
  position: relative;
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(145deg, #0b1a2e 0%, #1f3a5f 100%);
  overflow: hidden;
  padding: 60px 0;
}

.dark-mode .hero-banner {
  background: #050d1a;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  color: #fff;
}

.hero-content h1 {
  font-size: 3.2rem;
  font-weight: 800;
  letter-spacing: 1px;
  text-shadow: 0 8px 20px rgba(0, 0, 0, 0.5);
}

.hero-content p {
  font-size: 1.2rem;
  margin: 24px 0;
  opacity: 0.9;
}

.hero-badge {
  display: inline-block;
  background: rgba(255, 193, 7, 0.2);
  border: 1px solid var(--accent);
  padding: 6px 18px;
  border-radius: 40px;
  font-size: 0.9rem;
  margin-bottom: 20px;
  backdrop-filter: blur(4px);
}

.hero-slide-indicator {
  margin-top: 40px;
  display: flex;
  gap: 12px;
  justify-content: center;
}

.hero-dot {
  width: 14px;
  height: 14px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.3);
  transition: background var(--transition-normal), width var(--transition-normal);
  cursor: pointer;
}

.hero-dot.active {
  background: var(--accent);
  width: 36px;
}

/* ===== 品牌故事 ===== */
.brand-story,
.products,
.cases,
.news,
.faq-section,
.howto-section,
.contact-area {
  padding: 70px 0;
}

.counter-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 40px;
  margin: 40px 0;
}

.counter-item {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
}

.counter-item span {
  display: block;
  font-size: 1rem;
  font-weight: 400;
  opacity: 0.7;
}

/* ===== Footer ===== */
.footer {
  background: var(--footer-bg);
  color: #b0c4de;
  padding: 40px 24px;
  font-size: 0.9rem;
}

.dark-mode .footer {
  background: var(--footer-bg-dark);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 32px;
  justify-content: center;
  margin-bottom: 20px;
}

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

.footer-copy {
  text-align: center;
  border-top: 1px solid #2a3f5a;
  padding-top: 20px;
  margin-top: 20px;
}

/* ===== 滚动动画 ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow) ease, transform var(--transition-slow) ease;
}

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

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }

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

  .hero-content h1 {
    font-size: 2.2rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    gap: 20px;
  }

  .container {
    padding: 0 16px;
  }

  .hero-banner {
    min-height: 60vh;
    padding: 40px 0;
  }

  .brand-story,
  .products,
  .cases,
  .news,
  .faq-section,
  .howto-section,
  .contact-area {
    padding: 50px 0;
  }

  .counter-grid {
    gap: 24px;
  }

  .counter-item {
    font-size: 2rem;
  }
}

@media (min-width: 769px) {
  .menu-toggle {
    display: none;
  }
}

/* ===== 返回顶部按钮 ===== */
#backToTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--primary);
  border: none;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  font-size: 24px;
  color: #0b1a2e;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  display: none;
  z-index: 99;
  transition: background var(--transition-normal), transform var(--transition-fast);
}

#backToTop:hover {
  background: var(--primary-dark);
  transform: scale(1.1);
}

.dark-mode #backToTop {
  color: #0b1421;
}

/* ===== 新闻卡片链接 ===== */
.news .card a {
  color: var(--primary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.news .card a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

/* ===== 联系区域卡片内边距微调 ===== */
.contact-area .card h3 {
  margin-bottom: 8px;
}

.contact-area .card p {
  margin-bottom: 4px;
}

/* ===== 品牌故事卡片标题 ===== */
.brand-story .card h3 {
  margin-bottom: 10px;
  font-size: 1.2rem;
}

/* ===== 产品卡片标题 ===== */
.products .card h3 {
  margin-bottom: 10px;
  font-size: 1.2rem;
}

/* ===== FAQ卡片 ===== */
.faq-section .card h4 {
  margin-bottom: 6px;
  font-size: 1.05rem;
}

/* ===== HowTo卡片 ===== */
.howto-section .card h3 {
  margin-top: 16px;
  margin-bottom: 6px;
  font-size: 1.1rem;
}

.howto-section .card h3:first-child {
  margin-top: 0;
}

/* ===== 案例卡片 ===== */
.cases .card h3 {
  margin-bottom: 8px;
  font-size: 1.1rem;
}

/* ===== 页脚版权文字 ===== */
.footer-copy p {
  margin-bottom: 0;
  line-height: 1.5;
}

/* ===== 暗色模式下的微调 ===== */
.dark-mode .hero-badge {
  background: rgba(255, 193, 7, 0.15);
}

.dark-mode .btn:hover {
  box-shadow: 0 12px 28px rgba(240, 179, 75, 0.4);
}

/* ===== 滚动条美化 (可选) ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: #f1f1f1;
}

.dark-mode ::-webkit-scrollbar-track {
  background: #1a2a3a;
}

::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}