/* 全局变量与重置 */
:root {
    --primary: #0D47A1;
    --primary-dark: #0A357A;
    --primary-light: #42A5F5;
    --success: #10B981;
    --bg-light: #F0F5FB;
    --text-dark: #0A1F3D;
    --text-gray: #667085;
    --white: #FFFFFF;
    --border-radius: 12px;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 8px 24px rgba(13, 71, 161, 0.15);
    --shadow-lg: 0 16px 48px rgba(13, 71, 161, 0.2);
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background: var(--white);
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}
/* 通用按钮样式 */
.btn {
    padding: 10px 24px;
    border: none;
    border-radius: 24px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    font-family: inherit;
}
.btn-light {
    background: var(--white);
    color: var(--primary);
    font-weight: 600;
}
.btn-light:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.btn-dark {
    background: var(--text-dark);
    color: var(--white);
    font-size: 13px;
    padding: 8px 20px;
}
.btn-dark:hover {
    background: var(--primary);
    animation: btnBounce 0.4s ease;
}
@keyframes btnBounce {
    0% { transform: translateY(0); }
    30% { transform: translateY(-3px); }
    50% { transform: translateY(0); }
    70% { transform: translateY(-3px); }
    100% { transform: translateY(0); }
}
.btn-full {
    width: 100%;
}
.btn-sm {
    padding: 6px 16px;
    font-size: 12px;
}
/* ========== 导航栏：初始渐变背景 + 滚动后毛玻璃半透明白底 ========== */
.navbar {
    position: sticky;
    top: 0;
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    box-shadow: none;
    z-index: 100;
    transition: all 0.6s ease-in-out;
    -webkit-transition: all 0.6s ease-in-out;
    width: 100%;
    margin: 0;
    padding: 0;
}
/* 滚动后状态：半透明白底 + 毛玻璃模糊 + 轻阴影 */
.navbar--scrolled {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: var(--shadow-sm);
}
.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    position: relative;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    position: relative;
    height: 40px;
}
.navbar .logo-img {
    height: 40px;
    width: 40px;
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    transition: opacity 0.6s ease-in-out;
}
.logo-white {
    opacity: 1;
    z-index: 2;
}
.logo-color {
    opacity: 0;
    z-index: 1;
}
.navbar--scrolled .logo-white {
    opacity: 0;
}
.navbar--scrolled .logo-color {
    opacity: 1;
}
.navbar .logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--white);
    margin-left: 50px;
    transition: color 0.4s ease-in-out;
}
.navbar--scrolled .logo-text {
    color: var(--primary);
}
.nav-links {
    display: flex;
    gap: 32px;
}
.nav-links a {
    text-decoration: none;
    color: var(--white);
    font-size: 14px;
    font-weight: 500;
    transition: color 0.4s ease-in-out;
}
.nav-links a:hover {
    color: var(--primary-light);
}
.navbar--scrolled .nav-links a {
    color: var(--text-dark);
}
.navbar--scrolled .nav-links a:hover {
    color: var(--primary);
}
/* PC端咨询按钮 */
.nav-container .btn-primary.nav-cta-btn {
    padding: 7.5px 24px;
    background: var(--white);
    color: var(--primary);
    transition: all 0.4s ease-in-out;
}
.nav-container .btn-primary.nav-cta-btn:hover {
    background: var(--bg-light);
    transform: translateY(-1px);
}
.navbar--scrolled .btn-primary.nav-cta-btn {
    background: var(--primary);
    color: var(--white);
}
.navbar--scrolled .btn-primary.nav-cta-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

/* ===================== 汉堡菜单核心样式 ===================== */
/* 隐藏原生复选框 */
.menu-toggle-input {
    display: none;
}
/* 汉堡按钮 默认隐藏 移动端显示 */
.hamburger-btn {
    display: none;
    width: 32px;
    height: 32px;
    position: relative;
    cursor: pointer;
    transition: transform 0.2s ease;
}
/* 悬浮放大动效 */
.hamburger-btn:hover {
    transform: scale(1.1);
}
/* 汉堡三线 */
.hamburger-btn .bar {
    position: absolute;
    width: 100%;
    height: 3px;
    border-radius: 2px;
    left: 0;
    transition: all 0.3s ease;
    background: var(--white);
}
/* 滚动后汉堡线条变深蓝色 */
.navbar--scrolled .hamburger-btn .bar {
    background: var(--primary);
}
.bar:nth-child(1) { top: 6px; }
.bar:nth-child(2) { top: 14px; }
.bar:nth-child(3) { top: 22px; }
/* 勾选后 三线转为关闭X */
.menu-toggle-input:checked ~ .hamburger-btn .bar:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}
.menu-toggle-input:checked ~ .hamburger-btn .bar:nth-child(2) {
    opacity: 0;
}
.menu-toggle-input:checked ~ .hamburger-btn .bar:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}
/* 移动端下拉菜单 默认隐藏 */
.mobile-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(12px);
    box-shadow: var(--shadow-md);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    z-index: 99;
}
/* 展开菜单 */
.menu-toggle-input:checked ~ .mobile-dropdown-menu {
    max-height: 400px;
}
/* 移动端导航链接容器 */
.mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 24px 16px;
}
.mobile-link {
    font-size: 16px;
    color: var(--text-dark);
    text-decoration: none;
    padding: 8px 0;
    border-bottom: 1px solid #eee;
    transition: color 0.2s;
}
.mobile-link:hover {
    color: var(--primary);
}
.mobile-cta-btn {
    margin-top: 12px;
    text-align: center;
    background: var(--primary);
    color: white;
}
.mobile-cta-btn:hover {
    background: var(--primary-dark);
}

/* ========================
   响应式适配：iPad & 手机
   ======================== */
/* --- iPad (768px - 1024px) --- */
@media (max-width: 1024px) {
    .container {
        padding: 0 20px;
    }
    .nav-links {
        gap: 20px;
    }
}
/* --- 手机 (< 768px) 核心改造点 --- */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }
    .nav-container {
        height: 56px;
    }
    /* 隐藏PC横向导航、PC咨询按钮 */
    .nav-links,
    .nav-cta-btn {
        display: none !important;
    }
    /* 显示汉堡按钮 */
    .hamburger-btn {
        display: block;
    }
    .logo-img {
        height: 32px;
    }
    .logo-text {
        font-size: 16px;
    }
}
/* --- 小屏手机 (< 480px) --- */
@media (max-width: 480px) {
    .logo-img {
        height: 32px;
    }
    .logo-text {
        font-size: 16px;
    }
}