:root {
    --primary: #003366;    /* 工业深蓝 */
    --accent: #FF6600;     /* 转化橙 */
    --bg-light: #F8FAFC;   /* 背景浅灰 */
    --text-main: #1E293B;  /* 主文字 */
    --text-muted: #64748B; /* 次要文字 */
    --white: #FFFFFF;
}

/* 基础样式复位 */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text-main); line-height: 1.6; background: #fff; }

/* 响应式导航 */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed; width: 100%; top: 0; z-index: 1000;
    box-shadow: 0 2px 15px rgba(0,0,0,0.08);
}
.nav-container {
    max-width: 1200px; margin: 0 auto;
    display: flex; justify-content: space-between; align-items: center; padding: 15px 20px;
}
.logo { font-size: 24px; font-weight: 800; color: var(--primary); text-decoration: none; display: flex; align-items: center; }
.logo i { margin-right: 8px; color: var(--accent); }

.nav-menu { display: flex; list-style: none; }
.nav-menu li { margin-left: 25px; }
.nav-menu a { text-decoration: none; color: var(--text-main); font-weight: 500; font-size: 15px; transition: 0.3s; }
.nav-menu a:hover { color: var(--primary); }

.mobile-btn { display: none; font-size: 24px; cursor: pointer; color: var(--primary); }

/* 全局版块布局 */
section { padding: 90px 20px; max-width: 1200px; margin: 0 auto; }
.section-bg { background: var(--bg-light); max-width: 100%; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-header h2 { font-size: 32px; color: var(--primary); margin-bottom: 15px; }
.section-header p { color: var(--text-muted); font-size: 16px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }

/* 1. 首屏 Hero */
.hero {
    padding: 180px 20px 100px;
    background: linear-gradient(rgba(0,51,102,0.85), rgba(0,51,102,0.85)), url('https://images.unsplash.com/photo-1581092160562-40aa08e78837?auto=format&fit=crop&q=80') center/cover;
    color: #fff; text-align: center; max-width: 100%;
}
.hero h1 { font-size: 48px; margin-bottom: 20px; letter-spacing: 2px; }
.hero p { font-size: 20px; margin-bottom: 35px; opacity: 0.9; max-width: 800px; margin-inline: auto; }
.btn { padding: 14px 40px; border-radius: 4px; text-decoration: none; font-weight: bold; display: inline-block; transition: 0.3s; border: none; cursor: pointer; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: #e65c00; transform: translateY(-3px); }

/* 2. 行业应用 (重写回来的模块) */
.app-card { background: #fff; padding: 40px; border-radius: 8px; border-top: 4px solid var(--primary); box-shadow: 0 5px 20px rgba(0,0,0,0.05); transition: 0.3s; }
.app-card:hover { transform: translateY(-10px); }
.app-card i { font-size: 40px; color: var(--accent); margin-bottom: 20px; }
.app-card h3 { margin-bottom: 15px; color: var(--primary); }

/* 3. 案例模块 */
.case-card { background: #fff; border-radius: 12px; overflow: hidden; box-shadow: 0 10px 30px rgba(0,0,0,0.08); }
.case-img { height: 220px; background: #ddd; position: relative; }
.case-img img { width: 100%; height: 100%; object-fit: cover; }
.case-tag { position: absolute; top: 15px; left: 15px; background: var(--accent); color: #fff; padding: 4px 12px; font-size: 12px; border-radius: 4px; }
.case-info { padding: 25px; }

/* 4. 技术文章与 FAQ */
.flex-container { display: flex; gap: 40px; flex-wrap: wrap; }
.flex-left { flex: 2; min-width: 300px; }
.flex-right { flex: 1; min-width: 300px; }

.article-link { display: flex; justify-content: space-between; padding: 15px 0; border-bottom: 1px solid #eee; text-decoration: none; color: inherit; transition: 0.2s; }
.article-link:hover { color: var(--accent); padding-left: 10px; }

.faq-item { margin-bottom: 15px; background: #fff; border-radius: 6px; border: 1px solid #eee; }
.faq-q { padding: 15px; font-weight: bold; cursor: pointer; display: flex; justify-content: space-between; align-items: center; color: var(--primary); }
.faq-a { padding: 0 15px 15px; font-size: 14px; color: var(--text-muted); display: none; }
.faq-item.active .faq-a { display: block; }

/* 5. 询价表单 */
.quote-box { background: var(--primary); color: #fff; padding: 50px; border-radius: 15px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 30px; }
.form-group { display: flex; flex-direction: column; }
.form-group label { font-size: 14px; margin-bottom: 8px; opacity: 0.8; }
.form-group input, .form-group select, .form-group textarea { padding: 12px; border-radius: 4px; border: none; outline: none; }
.full-width { grid-column: span 2; }

/* 页脚 */
footer { background: #0f172a; color: #94a3b8; padding: 80px 20px 30px; }
.footer-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; }
.footer-grid h4 { color: #fff; margin-bottom: 25px; }
.footer-bottom { text-align: center; margin-top: 60px; padding-top: 20px; border-top: 1px solid #334155; font-size: 13px; }

/* 移动端适配 */
@media (max-width: 768px) {
    .hero h1 { font-size: 32px; }
    .nav-menu { display: none; position: absolute; top: 65px; left: 0; width: 100%; background: #fff; flex-direction: column; padding: 20px; box-shadow: 0 10px 15px rgba(0,0,0,0.1); }
    .nav-menu.active { display: flex; }
    .nav-menu li { margin: 15px 0; }
    .mobile-btn { display: block; }
    .form-row { grid-template-columns: 1fr; }
    .full-width { grid-column: span 1; }
    .quote-box { padding: 30px 20px; }
}