/* ========== CSS Variables — 清爽暖灰·精密制造风（与首页一致） ========== */
  :root {
    --bg:              #faf9f7;
    --surface:         #ffffff;
    --surface-alt:     #f4f2ee;
    --text-main:       #1f1f1f;
    --text-secondary:  #6b6b6b;
    --border:          #e8e5df;
    --primary:         #d94f1a;
    --primary-light:   #f7c9b6;
    --primary-hover:   #c04517;
    --accent:          #2a7d8c;
    --shadow:          rgba(0,0,0,.06);
    --shadow-md:       rgba(0,0,0,.10);
    --shadow-lg:       rgba(0,0,0,.14);
    --radius-sm:       8px;
    --radius-md:       12px;
    --radius-lg:       16px;
    --radius-full:     9999px;
    --transition:      .3s cubic-bezier(.4,0,.2,1);
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; font-size:16px; -webkit-font-smoothing:antialiased; -moz-osx-font-smoothing:grayscale; }
body { font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif; color:var(--text-main); background:var(--bg); line-height:1.75; overflow-x:hidden; }
a { text-decoration:none; color:inherit; transition:color var(--transition); }
img { max-width:100%; display:block; }
ul { list-style:none; }
button, input, select, textarea { font-family:inherit; outline:none; }
.container { max-width:1200px; margin:0 auto; padding:0 24px; }

/* ========== Utility ========== */
.section-badge {
    display:inline-flex; align-items:center; gap:8px;
    font-size:13px; font-weight:600; letter-spacing:1.2px; text-transform:uppercase;
    color:var(--primary); background:var(--primary-light);
    padding:6px 16px; border-radius:var(--radius-full); margin-bottom:16px;
}
.section-badge::before { content:''; width:6px; height:6px; background:var(--primary); border-radius:50%; }
.section-title { font-size:clamp(26px,3.5vw,36px); font-weight:700; line-height:1.25; letter-spacing:-.3px; color:var(--text-main); margin-bottom:16px; }
.section-desc { font-size:16px; line-height:1.8; color:var(--text-secondary); max-width:560px; }
.sub-title { color:var(--primary); font-size:13px; font-weight:700; letter-spacing:2px; text-transform:uppercase; margin-bottom:8px; }
.btn { display:inline-flex; align-items:center; gap:8px; padding:13px 30px; font-size:15px; font-weight:600; border-radius:var(--radius-sm); border:2px solid transparent; cursor:pointer; transition:all var(--transition); letter-spacing:.3px; }
.btn-primary { background:var(--primary); color:#fff; }
.btn-primary:hover { background:var(--primary-hover); transform:translateY(-2px); box-shadow:0 6px 20px rgba(217,79,26,.25); }
.btn-outline { background:transparent; color:var(--primary); border-color:var(--primary); }
.btn-outline:hover { background:var(--primary); color:#fff; transform:translateY(-2px); }
.btn-white { background:#fff; color:var(--primary); }
.btn-white:hover { background:var(--surface-alt); transform:translateY(-2px); }
.fade-in { opacity:0; transform:translateY(30px); transition:opacity .7s ease,transform .7s ease; }
.fade-in.visible { opacity:1; transform:translateY(0); }

/* ========== Top Bar ========== */
.top-bar { background:var(--surface); border-bottom:1px solid var(--border); padding:10px 0; font-size:13px; color:var(--text-secondary); }
.top-bar .container { display:flex; justify-content:space-between; align-items:center; }
.top-bar a { color:var(--text-secondary); }
.top-bar a:hover { color:var(--primary); }
.top-bar i { margin-right:6px; color:var(--primary); }
.top-social { display:flex; gap:14px; }
.top-social a { width:30px; height:30px; display:flex; align-items:center; justify-content:center; border-radius:50%; background:var(--surface-alt); font-size:13px; }
.top-social a:hover { background:var(--primary); color:#fff; }

/* ========== Navbar ========== */
.navbar { background:var(--surface); border-bottom:1px solid var(--border); padding:0; position:sticky; top:0; z-index:1000; transition:box-shadow var(--transition); }
.navbar.scrolled { box-shadow:0 2px 16px var(--shadow-md); }
.navbar .container { display:flex; align-items:center; justify-content:space-between; height:72px; }
.logo { font-size:22px; font-weight:800; letter-spacing:1.5px; color:var(--text-main); }
.logo span { color:var(--primary); }
.nav-links { display:flex; align-items:center; gap:6px; }
.nav-links a { padding:8px 16px; font-size:14px; font-weight:500; color:var(--text-secondary); border-radius:var(--radius-sm); transition:all var(--transition); position:relative; }
.nav-links a:hover, .nav-links a.active { color:var(--primary); background:var(--primary-light); }
.nav-links a.active::after { content:''; position:absolute; bottom:2px; left:50%; transform:translateX(-50%); width:18px; height:2px; background:var(--primary); border-radius:1px; }
.nav-right { display:flex; align-items:center; gap:12px; }
.lang-switch { font-size:13px; font-weight:500; color:var(--text-secondary); padding:6px 12px; border:1px solid var(--border); border-radius:var(--radius-sm); cursor:pointer; background:var(--surface); }
.lang-switch:hover { border-color:var(--primary); color:var(--primary); }
.hamburger { display:none; flex-direction:column; gap:5px; cursor:pointer; padding:6px; z-index:1001; }
.hamburger span { width:24px; height:2px; background:var(--text-main); border-radius:2px; transition:all var(--transition); }
.hamburger.active span:nth-child(1) { transform:rotate(45deg) translate(5px,5px); }
.hamburger.active span:nth-child(2) { opacity:0; }
.hamburger.active span:nth-child(3) { transform:rotate(-45deg) translate(5px,-5px); }
.mobile-nav { display:none; position:fixed; top:0; left:0; right:0; bottom:0; background:var(--surface); z-index:999; padding:100px 32px 40px; flex-direction:column; gap:4px; overflow-y:auto; }
.mobile-nav.active { display:flex; }
.mobile-nav a { padding:14px 16px; font-size:16px; font-weight:500; color:var(--text-main); border-radius:var(--radius-sm); }
.mobile-nav a:hover, .mobile-nav a.active { color:var(--primary); background:var(--primary-light); }
.mobile-nav .btn { margin-top:16px; text-align:center; justify-content:center; }

/* ========== Breadcrumb ========== */
.breadcrumb-bar { background:var(--surface-alt); border-bottom:1px solid var(--border); padding:14px 0; }
.breadcrumb { display:flex; align-items:center; gap:8px; font-size:13px; color:var(--text-secondary); }
.breadcrumb a { color:var(--text-secondary); }
.breadcrumb a:hover { color:var(--primary); }
.breadcrumb .sep { color:var(--border); }
.breadcrumb .current { color:var(--primary); font-weight:600; }

/* ========== Page Hero ========== */
.page-hero { background:var(--surface-alt); padding:72px 0 56px; text-align:center; position:relative; }
.page-hero h1 { font-size:clamp(28px,4vw,36px); font-weight:800; color:var(--text-main); margin-bottom:10px; }
.page-hero p { font-size:16px; color:var(--text-secondary); }

/* ========== About Intro ========== */
.about-intro { padding:96px 0; }
.about-grid { display:grid; grid-template-columns:1fr 1fr; gap:60px; align-items:center; }
.about-text h2 { font-size:clamp(24px,3vw,30px); font-weight:800; color:var(--text-main); margin-bottom:16px; }
.about-text p { color:var(--text-secondary); font-size:15px; line-height:1.8; margin-bottom:16px; }
.about-image { border-radius:var(--radius-lg); overflow:hidden; background:linear-gradient(135deg,var(--primary),#c04517); height:380px; display:flex; align-items:center; justify-content:center; }
.about-image i { font-size:100px; color:rgba(255,255,255,.2); }

/* ========== Timeline ========== */
.timeline-section { background:var(--surface-alt); padding:96px 0; }
.section-header { text-align:center; margin-bottom:56px; }
.section-header p { font-size:15px; color:var(--text-secondary); max-width:600px; margin:0 auto; }
.timeline { position:relative; max-width:800px; margin:0 auto; padding:20px 0; }
.timeline::before { content:''; position:absolute; left:50%; top:0; bottom:0; width:3px; background:var(--primary); transform:translateX(-50%); }
.timeline-item { position:relative; margin-bottom:40px; display:flex; align-items:center; }
.timeline-item:nth-child(odd) { flex-direction:row-reverse; }
.timeline-dot { width:18px; height:18px; background:var(--primary); border-radius:50%; position:absolute; left:50%; transform:translateX(-50%); z-index:2; border:3px solid var(--surface); box-shadow:0 0 0 3px var(--primary-light); }
.timeline-content { width:calc(50% - 40px); padding:24px; background:var(--surface); border-radius:var(--radius-md); box-shadow:var(--shadow); border:1px solid var(--border); transition:all var(--transition); }
.timeline-content:hover { box-shadow:var(--shadow-md); border-color:var(--primary-light); }
.timeline-year { color:var(--primary); font-size:20px; font-weight:800; margin-bottom:6px; }
.timeline-content h4 { font-size:16px; font-weight:700; color:var(--text-main); margin-bottom:6px; }
.timeline-content p { font-size:13px; color:var(--text-secondary); line-height:1.7; }

/* ========== Stats ========== */
.stats-section { padding:80px 0; background:var(--surface); }
.stats-numbers { display:grid; grid-template-columns:repeat(4,1fr); gap:30px; }
.stat-box { text-align:center; padding:30px 15px; border-radius:var(--radius-md); background:var(--primary-light); transition:all var(--transition); }
.stat-box:hover { transform:translateY(-5px); box-shadow:var(--shadow-md); }
.stat-box .number { font-size:42px; font-weight:900; color:var(--primary); line-height:1; margin-bottom:8px; }
.stat-box .label { font-size:14px; color:var(--text-secondary); font-weight:600; }

/* ========== Certifications ========== */
.cert-section { background:var(--surface-alt); padding:96px 0; }
.cert-grid { display:grid; grid-template-columns:repeat(5,1fr); gap:24px; align-items:center; }
.cert-item { text-align:center; padding:28px 15px; background:var(--surface); border-radius:var(--radius-md); border:1px solid var(--border); transition:all var(--transition); }
.cert-item:hover { transform:translateY(-5px); box-shadow:var(--shadow-md); border-color:var(--primary); }
.cert-icon { width:70px; height:70px; margin:0 auto 12px; background:var(--primary-light); border-radius:50%; display:flex; align-items:center; justify-content:center; font-size:14px; font-weight:800; color:var(--primary); border:2px solid var(--primary); }
.cert-item p { font-size:13px; color:var(--text-secondary); font-weight:600; }

/* ========== Factory ========== */
.factory-section { padding:96px 0; }
.factory-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:24px; }
.factory-card { border-radius:var(--radius-md); overflow:hidden; position:relative; height:240px; cursor:pointer; transition:all var(--transition); }
.factory-card .overlay { position:absolute; inset:0; background:linear-gradient(to top,rgba(217,79,26,.85),transparent); display:flex; align-items:flex-end; padding:24px; transition:all var(--transition); }
.factory-card:hover .overlay { background:linear-gradient(to top,rgba(217,79,26,.95),rgba(217,79,26,.3)); }
.factory-card h4 { color:#fff; font-size:16px; font-weight:700; }
.factory-card:nth-child(1) { background:linear-gradient(135deg,#c04517,var(--primary)); }
.factory-card:nth-child(2) { background:linear-gradient(135deg,var(--primary),#e06b3a); }
.factory-card:nth-child(3) { background:linear-gradient(135deg,#e06b3a,#c04517); }

/* ========== CTA ========== */
.cta-section { padding:80px 0; text-align:center; }
.cta-box { background:linear-gradient(135deg,var(--primary) 0%,#c04517 100%); border-radius:var(--radius-lg); padding:64px 48px; color:#fff; }
.cta-box h2 { font-size:clamp(24px,3vw,32px); font-weight:700; margin-bottom:12px; }
.cta-box p { font-size:16px; opacity:.9; margin-bottom:28px; max-width:520px; margin-left:auto; margin-right:auto; }
.cta-section .btn-white { padding:14px 36px; font-size:15px; border:none; cursor:pointer; transition:all var(--transition); }

/* ========== Footer ========== */
.footer { background:var(--surface); border-top:1px solid var(--border); padding:72px 0 0; }
.footer-grid { display:grid; grid-template-columns:1.5fr 1fr 1fr 1fr 1fr 1.2fr; gap:40px; margin-bottom:48px; }
.footer-brand .logo { margin-bottom:16px; }
.footer-brand p { font-size:14px; color:var(--text-secondary); line-height:1.8; margin-bottom:20px; }
.footer-social { display:flex; gap:10px; }
.footer-social a { width:38px; height:38px; display:flex; align-items:center; justify-content:center; border-radius:50%; background:var(--surface-alt); color:var(--text-secondary); font-size:15px; }
.footer-social a:hover { background:var(--primary); color:#fff; }
.footer-col h4 { font-size:14px; font-weight:700; text-transform:uppercase; letter-spacing:1px; color:var(--text-main); margin-bottom:18px; }
.footer-col ul li { margin-bottom:10px; }
.footer-col ul li a { font-size:14px; color:var(--text-secondary); }
.footer-col ul li a:hover { color:var(--primary); }
.footer-contact p { font-size:14px; color:var(--text-secondary); margin-bottom:8px; display:flex; align-items:center; gap:8px; }
.footer-contact i { color:var(--primary); width:16px; }
.footer-bottom { border-top:1px solid var(--border); padding-top:24px; display:flex; justify-content:space-between; align-items:center; font-size:13px; color:var(--text-secondary); }

/* ========== Back to Top ========== */
.back-to-top { position:fixed; bottom:32px; right:32px; width:44px; height:44px; background:var(--primary); color:#fff; border:none; border-radius:50%; font-size:18px; cursor:pointer; opacity:0; visibility:hidden; transform:translateY(12px); transition:all var(--transition); z-index:999; display:flex; align-items:center; justify-content:center; box-shadow:0 4px 16px rgba(217,79,26,.25); }
.back-to-top.visible { opacity:1; visibility:visible; transform:translateY(0); }
.back-to-top:hover { background:var(--primary-hover); transform:translateY(-2px); }

/* ========== Responsive ========== */
@media (max-width:1200px) { .footer-grid { grid-template-columns:1.5fr 1fr 1fr 1fr 1.5fr; } }
@media (max-width:1024px) {
    .cert-grid { grid-template-columns:repeat(3,1fr); }
    .stats-numbers { grid-template-columns:repeat(2,1fr); }
    .factory-grid { grid-template-columns:repeat(2,1fr); }
    .footer-grid { grid-template-columns:repeat(3,1fr); }
}
@media (max-width:768px) {
    .top-bar { display:none; } .hamburger { display:flex; }
    .nav-links { position:fixed; top:72px; left:0; right:0; background:var(--surface); flex-direction:column; padding:20px; gap:15px; transform:translateY(-100%); opacity:0; visibility:hidden; transition:all var(--transition); border-top:1px solid var(--border); box-shadow:var(--shadow-md); }
    .nav-links.active { transform:translateY(0); opacity:1; visibility:visible; }
    .nav-links a { font-size:16px; padding:8px 0; color:var(--text-main); }
    .about-grid { grid-template-columns:1fr; } .about-image { height:250px; }
    .timeline::before { left:20px; }
    .timeline-item, .timeline-item:nth-child(odd) { flex-direction:row; }
    .timeline-dot { left:20px; }
    .timeline-content { width:calc(100% - 60px); margin-left:40px; }
    .cert-grid { grid-template-columns:repeat(2,1fr); gap:12px; }
    .factory-grid { grid-template-columns:1fr; }
    .page-hero h1 { font-size:26px; }
    .about-text h2 { font-size:24px; }
    .footer-grid { grid-template-columns:1fr 1fr; gap:28px; } .footer-brand { grid-column:1 / -1; }
}
@media (max-width:480px) { .stats-numbers { grid-template-columns:1fr; } .footer-grid { grid-template-columns:1fr; } }