:root {
    /* 核心色系：深邃科技蓝 + 活力青 + 紫色光晕 */
    --primary-color: #0052cc;
    --primary-gradient: linear-gradient(135deg, #0052cc 0%, #007bff 100%);
    --accent-color: #00d4ff;
    --accent-gradient: linear-gradient(135deg, #00d4ff 0%, #007bff 100%);
    
    /* 文字颜色 */
    --text-color: #2c3e50;
    --text-light: #5f6c7b;
    --text-white: #ffffff;
    
    /* 背景色 */
    --bg-white: #ffffff;
    --bg-light: #eff4fb; /* 加深背景色差，使分界更明显 */
    --bg-dark: #1a1f2e;
    
    /* 视觉效果 */
    --shadow: 0 4px 20px rgba(0, 82, 204, 0.08);
    --shadow-hover: 0 15px 35px rgba(0, 82, 204, 0.15);
    --glow: 0 0 15px rgba(0, 212, 255, 0.3);
    --radius: 12px;
    --container-width: 1200px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased; /* 平滑字体渲染 */
    -moz-osx-font-smoothing: grayscale;
}

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

ul {
    list-style: none;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background-color: rgba(255, 255, 255, 0.85); /* 增加透明度 */
    backdrop-filter: blur(20px); /* 增加磨砂感 */
    border-bottom: 1px solid rgba(255, 255, 255, 0.5);
    box-shadow: 0 4px 20px rgba(0, 82, 204, 0.05); /* 蓝色系微阴影 */
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    height: 70px;
    display: flex;
    align-items: center;
}

/* 确保页面内容不被固定导航栏遮挡 */
body {
    padding-top: 70px;
}

.header-container {
    display: flex;
    justify-content: flex-start; /* 移除 space-between，让内容靠左对齐 */
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color); /* Logo改回科技蓝 */
    display: flex;
    align-items: center;
    margin-right: 40px; /* Logo 右侧增加间距 */
}

/* 新增 .nav 样式，使其填满剩余空间并布局 */
.nav {
    display: flex;
    align-items: center;
    flex: 1;
    justify-content: flex-end; /* 让所有子元素（导航链接+电话）整体靠右 */
}

.nav-list {
    display: flex;
    gap: 30px;
}

.nav-item a {
    font-weight: 500;
    color: var(--text-color); /* 文字改回深灰色 */
    position: relative;
}

.nav-item a:hover, .nav-item a.active {
    color: var(--primary-color); /* 悬停变为科技蓝 */
}

.nav-item a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: var(--primary-color); /* 下划线也改为科技蓝 */
    transition: width 0.3s ease;
}

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

.header-phone {
    margin-left: 30px; /* 改为固定间距，不再自动撑满 */
    display: flex;
    align-items: center;
    color: #e63946; /* 醒目的红色 */
    font-weight: 700;
    font-size: 18px; /* 调大字号 */
    white-space: nowrap; /* 强制不换行 */
}

.header-phone .phone-icon {
    margin-right: 8px;
    font-size: 18px;
}

.mobile-menu-btn {
    display: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-color); /* 移动端按钮改为深色 */
}

/* Hero Section (已删除) */
/* .hero-section {
    padding-top: 140px;
    padding-bottom: 80px;
    background: linear-gradient(135deg, #001d6c 0%, #0f62fe 100%);
    color: white;
    text-align: center;
    position: relative;
    overflow: hidden;
} */

/* 简单的背景纹理效果 */
/* .hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: radial-gradient(circle at 20% 80%, rgba(255,255,255,0.1) 0%, transparent 20%),
                      radial-gradient(circle at 80% 20%, rgba(255,255,255,0.1) 0%, transparent 20%);
    pointer-events: none;
} */

/* .hero-content h1 {
    font-size: 48px;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero-content p {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.9;
} */

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, #0052cc 0%, #00c6ff 100%); /* 炫酷渐变 */
    color: white;
    border: none;
    box-shadow: 0 4px 15px rgba(0, 198, 255, 0.4); /* 蓝色辉光 */
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 198, 255, 0.6); /* 增强辉光 */
}

.btn-outline {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(5px);
    color: white;
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: white;
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.3);
}

.btn-large {
    font-size: 18px;
    padding: 15px 40px;
}

/* Section Common */
.section {
    padding: 100px 0;
    position: relative;
}

/* 科技感分割线装饰 */
.section::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    height: 1px;
    background: radial-gradient(circle, rgba(0, 82, 204, 0.2) 0%, transparent 70%);
}

.section:last-child::after {
    display: none;
}

.section-title {
    text-align: center;
    font-size: 38px;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 15px;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-subtitle {
    text-align: center;
    font-size: 14px;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 4px;
    margin-bottom: 70px;
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-subtitle::after {
    content: '';
    display: block;
    width: 40px;
    height: 3px;
    background: var(--accent-gradient);
    margin: 15px auto 0;
    border-radius: 2px;
}

/* Features */
.features-section {
    background-color: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    text-align: center;
    padding: 50px 30px;
    border-radius: var(--radius);
    background: white;
    box-shadow: 0 10px 30px rgba(0,0,0,0.03); /* 初始淡阴影 */
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    border: 1px solid rgba(0, 82, 204, 0.05);
    position: relative;
    overflow: hidden;
}

.feature-card::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; width: 100%; height: 3px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.feature-card:hover::after {
    transform: scaleX(1);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    background: rgba(0, 82, 204, 0.05);
    border-radius: 50%;
    margin-left: auto;
    margin-right: auto;
    box-shadow: 0 0 20px rgba(0, 82, 204, 0.1); /* 柔和光晕 */
    /* 移除之前的文字渐变裁剪，恢复 Emoji 原色 */
    /* background: var(--primary-gradient); */
    /* -webkit-background-clip: text; */
    /* -webkit-text-fill-color: transparent; */
}

.feature-card h3 {
    margin-bottom: 15px;
    font-size: 22px;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-light);
    font-size: 14px;
}

/* Courses */
.courses-section {
    background-color: var(--bg-light);
    position: relative;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.course-card {
    background: white;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    display: flex;
    flex-direction: column;
    height: 100%;
    border: 1px solid rgba(0,0,0,0.03);
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 82, 204, 0.12); /* 悬停深蓝阴影 */
}

.course-header {
    background: var(--primary-gradient); /* 渐变表头 */
    padding: 25px;
    color: white;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    overflow: hidden;
}

/* 课程卡片表头光效 */
.course-header::after {
    content: '';
    position: absolute;
    top: -50%; left: -50%; width: 200%; height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.course-card:hover .course-header::after {
    opacity: 1;
}

.course-icon {
    font-size: 32px;
}

.course-title {
    font-size: 18px;
    font-weight: 600;
}

.course-body {
    padding: 25px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.course-desc {
    color: var(--text-light);
    margin-bottom: 20px;
    flex-grow: 1;
}

.course-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tag {
    background: rgba(0, 82, 204, 0.08);
    color: var(--primary-color);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.course-card:hover .tag {
    background: var(--primary-color);
    color: white;
}

/* About - 首屏简约专业风格 */
.about-section {
    background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 100%);
    color: var(--text-color);
    padding-top: 140px; /* 适配导航栏 */
    padding-bottom: 100px;
    position: relative;
    overflow: hidden;
}

/* 装饰性背景网格 - 极淡 */
.about-section::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-image: linear-gradient(rgba(0, 82, 204, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 82, 204, 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,1), rgba(0,0,0,0));
    -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,1), rgba(0,0,0,0));
    pointer-events: none;
}

/* 移除动态光晕效果，改用极简装饰 */
.about-section::after {
    display: none;
}

.about-content {
    animation: fadeInUp 0.8s ease-out;
    position: relative;
    z-index: 10;
}

.about-content .section-title {
    text-align: left;
    color: var(--text-color);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 42px;
    margin-bottom: 20px;
}

.about-content p {
    color: var(--text-light) !important; /* 强制覆盖内联样式 */
    font-size: 18px;
    line-height: 1.8;
    max-width: 600px;
}

.about-stats {
    flex: 1;
    min-width: 300px;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    position: relative;
    z-index: 10;
}

.stat-item {
    background: white;
    border: 1px solid rgba(0, 0, 0, 0.05);
    padding: 30px;
    text-align: center;
    border-radius: var(--radius);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
}

.stat-item:hover {
    transform: translateY(-5px);
    background: white;
    box-shadow: 0 15px 35px rgba(0, 82, 204, 0.1);
    border-color: rgba(0, 82, 204, 0.1);
}

.stat-number {
    display: block;
    font-size: 42px;
    font-weight: 700;
    color: var(--primary-color); /* 改回科技蓝 */
    margin-bottom: 5px;
    text-shadow: none;
}

.stat-label {
    color: var(--text-light);
    font-size: 14px;
    font-weight: 500;
}

/* CTA */
.cta-section {
    background: linear-gradient(135deg, #001d6c 0%, #0f62fe 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

/* 复用 Hero Section 的背景纹理 */
.cta-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: radial-gradient(circle at 10% 90%, rgba(255,255,255,0.05) 0%, transparent 20%),
                      radial-gradient(circle at 90% 10%, rgba(255,255,255,0.05) 0%, transparent 20%);
    pointer-events: none;
}

.cta-section h2 {
    margin-bottom: 20px;
    font-size: 32px;
}

.cta-section p {
    margin-bottom: 40px;
    opacity: 0.8;
}

/* Partners */
.partners-section {
    background-color: white;
}

.partners-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 30px;
    align-items: center;
    justify-items: center;
}

.partner-logo {
    width: 100%;
    height: 80px;
    background: #f8faff;
    border: 1px solid rgba(0,0,0,0.05);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--text-light);
    font-size: 18px;
    transition: all 0.3s ease;
    cursor: default;
}

.partner-logo:hover {
    transform: translateY(-5px);
    background: white;
    box-shadow: var(--shadow);
    color: var(--primary-color);
    border-color: rgba(0, 82, 204, 0.2);
}

/* Modal */
.modal {
    display: none; /* 默认隐藏 */
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.6); /* 半透明黑色背景 */
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s;
}

.modal-content {
    background-color: white;
    margin: 10% auto;
    padding: 40px;
    border-radius: var(--radius);
    width: 90%;
    max-width: 400px;
    text-align: center;
    position: relative;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    animation: slideIn 0.3s;
}

.close-btn {
    position: absolute;
    top: 15px;
    right: 20px;
    color: #aaa;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.close-btn:hover {
    color: var(--text-color);
}

.modal-content h3 {
    margin-bottom: 25px;
    color: var(--primary-color);
    font-size: 22px;
}

.qr-code-wrapper {
    margin: 20px 0;
    padding: 10px;
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: var(--radius);
    display: inline-block;
}

.qr-code {
    width: 200px; /* 限制二维码大小 */
    height: 200px;
    object-fit: contain;
    display: block;
}

.modal-content p {
    color: var(--text-light);
    font-size: 14px;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* Footer */
.footer {
    background-color: #333333; /* 改为深灰色 */
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: flex-start; /* 顶部对齐 */
    gap: 40px;
    margin-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding-bottom: 40px;
}

.footer-info {
    flex: 2; /* 增加左侧信息栏比重 */
    min-width: 250px;
}

.footer-links {
    flex: 1;
}

.footer-qrcode {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center; /* 居中对齐 */
    min-width: 150px;
}

.footer-qrcode h4 {
    margin-bottom: 15px;
    font-size: 16px;
    color: white;
}

.qrcode-box {
    background: white;
    padding: 10px;
    border-radius: var(--radius);
    text-align: center;
    width: 140px;
}

.qrcode-box img {
    width: 120px;
    height: 120px;
    object-fit: contain;
    display: block;
    margin-bottom: 5px;
}

.qrcode-box p {
    color: #333;
    font-size: 12px;
    margin: 0;
    font-weight: 500;
}

.footer-logo {
    font-size: 24px;
    font-weight: 700;
    color: white;
    margin-bottom: 20px;
    display: block;
}

.footer-contact p {
    margin-bottom: 10px;
    color: #a8a8a8;
}

.footer-links h4 {
    margin-bottom: 20px;
    font-size: 18px;
}

.footer-links ul li {
    margin-bottom: 10px;
}

.footer-links a {
    color: #a8a8a8;
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    color: #666;
    font-size: 14px;
}

.icp-info {
    margin-top: 5px;
}

.icp-info a {
    color: #666;
    text-decoration: none;
    transition: color 0.3s ease;
}

.icp-info a:hover {
    color: white;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-list {
        display: none; /* 简化处理，实际项目需要JS控制菜单展开 */
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .hero-content h1 {
        font-size: 32px;
    }
    
    .hero-content p {
        font-size: 16px;
    }
    
    .btn-outline {
        margin-left: 0;
        margin-top: 15px;
        display: block; /* 移动端垂直排列 */
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
}