/* ========== ChatGPT Work中文网 - Critical CSS ========== */
/* PageSpeed 100分优化 | 纯原生CSS | 零外部依赖 */

/* === CSS Reset & Base === */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;line-height:1.6;color:#1a1a2e;background:#fff;-webkit-font-smoothing:antialiased}
.skip-link{position:fixed;top:.5rem;left:.5rem;z-index:10000;padding:.7rem 1rem;background:#fff;color:var(--primary);border:2px solid var(--primary);border-radius:var(--radius);transform:translateY(-150%)}
.skip-link:focus{transform:translateY(0)}
:focus-visible{outline:3px solid rgba(37,99,235,.45);outline-offset:3px}
a{text-decoration:none;color:inherit;transition:opacity .2s}
img{max-width:100%;height:auto;display:block}
button{border:none;background:none;cursor:pointer;font-family:inherit}
ul,ol{list-style:none}

/* === CSS Variables === */
:root{
  --primary:#2563eb;--primary-dark:#1d4ed8;--primary-light:#dbeafe;
  --accent:#f59e0b;--accent-dark:#d97706;
  --success:#10b981;--danger:#ef4444;
  --dark:#0f172a;--dark-light:#1e293b;
  --gray-50:#f8fafc;--gray-100:#f1f5f9;--gray-200:#e2e8f0;--gray-300:#cbd5e1;--gray-400:#94a3b8;--gray-500:#64748b;--gray-600:#475569;--gray-700:#334155;--gray-800:#1e293b;--gray-900:#0f172a;
  --shadow-sm:0 1px 2px rgba(0,0,0,.05);--shadow:0 4px 6px -1px rgba(0,0,0,.1);--shadow-lg:0 10px 15px -3px rgba(0,0,0,.1);--shadow-xl:0 20px 25px -5px rgba(0,0,0,.1);
  --radius-sm:6px;--radius:10px;--radius-lg:16px;--radius-xl:24px;
  --container:1280px;--header-h:68px;
}

/* === Utility Classes === */
.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 1.5rem}
.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-between{justify-content:space-between}.justify-center{justify-content:center}.flex-wrap{flex-wrap:wrap}.gap-1{gap:.25rem}.gap-2{gap:.5rem}.gap-3{gap:.75rem}.gap-4{gap:1rem}.gap-6{gap:1.5rem}.gap-8{gap:2rem}
.grid{display:grid}.grid-cols-2{grid-template-columns:repeat(2,1fr)}.grid-cols-3{grid-template-columns:repeat(3,1fr)}.grid-cols-4{grid-template-columns:repeat(4,1fr)}
.hidden{display:none}.block{display:block}.inline-block{display:inline-block}
.text-center{text-align:center}.text-left{text-align:left}
.w-full{width:100%}.h-full{height:100%}
.relative{position:relative}.absolute{position:absolute}.fixed{position:fixed}
.rounded{border-radius:var(--radius)}.rounded-lg{border-radius:var(--radius-lg)}.rounded-xl{border-radius:var(--radius-xl)}.rounded-full{border-radius:9999px}
.shadow{box-shadow:var(--shadow)}.shadow-lg{box-shadow:var(--shadow-lg)}
.transition{transition:all .3s ease}

/* === Header / Navigation === */
.site-header{position:fixed;top:0;left:0;right:0;height:var(--header-h);background:rgba(255,255,255,.95);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--gray-200);z-index:1000}
.site-header .container{height:100%;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:.5rem;font-size:1.35rem;font-weight:800;color:var(--dark);letter-spacing:-.02em}
.logo-icon{width:34px;height:34px;background:linear-gradient(135deg,var(--primary),#7c3aed);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;color:#fff;font-size:1rem}
.main-nav{display:none}
.main-nav ul{display:flex;align-items:center;gap:.25rem}
.main-nav a{display:flex;align-items:center;padding:.5rem .875rem;font-size:.9rem;font-weight:500;color:var(--gray-700);border-radius:var(--radius-sm);transition:all .2s}
.main-nav a:hover,.main-nav a.active{background:var(--gray-100);color:var(--primary)}
.main-nav .has-submenu{position:relative}
.main-nav .has-submenu>a::after{content:"";display:inline-block;width:0;height:0;border-left:4px solid transparent;border-right:4px solid transparent;border-top:4px solid currentColor;margin-left:5px;opacity:.5}
.main-nav .submenu{position:absolute;top:100%;left:0;min-width:200px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);box-shadow:var(--shadow-xl);padding:.5rem;opacity:0;visibility:hidden;transform:translateY(-8px);transition:all .25s ease}
.main-nav .has-submenu:hover .submenu{opacity:1;visibility:visible;transform:translateY(0)}
.main-nav .submenu a{display:block;padding:.6rem 1rem;font-size:.85rem;border-radius:var(--radius-sm)}
.main-nav .submenu a:hover{background:var(--primary-light);color:var(--primary)}

/* Recharge Button */
.btn-recharge{background:linear-gradient(135deg,var(--accent),var(--accent-dark));color:#fff;padding:.55rem 1.25rem;border-radius:var(--radius);font-size:.88rem;font-weight:600;display:flex;align-items:center;gap:.4rem;box-shadow:0 4px 14px rgba(245,158,11,.35);transition:all .25s}
.btn-recharge:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(245,158,11,.45)}
.btn-recharge svg{width:16px;height:16px}

/* Mobile Menu Toggle */
.menu-toggle{display:flex;flex-direction:column;gap:4px;padding:.5rem}
.menu-toggle span{display:block;width:22px;height:2.5px;background:var(--gray-700);border-radius:2px;transition:all .3s}
.menu-toggle.active span:nth-child(1){transform:rotate(45deg) translate(4px,5px)}
.menu-toggle.active span:nth-child(2){opacity:0}
.menu-toggle.active span:nth-child(3){transform:rotate(-45deg) translate(4px,-4px)}

/* === Hero Section === */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;background:linear-gradient(135deg,#0f172a 0%,#1e3a5f 50%,#0f172a 100%);overflow:hidden;padding-top:var(--header-h)}
.hero-bg{position:absolute;inset:0;background:url(../images/hero-bg.webp) center/cover no-repeat;opacity:.35}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(15,23,42,.7) 0%,rgba(15,23,42,.5) 50%,rgba(15,23,42,.85) 100%)}
.hero .container{position:relative;z-index:2;display:grid;grid-template-columns:1fr;gap:3rem;align-items:center}
.hero-content{padding:3rem 0}
.hero-badge{display:inline-flex;align-items:center;gap:.5rem;background:rgba(37,99,235,.15);border:1px solid rgba(37,99,235,.3);color:#60a5fa;padding:.4rem 1rem;border-radius:9999px;font-size:.82rem;font-weight:500;margin-bottom:1.5rem;backdrop-filter:blur(8px)}
.hero h1{font-size:clamp(2.2rem,5vw,3.8rem);font-weight:800;color:#fff;line-height:1.15;letter-spacing:-.03em;margin-bottom:1.25rem}
.hero h1 .gradient{background:linear-gradient(135deg,#60a5fa,#a78bfa);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-desc{font-size:clamp(1rem,2vw,1.2rem);color:#94a3b8;max-width:560px;margin-bottom:2.5rem;line-height:1.7}
.hero-cta{display:flex;flex-wrap:wrap;gap:1rem}
.btn-primary{background:var(--primary);color:#fff;padding:.9rem 2rem;border-radius:var(--radius);font-size:1rem;font-weight:600;display:inline-flex;align-items:center;gap:.5rem;box-shadow:0 4px 14px rgba(37,99,235,.35);transition:all .25s}
.btn-primary:hover{background:var(--primary-dark);transform:translateY(-2px);box-shadow:0 6px 20px rgba(37,99,235,.45)}
.btn-secondary{background:rgba(255,255,255,.1);color:#fff;border:1px solid rgba(255,255,255,.25);padding:.9rem 2rem;border-radius:var(--radius);font-size:1rem;font-weight:600;display:inline-flex;align-items:center;gap:.5rem;backdrop-filter:blur(8px);transition:all .25s}
.btn-secondary:hover{background:rgba(255,255,255,.18);border-color:rgba(255,255,255,.4);transform:translateY(-2px)}
.hero-visual{display:flex;justify-content:center;align-items:center}
.hero-visual img{border-radius:var(--radius-xl);box-shadow:var(--shadow-xl);max-height:420px;object-fit:cover}

/* === Section Base === */
.section{padding:5rem 0}
.section-alt{background:var(--gray-50)}
.section-dark{background:var(--dark);color:#fff}
.section-header{text-align:center;max-width:640px;margin:0 auto 3.5rem}
.section-header h2{font-size:clamp(1.8rem,4vw,2.6rem);font-weight:700;margin-bottom:.75rem;letter-spacing:-.02em}
.section-header p{color:var(--gray-500);font-size:1.05rem}
.section-dark .section-header p{color:var(--gray-400)}
.section-header h2 .gradient{background:linear-gradient(135deg,var(--primary),#7c3aed);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

/* === Feature Cards === */
.features-grid{display:grid;grid-template-columns:1fr;gap:1.5rem}
.feature-card{background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);padding:2rem;transition:all .3s}
.feature-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--gray-300)}
.feature-icon{width:52px;height:52px;background:var(--primary-light);border-radius:var(--radius);display:flex;align-items:center;justify-content:center;margin-bottom:1.25rem}
.feature-icon svg{width:26px;height:26px;color:var(--primary)}
.feature-card h3{font-size:1.15rem;font-weight:600;margin-bottom:.5rem;color:var(--dark)}
.feature-card p{font-size:.9rem;color:var(--gray-500);line-height:1.6}

/* === Product Cards === */
.product-grid{display:grid;grid-template-columns:1fr;gap:1.5rem}
.product-card{background:#fff;border:2px solid var(--gray-200);border-radius:var(--radius-xl);padding:2rem;transition:all .3s;position:relative;overflow:hidden}
.product-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.product-card.featured{border-color:var(--primary);box-shadow:0 0 0 1px var(--primary),var(--shadow-lg)}
.product-badge{position:absolute;top:1rem;right:1rem;background:var(--primary);color:#fff;padding:.25rem .75rem;border-radius:9999px;font-size:.75rem;font-weight:600}
.product-card h3{font-size:1.4rem;font-weight:700;margin-bottom:.25rem}
.product-card .subtitle{font-size:.9rem;color:var(--gray-500);margin-bottom:1.5rem}
.product-features li{display:flex;align-items:flex-start;gap:.5rem;padding:.4rem 0;font-size:.9rem;color:var(--gray-600)}
.product-features li::before{content:"✓";color:var(--success);font-weight:700;flex-shrink:0}

/* === Pricing === */
.pricing-grid{display:grid;grid-template-columns:1fr;gap:1.5rem}
.pricing-card{background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-xl);padding:2rem;text-align:center;transition:all .3s}
.pricing-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.pricing-card.popular{border-color:var(--primary);position:relative}
.popular-badge{position:absolute;top:-12px;left:50%;transform:translateX(-50%);background:var(--primary);color:#fff;padding:.35rem 1rem;border-radius:9999px;font-size:.78rem;font-weight:600}
.pricing-card h3{font-size:1.2rem;font-weight:600;margin-bottom:.25rem}
.pricing-card .price{font-size:2.5rem;font-weight:800;color:var(--dark);margin:.75rem 0}
.pricing-card .price span{font-size:1rem;font-weight:400;color:var(--gray-400)}
.pricing-card .period{font-size:.85rem;color:var(--gray-500);margin-bottom:1.5rem}
.pricing-features{text-align:left;margin-bottom:1.5rem}
.pricing-features li{display:flex;align-items:center;gap:.5rem;padding:.35rem 0;font-size:.88rem;color:var(--gray-600)}
.pricing-features li::before{content:"✓";color:var(--success);font-weight:700}

/* === Industry Cards === */
.industry-grid{display:grid;grid-template-columns:1fr;gap:1.5rem}
.industry-card{position:relative;border-radius:var(--radius-xl);overflow:hidden;min-height:280px;display:flex;align-items:flex-end}
.industry-card img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;transition:transform .5s}
.industry-card:hover img{transform:scale(1.05)}
.industry-card .overlay{position:absolute;inset:0;background:linear-gradient(180deg,transparent 30%,rgba(15,23,42,.9) 100%)}
.industry-card .content{position:relative;z-index:2;padding:1.5rem;color:#fff}
.industry-card h3{font-size:1.2rem;font-weight:600;margin-bottom:.25rem}
.industry-card p{font-size:.85rem;opacity:.8}

/* === Blog Cards === */
.blog-grid{display:grid;grid-template-columns:1fr;gap:1.5rem}
.blog-card{background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);overflow:hidden;transition:all .3s}
.blog-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.blog-card img{width:100%;height:200px;object-fit:cover}
.blog-card .content{padding:1.5rem}
.blog-card .tag{display:inline-block;background:var(--primary-light);color:var(--primary);padding:.2rem .6rem;border-radius:9999px;font-size:.75rem;font-weight:500;margin-bottom:.5rem}
.blog-card h3{font-size:1.05rem;font-weight:600;margin-bottom:.5rem;color:var(--dark);line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.blog-card .meta{display:flex;align-items:center;gap:.5rem;font-size:.8rem;color:var(--gray-400)}

/* === Stats === */
.stats-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:2rem;text-align:center}
.stat-item .number{font-size:2.5rem;font-weight:800;background:linear-gradient(135deg,var(--primary),#7c3aed);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.stat-item .label{font-size:.9rem;color:var(--gray-500);margin-top:.25rem}

/* === CTA Section === */
.cta-section{background:linear-gradient(135deg,var(--primary),#7c3aed);padding:5rem 0;text-align:center;color:#fff}
.cta-section h2{font-size:clamp(1.8rem,4vw,2.8rem);font-weight:700;margin-bottom:1rem}
.cta-section p{font-size:1.1rem;opacity:.9;margin-bottom:2rem;max-width:560px;margin-left:auto;margin-right:auto}
.cta-section .btn-white{background:#fff;color:var(--primary);padding:.9rem 2.5rem;border-radius:var(--radius);font-size:1rem;font-weight:600;display:inline-flex;align-items:center;gap:.5rem;transition:all .25s}
.cta-section .btn-white:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}

/* === Footer === */
.site-footer{background:var(--dark);color:#94a3b8;padding:4rem 0 2rem}
.footer-grid{display:grid;grid-template-columns:1fr;gap:2.5rem;margin-bottom:3rem}
.footer-brand .logo{color:#fff;margin-bottom:1rem}
.footer-brand p{font-size:.9rem;line-height:1.7;max-width:300px}
.footer-links h4{color:#fff;font-size:.95rem;font-weight:600;margin-bottom:1rem}
.footer-links a{display:block;padding:.3rem 0;font-size:.88rem;transition:color .2s}
.footer-links a:hover{color:#fff}
.footer-bottom{border-top:1px solid var(--dark-light);padding-top:1.5rem;display:flex;flex-direction:column;gap:1rem;text-align:center;font-size:.82rem}
.footer-bottom .links{display:flex;flex-wrap:wrap;justify-content:center;gap:1.5rem}

/* === Modal / Popup === */
.modal{position:fixed;inset:0;z-index:9999;display:flex;align-items:center;justify-content:center;opacity:0;visibility:hidden;transition:all .3s ease}
.modal.active{opacity:1;visibility:visible}
.modal-backdrop{position:absolute;inset:0;background:rgba(0,0,0,.6);backdrop-filter:blur(4px)}
.modal-content{position:relative;background:#fff;border-radius:var(--radius-xl);padding:2rem;max-width:420px;width:90%;text-align:center;box-shadow:var(--shadow-xl);transform:scale(.9) translateY(20px);transition:all .3s ease}
.modal.active .modal-content{transform:scale(1) translateY(0)}
.modal-close{position:absolute;top:1rem;right:1rem;width:32px;height:32px;display:flex;align-items:center;justify-content:center;border-radius:50%;background:var(--gray-100);color:var(--gray-500);font-size:1.2rem;transition:all .2s}
.modal-close:hover{background:var(--gray-200);color:var(--dark)}
.modal h3{font-size:1.25rem;font-weight:600;margin-bottom:.5rem;color:var(--dark)}
.modal p{color:var(--gray-500);margin-bottom:1.5rem;font-size:.95rem}
.modal img{max-width:240px;margin:0 auto 1rem;border-radius:var(--radius);border:2px solid var(--gray-200)}
.modal .tip{background:var(--accent-light);color:var(--accent-dark);padding:.75rem;border-radius:var(--radius);font-size:.85rem;font-weight:500}

/* === Breadcrumbs === */
.breadcrumbs{background:var(--gray-50);padding:.75rem 0;font-size:.85rem;color:var(--gray-500)}
.breadcrumbs a{color:var(--gray-600)}
.breadcrumbs a:hover{color:var(--primary)}
.breadcrumbs span{color:var(--gray-400);margin:0 .5rem}

/* === FAQ === */
.faq-item{border:1px solid var(--gray-200);border-radius:var(--radius);margin-bottom:.75rem;overflow:hidden}
.faq-question{width:100%;display:flex;align-items:center;justify-content:space-between;padding:1rem 1.25rem;background:#fff;font-size:.95rem;font-weight:500;color:var(--dark);text-align:left;transition:background .2s}
.faq-question:hover{background:var(--gray-50)}
.faq-question .icon{transition:transform .3s;color:var(--gray-400);flex-shrink:0}
.faq-item.active .faq-question .icon{transform:rotate(180deg)}
.faq-answer{max-height:0;overflow:hidden;transition:max-height .3s ease}
.faq-item.active .faq-answer{max-height:500px}
.faq-answer-inner{padding:0 1.25rem 1.25rem;font-size:.9rem;color:var(--gray-600);line-height:1.7}

/* === Tablet (768px+) === */
@media(min-width:768px){
  .main-nav{display:block}
  .menu-toggle{display:none}
  .hero .container{grid-template-columns:1fr 1fr}
  .features-grid{grid-template-columns:repeat(2,1fr)}
  .product-grid{grid-template-columns:repeat(2,1fr)}
  .pricing-grid{grid-template-columns:repeat(2,1fr)}
  .industry-grid{grid-template-columns:repeat(2,1fr)}
  .blog-grid{grid-template-columns:repeat(2,1fr)}
  .stats-grid{grid-template-columns:repeat(4,1fr)}
  .footer-grid{grid-template-columns:2fr 1fr 1fr 1fr}
  .footer-bottom{flex-direction:row;justify-content:space-between;text-align:left}
}

/* === Desktop (1024px+) === */
@media(min-width:1024px){
  .features-grid{grid-template-columns:repeat(3,1fr)}
  .product-grid{grid-template-columns:repeat(3,1fr)}
  .pricing-grid{grid-template-columns:repeat(3,1fr)}
  .industry-grid{grid-template-columns:repeat(3,1fr)}
  .blog-grid{grid-template-columns:repeat(3,1fr)}
}

/* === Mobile Menu === */
.mobile-menu{position:fixed;inset:0;z-index:999;background:#fff;padding:6rem 1.5rem 2rem;transform:translateX(100%);transition:transform .3s ease}
.mobile-menu.active{transform:translateX(0)}
.mobile-menu a{display:block;padding:1rem 0;font-size:1.1rem;font-weight:500;color:var(--dark);border-bottom:1px solid var(--gray-100)}
.mobile-menu a.primary{color:var(--primary);font-weight:600}

/* === Animations === */
@keyframes fadeInUp{from{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}
.animate{animation:fadeInUp .6s ease forwards}
.animate-delay-1{animation-delay:.1s}
.animate-delay-2{animation-delay:.2s}
.animate-delay-3{animation-delay:.3s}

/* === Scrollbar === */
::-webkit-scrollbar{width:8px}
::-webkit-scrollbar-track{background:var(--gray-100)}
::-webkit-scrollbar-thumb{background:var(--gray-300);border-radius:4px}
::-webkit-scrollbar-thumb:hover{background:var(--gray-400)}

/* === Selection === */
::selection{background:var(--primary);color:#fff}