* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", sans-serif;
}

body {
  background: linear-gradient(120deg, #0a0f1c, #05080f);
  color: #fff;
  animation: fadeIn 1.2s ease-in;
}

/* 页面渐入 */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: scale(1.02);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* 导航栏 */
header {
  display: flex;
  justify-content: space-between;
  padding: 20px 50px;
  position: fixed;
  width: 100%;
  background: rgba(0,0,0,0.4);
  backdrop-filter: blur(12px);
  z-index: 1000;
}

.logo {
  font-size: 22px;
  color: #4da3ff;
}

nav a {
  margin-left: 20px;
  color: #ccc;
  text-decoration: none;
  transition: 0.3s;
}

nav a:hover {
  color: #4da3ff;
}

/* Hero */
.hero {
  height: 100vh;
  position: relative;
  color: #4da3ff;
}

.hero video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(35%);
}

.hero-content {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.hero h1 {
  font-size: 60px;
}

.hero button {
  margin-top: 20px;
  padding: 10px 25px;
  background: #4da3ff;
  border: none;
  border-radius: 5px;
}

/* 内容区 */
.section {
  padding: 100px 50px;
  text-align: center;
}

.section h2 {
  color: #4da3ff;
  margin-bottom: 40px;
}

/* 卡片布局 */
.cards {
  display: flex;
  justify-content: center;
  gap: 30px;
}

/* 卡片 */
.card {
  position: relative;
  width: 260px;
  height: 180px;
  overflow: hidden;
  border-radius: 12px;
  cursor: pointer;
  transition: 0.4s;
  color:hsl(184, 100%, 50%)
}

.card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: 0.4s;
}

/* 悬停放大 */
.card:hover {
  transform: scale(1.08);
}

.card:hover img {
  transform: scale(1.2);
}

/* 遮罩文字 */
.overlay {
  position: absolute;
  bottom: 0;
  width: 100%;
  padding: 20px;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
}

.overlay h3 {
  margin-bottom: 5px;
}

.overlay p {
  font-size: 12px;
  color: #ccc;
}

/* 页脚 */
footer {
  text-align: center;
  padding: 30px;
  color: #666;
}

/* 手机适配 */
@media (max-width: 768px) {

  header {
    padding: 15px 20px;
  }

  nav {
    display: none; /* 简单处理：先隐藏导航 */
  }

  .hero h1 {
    font-size: 32px;
  }

  .section {
    padding: 60px 20px;
  }

  .cards {
    flex-direction: column; /* 横排 → 竖排 */
    align-items: center;
  }

  .card {
    width: 90%;
    height: 180px;
  }

}

@media (max-width: 768px) {
  .hero video {
    object-fit: contain;
  }
}

/* ！！！汉堡菜单！！！ */
/* 汉堡按钮（默认隐藏） */
.menu-toggle {
  display: none;
  font-size: 28px;
  cursor: pointer;
}

/* 手机适配 */
@media (max-width: 768px) {

  .menu-toggle {
    display: block;
  }

  nav {
    position: fixed;
    top: 0;
    right: -100%; /* 初始隐藏 */
    width: 60%;
    height: 100vh;
    background: #0a0f1c;
    display: flex;
    flex-direction: column;
    padding-top: 80px;
    transition: 0.3s;
  }

  nav a {
    margin: 20px;
    font-size: 18px;
  }

  /* 打开状态 */
  nav.active {
    right: 0;
  }
}