/* v=20261018b: 手机logo改max-width防盖☰ */
/* ============================================
   CAAC.AI 民航人工智能创新实验室
   全站共享样式表
   配色：政务蓝（#015293）+ 哑光金（#C0B283）
   ============================================ */

/* ---- 设计令牌 ---- */
:root {
    /* 红色系 - 主色调 */
    --red-primary: #015293;
    --red-dark: #01447A;
    --red-deep: #013359;
    --red-light: #3A7CB8;
    --red-bg: #E8F0F8;

    /* 黄色系 - 辅色调 */
    --yellow-primary: #C0B283;
    --yellow-dark: #A89759;
    --yellow-light: #DDD5B5;
    --yellow-bg: #F7F4EC;

    /* 红色点缀 - 用于强调与装饰线 */
    --gov-red: #C8102E;
    --gov-red-dark: #A50D26;

    /* 中性色 */
    --text-primary: #1a1a1a;
    --text-secondary: #555;
    --text-light: #888;
    --bg-white: #ffffff;
    --bg-gray: #f8f9fa;
    --bg-gray-2: #f0f1f3;
    --bg-dark: #1a1a1a;
    --bg-dark-2: #2a2a2a;
    --border-color: #e0e0e0;

    /* 渐变 */
    --gradient-main: #015293;
    --gradient-hero: #015293;
    --gradient-yellow: #C0B283;
    --gradient-red: #015293;

    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 20px rgba(1,82,147,0.12);
    --shadow-lg: 0 8px 40px rgba(1,82,147,0.18);
    --shadow-card: 0 2px 12px rgba(0,0,0,0.08);

    /* 尺寸 */
    --header-height: 78px;
    --max-width: 1400px;
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
}

/* ---- 基础重置 ---- */
* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-primary);
    background: var(--bg-white);
    line-height: 1.6;
    overflow-x: hidden;
    padding-top: var(--header-height);
}

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

/* ---- 通用布局 ---- */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.text-center { text-align: center; }
.mt-40 { margin-top: 20px; }

/* ---- 滚动渐入动画 ---- */
/* 渐入动画（默认可见，JS 加载后才启用隐藏→显示效果） */
.fade-in {
    opacity: 1;
    transform: none;
    transition: opacity 0.6s ease, transform 0.6s ease;
}
/* JS 启用后才隐藏 */
html.js-ready .fade-in {
    opacity: 0;
    transform: translateY(20px);
}
html.js-ready .fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   顶部导航栏（全站共享）
   ============================================ */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--header-height);
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 48px;
}

/* 全站 HEADER 底部分隔横线：距 LOGO/菜单底部 10px，属 HEADER 一部分 */
.header::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 2px;
    background: var(--yellow-dark);
    z-index: 1;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 7px 14px;
    text-decoration: none;
}

/* LOGO 图标块：蓝底金字 */
.logo-mark {
    background: #015293;
    color: var(--yellow-primary);
    font-size: 19px;
    font-weight: 800;
    letter-spacing: 0.5px;
    padding: 12px 20px;
    border-radius: 10px;
    box-shadow: var(--shadow-md);
    white-space: nowrap;
    transition: all 0.3s;
}

.logo:hover .logo-mark {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

/* LOGO 右侧文字 */
.logo-info {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-info-cn {
    font-size: 18px;
    font-weight: 700;
    color: #1a1a1a;
    letter-spacing: 1px;
}


.logo-info-domain {
    font-size: 12px;
    font-weight: 400;
    color: #999;
    letter-spacing: 4px;
    margin-top: 1px;
}

.nav {
    display: flex;
    gap: 16px 32px;
    align-items: center;
    margin-left: auto;
}

.nav a {
    color: var(--text-primary);
    font-size: 15px;
    font-weight: 500;
    padding: 4px 4px;
    position: relative;
    transition: color 0.3s;
}

.nav a:hover, .nav a.active { color: var(--red-primary); }
.nav a.active { font-weight: 700; }

/* 下划线指示器 */
.nav a::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 4px;
    right: 4px;
    height: 2px;
    background: var(--red-primary);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}
.nav a:hover::after,
.nav a.active::after { transform: scaleX(1); }

/* CTA 按钮 */
.nav-cta {
    background: var(--red-primary) !important;
    color: #fff !important;
    padding: 4px 20px !important;
    border-radius: 8px;
    font-weight: 600 !important;
    transition: all 0.3s;
}
.nav-cta:hover {
    background: var(--red-dark) !important;
    color: #fff !important;
    transform: translateY(-1px);
}
.nav-cta::after { display: none; }

/* 汉堡按钮（默认隐藏，移动端显示） */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-primary);
    padding: 2px 8px;
}

.section {
    padding: 27px 0;
}

.section-gray { background: #fff; }
.section-dark { background: var(--bg-dark); color: #fff; }
.section-yellow-bg { background: #fff; }

.section-tag {
    display: inline-block;
    background: var(--red-bg);
    color: var(--red-primary);
    padding: 2px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 4px;
}

.section-tag.yellow {
    background: var(--yellow-bg);
    color: var(--yellow-dark);
}

.section-tag.dark {
    background: rgba(192,178,131,0.15);
    color: var(--yellow-primary);
}

.section-title {
    font-size: 32px;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 5px;
    line-height: 1.3;
}

.section-title .accent {
    color: var(--yellow-dark);
}

.section-title.white { color: #fff; }
.section-title.white .accent {
    color: var(--yellow-primary);
}

.section-desc {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 700px;
    margin-bottom: 15px;
}

.section-dark .section-desc { color: rgba(255,255,255,0.7); }

/* ============================================
   按钮
   ============================================ */
.btn {
    padding: 5.5px 28px;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 4px 8px;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--yellow-primary);
    color: #013359;
    box-shadow: 0 4px 20px rgba(192,178,131,0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 28px rgba(192,178,131,0.55);
}

.btn-red {
    background: #015293;
    color: #fff;
    box-shadow: 0 4px 20px rgba(1,82,147,0.3);
}

.btn-red:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 28px rgba(1,82,147,0.4);
}

.btn-outline {
    background: transparent;
    color: var(--red-primary);
    border: 2px solid var(--red-primary);
}

.btn-outline:hover {
    background: var(--red-primary);
    color: #fff;
}

.btn-outline-white {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255,255,255,0.5);
}

.btn-outline-white:hover {
    background: rgba(255,255,255,0.1);
    border-color: #fff;
}

/* ============================================
   页面横幅（子页面顶部）
   ============================================ */
.page-banner {
    background: #F5F8FC;
    padding: 20px 0 17px;
    text-align: center;
    color: var(--text-secondary);
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--border-color);
}

.page-banner h1 {
    font-size: 32px;
    color: var(--red-primary);
    margin-bottom: 4px;
    letter-spacing: 1px;
}

/* 红色装饰短线 */
.page-banner::after {
    content: '';
    display: block;
    width: 48px;
    height: 3px;
    background: var(--gov-red);
    border-radius: 2px;
    margin: 7px auto 0;
}

.page-banner::before {
    content: '';
}

/* 面包屑导航 */
.breadcrumb {
    background: #fff;
    padding: 5px 0;
    font-size: 14px;
    color: var(--text-light);
    border-bottom: 1px solid var(--border-color);
}

.breadcrumb a { color: var(--red-primary); }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { margin: 0 8px; }

/* ============================================
   卡片网格
   ============================================ */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 9px 18px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px 16px; }

/* 通用卡片 */
.card {
    background: #fff;
    border-radius: var(--radius-md);
    padding: 12px 24px;
    box-shadow: var(--shadow-card);
    transition: all 0.3s;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.card-border-top { border-top: 4px solid var(--red-primary); }
.card-border-top.yellow { border-top-color: var(--yellow-dark); }

/* 图标圆 */
.icon-circle {
    width: 48px; height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 22px;
    margin-bottom: 6px;
}

.icon-circle.red { background: #015293; color: #fff; }
.icon-circle.yellow { background: var(--yellow-dark); color: #fff; }
.icon-circle.light-red { background: var(--red-bg); color: var(--red-primary); }
.icon-circle.light-yellow { background: var(--yellow-bg); color: var(--yellow-dark); }

/* ============================================
   数据统计块
   ============================================ */
.stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 4.5px 0;
    border-bottom: 1px solid var(--border-color);
}

.stat-row:last-child { border-bottom: none; }

.stat-label { font-size: 14px; color: var(--text-secondary); }

.stat-value {
    font-size: 22px;
    font-weight: 800;
    color: var(--red-primary);
}

.stat-value span {
    font-size: 13px;
    font-weight: 400;
    color: var(--text-light);
}

/* 大数字展示 */
.big-stat {
    text-align: center;
}

.big-stat-num {
    font-size: 36px;
    font-weight: 900;
    color: #015293;
    line-height: 1;
}

.big-stat-label {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 3px;
}

/* ============================================
   时间线
   ============================================ */
.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 10px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #015293;
    border-radius: 1px;
}

.timeline-item {
    position: relative;
    padding-bottom: 14px;
    margin-bottom: 4px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -36px;
    top: 4px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--red-primary);
    border: 3px solid #fff;
    box-shadow: 0 0 0 2px var(--red-primary);
}

.timeline-date {
    display: inline-block;
    background: var(--red-bg);
    color: var(--red-primary);
    padding: 1.5px 14px;
    border-radius: 16px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 4px;
}

.timeline-item h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 3px;
}

.timeline-item p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   底部 Footer（全站共享）
   ============================================ */
.footer {
    background: #F8F9FA;
    color: var(--text-secondary);
    padding: 30px 0 0;
    margin-top: 40px;
    border-top: 3px solid var(--red-primary);
}

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

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 24px 48px;
    padding-bottom: 24px;
}

.footer-brand h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.footer-brand p {
    font-size: 14px;
    line-height: 2;
    color: #999;
}

.footer-col h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 9px;
    padding-left: 10px;
    border-left: 3px solid var(--gov-red);
}

.footer-col ul li {
    margin-bottom: 6px;
    font-size: 14px;
    color: #999;
}

.footer-col ul li a {
    color: #666;
    transition: color 0.2s;
}

.footer-col ul li a:hover {
    color: var(--yellow-primary);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding: 12px 0;
    text-align: center;
    font-size: 13px;
    color: #888;
}

/* ---- 响应式 ---- */
@media (max-width: 768px) {
    /* 移动端导航 */
    .header { padding: 0 20px; }
    .logo { position: absolute; left: 20px; max-width: calc(100% - 80px); }
    .nav-toggle { display: block; position: relative; z-index: 2; }
    .nav {
        display: none;
        position: fixed;
        top: var(--header-height);
        left: 0; right: 0;
        background: #fff;
        flex-direction: column;
        gap: 0;
        padding: 8px 0;
        box-shadow: var(--shadow-md);
        border-top: 1px solid var(--border-color);
        z-index: 999;
    }
    .nav.open { display: flex; }
    .nav li { width: 100%; }
    .nav a {
        display: block;
        padding: 7px 24px;
        font-size: 16px;
        border-bottom: 1px solid var(--border-color);
    }
    .nav a::after { display: none; }
    .nav-cta {
        margin: 6px 24px;
        text-align: center;
        border-bottom: none !important;
    }

    /* 布局网格折叠：3列→1列，4列→2列 */
    .grid-3 { grid-template-columns: 1fr; gap: 7px 14px; }
    .grid-4 { grid-template-columns: repeat(2, 1fr); gap: 6px 12px; }
    /* fixed 头部防被横向溢出撑宽 */
    .header { max-width: 100vw; }
    /* Footer */
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 16px 32px;
    }
    .footer-brand {
        grid-column: 1 / -1;
    }
    /* 页脚链接加大点击区 */
    .footer-col a {
        display: inline-block;
        padding: 2.5px 0;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    /* 手机端 LOGO 收紧，防压右侧汉堡 */
    .logo { gap: 5px 10px; }
    .logo-mark { font-size: 15px; padding: 9px 12px; }
    .logo-info-cn { font-size: 15px; letter-spacing: 0.5px; }
    .logo-info-domain { font-size: 9.5px; letter-spacing: 2px; }
}
/* ============================================
   导航下拉菜单（中心介绍） 20261017
   ============================================ */
.nav-drop { position: relative; }

.nav-caret {
    font-size: 11px;
    margin-left: 3px;
    display: inline-block;
    transition: transform 0.3s ease;
}

.nav-drop-menu {
    position: absolute;
    top: 100%;
    left: -16px;
    min-width: 168px;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 8px 28px rgba(1, 82, 147, 0.14);
    border: 1px solid rgba(192, 178, 131, 0.35);
    padding: 4px 0;
    margin: 0;
    list-style: none;
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition: all 0.25s ease;
    z-index: 1000;
}

.nav-drop:hover .nav-drop-menu,
.nav-drop.open .nav-drop-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(4px);
}

.nav-drop:hover .nav-caret { transform: rotate(180deg); }

.nav-drop-menu li { list-style: none; }

.nav-drop-menu a {
    display: block;
    padding: 5px 22px;
    font-size: 14px;
    color: var(--text-primary) !important;
    white-space: nowrap;
    transition: all 0.2s;
}

.nav-drop-menu a::after { display: none; }

.nav-drop-menu a:hover {
    color: var(--red-primary) !important;
    background: rgba(200, 16, 46, 0.05);
}

.nav-drop-menu a.active {
    color: var(--red-primary) !important;
    font-weight: 600;
    background: rgba(200, 16, 46, 0.04);
}

/* 箭头小三角 */
.nav-drop-menu::before {
    content: '';
    position: absolute;
    top: -5px;
    left: 32px;
    width: 10px;
    height: 10px;
    background: #fff;
    border-left: 1px solid rgba(192, 178, 131, 0.35);
    border-top: 1px solid rgba(192, 178, 131, 0.35);
    transform: rotate(45deg);
}

/* 移动端：下拉改为点击展开、内嵌显示 */
@media (max-width: 768px) {
    .nav-drop-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: none;
        border-left: 2px solid rgba(192, 178, 131, 0.5);
        border-radius: 0;
        margin: 2px 0 4px 12px;
        padding: 0 0 0 4px;
        display: none;
        background: rgba(1, 82, 147, 0.03);
    }
    .nav-drop.open .nav-drop-menu { display: block; }
    .nav-drop-menu::before { display: none; }
    .nav-caret { float: right; }
}