/* 变量与基础 */
:root {
    --primary-color: #4E23DC; /* 科技蓝 */
    --secondary-color: #6C63FF;
    --accent-color: #00F0FF; /* 强调色，用于点缀 */
    --dark-color: #1A1A2E; /* 深色背景 */
    --light-color: #F0F2F5; /* 浅色背景 */
    --text-color-dark: #333;
    --text-color-light: #E0E0E0; /* 用于深色背景上的浅色文本 */
    --success-color: #28a745;
    --danger-color: #dc3545;
    --max-width: 1200px;
    --transition: all 0.3s ease;
    --font-family-heading: 'Inter', 'Roboto', 'Montserrat', sans-serif; /* 标题字体 */
    --font-family-body: 'PingFang SC', 'Microsoft YaHei', sans-serif; /* 正文字体 */
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: var(--font-family-body);
    line-height: 1.6; color: var(--text-color-dark); background-color: var(--light-color);
    overflow-x: hidden;
}
a { text-decoration: none; color: var(--dark-color); }
ul { list-style: none; }
img { max-width: 100%; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; width: 100%; }

/* 按钮 */
.btn {
    display: inline-block; background: var(--primary-color); color: #fff;
    padding: 10px 25px; border: none; border-radius: 5px; cursor: pointer;
    font-size: 16px; font-weight: 500; transition: var(--transition);
}
.btn:hover { background: #3a1bb0; transform: translateY(-3px); }
.btn-outline { background: transparent; border: 2px solid var(--primary-color); color: var(--primary-color); }
.btn-outline:hover { background: var(--primary-color); color: #fff; }

.highlight-text {
    color: var(--primary-color);
    font-size: 1.2em; /* 相对于父元素的字体大小 */
    font-weight: 600;
}

/* 导航 */
.navbar {
    position: fixed; top: 0; left: 0; width: 100%;
    background-color: var(--dark-color); box-shadow: 0 2px 10px rgba(0,0,0,0.5);
    z-index: 1000; height: 80px; display: flex; align-items: center;
}
.navbar .container { display: flex; justify-content: space-between; align-items: center; height: 100%; padding-left: 10px; }
.logo a { display: flex; align-items: center; color: var(--text-color-light); font-weight: 700; font-size: 1.5rem; }
.logo img { height: 40px; margin-right: 10px; }
.nav-menu { display: flex; align-items: center; }
.nav-menu li { margin-left: 80px; }
.nav-menu a { color: var(--text-color-light); font-weight: 500; font-size: 1rem; transition: var(--transition); position: relative; padding: 5px 0; }
.nav-menu a:hover, .nav-menu a.active { color: var(--primary-color); }
.nav-menu a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--primary-color); transition: var(--transition); }
.nav-menu a:hover::after, .nav-menu a.active::after { width: 100%; }
.nav-toggle { display: none; flex-direction: column; cursor: pointer; }
.nav-toggle span { display: block; width: 25px; height: 3px; background-color: var(--text-color-light); margin-bottom: 5px; border-radius: 2px; transition: var(--transition); }
main { margin-top: 80px; }

/* 通用分区与卡片 */
.features { padding: 80px 0; background-color: var(--light-color); }
.section-title { text-align: center; margin-bottom: 50px; font-size: 2.2rem; color: var(--dark-color); position: relative; }
.section-title::after { content: ''; position: absolute; bottom: -10px; left: 50%; transform: translateX(-50%); width: 80px; height: 3px; background: var(--primary-color); }
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px,1fr)); gap: 30px; }
.feature-card { background: #fff; padding: 30px; border-radius: 10px; box-shadow: 0 5px 15px rgba(0,0,0,0.1); text-align: center; transition: var(--transition); }
.feature-card:hover { transform: translateY(-10px); box-shadow: 0 10px 20px rgba(0,0,0,0.1); }
.feature-card i { font-size: 3rem; color: var(--primary-color); margin-bottom: 20px; }
.feature-card h3 { font-size: 1.5rem; margin-bottom: 15px; }

/* 关于我们与预览 */
.about-preview { padding: 80px 0; }
.about-preview .container { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.about-content p { margin-bottom: 30px; font-size: 1.1rem; line-height: 1.8; }
.about-image img { border-radius: 10px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); }

/* 关于页面首屏 */
.about-hero { background: linear-gradient(135deg, var(--primary-color), var(--secondary-color)); color: #fff; text-align: center; min-height: 100vh; display: flex; align-items: center; justify-content: center; }
.about-hero .container { padding: 80px 0; }
.about-hero h1 { font-size: 3rem; margin-bottom: 20px; }
.about-hero p { font-size: 1.2rem; max-width: 600px; margin: 0 auto 30px; }
.about-content { padding: 80px 0; }
.about-content .container { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.about-text .section-title { text-align: left; margin-bottom: 30px; }
.about-text .section-title::after { left: 0; transform: none; }
.about-text p { margin-bottom: 20px; font-size: 1.1rem; line-height: 1.8; color: #666; }

/* 页脚 */
footer { background-color: #000; color: #fff; padding: 60px 0 20px; }
.footer-content { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px,1fr)); gap: 30px; margin-bottom: 40px; }
.footer-logo { display: flex; align-items: center; margin-bottom: 20px; }
.footer-logo img.logo-icon { height: 40px; margin-right: 10px; }
.footer-links h3, .footer-contact h3, .footer-social h3 { font-size: 1.2rem; margin-bottom: 20px; position: relative; }
.footer-links h3::after, .footer-contact h3::after, .footer-social h3::after { content: ''; position: absolute; bottom: -8px; left: 0; width: 40px; height: 2px; background: var(--primary-color); }
.footer-links ul li { margin-bottom: 10px; }
.footer-links ul li a { color: #ccc; transition: var(--transition); }
.footer-links ul li a:hover { color: var(--primary-color); padding-left: 5px; }
.footer-contact p { margin-bottom: 15px; color: #ccc; display: flex; align-items: center; }
.footer-contact p i { margin-right: 10px; color: var(--primary-color); }
.social-icons { display: flex; gap: 15px; }
.social-icons a { display: flex; align-items: center; justify-content: center; width: 40px; height: 40px; background: #333; border-radius: 50%; color: #fff; transition: var(--transition); }
.social-icons a:hover { background: var(--primary-color); transform: translateY(-5px); }
.footer-bottom { text-align: center; padding-top: 20px; border-top: 1px solid #444; font-size: 0.9rem; color: #ccc; }
.footer-bottom a { color: #ccc; transition: var(--transition); }
.footer-bottom a:hover { color: var(--primary-color); }

/* LOGO尺寸 */
.logo-icon { height: 40px; width: auto; margin-right: 10px; }
.logo-text { height: 30px; width: auto; }

/* 下拉箭头（保留给其他页面使用） */
.scroll-indicator { position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%); display: flex; flex-direction: column; align-items: center; animation: bounce 2s infinite; cursor: pointer; }
.scroll-indicator span { display: block; width: 10px; height: 10px; border-right: 2px solid #fff; border-bottom: 2px solid #fff; transform: rotate(45deg); margin: -5px 0; opacity: 0.7; }
.scroll-indicator span:nth-child(1) { animation: scroll-delay 2s infinite; }
.scroll-indicator span:nth-child(2) { animation: scroll-delay 2s infinite 0.2s; }
.scroll-indicator span:nth-child(3) { animation: scroll-delay 2s infinite 0.4s; }
@keyframes bounce { 0%,20%,50%,80%,100% { transform: translateX(-50%) translateY(0); } 40% { transform: translateX(-50%) translateY(-20px); } 60% { transform: translateX(-50%) translateY(-10px); } }
@keyframes scroll-delay { 0%,20%,50%,80%,100% { opacity: 0.7; transform: rotate(45deg) translate(0,0);} 40% { opacity: 1; transform: rotate(45deg) translate(-5px,-5px);} 60% { opacity: 0.7; transform: rotate(45deg) translate(0,0);} }

/* 响应式 */
@media (max-width: 992px) {
    .about-preview .container { grid-template-columns: 1fr; }
    .about-image { order: -1; margin-bottom: 30px; }
}
@media (max-width: 768px) {
    .navbar { height: 70px; }
    main { margin-top: 70px; }
    .nav-toggle { display: flex; }
    .nav-menu { position: fixed; top: 70px; left: -100%; width: 100%; height: calc(100vh - 70px); background-color: var(--dark-color); flex-direction: column; align-items: center; justify-content: flex-start; padding-top: 40px; transition: var(--transition); box-shadow: 0 5px 10px rgba(0,0,0,0.1); }
    .nav-menu.active { left: 0; }
    .nav-menu.active .nav-menu a { color: var(--text-color-light); }
    .nav-menu.active .nav-menu a:hover,
    .nav-menu.active .nav-menu a.active { color: var(--primary-color); }
    .nav-menu.active .nav-menu a::after { background: var(--primary-color); }
    .nav-menu li { margin: 15px  0; }
    .section-title { font-size: 1.8rem; }
}
@media (max-width: 576px) {
    .feature-grid { grid-template-columns: 1fr; }
    .footer-content { grid-template-columns: 1fr; }
    .footer-logo { justify-content: center; }
    .footer-logo .company-intro { color: #ccc; font-size: 0.6rem; line-height: 1.6; margin-top: 15px; max-width: 300px; }
    .footer-links h3::after, .footer-contact h3::after, .footer-social h3::after { left: 50%; transform: translateX(-50%); }
    .footer-links, .footer-contact, .footer-social { text-align: center; }
    .footer-contact p { justify-content: center; }
    .social-icons { justify-content: center; }
}