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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  transition: background var(--transition), color var(--transition);
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--primary-dark);
}

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

ul, ol {
  list-style: none;
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 区块 */
.section {
  padding: 80px 0;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text);
}

.section-sub {
  font-size: 1.1rem;
  color: var(--text-light);
  margin-bottom: 48px;
  max-width: 600px;
}

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

/* 网格系统 */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

/* 卡片 */
.card {
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 14px 36px;
  background: var(--gradient);
  color: #fff;
  border-radius: 50px;
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
  text-align: center;
}

.btn:hover {
  transform: scale(1.03);
  box-shadow: 0 8px 25px rgba(108, 99, 255, 0.4);
  color: #fff;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

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

/* 徽章 */
.badge {
  display: inline-block;
  padding: 4px 16px;
  background: var(--gradient);
  color: #fff;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}

/* ===== Header ===== */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: var(--glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--glass-border);
  transition: background var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text);
}

.logo svg {
  width: 36px;
  height: 36px;
}

nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

nav a {
  padding: 8px 16px;
  border-radius: 8px;
  color: var(--text);
  font-weight: 500;
  font-size: 0.95rem;
  transition: background var(--transition), color var(--transition);
}

nav a:hover,
nav a.active {
  background: var(--primary);
  color: #fff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}

.menu-toggle span {
  width: 26px;
  height: 3px;
  background: var(--text);
  border-radius: 4px;
  transition: var(--transition);
}

.dark-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text);
  font-size: 1.2rem;
  border-radius: 50%;
  transition: background var(--transition);
}

.dark-toggle:hover {
  background: var(--border);
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient);
  position: relative;
  overflow: hidden;
  padding-top: 80px;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1200 800'%3E%3Ccircle cx='200' cy='200' r='300' fill='rgba(255,255,255,0.05)'/%3E%3Ccircle cx='1000' cy='600' r='400' fill='rgba(255,255,255,0.04)'/%3E%3C/svg%3E") no-repeat center/cover;
  pointer-events: none;
}

.hero-content {
  text-align: center;
  color: #fff;
  padding: 40px 24px;
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 20px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero p {
  font-size: 1.25rem;
  opacity: 0.9;
  margin-bottom: 36px;
}

.hero .btn {
  background: #fff;
  color: var(--primary);
  font-weight: 700;
}

.hero .btn:hover {
  box-shadow: 0 8px 30px rgba(255, 255, 255, 0.3);
}

.hero-badges {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 24px;
}

.hero-badges span {
  background: rgba(255, 255, 255, 0.15);
  padding: 8px 20px;
  border-radius: 30px;
  font-size: 0.9rem;
  backdrop-filter: blur(4px);
}

/* ===== Carousel ===== */
.carousel {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  margin: 40px 0;
}

.carousel-track {
  display: flex;
  transition: transform 0.6s ease;
}

.carousel-slide {
  min-width: 100%;
  padding: 60px 40px;
  background: var(--gradient);
  color: #fff;
  text-align: center;
}

.carousel-slide h3 {
  font-size: 1.8rem;
  margin-bottom: 12px;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.2);
  border: none;
  color: #fff;
  font-size: 2rem;
  padding: 12px 18px;
  cursor: pointer;
  border-radius: 50%;
  backdrop-filter: blur(4px);
  transition: background var(--transition);
}

.carousel-btn:hover {
  background: rgba(255, 255, 255, 0.4);
}

.carousel-prev {
  left: 16px;
}

.carousel-next {
  right: 16px;
}

.carousel-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 16px;
}

.carousel-dots button {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid var(--primary);
  background: transparent;
  cursor: pointer;
  transition: background var(--transition);
}

.carousel-dots button.active {
  background: var(--primary);
}

/* ===== FAQ ===== */
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.05rem;
  padding: 8px 0;
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  transition: transform var(--transition);
}

.faq-item.open .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 8px;
  color: var(--text-light);
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding: 12px 8px;
}

/* ===== 数字动画 ===== */
.stat-number {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--primary);
}

/* ===== Footer ===== */
footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand p {
  color: var(--text-light);
  margin-top: 12px;
  max-width: 300px;
}

.footer-links h4 {
  margin-bottom: 16px;
  font-weight: 700;
}

.footer-links a {
  display: block;
  padding: 4px 0;
  color: var(--text-light);
  font-size: 0.95rem;
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--text-light);
  font-size: 0.9rem;
}

/* ===== Back to top ===== */
.back-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  width: 48px;
  height: 48px;
  background: var(--gradient);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 1.4rem;
  cursor: pointer;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
  z-index: 999;
}

.back-top.visible {
  opacity: 1;
  visibility: visible;
}

/* ===== Scroll reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* ===== Breadcrumb ===== */
.breadcrumb {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  padding: 16px 0;
  color: var(--text-light);
  font-size: 0.9rem;
}

.breadcrumb a {
  color: var(--text-light);
}

.breadcrumb a:hover {
  color: var(--primary);
}

.breadcrumb span::before {
  content: '/';
  margin: 0 8px;
  color: var(--border);
}

/* ===== 响应式 ===== */
@media (max-width: 992px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr 1fr;
  }

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

  .hero h1 {
    font-size: 2.8rem;
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  nav {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--glass);
    backdrop-filter: blur(16px);
    padding: 16px;
    border-bottom: 1px solid var(--glass-border);
  }

  nav.open {
    display: flex;
  }

  nav a {
    padding: 12px 16px;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

  .section-title {
    font-size: 1.8rem;
  }

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

  .back-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.8rem;
  }

  .container {
    padding: 0 16px;
  }

  .section {
    padding: 48px 0;
  }
}