/* ========== 全局变量 ========== */
:root {
  --primary: #1565C0;
  --primary-light: #42A5F5;
  --accent: #E74C3C;
  --gold: #F5D316;
  --bg: #f5f7fa;
  --text: #333;
  --text-light: #666;
  --text-lighter: #999;
  --white: #fff;
  --shadow: 0 2px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.12);
  --radius: 12px;
  --max-width: 1200px;
  --header-height: 64px;
}

/* ========== 全局重置 ========== */
* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== 导航栏 ========== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 8px rgba(0,0,0,0.06);
  transition: box-shadow 0.3s;
}

.header.scrolled {
  box-shadow: 0 2px 20px rgba(0,0,0,0.1);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
}

.logo-img { height: 40px; width: auto; }
.logo-icon { font-size: 28px; line-height: 1; }

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

.nav-link {
  padding: 8px 18px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  transition: all 0.25s;
}

.nav-link:hover { background: rgba(21,101,192,0.08); color: var(--primary); }

.nav-link.active {
  background: rgba(21,101,192,0.1);
  color: var(--primary);
  font-weight: 600;
}

.nav-link-highlight {
  background: var(--primary);
  color: var(--white) !important;
  font-weight: 600;
  padding: 8px 22px;
}

.nav-link-highlight:hover {
  background: #0d47a1 !important;
  transform: translateY(-1px);
}

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ========== 轮播图 ========== */
.carousel {
  position: relative;
  width: 100%;
  height: 520px;
  margin-top: var(--header-height);
  overflow: hidden;
}

.carousel-track {
  display: flex;
  height: 100%;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.carousel-slide {
  min-width: 100%;
  height: 100%;
  position: relative;
}

.carousel-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.carousel-content {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-start;
  height: 100%;
  color: #fff;
  text-align: left;
  padding: 20px 0 0 60px;
}

.carousel-content h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 16px;
  text-shadow: 0 2px 12px rgba(0,0,0,0.2);
  animation: fadeInUp 0.8s ease;
}

.carousel-content p {
  font-size: 20px;
  opacity: 0.9;
  text-shadow: 0 1px 6px rgba(0,0,0,0.15);
  animation: fadeInUp 0.8s ease 0.2s both;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* 轮播指示点 */
.carousel-dots {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 3;
}

.carousel-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,0.4);
  cursor: pointer;
  transition: all 0.3s;
}

.carousel-dot.active {
  background: #fff;
  width: 28px;
  border-radius: 5px;
}

/* 轮播箭头 */
.carousel-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 3;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.3);
  background: rgba(255,255,255,0.12);
  color: #fff;
  font-size: 28px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.25s;
  backdrop-filter: blur(4px);
  line-height: 1;
}

.carousel-arrow:hover {
  background: rgba(255,255,255,0.25);
  border-color: rgba(255,255,255,0.6);
}

.carousel-prev { left: 24px; }
.carousel-next { right: 24px; }

/* ========== 功能区 ========== */
.features {
  padding: 80px 0 100px;
  background: var(--white);
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  color: var(--text);
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-light);
  font-size: 16px;
  margin-bottom: 56px;
}

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

.feature-card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 40px 32px;
  text-align: center;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}

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

.feature-icon {
  font-size: 48px;
  margin-bottom: 16px;
  line-height: 1;
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.feature-card p {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 16px;
}

.feature-tag {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 12px;
  background: rgba(21,101,192,0.08);
  color: var(--primary);
  font-weight: 500;
}

.feature-link {
  display: inline-block;
  padding: 6px 22px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  background: var(--primary);
  color: var(--white);
  transition: all 0.25s;
}

.feature-link:hover {
  background: #0d47a1;
  transform: scale(1.05);
}

/* ========== 页脚 ========== */
.footer {
  background: #DBEAFE;
  color: rgba(255,255,255,0.7);
  padding: 48px 0 36px;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
  font-size: 14px;
}

.footer-info { display: flex; justify-content: center; }
.footer-logo { width: 40%; height: auto; opacity: 1; }

.footer-links {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-links a {
  color: rgba(0,0,0,0.6);
  transition: color 0.2s;
}

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

.footer-divider { color: rgba(0,0,0,0.2); }

.footer-icp {
  padding-top: 12px;
  border-top: 1px solid rgba(0,0,0,0.08);
  font-size: 12px;
  color: rgba(0,0,0,0.4);
}

.footer-icp a { color: rgba(0,0,0,0.4); transition: color 0.2s; }
.footer-icp a:hover { color: rgba(0,0,0,0.7); }

/* ========== 响应式 ========== */
@media (max-width: 900px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }

  .carousel { height: 400px; }

  .carousel-content h1 { font-size: 32px; }
  .carousel-content p  { font-size: 16px; }

  .nav { display: none; }

  .nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(12px);
    padding: 16px 24px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    gap: 4px;
  }

  .nav.open .nav-link {
    width: 100%;
    text-align: center;
    padding: 12px;
  }

  .menu-toggle { display: flex; }
}

@media (max-width: 560px) {
  .feature-grid { grid-template-columns: 1fr; }

  .carousel { height: 320px; }

  .carousel-content h1 { font-size: 26px; }
  .carousel-content p  { font-size: 14px; }

  .carousel-arrow { width: 36px; height: 36px; font-size: 20px; }
}