/* 全局设置 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: 'Helvetica Neue', Helvetica, 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
    color: #333;
    line-height: 1.6;
    background-color: #fff;
}
a { text-decoration: none; color: inherit; transition: 0.3s; }
ul { list-style: none; }
html { scroll-behavior: smooth; }

/* 布局工具 */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 100px 0; }
.bg-light { background-color: #f9f9f9; }
.text-center { text-align: center; }

/* 导航栏 */
header {
    padding: 20px 0;
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid #eee;
}
header .container { display: flex; justify-content: space-between; align-items: center; }
.logo { font-weight: 700; font-size: 1.5rem; letter-spacing: 2px; }
nav ul { display: flex; gap: 30px; align-items: center; }
nav a { font-size: 0.9rem; font-weight: 500; color: #555; }
nav a:hover { color: #000; }
.btn-nav { border: 1px solid #333; padding: 8px 20px; border-radius: 50px; }
.btn-nav:hover { background: #333; color: #fff; }

/* 首页 Hero (背景图模式) */
.hero {
    height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background-size: cover;
    background-position: center;
    background-attachment: fixed; /* 视差滚动效果 */
    color: #fff;
}
.hero-content h1 { font-size: 3.5rem; margin-bottom: 20px; text-shadow: 0 2px 10px rgba(0,0,0,0.3); }
.hero-content p { font-size: 1.2rem; margin-bottom: 40px; opacity: 0.9; max-width: 600px; margin-left: auto; margin-right: auto;}
.btn-primary {
    background-color: #333;
    color: #fff;
    padding: 15px 40px;
    border-radius: 50px;
    font-size: 1rem;
    display: inline-block;
    border: 2px solid #333;
}
.btn-primary:hover { background-color: transparent; color: #333; }
/* Hero区域里的特殊按钮样式 */
.hero .btn-primary { background-color: #fff; color: #333; border-color: #fff; }
.hero .btn-primary:hover { background-color: transparent; color: #fff; }

/* 通用标题 */
.section-title { font-size: 2rem; margin-bottom: 10px; text-align: center; font-weight: 600; letter-spacing: 1px;}
.section-subtitle { text-align: center; color: #888; margin-bottom: 60px; font-weight: 300;}

/* 项目案例网格 */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}
.card { display: block; border-radius: 12px; overflow: hidden; background: #fff; box-shadow: 0 5px 15px rgba(0,0,0,0.05); transition: transform 0.3s ease; }
.card:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0,0,0,0.1); }
.card-image {
    width: 100%;
    height: 280px;
    background-color: #eee;
    background-size: cover;
    background-position: center;
}
.card-info { padding: 25px; text-align: center; }
.card-info h3 { font-size: 1.2rem; margin-bottom: 5px; color: #222; }
.card-info p { color: #999; font-size: 0.9rem; text-transform: uppercase; letter-spacing: 1px; }

/* 关于我们：流程网格 */
.process-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
}
.process-item {
    background: #fff;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    border: 1px solid #eee;
}
.step-num {
    font-size: 3rem;
    font-weight: 700;
    color: #eee;
    line-height: 1;
    margin-bottom: 15px;
}
.process-item h3 { margin-bottom: 10px; font-size: 1.1rem; }
.process-item p { font-size: 0.9rem; color: #666; }

/* 分割线 */
.divider { border: 0; height: 1px; background: #e0e0e0; margin: 60px 0; }

/* 关于我们：标签云 */
.category-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    max-width: 800px;
    margin: 0 auto;
}
.category-tags span {
    padding: 10px 25px;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 50px;
    color: #555;
    font-size: 0.95rem;
}
.category-tags span:hover { border-color: #333; color: #333; background: #f4f4f4;}

/* 底部联系 */
.footer-section { background-color: #222; color: #fff; text-align: center; }
.contact-box h2 { margin-bottom: 20px; }
.contact-box p { color: #ccc; margin-bottom: 40px; }
.white-btn { border-color: #fff; background: #fff; color: #222; }
.white-btn:hover { background: transparent; color: #fff; }
.contact-details { margin-top: 60px; color: #888; font-size: 0.9rem; }
.copyright { margin-top: 80px; font-size: 0.8rem; color: #555; border-top: 1px solid #333; padding-top: 20px; }

/* 手机适配 */
@media (max-width: 768px) {
    .hero-content h1 { font-size: 2.2rem; }
    nav ul { display: none; } /* 临时隐藏手机菜单 */
    .portfolio-grid { grid-template-columns: 1fr; }
}