/* ============================================
   iiug2017.org — 名爵公众号 · 蓝绿主题
   Inspired by original blue/green gradient style
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;700;900&display=swap');

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:'Noto Sans SC','PingFang SC','Microsoft YaHei','Inter',sans-serif;
  color:#333;background:#f7f8fa;line-height:1.7;
  -webkit-font-smoothing:antialiased;
}

:root{
  --primary:#2563eb;
  --primary-dark:#1d4ed8;
  --primary-deeper:#0f172a;
  --secondary:#10b981;
  --secondary-dark:#059669;
  --grad-main:linear-gradient(135deg,#2563eb 0%,#10b981 100%);
  --grad-hero:linear-gradient(135deg,#2563eb 0%,#0f172a 100%);
  --bg-section:#f7f8fa;
  --bg-card:#fff;
  --text-dark:#1f2d3d;
  --text-body:#4b5563;
  --text-muted:#94a3b8;
  --radius:8px;
  --radius-lg:12px;
  --shadow:0 5px 15px rgba(0,0,0,.05);
  --shadow-hover:0 10px 24px rgba(0,0,0,.1);
  --nav-height:64px;
  --container:1200px;
}

.container{width:92%;max-width:var(--container);margin:0 auto}
@media(min-width:640px){.container{width:90%}}

.text-center{text-align:center}
.flex{display:flex}
.items-center{align-items:center}
.justify-center{justify-content:center}
.justify-between{justify-content:space-between}
.flex-col{flex-direction:column}
.flex-wrap{flex-wrap:wrap}
.gap-2{gap:.5rem}.gap-3{gap:.75rem}.gap-4{gap:1rem}.gap-6{gap:1.5rem}.gap-8{gap:2rem}
.mx-auto{margin:0 auto}
.mb-2{margin-bottom:.5rem}.mb-3{margin-bottom:.75rem}.mb-4{margin-bottom:1rem}
.mb-6{margin-bottom:1.5rem}.mb-8{margin-bottom:2rem}.mb-10{margin-bottom:2.5rem}.mb-12{margin-bottom:3rem}
.mt-4{margin-top:1rem}.mt-6{margin-top:1.5rem}.mt-8{margin-top:2rem}.mt-10{margin-top:2.5rem}
.max-w-2xl{max-width:42rem}.max-w-3xl{max-width:48rem}.max-w-4xl{max-width:56rem}.max-w-5xl{max-width:64rem}
.overflow-hidden{overflow:hidden}.overflow-x-auto{overflow-x:auto}
.hidden{display:none}.block{display:block}

/* Grid */
.grid-2{display:grid;grid-template-columns:1fr;gap:1.5rem}
.grid-3{display:grid;grid-template-columns:1fr;gap:1.5rem}
.grid-4{display:grid;grid-template-columns:1fr 1fr;gap:1.25rem}
@media(min-width:768px){
  .grid-2{grid-template-columns:1fr 1fr}
  .grid-3{grid-template-columns:1fr 1fr 1fr}
  .grid-4{grid-template-columns:repeat(4,1fr)}
}

/* --- Header / Nav --- */
.site-header{background:#fff;box-shadow:0 2px 10px rgba(0,0,0,.08);position:sticky;top:0;z-index:100}
.nav-container{display:flex;justify-content:space-between;align-items:center;height:var(--nav-height)}
.nav-brand{font-size:1.15rem;font-weight:800;color:var(--primary);display:flex;align-items:center;gap:.5rem;text-decoration:none}
.nav-brand i{color:var(--secondary)}
.nav-links{display:none;list-style:none;align-items:center}
@media(min-width:768px){.nav-links{display:flex}}
.nav-links a{text-decoration:none;color:#333;font-weight:500;font-size:.88rem;padding:.3rem .65rem;transition:color .2s}
.nav-links a:hover,.nav-links a.active{color:var(--primary)}
.nav-cta{display:none;gap:.5rem;align-items:center}
@media(min-width:768px){.nav-cta{display:flex}}
.nav-toggle{display:flex;font-size:1.4rem;cursor:pointer;background:none;border:none;color:#333}
@media(min-width:768px){.nav-toggle{display:none}}

.mobile-menu{max-height:0;overflow:hidden;transition:max-height .35s;background:#fff;border-bottom:1px solid #e5e7eb}
.mobile-menu.open{max-height:400px}
.mobile-menu-inner{display:flex;flex-direction:column;padding:.5rem 1rem 1rem;gap:.25rem}
.mobile-menu-inner a{text-decoration:none;color:#333;font-weight:500;padding:.5rem 0;font-size:.88rem}
.mobile-menu-inner a:hover{color:var(--primary)}
.mobile-cta{display:flex;flex-direction:column;gap:.5rem;padding-top:.5rem;border-top:1px solid #e5e7eb}

/* --- Buttons --- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.4rem;
  background:var(--grad-main);color:#fff;padding:.6rem 1.4rem;
  border-radius:var(--radius);text-decoration:none;font-weight:600;
  font-size:.88rem;border:none;cursor:pointer;transition:all .2s;
}
.btn:hover{transform:translateY(-2px);box-shadow:0 6px 16px rgba(0,0,0,.12)}
.btn-sm{padding:.4rem 1rem;font-size:.8rem}
.btn-lg{padding:.75rem 1.8rem;font-size:.95rem}
.btn-outline{background:transparent;border:2px solid rgba(255,255,255,.5);color:#fff}
.btn-outline:hover{background:rgba(255,255,255,.1);border-color:#fff}
.btn-white{background:#fff;color:var(--primary)}
.btn-white:hover{color:var(--primary-dark)}
.btn-block{width:100%;text-align:center}

/* --- Hero --- */
.hero-section{
  background:var(--grad-hero);color:#fff;
  padding-top:calc(var(--nav-height) + 1rem);
  padding-bottom:3rem;
}
@media(min-width:768px){
  .hero-section{padding-top:calc(var(--nav-height) + 2rem);padding-bottom:4rem}
}

.hero-grid{display:grid;grid-template-columns:1fr;gap:2rem;align-items:center}
@media(min-width:768px){.hero-grid{grid-template-columns:1.2fr 1fr}}
@media(max-width:767px){.hero-right{order:-1}}

.hero-left h1{font-size:clamp(1.6rem,4vw,2.6rem);font-weight:900;margin-bottom:.75rem;line-height:1.2}
.hero-left h1 .highlight{color:#34d399}
.hero-left p{font-size:clamp(.95rem,1.5vw,1.1rem);opacity:.92;margin-bottom:1.25rem;max-width:32rem}
.hero-right img{width:100%;height:auto;max-width:500px;border-radius:var(--radius-lg);box-shadow:0 10px 30px rgba(0,0,0,.25);transition:all .4s}
.hero-right img:hover{transform:scale(1.02)}
.hero-kws{display:flex;flex-wrap:wrap;gap:.4rem;margin-top:.5rem}
.hero-kw{display:inline-block;font-size:.7rem;padding:.15rem .55rem;border-radius:4px;background:rgba(255,255,255,.12);color:rgba(255,255,255,.85)}
.hero-buttons{display:flex;flex-wrap:wrap;gap:.75rem;margin-top:.5rem}
.hero-buttons .btn-cursor{cursor:default}

/* --- Tagline Banner --- */
.tagline-banner{
  background:var(--grad-main);color:#fff;text-align:center;padding:1rem 1rem;
}
.tagline-text{font-size:clamp(1rem,2vw,1.3rem);font-weight:800;letter-spacing:.04em}
.tagline-sub{font-size:.8rem;opacity:.85;margin-top:.2rem}

/* --- Section --- */
.section{padding:3.5rem 0}
.section-alt{background:#f7f8fa}
@media(min-width:768px){.section{padding:4.5rem 0}}

.section-label{
  display:inline-block;font-size:.7rem;font-weight:700;letter-spacing:.08em;
  text-transform:uppercase;color:var(--primary);
  margin-bottom:.4rem;
}
.section-title{
  font-size:clamp(1.3rem,2.8vw,2rem);font-weight:800;
  color:var(--text-dark);margin-bottom:.5rem;
}
.section-title::after{
  content:'';display:block;width:50px;height:3px;
  background:var(--grad-main);margin:.5rem auto 0;border-radius:2px;
}
.section-title.no-line::after{display:none}
.section-title .highlight{color:var(--primary)}
.section-desc{color:var(--text-body);max-width:40rem;margin:0 auto 2rem;font-size:.9rem}

/* --- Cards --- */
.card{
  background:var(--bg-card);border-radius:var(--radius-lg);
  padding:1.5rem;box-shadow:var(--shadow);transition:all .25s;
  border:1px solid rgba(0,0,0,.04);
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-hover)}
.card-icon{
  width:44px;height:44px;border-radius:var(--radius);
  background:rgba(37,99,235,.08);display:flex;align-items:center;justify-content:center;
  color:var(--primary);font-size:1.2rem;margin-bottom:.75rem;
}
.card-tag{
  display:inline-block;font-size:.65rem;font-weight:600;padding:.15rem .5rem;
  border-radius:4px;background:rgba(37,99,235,.08);color:var(--primary);
  margin-bottom:.4rem;
}
.card h3{font-size:1rem;font-weight:700;color:var(--text-dark);margin-bottom:.35rem}
.card p{color:var(--text-body);font-size:.85rem;line-height:1.55}

/* --- Step number --- */
.step-num{
  width:34px;height:34px;min-width:34px;border-radius:50%;
  background:var(--grad-main);color:#fff;
  display:flex;align-items:center;justify-content:center;
  font-weight:700;font-size:.8rem;
}

/* --- Stats --- */
.stats-banner{
  background:#fff;border-radius:var(--radius-lg);
  padding:1.25rem 1rem;box-shadow:var(--shadow);
  border:1px solid rgba(0,0,0,.04);
}
.stats-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:.75rem;text-align:center}
@media(min-width:640px){.stats-grid{grid-template-columns:repeat(4,1fr)}}
.stat-item .stat-num{font-size:1.7rem;font-weight:800;background:var(--grad-main);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.stat-item .stat-label{font-size:.78rem;color:var(--text-body);margin-top:.1rem}

/* --- Testimonials --- */
.test-card{background:#fff;border-radius:var(--radius-lg);padding:1.5rem;box-shadow:var(--shadow);transition:all .25s}
.test-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-hover)}
.test-stars{color:#f59e0b;margin-bottom:.5rem;font-size:.85rem}
.test-card blockquote{color:var(--text-body);font-size:.85rem;line-height:1.55;margin-bottom:.75rem;font-style:italic}
.test-author{display:flex;align-items:center;gap:.6rem}
.test-avatar{
  width:36px;height:36px;border-radius:50%;
  background:var(--grad-main);color:#fff;
  display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.75rem;
}
.test-name{font-weight:600;font-size:.82rem;color:var(--text-dark)}
.test-title{font-size:.7rem;color:var(--text-muted)}

/* --- FAQ Accordion --- */
.faq-list{max-width:44rem;margin:0 auto;display:flex;flex-direction:column;gap:.6rem}
.faq-item{border:1px solid #e5e7eb;border-radius:var(--radius-lg);overflow:hidden;background:#fff}
.faq-question{
  width:100%;display:flex;align-items:center;justify-content:space-between;
  padding:.8rem 1.1rem;background:#f7f8fa;border:none;
  cursor:pointer;font-weight:600;font-size:.9rem;text-align:left;color:var(--text-dark);
  transition:background .2s;
}
.faq-question:hover{background:#e5e7eb}
.faq-icon{font-size:1.1rem;color:var(--primary);transition:transform .3s;font-weight:700}
.faq-item.active .faq-icon{transform:rotate(45deg)}
.faq-answer{max-height:0;overflow:hidden;transition:max-height .4s}
.faq-item.active .faq-answer{max-height:500px}
.faq-answer-inner{padding:.65rem 1.1rem .9rem;color:var(--text-body);font-size:.85rem;line-height:1.55}

/* --- CTA --- */
.cta-section{background:var(--grad-hero);color:#fff;text-align:center}
.cta-section h2{font-size:clamp(1.3rem,2.5vw,1.8rem);font-weight:800;margin-bottom:.6rem}
.cta-section p{opacity:.9;margin-bottom:1.25rem;font-size:.9rem}
.cta-actions{display:flex;flex-wrap:wrap;gap:.75rem;justify-content:center}

/* --- Contact --- */
.contact-grid{display:grid;grid-template-columns:1fr;gap:1.25rem;max-width:44rem;margin:0 auto}
@media(min-width:768px){.contact-grid{grid-template-columns:1fr 1fr}}
.contact-card{background:#fff;border-radius:var(--radius-lg);padding:1.5rem;box-shadow:var(--shadow)}
.contact-card h3{font-size:1rem;font-weight:700;margin-bottom:.75rem;color:var(--text-dark)}
.contact-item{display:flex;align-items:flex-start;gap:.6rem;margin-bottom:.6rem}
.contact-ico{
  width:34px;height:34px;min-width:34px;border-radius:var(--radius);
  background:rgba(37,99,235,.08);display:flex;align-items:center;justify-content:center;
  color:var(--primary);font-size:.85rem;
}
.contact-label{font-size:.7rem;color:var(--text-muted)}
.contact-val{font-size:.85rem;font-weight:600;color:var(--primary)}

/* Warning Bar */
.warning-bar{
  background:var(--primary-deeper);color:#93c5fd;text-align:center;
  font-size:.75rem;padding:.35rem 1rem;
}

/* --- Data Table --- */
.data-table{width:100%;border-collapse:collapse;font-size:.85rem}
.data-table th{
  background:rgba(37,99,235,.06);color:var(--primary-dark);font-weight:700;
  padding:.65rem .75rem;text-align:left;border-bottom:2px solid #e5e7eb;
}
.data-table td{padding:.55rem .75rem;border-bottom:1px solid #e5e7eb;color:var(--text-body)}
.data-table tr:hover td{background:rgba(37,99,235,.03)}

/* --- Timeline --- */
.timeline{position:relative;padding-left:1.5rem;max-width:40rem;margin:0 auto}
.timeline::before{
  content:'';position:absolute;left:6px;top:0;bottom:0;
  width:2px;background:var(--grad-main);
}
.tl-item{position:relative;margin-bottom:1.25rem}
.tl-item::before{
  content:'';position:absolute;left:-1.35rem;top:.35rem;
  width:10px;height:10px;border-radius:50%;
  background:var(--primary);border:2px solid #fff;
}
.tl-date{font-size:.7rem;color:var(--primary);font-weight:600;margin-bottom:.15rem}
.tl-content{background:#fff;border-radius:var(--radius);padding:.75rem .9rem;box-shadow:var(--shadow)}
.tl-content h4{font-size:.85rem;font-weight:700;color:var(--text-dark);margin-bottom:.1rem}
.tl-content p{font-size:.8rem;color:var(--text-body)}

/* --- Brand Strip --- */
.brand-strip{display:flex;flex-wrap:wrap;justify-content:center;gap:.75rem}
.brand-strip span{
  font-size:.8rem;padding:.3rem .85rem;background:#fff;
  border:1px solid #e5e7eb;border-radius:20px;color:var(--text-body);font-weight:500;
}

/* --- Guide Steps --- */
.guide-steps{display:flex;flex-direction:column;gap:.75rem;max-width:36rem;margin:0 auto}
.guide-step{
  display:flex;align-items:center;gap:1rem;
  padding:.75rem 1rem;background:#fff;border-radius:var(--radius-lg);
  box-shadow:var(--shadow);border:1px solid rgba(0,0,0,.04);
}

/* --- Download Card --- */
.download-card{
  background:var(--grad-hero);border-radius:var(--radius-lg);padding:2rem 1.5rem;color:#fff;text-align:center;
}

/* --- Footer --- */
.site-footer{background:var(--primary-deeper);color:rgba(255,255,255,.8);padding:2.5rem 0 1.5rem}
.footer-grid{display:grid;grid-template-columns:1fr;gap:1.5rem;margin-bottom:1.5rem}
@media(min-width:640px){.footer-grid{grid-template-columns:2fr 1fr 1fr 1fr}}
.footer-brand .f-logo{font-size:1.05rem;font-weight:800;color:#fff;display:flex;align-items:center;gap:.4rem}
.footer-brand .f-logo i{color:var(--secondary)}
.footer-brand p{font-size:.8rem;margin-top:.4rem;color:rgba(255,255,255,.55);line-height:1.5}
.footer-col h4{font-size:.85rem;font-weight:700;color:#fff;margin-bottom:.6rem}
.footer-col a{display:block;font-size:.8rem;color:rgba(255,255,255,.5);text-decoration:none;margin-bottom:.35rem;transition:color .2s}
.footer-col a:hover{color:#93c5fd}
.footer-bottom{border-top:1px solid rgba(255,255,255,.08);padding-top:1rem;display:flex;flex-direction:column;align-items:center;gap:.5rem}
@media(min-width:640px){.footer-bottom{flex-direction:row;justify-content:space-between}}
.footer-bottom p{font-size:.75rem;color:rgba(255,255,255,.4)}
.footer-social{display:flex;gap:.5rem}
.footer-social a{
  width:30px;height:30px;border-radius:50%;background:rgba(255,255,255,.06);
  color:rgba(255,255,255,.5);display:flex;align-items:center;justify-content:center;
  text-decoration:none;font-size:.8rem;transition:all .2s;
}
.footer-social a:hover{background:var(--primary);color:#fff}

/* --- Back to top --- */
.back-top{
  position:fixed;bottom:1.5rem;right:1.5rem;width:40px;height:40px;border-radius:50%;
  background:var(--grad-main);color:#fff;border:none;
  display:flex;align-items:center;justify-content:center;cursor:pointer;
  font-size:.9rem;box-shadow:0 4px 12px rgba(0,0,0,.15);
  opacity:0;visibility:hidden;transition:all .3s;z-index:99;
}
.back-top.visible{opacity:1;visibility:visible}

/* --- Reveal --- */
.reveal{opacity:0;transform:translateY(20px);transition:all .5s}
.reveal.visible{opacity:1;transform:translateY(0)}

/* --- Selection --- */
::selection{background:rgba(37,99,235,.15)}

/* --- Scrollbar --- */
::-webkit-scrollbar{width:5px}
::-webkit-scrollbar-track{background:#f1f5f9}
::-webkit-scrollbar-thumb{background:var(--primary);border-radius:3px}