/* ===================== 1. 全局基础重置（仅保留一次） ===================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ===================== 2. 导航栏独立模块 CSS（仅nav相关，可抽离独立文件） ===================== */
/* 导航私有变量，不污染全局 */
:root {
    --nav-primary: #4F46E5;
    --nav-primary-hover: #4338ca;
    --nav-radius-full: 9999px;
    --nav-gray-border: #e5e5e7;
    --nav-text: #1d1d1f;
    --nav-gray-bg-hover: #f5f5f7;
    --nav-shadow-dropdown: 0 4px 20px rgba(0,0,0,0.12);
    --nav-blur-bg: rgba(255, 255, 255, 0.8);
}

/* 导航外层容器（统一整合三套冲突导航样式，固定磨砂玻璃置顶） */
.nav-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    width: 100%;
    padding: 0 24px;
    background: var(--nav-blur-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid #f0f0f0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: 9999;
}

/* 左侧容器：语言选择 + Logo */
.left-part {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Logo 统一样式，删除重复两套logo代码 */
.logo {
    display: block;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: url("/images/logo.png") no-repeat center / contain;
    flex-shrink: 0;
}


/* PC端语言下拉、移动端语言下拉区分 */
.pc-only-lang {
    display: flex;
    align-items: center;
    margin-left: 20px;
}

/* iOS风格语言下拉 公共基础 */
.lang-dropdown {
    position: relative;
    display: inline-block;
}
.lang-trigger {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: #fff;
    border: 1px solid var(--nav-gray-border);
    border-radius: var(--nav-radius-full);
    font-size: 14px;
    color: var(--nav-text);
    white-space: nowrap;
}
.lang-trigger::after {
    content: "▼";
    font-size: 10px;
    color: #86868b;
}
.lang-panel {
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    min-width: 160px;
    background: #fff;
    border-radius: 14px;
    box-shadow: var(--nav-shadow-dropdown);
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transform: translateY(4px);
    transition: all 0.2s ease;
}
.lang-dropdown:hover .lang-panel {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.lang-panel a {
    display: block;
    padding: 11px 16px;
    font-size: 14px;
    color: var(--nav-text);
    text-decoration: none;
}
.lang-panel a:hover {
    background: var(--nav-gray-bg-hover);
}
.lang-panel a.active {
    color: #007aff;
    font-weight: 500;
}

/* 汉堡开关checkbox（默认隐藏） */
.mobile-menu-toggle {
    display: none;
}

/* 汉堡按钮 */
.mobile-menu-button {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}
.mobile-menu-button .bar {
    width: 24px;
    height: 2px;
    background: #333;
    transition: all 0.3s ease;
}
/* 汉堡点击叉号动画 */
.mobile-menu-toggle:checked ~ .mobile-menu-button .bar:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}
.mobile-menu-toggle:checked ~ .mobile-menu-button .bar:nth-child(2) {
    opacity: 0;
}
.mobile-menu-toggle:checked ~ .mobile-menu-button .bar:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

/* 汉堡下拉菜单容器 PC默认横向展示 */
.mobile-menu-content {
    display: flex;
    align-items: center;
    gap: 32px;
}

/* 中间导航链接区域 */
.middle-part {
    display: flex;
    gap: 28px;
}
.nav-link {
    color: var(--nav-text);
    font-size: 15px;
    text-decoration: none;
    transition: color 0.2s ease;
}
.nav-link:hover {
    color: var(--nav-primary);
}
.nav-link.active {
    color: var(--nav-primary);
    font-weight: 500;
}

/* 右侧登录注册区域 */
.right-part {
    display: flex;
    align-items: center;
    gap: 16px;
}
.user-center-link {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--nav-text);
    font-size: 14px;
    text-decoration: none;
    transition: color 0.2s ease;
}
.user-center-link:hover {
    color: var(--nav-primary);
}

/* 登录注册按钮 */
.login-btn, .register-btn {
    padding: 6px 14px;
    border-radius: var(--nav-radius-full);
    font-size: 14px;
    border: none;
    cursor: pointer;
    transition: background-color 0.2s ease;
}
.login-btn {
    background: transparent;
    border: 1px solid var(--nav-primary);
    color: var(--nav-primary);
}
.login-btn:hover {
    background: rgba(79, 70, 229, 0.08);
}
.register-btn {
    background: var(--nav-primary);
    color: #fff;
}
.register-btn:hover {
    background: var(--nav-primary-hover);
}

/* ========== 导航移动端响应式断点（仅导航相关，无重复媒体查询） ========== */
@media (max-width: 768px) {
    .lang-panel{
        left:0!important;
        right:auto!important;
    }
    .logo {
        display: none;
    }
    /* 显示汉堡按钮 */
    .mobile-menu-button {
        display: flex;
    }
    /* 汉堡弹窗样式 */
    .mobile-menu-content {
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background: #fff;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        display: none;
    }
    .mobile-menu-toggle:checked ~ .mobile-menu-content {
        display: flex;
    }
    /* 导航链接竖排 */
    .middle-part {
        flex-direction: column;
        gap: 16px;
        width: 100%;
    }
    .nav-link {
        width: 100%;
        padding: 6px 0;
    }
    /* 右侧按钮通栏居中 */
    .right-part {
        width: 100%;
        justify-content: center;
        margin-top: 16px;
        flex-direction: column;
    }
    .login-btn, .register-btn {
        width: 100%;
        text-align: center;
    }
    /* 切换语言下拉显隐 */
    .pc-only-lang {
        display: none;
    }
    .mobile-only-lang {
        display: inline-block;
        width: 100%;
    }
}

/* ===================== 3. 英雄区域核心样式 (pte-前缀防冲突) ===================== */
.pte-hero-section {
    position: relative;
    height: 315px;
    overflow: hidden;
    margin-top: 64px; /* 避开fixed导航高度 */
}
.pte-hero-bg {
    position: absolute;
    inset: 0;
    background-image: url('https://ai-public.mastergo.com/ai/img_res/2d8b56c78f96c021b647f348b0cbfbb8.jpg');
    background-size: cover;
    background-position: center;
}
.pte-hero-content {
    position: relative;
    height: 100%;
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    align-items: center;
}
.pte-hero-text-wrapper {
    width: 100%;
    text-align: center;
}
.pte-hero-main-title {
    font-size: 2.5rem;
    font-weight: bold;
    color: white;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}
.pte-hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 1rem;
}
.pte-hero-description {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 1rem;
}
.pte-hero-button-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}
/* 英雄区按钮通用 */
.pte-hero-btn {
    border-radius: 4px;
    padding: 0.75rem 1.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s ease;
    white-space: nowrap;
    text-decoration: none;
    display: inline-block;
    text-align: center;
    width: 100%;
    max-width: 200px;
    font-size: 13px;
    border: none;
    outline: none;
}
.pte-hero-btn-primary {
    background-color: #4F7AFF;
    color: white;
}
.pte-hero-btn-primary:hover {
    background-color: rgba(79, 122, 255, 0.9);
}
.pte-hero-btn-white {
    background-color: white;
    color: #4F7AFF;
}
.pte-hero-btn-white:hover {
    background-color: rgba(255, 255, 255, 0.9);
}
.pte-hero-btn-transparent {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
}
.pte-hero-btn-transparent:hover {
    background-color: rgba(255, 255, 255, 0.3);
}

/* 平板/桌面端适配 (768px以上) */
@media (min-width: 768px) {
    .lang-dropdown.mobile-only-lang {
        display: none;
    }
    
    
    .pte-hero-section {
        height: 500px;
    }
    .pte-hero-content {
        padding: 0 2rem;
    }
    .pte-hero-text-wrapper {
        width: 50%;
        text-align: left;
    }
    .pte-hero-main-title {
        font-size: 3.75rem;
        margin-bottom: 2.5rem;
        text-align: left;
    }
    .pte-hero-subtitle {
        font-size: 2.25rem;
        margin-bottom: 3rem;
    }
    .pte-hero-description {
        font-size: 1.25rem;
        margin-bottom: 3rem;
    }
    .pte-hero-button-group {
        flex-direction: row;
        align-items: center;
        gap: 1rem;
    }
    .pte-hero-btn {
        width: auto;
    }
}
/* 中大型桌面 */
@media (min-width: 1024px) {
    .pte-hero-content {
        padding: 0 3rem;
    }
}
/* 超大桌面 */
@media (min-width: 1280px) {
    .pte-hero-content {
        padding: 0 4rem;
    }
}

/* ===================== 4. 联系图标模块 ===================== */
.contact-us-icons {
    display: flex;
    gap: 10px;
    align-items: center;    
}
.contact-us-icons img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: contain;
}