/* 通用重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Microsoft YaHei', Arial, sans-serif;
  font-size: 14px;
  line-height: 1.4;
  color: #eee;

  /* 背景图片 + 叠加渐变效果 */
  background:
    linear-gradient(135deg, rgba(15, 32, 39, 0.85), rgba(44, 83, 100, 0.85)),
    url('/bj.jpg') no-repeat center center fixed;
  background-size: cover;

  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  width: 90%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 20px 10px;
}

/* 头部 */
header {
  background-color: rgba(10, 25, 40, 0.85);
  padding: 12px 0;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
  position: sticky;
  top: 0;
  z-index: 1000;
}

header h1 a {
  color: #00bfff;
  font-size: 1.8rem;
  font-weight: bold;
  text-decoration: none;
  letter-spacing: 1.5px;
  transition: color 0.3s ease;
}

header h1 a:hover {
  color: #1e90ff;
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 10px;
  flex-wrap: wrap;
}

nav ul li a {
  color: #cce7ff;
  font-weight: 600;
  font-size: 0.9rem;
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 8px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

nav ul li a:hover,
nav ul li a:focus {
  background-color: #00bfff;
  color: #0a0a0a;
  outline: none;
}

/* 介绍区 */
.intro {
  text-align: center;
  padding: 30px 0 20px;
  max-width: 850px;
  margin: 0 auto 40px;
}

.intro h2 {
  font-size: 2.2rem;
  margin-bottom: 12px;
  color: #00d4ff;
  text-shadow: 0 0 6px #00d4ff;
}

.intro p {
  font-size: 1rem;
  color: #d0e9ff;
  margin-bottom: 25px;
  line-height: 1.4;
}

/* 按钮组 */
.cta-btns {
  display: flex;
  justify-content: center;
  gap: 18px;
}

.btn-primary {
  background-color: #00bfff;
  color: #0a0a0a;
  padding: 12px 28px;
  font-weight: 700;
  font-size: 1rem;
  border: none;
  border-radius: 40px;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(0, 191, 255, 0.7);
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.btn-primary:hover,
.btn-primary:focus {
  background-color: #0096d6;
  box-shadow: 0 6px 18px rgba(0, 150, 214, 0.9);
  color: #fff;
  outline: none;
}

/* 核心功能 */
.features {
  background-color: rgba(15, 32, 39, 0.7);
  padding: 30px 20px;
  border-radius: 16px;
  max-width: 850px;
  margin: 0 auto 50px;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
}

.features h2 {
  color: #00d4ff;
  font-size: 1.7rem;
  margin-bottom: 20px;
  text-align: center;
  text-shadow: 0 0 5px #00d4ff;
}

.features ul {
  list-style: none;
  padding-left: 0;
  color: #d0e9ff;
  font-size: 1rem;
  line-height: 2;
  max-width: 700px;
  margin: 0 auto;
}

.features ul li::before {
  content: "✔";
  color: #00bfff;
  margin-right: 10px;
  font-weight: 900;
}

/* 图片画廊 */
.gallery {
  max-width: 1100px;
  margin: 0 auto 50px;
  padding: 0 10px;
  text-align: center;
}

.gallery h2 {
  font-size: 1.8rem;
  margin-bottom: 20px;
  color: #00d4ff;
  text-shadow: 0 0 6px #00d4ff;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 18px;
}

.gallery-grid img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: 0 5px 16px rgba(0, 191, 255, 0.6);
  transition: transform 0.25s ease;
  cursor: pointer;
}

.gallery-grid img:hover,
.gallery-grid img:focus {
  transform: scale(1.04);
  outline: none;
}

/* SEO 内容区域 */
.seo-content {
  background: rgba(15, 32, 39, 0.6);
  padding: 30px 20px;
  border-radius: 16px;
  max-width: 850px;
  margin: 0 auto 50px;
  color: #ccefff;
  font-size: 0.95rem;
  line-height: 1.6;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
}

.seo-content h2,
.seo-content h3 {
  color: #00bfff;
  margin-bottom: 15px;
  text-shadow: 0 0 5px #00bfff;
}

.seo-content ul {
  list-style: none;
  padding-left: 1.2em;
  margin-bottom: 18px;
}

.seo-content ul li {
  margin-bottom: 10px;
  position: relative;
  padding-left: 18px;
}

.seo-content ul li::before {
  content: "✓";
  color: #00bfff;
  position: absolute;
  left: 0;
  font-weight: 700;
}

/* 免费试用提示 */
.free-trial {
  text-align: center;
  margin-bottom: 50px;
  font-size: 1rem;
  color: #b3e0ff;
}

.free-trial a {
  color: #00bfff;
  font-weight: 700;
  text-decoration: underline;
  transition: color 0.3s ease;
}

.free-trial a:hover,
.free-trial a:focus {
  color: #0096d6;
  outline: none;
}

/* 页脚 */
footer {
  background-color: rgba(10, 25, 40, 0.85);
  padding: 16px 0;
  text-align: center;
  font-size: 0.85rem;
  color: #a0cfff;
  box-shadow: inset 0 1px 3px rgba(255, 255, 255, 0.1);
  user-select: none;
}

/* 响应式 */
@media (max-width: 768px) {
  .intro h2 {
    font-size: 1.8rem;
  }
  .features h2, .gallery h2, .seo-content h2 {
    font-size: 1.4rem;
  }
  nav ul {
    flex-wrap: wrap;
    gap: 12px;
  }
  .gallery-grid {
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  }
  .btn-primary {
    padding: 10px 22px;
    font-size: 0.9rem;
  }
}