/* ===== 基础重置 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: #1a2b4a; line-height: 1.6; background: #fff;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== 导航栏 ===== */
#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(10, 31, 61, 0.85); backdrop-filter: blur(10px);
}
.nav-container {
  max-width: 1200px; margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo img { height: 96px; }
.nav-menu { display: flex; gap: 32px; }
.nav-menu a { color: #cfe3ff; font-size: 15px; }
.nav-menu a:hover { color: #00e5ff; }
.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-link { color: #cfe3ff; font-size: 14px; }
.nav-cta {
  background: linear-gradient(135deg, #00c9c9, #0099ff);
  color: #fff; padding: 8px 20px; border-radius: 20px; font-size: 14px;
}
.nav-toggle { display: none; color: #fff; font-size: 24px; cursor: pointer; }
/* 移动端登录注册项，PC端隐藏 */
.mobile-auth-item { display: none; }
.mobile-auth-divider { border-top: 1px solid rgba(255,255,255,0.15); padding-top: 14px; margin-top: 4px; }
.mobile-auth-item .nav-cta { display: inline-block; margin-top: 4px; }

/* ===== Hero ===== */
.hero {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #0a1f3d 0%, #0d2d5c 50%, #0066a3 100%);
}
.hero-bg {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(0,200,255,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,200,255,0.05) 1px, transparent 1px);
  background-size: 50px 50px;
}
.hero-content { position: relative; text-align: center; padding: 0 24px; max-width: 900px; }
.hero-logo {
  display: inline-block; width: 240px; max-width: 70%;
  margin-bottom: 26px;
  filter: drop-shadow(0 6px 24px rgba(0, 200, 255, 0.28));
}
.hero-title { font-size: 64px; font-weight: 800; color: #fff; letter-spacing: 4px; margin-bottom: 16px; }
.hero-subtitle { font-size: 22px; color: #00e5ff; margin-bottom: 32px; font-weight: 300; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-bottom: 40px; }
.hero-tags span {
  background: rgba(255,255,255,0.1); border: 1px solid rgba(0,229,255,0.4);
  color: #cfe3ff; padding: 6px 18px; border-radius: 20px; font-size: 14px;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  padding: 14px 36px; border-radius: 30px; font-size: 16px; font-weight: 600;
  transition: transform 0.2s, box-shadow 0.2s; cursor: pointer; display: inline-block; border: none;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0,200,255,0.3); }
.btn-primary { background: linear-gradient(135deg, #00c9c9, #0099ff); color: #fff; }
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,0.5); }
.btn-block { width: 100%; }
.hero-scroll {
  position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%);
  color: rgba(255,255,255,0.6); font-size: 24px; animation: bounce 2s infinite;
}
@keyframes bounce { 0%,100% { transform: translate(-50%,0); } 50% { transform: translate(-50%,8px); } }

/* ===== Section ===== */
.section { padding: 100px 0; }
.section-dark { background: linear-gradient(135deg, #0a1f3d 0%, #0d2d5c 100%); color: #fff; }
.section-title { font-size: 36px; font-weight: 700; text-align: center; margin-bottom: 12px; }
.section-dark .section-title { color: #fff; }
.section-desc { text-align: center; color: #6b7fa0; margin-bottom: 60px; font-size: 16px; }
.section-dark .section-desc { color: #9fc0e8; }

/* ===== 服务区 ===== */
.services-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.service-card {
  background: #f8faff; border-radius: 16px; padding: 36px 28px;
  transition: transform 0.3s, box-shadow 0.3s; border: 1px solid #e4ecf7;
}
.service-card:hover { transform: translateY(-6px); box-shadow: 0 12px 30px rgba(10,31,61,0.1); }
.service-icon { font-size: 40px; margin-bottom: 16px; }
.service-card h3 { font-size: 20px; margin-bottom: 10px; color: #0a1f3d; }
.service-card p { color: #6b7fa0; font-size: 14px; }

/* ===== 案例区 ===== */
.section-cases {
  position: relative; overflow: hidden;
  background: linear-gradient(180deg, #ffffff 0%, #f4f9ff 55%, #ffffff 100%);
}
/* 与首屏呼应的浅色网格，顶部渐隐，不影响卡片可读性 */
.section-cases::before {
  content: ''; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(0,153,255,0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,153,255,0.06) 1px, transparent 1px);
  background-size: 50px 50px;
  -webkit-mask-image: radial-gradient(circle at 50% 0%, #000 0%, transparent 72%);
  mask-image: radial-gradient(circle at 50% 0%, #000 0%, transparent 72%);
}
.section-cases .container { position: relative; }

/* 分类筛选 */
.cases-search { display: flex; justify-content: center; margin-bottom: 18px; }
.cases-search input {
  width: 100%; max-width: 480px; padding: 12px 20px; border-radius: 24px;
  border: 1px solid #e4ecf7; background: #fff; color: #1a2b4a;
  font-size: 14px; font-family: inherit;
  transition: border-color 0.25s, box-shadow 0.25s;
}
.cases-search input::placeholder { color: #9fb3cf; }
.cases-search input:focus { outline: none; border-color: #00c9c9; box-shadow: 0 4px 14px rgba(0,200,255,0.16); }

.cases-filter { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-bottom: 40px; }
.cases-filter button {
  display: inline-flex; align-items: center; gap: 6px;
  background: #fff; border: 1px solid #e4ecf7; color: #1a2b4a;
  padding: 8px 18px; border-radius: 20px; font-size: 14px; font-family: inherit;
  cursor: pointer; transition: color 0.25s, border-color 0.25s, background 0.25s, box-shadow 0.25s;
}
.cases-filter button em { font-style: normal; font-size: 12px; color: #8aa8cc; transition: color 0.25s; }
.cases-filter button:hover { border-color: #00c9c9; color: #0099ff; box-shadow: 0 4px 14px rgba(0,200,255,0.16); }
.cases-filter button:hover em { color: #0099ff; }
.cases-filter button.active {
  background: linear-gradient(135deg, #00c9c9, #0099ff);
  border-color: transparent; color: #fff;
  box-shadow: 0 6px 18px rgba(0,150,255,0.28);
}
.cases-filter button.active em { color: rgba(255,255,255,0.85); }

/* 案例滚动区：案例多时在框内滚动，避免整段把页面铺满 */
.cases-scroll {
  position: relative;
  max-height: 74vh;
  overflow-y: auto;
  padding-right: 8px;
  scrollbar-width: thin;
  scrollbar-color: #9fd4f5 #eef5fd;
  /* 底部内容柔和淡出：不使用叠加色块，避免与背景渐变产生色差 */
  -webkit-mask-image: linear-gradient(180deg, #000 0, #000 calc(100% - 30px), transparent 100%);
  mask-image: linear-gradient(180deg, #000 0, #000 calc(100% - 30px), transparent 100%);
}
.cases-scroll::-webkit-scrollbar { width: 8px; }
.cases-scroll::-webkit-scrollbar-track { background: #eef5fd; border-radius: 8px; }
.cases-scroll::-webkit-scrollbar-thumb { background: linear-gradient(180deg, #00c9c9, #0099ff); border-radius: 8px; }
.cases-scroll::-webkit-scrollbar-thumb:hover { background: linear-gradient(180deg, #00e5ff, #0099ff); }
.cases-hint { display: none; text-align: center; color: #6b7fa0; font-size: 13px; margin-top: 14px; }

/* 案例卡片 */
.cases-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.case-card {
  position: relative; overflow: hidden;
  background: #fff; border: 1px solid #e4ecf7; border-radius: 16px; padding: 26px 26px 24px;
  display: flex; flex-direction: column;
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}
/* 顶部渐变线：鼠标悬停时从左展开 */
.case-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, #00c9c9, #0099ff);
  transform: scaleX(0); transform-origin: left; transition: transform 0.35s;
}
.case-card:hover {
  transform: translateY(-6px); border-color: rgba(0,201,201,0.45);
  box-shadow: 0 14px 34px rgba(10,31,61,0.12);
}
.case-card:hover::before { transform: scaleX(1); }
/* 项目封面图：撑满卡片顶部 */
.case-cover {
  height: 150px; margin: -26px -26px 18px;
  border-radius: 15px 15px 0 0; overflow: hidden; background: #eef5fd;
}
.case-cover img { width: 100%; height: 100%; object-fit: cover; display: block; }
.case-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 16px; }
.case-icon {
  width: 44px; height: 44px; border-radius: 12px; flex: 0 0 auto;
  background: linear-gradient(135deg, rgba(0,201,201,0.14), rgba(0,153,255,0.14));
  display: flex; align-items: center; justify-content: center; font-size: 22px;
}
.case-tag {
  background: rgba(0,153,255,0.1); color: #0099ff;
  font-size: 12px; padding: 4px 12px; border-radius: 12px; white-space: nowrap;
}
.case-card h3 { font-size: 18px; margin-bottom: 10px; color: #0a1f3d; line-height: 1.45; }
.case-desc {
  color: #6b7fa0; font-size: 14px; margin-bottom: 16px;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.case-features { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.case-features span {
  background: #f8faff; border: 1px solid #e4ecf7; color: #1a2b4a;
  font-size: 12px; padding: 4px 10px; border-radius: 6px;
}
.case-foot { margin-top: auto; padding-top: 14px; border-top: 1px dashed #e4ecf7; }
.case-tech { color: #0099ff; font-size: 13px; line-height: 1.6; }
.case-demo { display: inline-block; margin-top: 10px; font-size: 13px; font-weight: 600; color: #0099ff; }
.case-demo:hover { color: #00c9c9; }
.cases-empty { display: none; text-align: center; color: #6b7fa0; font-size: 14px; }
/* 手机端「展开全部」 */
.cases-more { grid-column: 1 / -1; text-align: center; margin-top: 8px; }
.cases-more button {
  background: #fff; border: 1px solid #e4ecf7; color: #1a2b4a;
  padding: 10px 26px; border-radius: 24px; font-size: 14px; font-family: inherit;
  cursor: pointer; transition: color 0.25s, border-color 0.25s, box-shadow 0.25s;
}
.cases-more button:hover { border-color: #00c9c9; color: #0099ff; box-shadow: 0 4px 14px rgba(0,200,255,0.16); }

/* ===== 流程 ===== */
.process-steps { display: flex; align-items: flex-start; justify-content: center; gap: 8px; flex-wrap: wrap; }
.step { text-align: center; max-width: 160px; }
.step-num {
  width: 56px; height: 56px; border-radius: 50%; margin: 0 auto 16px;
  background: linear-gradient(135deg, #00c9c9, #0099ff); color: #fff;
  font-size: 24px; font-weight: 700; display: flex; align-items: center; justify-content: center;
}
.step h4 { font-size: 17px; margin-bottom: 8px; color: #fff; }
.step p { font-size: 13px; color: #9fc0e8; }
.step-arrow { color: #00e5ff; font-size: 24px; padding-top: 16px; }

/* ===== 优势 ===== */
.advantages-grid { display: grid; grid-template-columns: repeat(2,1fr); gap: 24px; }
.adv-card {
  background: #f8faff; border-left: 4px solid #00c9c9;
  padding: 28px 32px; border-radius: 8px;
}
.adv-card h3 { font-size: 18px; margin-bottom: 8px; color: #0a1f3d; }
.adv-card p { color: #6b7fa0; font-size: 14px; }

/* ===== 联系 ===== */
.contact-wrap { display: grid; grid-template-columns: 1.5fr 1fr; gap: 40px; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 14px 18px; margin-bottom: 16px;
  border: 1px solid rgba(255,255,255,0.2); border-radius: 8px;
  background: rgba(255,255,255,0.08); color: #fff; font-size: 15px; font-family: inherit;
}
.contact-form input::placeholder, .contact-form textarea::placeholder { color: #8aa8cc; }
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: #00e5ff; }
.contact-info h4 { font-size: 18px; margin-bottom: 20px; color: #fff; }
.contact-info p { color: #cfe3ff; margin-bottom: 12px; font-size: 15px; }
.contact-note { font-size: 12px; color: #6b8db5 !important; margin-top: 20px; }

/* ===== 页脚 ===== */
footer { background: #061328; color: #6b8db5; text-align: center; padding: 24px 0; font-size: 13px; }

/* ===== 回到顶部 ===== */
.back-to-top {
  position: fixed; right: 24px; bottom: 28px; width: 46px; height: 46px; border-radius: 50%;
  border: none; cursor: pointer; font-size: 20px; line-height: 1; z-index: 900;
  background: linear-gradient(135deg, #00c9c9, #0099ff); color: #fff;
  box-shadow: 0 8px 20px rgba(0,150,255,0.32);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: opacity 0.25s, transform 0.25s, visibility 0.25s;
}
.back-to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { box-shadow: 0 10px 26px rgba(0,200,255,0.45); }

/* ===== 登录/注册页 ===== */
.auth-page {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #0a1f3d 0%, #0d2d5c 50%, #0066a3 100%);
  padding: 20px;
}
.auth-container { width: 100%; max-width: 420px; }
.auth-card {
  background: rgba(255,255,255,0.06); backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,0.1); border-radius: 20px; padding: 40px 36px;
}
.auth-logo { text-align: center; margin-bottom: 24px; }
.auth-logo img { height: 96px; }
.auth-title { color: #fff; font-size: 26px; text-align: center; margin-bottom: 8px; }
.auth-subtitle { color: #9fc0e8; font-size: 14px; text-align: center; margin-bottom: 32px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; color: #cfe3ff; font-size: 13px; margin-bottom: 6px; }
.form-group input {
  width: 100%; padding: 12px 16px; border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.15); background: rgba(255,255,255,0.08);
  color: #fff; font-size: 15px; font-family: inherit;
}
.form-group input::placeholder { color: #8aa8cc; }
.form-group input:focus { outline: none; border-color: #00e5ff; }
.form-error { color: #ff6b6b; font-size: 13px; min-height: 20px; margin-bottom: 8px; }
.auth-switch { text-align: center; color: #9fc0e8; font-size: 14px; margin-top: 20px; }
.auth-switch a { color: #00e5ff; }
.auth-back { text-align: center; margin-top: 12px; }
.auth-back a { color: #8aa8cc; font-size: 13px; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .services-grid { grid-template-columns: repeat(2,1fr); }
  .cases-grid { grid-template-columns: repeat(2,1fr); }
  .advantages-grid { grid-template-columns: 1fr; }
  .contact-wrap { grid-template-columns: 1fr; }
  .process-steps { flex-direction: column; align-items: center; }
  .step-arrow { transform: rotate(90deg); padding: 0; }
}
@media (max-width: 640px) {
  .nav-logo img { height: 44px; }
  .nav-container { padding: 10px 14px; position: relative; }
  /* 移动端禁用毛玻璃：backdrop-filter 在部分手机浏览器会使下拉菜单无法绘制 */
  #navbar { backdrop-filter: none; -webkit-backdrop-filter: none; background: rgba(10,31,61,0.97); }
  /* 登录/注册常驻顶部右侧，不藏进汉堡菜单 */
  .nav-right { display: flex; gap: 10px; align-items: center; margin-left: auto; flex-shrink: 0; }
  .nav-right .nav-link { font-size: 13px; white-space: nowrap; }
  .nav-right .nav-cta { padding: 7px 15px; font-size: 13px; border-radius: 18px; }
  .nav-toggle { display: block; font-size: 22px; flex-shrink: 0; }
  /* 汉堡菜单只放锚点，登录注册不再重复 */
  .mobile-auth-item { display: none !important; }
  /* 下拉菜单：相对 nav-container 定位，全宽、层级最高、完整可见 */
  .nav-menu {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    background: rgba(10,31,61,0.99); flex-direction: column; padding: 16px 24px;
    gap: 14px; z-index: 1001; box-shadow: 0 10px 24px rgba(0,0,0,0.35);
  }
  .nav-menu.active { display: flex; }
  .nav-menu a { font-size: 15px; }
  .hero-logo { width: 180px; margin-bottom: 20px; }
  .hero-title { font-size: 34px; letter-spacing: 2px; }
  .hero-subtitle { font-size: 16px; }
  .hero-tags span { font-size: 13px; padding: 5px 14px; }
  .hero-actions .btn { padding: 12px 26px; font-size: 15px; width: 80%; text-align: center; }
  .services-grid { grid-template-columns: 1fr; }
  .cases-grid { grid-template-columns: 1fr; }
  /* 手机上不做框内滚动（避免和页面滚动打架），改用「展开全部」按钮 */
  .cases-scroll {
    max-height: none; overflow: visible; padding-right: 0;
    -webkit-mask-image: none; mask-image: none;
  }
  .cases-hint { display: none !important; }
  /* 手机上分类按钮改为横向滑动，避免换行占掉半屏 */
  .cases-filter {
    flex-wrap: nowrap; overflow-x: auto; justify-content: flex-start;
    gap: 8px; margin-bottom: 28px; padding-bottom: 4px; scrollbar-width: none;
  }
  .cases-filter::-webkit-scrollbar { display: none; }
  .cases-filter button { flex: 0 0 auto; padding: 7px 16px; font-size: 13px; }
  .case-card { padding: 22px 20px; }
  .case-cover { height: 132px; margin: -22px -20px 14px; }
  .case-head { margin-bottom: 14px; }
  .section { padding: 60px 0; }
  .section-title { font-size: 26px; }
  .service-card { padding: 28px 22px; }
  .contact-wrap { gap: 28px; }
  .auth-card { padding: 30px 24px; }
  .auth-logo img { height: 72px; }
  .auth-title { font-size: 22px; }
  footer { padding: 20px 16px; font-size: 12px; }
}