/* =====================================================
   全局基础
===================================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    color: #222;
    background: #ffffff;
    line-height: 1.7;
    padding-top: 2px; /* 浮动导航预留 */
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    width: 1200px;
    margin: 0 auto;
}

/* =====================================================
   Header & Navigation（浮动 + 首页透明）
===================================================== */
header {
    position: sticky;
    top: 0;
    z-index: 999;
    background: #0B1C2D;
    color: #fff;
    transition: all 0.3s ease;
}

header.transparent {
    background: transparent;
    box-shadow: none;
}

header.scrolled {
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}

header.scrolled::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 1px;
    background: rgba(255,255,255,0.08);
}

.header-inner {
    height: 72px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}


/* =====================================================
   Logo：图片 + 文字（政企规范）
===================================================== */
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 600;
    letter-spacing: 1px;
    white-space: nowrap;
}

.logo img {
    height: 34px;
    width: auto;
    display: block;
}

header.transparent .logo span {
    color: #ffffff;
}

header.scrolled .logo span {
    color: #ffffff;
}

nav a {
    margin-left: 32px;
    font-size: 15px;
    color: rgba(255,255,255,0.8);
    position: relative;
    transition: color 0.3s ease;
}

nav a:hover {
    color: #4DA3FF;
}

/* 当前页面高亮 */
nav a.active {
    color: #4DA3FF;
}

nav a.active::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 100%;
    height: 2px;
    background: currentColor;
}

/* mobile menu */
.menu-btn {
  display: none;
  font-size: 26px;
  color: #fff;
  cursor: pointer;
}

.nav-mobile {
  display: none;
  flex-direction: column;
  background: #0b1c2d;
}

.nav-mobile a {
  padding: 14px 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  color: #fff;
}

/* =====================================================
   Banner（发布会级首屏）
===================================================== */
.banner {
    min-height: 48vh;
    background: linear-gradient(120deg, #0B1C2D, #123B6E);
    color: #fff;
    display: flex;
    align-items: center;
    text-align: center;
}

.banner h1 {
    font-size: 46px;
    font-weight: 600;
    margin-bottom: 20px;
}

.banner p {
    font-size: 20px;
    max-width: 820px;
    margin: 0 auto 18px;
    opacity: 0.9;
}

/* Banner 小指标（发布会风） */
.banner-stats {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 18px;
    font-size: 14px;
    color: rgba(255,255,255,0.75);
    margin-bottom: 30px;
    letter-spacing: 1px;
}

.banner-stats i {
    width: 4px;
    height: 4px;
    background: rgba(255,255,255,0.6);
    border-radius: 50%;
}

/* 主按钮 */
.cta-btn {
    display: inline-block;
    padding: 12px 36px;
    background: #4DA3FF;
    color: #fff;
    border-radius: 4px;
    font-size: 16px;
    transition: all 0.3s ease;
}

.cta-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(77,163,255,0.35);
}

/* 下滑指示 */
.scroll-indicator {
    margin: 60px auto 0;
    width: 24px;
    height: 40px;
    border: 2px solid rgba(255,255,255,0.7);
    border-radius: 20px;
    position: relative;
}

.scroll-indicator span {
    width: 6px;
    height: 6px;
    background: #fff;
    border-radius: 50%;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollDown 1.8s infinite;
}

@keyframes scrollDown {
    0% { opacity: 0; top: 8px; }
    30% { opacity: 1; }
    100% { opacity: 0; top: 24px; }
}

/* =====================================================
   Section 通用
===================================================== */
.section {
    padding: 90px 0;
}

.section.gray {
    background: #F5F7FA;
}

.section h2 {
    font-size: 34px;
    text-align: center;
    margin-bottom: 40px;
    font-weight: 600;
}

/* =====================================================
   卡片系统
===================================================== */
.card-group {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.card {
    background: #fff;
    padding: 32px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
}

.card h3 {
    font-size: 20px;
    margin-bottom: 15px;
}

.card p {
    color: #555;
    font-size: 16px;
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.08);
}

/* =====================================================
   横向数据指标
===================================================== */
.stats {
    display: flex;
    justify-content: space-between;
    text-align: center;
}

.stat {
    flex: 1;
}

.stat .num {
    font-size: 42px;
    font-weight: 700;
    color: #0B3C6D;
}

.stat .label {
    margin-top: 10px;
    font-size: 16px;
    color: #555;
}

/* =====================================================
   Reveal 动画
===================================================== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeUp 1.2s ease-out forwards;
}

@keyframes fadeUp {
    to { opacity: 1; transform: translateY(0); }
}

.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.9s ease;
}

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

/* =====================================================
   Footer
===================================================== */
footer {
    background: #0B1C2D;
    color: #aaa;
    padding: 40px 0;
    font-size: 14px;
    text-align: center;
}

/* =====================================================
   响应式增强（不破坏 PC，仅覆盖）
===================================================== */

/* ===============================
   通用容器适配
=============================== */
@media (max-width: 1200px) {
    .container {
        width: 100%;
        padding: 0 20px;
    }
}

/* ===============================
   移动端（手机）
=============================== */
@media (max-width: 768px) {

    /* Header */
    .header-inner {
        height: 64px;
    }

    nav {
        display: none;
    }

    .menu-btn {
        display: block;
        font-size: 26px;
        cursor: pointer;
        color: #fff;
    }

    /* Banner 精简 */
    .banner {
        min-height: auto;
        padding: 90px 0 60px;
    }

    .banner h1 {
        font-size: 24px;
        line-height: 1.4;
        margin-bottom: 12px;
    }

    .banner p {
        font-size: 15px;
        line-height: 1.8;
        padding: 0 10px;
    }

    .banner-stats,
    .scroll-indicator {
        display: none;
    }

    .cta-btn {
        padding: 10px 26px;
        font-size: 14px;
    }

    /* Section */
    .section {
        padding: 60px 0;
    }

    .section h2 {
        font-size: 24px;
        margin-bottom: 30px;
    }

    /* 卡片系统 */
    .card-group {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .card {
        padding: 24px;
    }

    .card h3 {
        font-size: 18px;
    }

    .card p {
        font-size: 15px;
    }

    /* 数据指标纵向 */
    .stats {
        flex-direction: column;
        gap: 30px;
    }

    .stat .num {
        font-size: 32px;
    }

    .stat .label {
        font-size: 14px;
    }

    /* Logo 缩放 */
    .logo {
        font-size: 16px;
        gap: 8px;
    }

    .logo img {
        height: 30px;
    }
}

/* ===============================
   平板（横屏 / 会议模式）
=============================== */
@media (min-width: 769px) and (max-width: 1024px) {

    .container {
        max-width: 960px;
        padding: 0 32px;
    }

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

    .banner p {
        font-size: 17px;
    }

    .section {
        padding: 70px 0;
    }

    .section h2 {
        font-size: 28px;
    }

    .card-group {
        grid-template-columns: repeat(2, 1fr);
        gap: 26px;
    }

    .stat .num {
        font-size: 36px;
    }
}

/* ================= Responsive ================= */
@media (max-width: 768px) {
  nav {
    display: none;
  }

  .menu-btn {
    display: block;
  }

  .nav-mobile.show {
    display: flex;
  }

  .banner {
    padding: 110px 20px 60px;
  }

  .banner h1 {
    font-size: 24px;
  }

  .banner p {
    font-size: 15px;
  }

  .card-group {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .card-group {
    grid-template-columns: repeat(2, 1fr);
  }
}