/* ===== VARIABLES ===== */
:root{--primary:#2563eb;--accent:#6366f1;--text:#111827;--text-s:#374151;--text-m:#6b7280;--text-main:#111827;--text-muted:#6b7280;--bg:#f9fafb;--bg-w:#fff;--bg-card:#fff;--bg-alt:#f3f4f6;--border:#e5e7eb;--border-l:#f3f4f6}
[data-theme="dark"]{--text:#f9fafb;--text-s:#d1d5db;--text-m:#9ca3af;--text-main:#f9fafb;--text-muted:#9ca3af;--bg:#030712;--bg-w:#0c0f1a;--bg-card:#0c0f1a;--bg-alt:#0a0f1d;--border:#1f2937;--border-l:#111827}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:'Inter','Noto Sans SC','PingFang SC',sans-serif;background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased}
a{text-decoration:none;color:inherit}
button{cursor:pointer;font-family:inherit}
img{max-width:100%;display:block}

/* ===== NAVIGATION ===== */
.nav{position:fixed;top:0;left:0;right:0;height:64px;z-index:100;background:rgba(255,255,255,0.92);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border-bottom:1px solid var(--border);transition:background .3s}
[data-theme="dark"] .nav{background:rgba(3,7,18,0.92);border-color:var(--border)}
.nav-in{max-width:1280px;margin:0 auto;height:100%;display:flex;align-items:center;justify-content:space-between;padding:0 40px}
.nav-logo{display:flex;align-items:center;gap:10px;font-size:18px;font-weight:700;color:var(--text-main);text-decoration:none}
.nav-logo .mark{width:36px;height:36px;background:linear-gradient(135deg,var(--primary),var(--accent));border-radius:10px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:16px;flex-shrink:0}
.nav-links{display:flex;align-items:center;gap:28px;list-style:none}
.nav-links a{color:var(--text-muted);text-decoration:none;font-size:14px;font-weight:500;transition:color .2s}
.nav-links a:hover{color:var(--primary)}
.nav-right{display:flex;align-items:center;gap:12px}
.nav-toggle{display:none;background:none;border:none;color:var(--text-main);padding:4px;cursor:pointer;flex-direction:column;gap:5px;width:40px;height:40px;align-items:center;justify-content:center}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--text-main);border-radius:2px;transition:.3s}
.nav-toggle.active span:first-child{transform:rotate(45deg) translate(5px,5px)}
.nav-toggle.active span:nth-child(2){opacity:0}
.nav-toggle.active span:last-child{transform:rotate(-45deg) translate(5px,-5px)}
.theme-btn{width:36px;height:36px;border-radius:8px;border:1px solid var(--border);background:transparent;color:var(--text-muted);display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all .2s}
.theme-btn:hover{background:var(--border-l)}
.home-btn{display:none;width:40px;height:40px;border-radius:8px;border:none;background:none;color:var(--text-main);align-items:center;justify-content:center;cursor:pointer;transition:background .2s;text-decoration:none}
.home-btn:hover{background:var(--bg-alt)}
@media(max-width:768px){.home-btn{display:flex!important}}
.sun,.moon{width:18px;height:18px}
[data-theme="dark"] .sun{display:none}
[data-theme="light"] .moon{display:none}

/* ===== BUTTONS ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border-radius:12px;font-size:15px;font-weight:600;cursor:pointer;text-decoration:none;transition:all .2s;border:none}
.btn-w{background:#fff;color:#1d4ed8;padding:14px 32px}
.btn-w:hover{background:#f0f4ff;transform:translateY(-1px)}
.btn-o{background:rgba(255,255,255,0.06);color:#fff;border:1px solid rgba(255,255,255,0.12);padding:14px 32px}
.btn-o:hover{background:rgba(255,255,255,0.12)}
.btn-p{background:var(--primary);color:#fff;padding:14px 32px}
.btn-p:hover{background:#1d4ed8;transform:translateY(-1px)}

/* ===== SECTIONS ===== */
.sect{max-width:1280px;margin:0 auto;padding:80px 40px}
.sect-header{text-align:center;margin-bottom:56px}
.sect-label{font-size:12px;letter-spacing:3px;color:var(--primary);text-transform:uppercase;font-weight:600;margin-bottom:12px;display:block}
.sect-header h2{font-size:clamp(1.8rem,3.5vw,2.4rem);font-weight:700;margin-bottom:14px;letter-spacing:-0.5px}
.sect-header p{color:var(--text-m);font-size:16px;max-width:600px;margin:0 auto;line-height:1.7}

/* ===== GRID ===== */
.g3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.g2{display:grid;grid-template-columns:repeat(2,1fr);gap:24px}
.g4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.g5{display:grid;grid-template-columns:repeat(5,1fr);gap:20px}

/* ===== CARDS ===== */
.card{background:var(--bg-w);border:1px solid var(--border);border-radius:16px;transition:all .3s}
.card:hover{transform:translateY(-4px);box-shadow:0 20px 60px rgba(0,0,0,0.06)}

/* ===== FOOTER ===== */
.ft{background:#0c1222;color:#e2e8f0}
.ft-in{max-width:1280px;margin:0 auto;padding:64px 40px 32px;display:grid;grid-template-columns:1.8fr repeat(3,1fr);gap:48px}
.ft-brand .company{color:#fff;font-size:15px;font-weight:600;margin-top:12px;display:block}
.ft-brand p{color:rgba(226,232,240,0.35);font-size:14px;line-height:1.8;margin-top:8px}
.ft-col h4{font-size:12px;font-weight:600;color:rgba(226,232,240,0.5);margin-bottom:16px;letter-spacing:1px;text-transform:uppercase}
.ft-col a{display:block;color:rgba(226,232,240,0.35);font-size:14px;text-decoration:none;margin-bottom:10px;transition:color .2s}
.ft-col a:hover{color:#93bbfc}
.ft-bot{text-align:center;padding:24px 0;color:rgba(226,232,240,0.2);font-size:12px;border-top:1px solid rgba(226,232,240,0.06)}

/* ===== ANIMATIONS ===== */
.fade{opacity:0;transform:translateY(24px);transition:opacity .7s ease,transform .7s ease}
.fade.v{opacity:1;transform:translateY(0)}

/* ===== RESPONSIVE: TABLET ===== */
@media(max-width:1024px){
  .g3,.g2{grid-template-columns:repeat(2,1fr)}
  .g4{grid-template-columns:repeat(2,1fr)}
  .g5{grid-template-columns:repeat(3,1fr)}
  .ft-in{grid-template-columns:1fr 1fr}
}

/* ===== RESPONSIVE: MOBILE ===== */
@media(max-width:768px){
  .nav-in{padding:0 20px}
  .nav-links{display:none!important}
  .nav-toggle{display:flex!important}
  .sect{padding:60px 20px}
  .sect-header{margin-bottom:40px}
  .sect-header h2{font-size:clamp(1.5rem,6vw,1.8rem)}
  .g3,.g2,.g4,.g5{grid-template-columns:1fr}
  .ft-in{grid-template-columns:1fr;gap:32px;padding:48px 20px 24px}
}

/* 子页面banner */
.page-banner{background:linear-gradient(135deg,#2563EB,#6366F1);padding:120px 40px 80px;text-align:center;color:#fff;position:relative;overflow:hidden}
.page-banner::before{content:'';position:absolute;inset:0;background:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")}
.page-banner h1{font-size:clamp(2rem,4vw,3rem);font-weight:800;margin-bottom:16px;position:relative;letter-spacing:-1px}
.page-banner p{font-size:16px;color:rgba(255,255,255,0.85);max-width:640px;margin:0 auto;line-height:1.8;position:relative}
.breadcrumb{display:flex;align-items:center;gap:8px;margin-bottom:20px;justify-content:center;position:relative}
.breadcrumb a{color:rgba(255,255,255,0.7);font-size:14px;text-decoration:none;transition:color .2s}
.breadcrumb a:hover{color:#fff}
.breadcrumb span{color:rgba(255,255,255,0.4);font-size:14px}
/* 返回按钮 */
.back-btn{display:inline-flex;align-items:center;gap:8px;padding:12px 24px;background:var(--bg-w);border:1px solid var(--border);border-radius:12px;font-size:14px;font-weight:600;color:var(--text-main);text-decoration:none;transition:all .2s;margin-bottom:32px}
.back-btn:hover{transform:translateY(-2px);box-shadow:0 8px 20px rgba(0,0,0,0.08)}
/* 场景标签 */
.scenario-grid{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-top:24px}

/* ===== PAGE SLICE (lazy load) ===== */
.page-slice { width: 100%; display: block; position: relative; line-height: 0; }
.page-slice img { width: 100%; height: auto; display: block; opacity: 0; transition: opacity 0.3s ease; }
.page-slice.loaded img { opacity: 1; }
.page-slice .placeholder { position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: #f5f5f5; }
.page-slice.loaded .placeholder { display: none; }
.spinner { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 20px; height: 20px; border: 2px solid #e0e0e0; border-top-color: #333; border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: translate(-50%, -50%) rotate(360deg); } }