/* ================= 1. 核心变量与基础重置 ================= */

:root {

    --primary: #0069b4;

    --dark: #1a1a1a;

    --gray: #666;

    --light-bg: #f5f7f9;

    --transition-smooth: all 0.8s cubic-bezier(0.2, 0.6, 0.2, 1);

    --header-pc: 80px;

    --header-mo: 60px;

}

* { 

    margin: 0; padding: 0; box-sizing: border-box; 

}

body {

    font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

    color: var(--dark);

    line-height: 1.6;

    overflow-x: hidden;

    background-color: #fff;

}

a { text-decoration: none; color: inherit; transition: 0.3s; }

ul { list-style: none; }



/*footer { background: #111; color: #fff; padding: 60px 0; text-align: center; font-size: 14px; opacity: 0.7; }*/



footer {

    background: #1a1a1a;

    color: #fff;

    padding: 4rem 5% 2rem;

}



.footer-content {

    display: grid;

    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));

    gap: 2rem;

    margin-bottom: 3rem;

}



.footer-col h4 {

    font-size: 1.2rem;

    margin-bottom: 1.5rem;

    color: var(--white);

}



.footer-col ul li {

    margin-bottom: 0.8rem;

}



.footer-col ul li a {

    color: #999;

    transition: var(--transition);

}



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



.copyright {

    text-align: center;

    padding-top: 2rem;

    border-top: 1px solid #333;

    color: #666;

    font-size: 0.9rem;

}



/* --- Keyframes --- */

@keyframes fadeUp {

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

}



/* --- Mobile 适配 --- */

@media (max-width: 768px) {

    .hero h1 { font-size: 2.5rem; }

    .nav-links { display: none; } /* 简化处理：移动端隐藏菜单 */

}

/* ================= 2. 导航栏 (Header) ================= */

.header {

    position: fixed;

    top: 0;

    left: 0;

    width: 100%;

    height: var(--header-pc);

    background: rgba(255, 255, 255, 0.95);

    backdrop-filter: blur(10px);

    z-index: 1000;

    box-shadow: 0 2px 15px rgba(0,0,0,0.05);

    transition: 0.3s;

}



.container {

    max-width: 1400px;

    margin: 0 auto;

    padding: 0 40px;

    height: 100%;

    display: flex;

    justify-content: space-between;

    align-items: center;

}

#logo{
    opacity: 100;
}

.logo {

    font-size: 24px;

    font-weight: 800;

    color: var(--primary);

    letter-spacing: -1px;

    z-index: 1001;            

}

.logo span { 

    color: #666; font-weight: 400; font-size: 16px; margin-left: 8px; 

}



/* PC 菜单布局 */

.nav-list { display: flex; height: 100%; }

.nav-item { height: 100%; display: flex; align-items: center; }

.nav-link {

    padding: 0 25px;

    font-size: 16px;

    font-weight: 500;

    height: 100%;

    display: flex;

    align-items: center;

    position: relative;

}

.nav-link::after {

    content: '';

    position: absolute;

    bottom: 0; left: 0;

    width: 0; height: 4px;

    background: var(--primary);

    transition: 0.3s;

}

.nav-item:hover .nav-link { color: var(--primary); }

.nav-item:hover .nav-link::after { width: 100%; }



/* --- PC端：横向全宽大菜单 --- */

.mega-menu {

    position: absolute;

    top: var(--header-pc);

    left: 0;

    width: 100vw;

    background: #fff;

    border-top: 1px solid #eee;

    box-shadow: 0 20px 40px rgba(0,0,0,0.08);

    padding: 50px 0;

    opacity: 0;

    visibility: hidden;

    transform: translateY(15px);

    transition: var(--transition-smooth);

    z-index: 999;

}

.nav-item:hover .mega-menu {

    opacity: 1;

    visibility: visible;

    transform: translateY(0);

}

.mega-grid {

    max-width: 1200px;

    margin: 0 auto;

    display: grid;

    grid-template-columns: repeat(4, 1fr);

    gap: 40px;

    padding: 0 20px;

}

.mega-col h4 {

    color: var(--primary);

    margin-bottom: 20px;

    font-size: 16px;

    border-left: 3px solid var(--primary);

    padding-left: 10px;

}

.mega-col a {

    display: block;

    padding: 8px 0;

    font-size: 14px;

    color: var(--gray);

}

.mega-col a:hover { color: var(--primary); transform: translateX(5px); }



/* ================= 3. 移动端菜单开关 (Hamburger) ================= */

.menu-toggle {

    display: none;

    flex-direction: column;

    gap: 6px;

    cursor: pointer;

    z-index: 1002;

}

.menu-toggle span {

    width: 28px;

    height: 2px;

    background: var(--dark);

    transition: 0.3s;

}



/* ================= 4. 滚动渐现动画 (Reveal) ================= */

.reveal {

    opacity: 0;

    transform: translateY(40px);

    transition: var(--transition-smooth);

}

.reveal.active {

    opacity: 1;

    transform: translateY(0);

}

.delay-1 { transition-delay: 0.15s; }

.delay-2 { transition-delay: 0.3s; }

.delay-3 { transition-delay: 0.45s; }

/* ================= 6. 移动端响应式处理 (Max 991px) ================= */

@media (max-width: 991px) {

    .container { padding: 0 20px; }

    .header { height: var(--header-mo); }

    .menu-toggle { display: flex; }



    /* 移动端菜单激活状态 */

    .is-active.menu-toggle span:nth-child(1) { transform: translateY(8px) rotate(45deg); }

    .is-active.menu-toggle span:nth-child(2) { opacity: 0; }

    .is-active.menu-toggle span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }



    .nav-list {

        position: fixed;

        top: var(--header-mo);

        left: 100%;

        width: 100%;

        height: calc(100vh - var(--header-mo));

        background: #fff;

        flex-direction: column;

        transition: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

        overflow-y: auto;

        display: block;

    }

    .nav-list.open { left: 0; }

    .nav-item { display: block; height: auto; border-bottom: 1px solid #f0f0f0; }

    .nav-link { height: 65px; justify-content: space-between; padding: 0 30px; font-size: 18px; }

    .nav-link::after { display: none; }

    

    /* 移动端下拉 */

    .mega-menu {

        position: static;

        width: 100%;

        display: none;

        opacity: 1;

        visibility: visible;

        transform: none;

        padding: 20px 0;

        background: #f9f9f9;

        box-shadow: none;

    }

    .nav-item.active .mega-menu { display: block; }

    .mega-grid { grid-template-columns: 1fr; gap: 30px; padding: 0 40px; }

    .mega-col h4 { border: none; padding: 0; margin-bottom: 10px; font-size: 15px; }



    /* 移动端内容适配 */

    .hero-content h1 { font-size: 36px; }

    .hero-content p { font-size: 16px; padding: 0 20px; }

    .card-grid { grid-template-columns: 1fr; padding: 0 20px; }

    .section { padding: 60px 0; }