/* ===================================================================
   域名到期通知系统 — 品牌首页样式 v2
   包含：入场动画、渐变光效、粒子装饰、卡片光晕、
         毛玻璃、脉冲按钮、滚动触发、连接线等
   =================================================================== */

/* ---------- CSS Variables ---------- */
:root {
  --c-bg:        #f8fafc;
  --c-white:     #ffffff;
  --c-text:      #1e293b;
  --c-muted:     #64748b;
  --c-border:    #e2e8f0;
  --c-primary:   #1463ff;
  --c-primary-d: #0b4fd6;
  --c-accent:    #7c3aed;
  --c-success:   #059669;
  --c-warning:   #d97706;
  --c-danger:    #dc2626;
  --c-hero-from: #0f172a;
  --c-hero-mid:  #1a2744;
  --c-hero-to:   #0f2b4a;
  --shadow-sm:   0 1px 2px rgba(0,0,0,.05);
  --shadow-md:   0 4px 16px rgba(0,0,0,.08);
  --shadow-lg:   0 12px 40px rgba(0,0,0,.12);
  --shadow-xl:   0 24px 64px rgba(0,0,0,.16);
  --radius-sm:   8px;
  --radius-md:   12px;
  --radius-lg:   20px;
  --radius-xl:   28px;
  --transition:  .3s cubic-bezier(.4,0,.2,1);
  --max-w:       1200px;
}

/* ---------- Reset ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:80px}
body{
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;
  color:var(--c-text);background:var(--c-bg);line-height:1.7;
  -webkit-font-smoothing:antialiased;overflow-x:hidden;
}
a{color:var(--c-primary);text-decoration:none;transition:color var(--transition)}
a:hover{color:var(--c-primary-d)}
img{max-width:100%;display:block}

/* ===================================================================
   Scroll-triggered fade-in animation
   =================================================================== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(32px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes pulse {
  0%,100% { box-shadow: 0 0 0 0 rgba(20,99,255,.4); }
  50%     { box-shadow: 0 0 0 14px rgba(20,99,255,0); }
}
@keyframes float {
  0%,100% { transform: translateY(0) rotate(0deg); }
  33%     { transform: translateY(-12px) rotate(1deg); }
  66%     { transform: translateY(6px) rotate(-1deg); }
}
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
@keyframes gradientShift {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.animate-in {
  animation: fadeInUp .7s cubic-bezier(.22,1,.36,1) both;
}
.animate-in:nth-child(1){animation-delay:0s}
.animate-in:nth-child(2){animation-delay:.1s}
.animate-in:nth-child(3){animation-delay:.2s}
.animate-in:nth-child(4){animation-delay:.3s}
.animate-in:nth-child(5){animation-delay:.4s}
.animate-in:nth-child(6){animation-delay:.5s}

/* ===================================================================
   Navbar — sticky glass
   =================================================================== */
.navbar{
  position:sticky;top:0;z-index:100;
  display:flex;align-items:center;justify-content:space-between;
  height:68px;padding:0 28px;
  background:rgba(255,255,255,.82);
  backdrop-filter:blur(16px) saturate(180%);
  -webkit-backdrop-filter:blur(16px) saturate(180%);
  border-bottom:1px solid rgba(226,232,240,.6);
  transition:box-shadow var(--transition);
}
.navbar.scrolled{box-shadow:var(--shadow-md)}
.navbar .logo{
  display:flex;align-items:center;gap:10px;
  font-size:21px;font-weight:800;color:var(--c-text);
  letter-spacing:-.5px;transition:opacity var(--transition);
}
.navbar .logo:hover{opacity:.8}
.navbar .logo .icon{
  width:38px;height:38px;
  background:linear-gradient(135deg,var(--c-primary),var(--c-accent));
  border-radius:11px;display:flex;align-items:center;justify-content:center;
  color:#fff;font-size:19px;font-weight:700;
  box-shadow:0 4px 12px rgba(20,99,255,.3);
}
.nav-links{display:flex;align-items:center;gap:32px;list-style:none}
.nav-links a{
  position:relative;color:var(--c-muted);font-weight:500;font-size:15px;
  padding:6px 0;transition:color var(--transition);
}
.nav-links a::after{
  content:'';position:absolute;bottom:0;left:0;width:0;height:2px;
  background:var(--c-primary);border-radius:2px;
  transition:width var(--transition);
}
.nav-links a:hover{color:var(--c-primary)}
.nav-links a:hover::after{width:100%}
.nav-actions{display:flex;align-items:center;gap:10px}

/* ===================================================================
   Buttons — glow + scale
   =================================================================== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:6px;
  height:44px;padding:0 24px;
  font-size:15px;font-weight:600;border-radius:10px;
  cursor:pointer;transition:all var(--transition);
  border:1px solid transparent;white-space:nowrap;
  position:relative;overflow:hidden;
}
.btn:active{transform:scale(.96)}
.btn-primary{
  color:#fff;
  background:linear-gradient(135deg,var(--c-primary),#3b82f6);
  border-color:transparent;
  box-shadow:0 2px 8px rgba(20,99,255,.25);
}
.btn-primary:hover{
  color:#fff;transform:translateY(-1px);
  box-shadow:0 6px 20px rgba(20,99,255,.4);
}
.btn-primary.pulse{animation:pulse 2s infinite}
.btn-outline{
  color:var(--c-primary);background:transparent;
  border:1.5px solid var(--c-primary);
}
.btn-outline:hover{
  background:var(--c-primary);color:#fff;
  transform:translateY(-1px);box-shadow:0 6px 20px rgba(20,99,255,.25);
}
.btn-lg{height:54px;padding:0 36px;font-size:18px;border-radius:12px}
.btn-ghost{
  color:var(--c-muted);background:transparent;border-color:transparent;
}
.btn-ghost:hover{
  color:var(--c-primary);background:rgba(20,99,255,.06);
}

/* ===================================================================
   Hero — particles + gradient mesh
   =================================================================== */
.hero{
  position:relative;overflow:hidden;
  background:linear-gradient(160deg,var(--c-hero-from) 0%,var(--c-hero-mid) 45%,#0b2342 75%,#0a1a33 100%);
  background-size:400% 400%;animation:gradientShift 15s ease infinite;
  color:#fff;text-align:center;
  padding:120px 24px 90px;
}
.hero::before{
  content:'';position:absolute;inset:0;z-index:0;
  background:
    radial-gradient(ellipse 60% 50% at 20% 50%,rgba(124,58,237,.18),transparent),
    radial-gradient(ellipse 50% 50% at 80% 20%,rgba(59,130,246,.15),transparent),
    radial-gradient(ellipse 40% 40% at 50% 80%,rgba(20,99,255,.12),transparent);
}
/* animated mesh grid */
.hero::after{
  content:'';position:absolute;inset:0;z-index:0;opacity:.04;
  background-image:
    linear-gradient(rgba(255,255,255,.3) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.3) 1px,transparent 1px);
  background-size:60px 60px;
  animation:float 20s ease-in-out infinite;
}
.hero-content{position:relative;z-index:1;max-width:820px;margin:0 auto}
.hero h1{
  font-size:clamp(34px,5.5vw,60px);font-weight:900;line-height:1.12;
  letter-spacing:-1.5px;margin-bottom:22px;
  animation:fadeInUp .8s cubic-bezier(.22,1,.36,1) both;
}
.hero h1 .gradient-text{
  background:linear-gradient(135deg,#60a5fa 0%,#a78bfa 40%,#f472b6 80%);
  background-size:200% auto;
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
  animation:shimmer 4s linear infinite;
}
.hero p{
  font-size:clamp(16px,2vw,20px);color:rgba(255,255,255,.65);
  max-width:620px;margin:0 auto 40px;line-height:1.75;
  animation:fadeInUp .8s .15s cubic-bezier(.22,1,.36,1) both;
}
.hero-btns{
  display:flex;gap:16px;justify-content:center;flex-wrap:wrap;
  animation:fadeInUp .8s .3s cubic-bezier(.22,1,.36,1) both;
}
.hero-btns .btn-outline{
  color:#fff;border-color:rgba(255,255,255,.3);
  backdrop-filter:blur(4px);
}
.hero-btns .btn-outline:hover{
  background:rgba(255,255,255,.1);border-color:rgba(255,255,255,.55);
  color:#fff;box-shadow:0 0 24px rgba(255,255,255,.1);
}
.hero-stats{
  display:flex;justify-content:center;gap:56px;
  margin-top:64px;flex-wrap:wrap;
  animation:fadeInUp .8s .45s cubic-bezier(.22,1,.36,1) both;
}
.hero-stat{text-align:center;transition:transform var(--transition)}
.hero-stat:hover{transform:translateY(-4px)}
.hero-stat .num{font-size:40px;font-weight:900;line-height:1;letter-spacing:-1px}
.hero-stat .num.count-up{transition:all .6s cubic-bezier(.22,1,.36,1)}
.hero-stat .label{
  font-size:14px;color:rgba(255,255,255,.5);margin-top:8px;
  letter-spacing:.5px;text-transform:uppercase;
}

/* ===================================================================
   Section common
   =================================================================== */
.section{
  padding:90px 24px;
  position:relative;overflow:hidden;
}
.section-alt{background:var(--c-white)}
.section-header{text-align:center;max-width:680px;margin:0 auto 60px}
.section-header .tag{
  display:inline-block;padding:5px 14px;
  font-size:13px;font-weight:700;color:var(--c-primary);
  background:rgba(20,99,255,.08);border-radius:999px;
  margin-bottom:16px;letter-spacing:1px;text-transform:uppercase;
}
.section-header h2{
  font-size:clamp(28px,4vw,40px);font-weight:800;margin-bottom:14px;
  letter-spacing:-.5px;line-height:1.2;
}
.section-header p{font-size:17px;color:var(--c-muted);line-height:1.7}
.container{width:min(var(--max-w),100%);margin:0 auto}

/* ===================================================================
   Features grid — card glow on hover
   =================================================================== */
.features-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
  gap:28px;
}
.feature-card{
  padding:36px 30px;
  background:var(--c-white);
  border:1px solid var(--c-border);
  border-radius:var(--radius-lg);
  transition:all .35s cubic-bezier(.4,0,.2,1);
  position:relative;overflow:hidden;
  cursor:default;
}
/* card glow line on top */
.feature-card::before{
  content:'';position:absolute;top:0;left:20%;right:20%;height:3px;
  border-radius:0 0 3px 3px;
  background:linear-gradient(90deg,transparent,var(--c-primary),transparent);
  opacity:0;transition:opacity .35s ease;
}
.feature-card:hover{
  transform:translateY(-6px);
  box-shadow:var(--shadow-xl);
  border-color:transparent;
}
.feature-card:hover::before{opacity:1}
.feature-card .icon{
  width:52px;height:52px;border-radius:14px;
  display:flex;align-items:center;justify-content:center;
  font-size:26px;margin-bottom:20px;
  transition:transform .35s cubic-bezier(.4,0,.2,1);
}
.feature-card:hover .icon{transform:scale(1.1) rotate(-5deg)}
.feature-card h3{font-size:19px;font-weight:700;margin-bottom:8px}
.feature-card p{font-size:14px;color:var(--c-muted);line-height:1.75}

.icon-blue{background:linear-gradient(135deg,#eff6ff,#dbeafe);color:var(--c-primary);box-shadow:0 4px 12px rgba(20,99,255,.12)}
.icon-green{background:linear-gradient(135deg,#ecfdf5,#d1fae5);color:var(--c-success);box-shadow:0 4px 12px rgba(5,150,105,.12)}
.icon-purple{background:linear-gradient(135deg,#f5f3ff,#ede9fe);color:var(--c-accent);box-shadow:0 4px 12px rgba(124,58,237,.12)}
.icon-orange{background:linear-gradient(135deg,#fff7ed,#fed7aa);color:var(--c-warning);box-shadow:0 4px 12px rgba(217,119,6,.12)}
.icon-cyan{background:linear-gradient(135deg,#ecfeff,#cffafe);color:#0891b2;box-shadow:0 4px 12px rgba(8,145,178,.12)}
.icon-rose{background:linear-gradient(135deg,#fff1f2,#fecdd3);color:#e11d48;box-shadow:0 4px 12px rgba(225,29,72,.12)}

/* ===================================================================
   How It Works — connected steps
   =================================================================== */
.steps{
  display:flex;gap:0;justify-content:center;flex-wrap:wrap;
  position:relative;
}
.step-card{
  flex:1;min-width:220px;max-width:320px;
  text-align:center;padding:36px 24px;
  position:relative;
}
.step-card + .step-card::before{
  content:'';position:absolute;top:64px;left:-16px;
  width:32px;height:2px;
  background:linear-gradient(90deg,var(--c-border),var(--c-primary),var(--c-border));
  border-radius:1px;
}
.step-card .step-num{
  width:60px;height:60px;border-radius:50%;
  background:linear-gradient(135deg,var(--c-primary),var(--c-accent));
  color:#fff;font-size:26px;font-weight:900;
  display:flex;align-items:center;justify-content:center;
  margin:0 auto 20px;
  box-shadow:0 8px 24px rgba(20,99,255,.25);
  transition:transform var(--transition),box-shadow var(--transition);
}
.step-card:hover .step-num{
  transform:scale(1.1);
  box-shadow:0 12px 32px rgba(20,99,255,.35);
}
.step-card h4{font-size:18px;font-weight:700;margin-bottom:8px}
.step-card p{font-size:14px;color:var(--c-muted);line-height:1.7}

/* ===================================================================
   Stats bar — animated gradient
   =================================================================== */
.stats-bar{
  background:linear-gradient(135deg,var(--c-primary),#3b82f6,var(--c-accent),#8b5cf6);
  background-size:300% 300%;
  animation:gradientShift 8s ease infinite;
  color:#fff;padding:60px 24px;
  position:relative;overflow:hidden;
}
.stats-bar::before{
  content:'';position:absolute;inset:0;
  background:radial-gradient(ellipse at 30% 50%,rgba(255,255,255,.08),transparent),
             radial-gradient(ellipse at 70% 50%,rgba(255,255,255,.05),transparent);
}
.stats-inner{
  display:flex;justify-content:center;gap:72px;flex-wrap:wrap;
  max-width:var(--max-w);margin:0 auto;position:relative;z-index:1;
}
.stats-inner .item{
  text-align:center;transition:transform var(--transition);
}
.stats-inner .item:hover{transform:translateY(-3px)}
.stats-inner .item .num{
  font-size:42px;font-weight:900;letter-spacing:-1px;
}
.stats-inner .item .label{
  font-size:15px;opacity:.75;margin-top:6px;font-weight:500;
}

/* ===================================================================
   Pricing — tilt + shine
   =================================================================== */
.pricing-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
  gap:28px;max-width:960px;margin:0 auto;
}
.pricing-card{
  padding:44px 32px;
  background:var(--c-white);
  border:1px solid var(--c-border);
  border-radius:var(--radius-xl);
  text-align:center;position:relative;
  transition:all .35s cubic-bezier(.4,0,.2,1);
}
.pricing-card:hover{
  box-shadow:var(--shadow-lg);
  border-color:transparent;
}
.pricing-card.featured{
  border:2px solid var(--c-primary);
  box-shadow:0 8px 40px rgba(20,99,255,.15);
}
.pricing-card.featured:hover{box-shadow:0 16px 56px rgba(20,99,255,.2)}
.pricing-card.featured::before{
  content:'推荐';
  position:absolute;top:-14px;left:50%;transform:translateX(-50%);
  background:linear-gradient(135deg,var(--c-primary),#3b82f6);
  color:#fff;padding:5px 22px;border-radius:999px;
  font-size:13px;font-weight:700;
  box-shadow:0 4px 12px rgba(20,99,255,.3);
  animation:pulse 2.5s infinite;
}
.pricing-card h3{font-size:22px;font-weight:800;margin-bottom:4px}
.pricing-card .price{
  font-size:52px;font-weight:900;margin:20px 0 4px;
  background:linear-gradient(135deg,var(--c-text),var(--c-primary));
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
}
.pricing-card .price sub{
  font-size:17px;font-weight:500;color:var(--c-muted);
  -webkit-text-fill-color:var(--c-muted);
}
.pricing-card .desc{color:var(--c-muted);font-size:15px;margin-bottom:28px}
.pricing-card ul{list-style:none;text-align:left;margin-bottom:32px}
.pricing-card ul li{
  padding:10px 0;font-size:14px;color:var(--c-muted);
  border-bottom:1px solid var(--c-border);
  display:flex;align-items:center;gap:8px;
}
.pricing-card ul li::before{
  content:'';
  display:inline-block;width:18px;height:18px;
  background:var(--c-success);border-radius:50%;
  mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3E%3Cpath d='M16.7 5.3l-8.4 8.4-4.6-4.6L2.3 10.5l5.9 5.9 9.9-9.9z'/%3E%3C/svg%3E") center/contain;
  -webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3E%3Cpath d='M16.7 5.3l-8.4 8.4-4.6-4.6L2.3 10.5l5.9 5.9 9.9-9.9z'/%3E%3C/svg%3E") center/contain;
  flex-shrink:0;
}
.pricing-card ul li:last-child{border-bottom:0}

/* ===================================================================
   CTA Banner — depth
   =================================================================== */
.cta-banner{
  background:linear-gradient(135deg,var(--c-hero-from),#1e3a5f,var(--c-hero-to));
  background-size:400% 400%;animation:gradientShift 12s ease infinite;
  color:#fff;text-align:center;padding:80px 24px;
  position:relative;overflow:hidden;
}
.cta-banner::before{
  content:'';position:absolute;inset:0;
  background:
    radial-gradient(ellipse 60% 40% at 50% 50%,rgba(20,99,255,.15),transparent);
}
.cta-banner .container{position:relative;z-index:1}
.cta-banner h2{font-size:clamp(26px,4vw,36px);font-weight:800;margin-bottom:12px}
.cta-banner p{color:rgba(255,255,255,.65);font-size:18px;margin-bottom:32px}
.cta-banner .btn-primary{
  background:#fff;color:var(--c-primary);border-color:#fff;
  box-shadow:0 8px 32px rgba(0,0,0,.2);
}
.cta-banner .btn-primary:hover{
  background:#f0f4ff;color:var(--c-primary-d);
  box-shadow:0 12px 40px rgba(0,0,0,.3);
}

/* ===================================================================
   FAQ — smooth accordion
   =================================================================== */
.faq-list{max-width:780px;margin:0 auto}
.faq-item{
  background:var(--c-white);
  border:1px solid var(--c-border);
  border-radius:var(--radius-md);
  margin-bottom:14px;overflow:hidden;
  transition:box-shadow var(--transition),border-color var(--transition);
}
.faq-item:hover{border-color:#cbd5e1}
.faq-item.open{box-shadow:var(--shadow-sm);border-color:var(--c-primary)}
.faq-q{
  width:100%;display:flex;align-items:center;justify-content:space-between;
  padding:20px 24px;font:inherit;font-size:16px;font-weight:600;
  background:none;border:none;cursor:pointer;color:var(--c-text);
  text-align:left;transition:color var(--transition);
  user-select:none;
}
.faq-q:hover{color:var(--c-primary)}
.faq-q::after{
  content:'+';font-size:24px;color:var(--c-muted);font-weight:300;
  transition:transform .3s ease,color var(--transition);
  flex-shrink:0;margin-left:12px;
}
.faq-item.open .faq-q::after{content:'−';transform:rotate(180deg);color:var(--c-primary)}
.faq-a{
  max-height:0;overflow:hidden;
  padding:0 24px;font-size:15px;color:var(--c-muted);line-height:1.8;
  transition:max-height .4s cubic-bezier(.4,0,.2,1),padding .4s ease;
}
.faq-item.open .faq-a{
  max-height:300px;padding:0 24px 20px;
}

/* ===================================================================
   Footer
   =================================================================== */
.footer{
  background:#0b1120;color:rgba(255,255,255,.55);
  padding:64px 24px 36px;
  position:relative;overflow:hidden;
}
.footer::before{
  content:'';position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(20,99,255,.3),transparent);
}
.footer-grid{
  display:grid;
  grid-template-columns:2fr 1fr 1fr 1fr;
  gap:48px;max-width:var(--max-w);margin:0 auto 44px;
}
.footer-col .f-logo{
  font-size:20px;font-weight:800;color:#fff;margin-bottom:12px;
}
.footer-col h4{color:#fff;font-size:15px;font-weight:700;margin-bottom:18px}
.footer-col p,.footer-col a{font-size:14px;line-height:2.2;display:block}
.footer-col a{color:rgba(255,255,255,.45);transition:color var(--transition),transform var(--transition)}
.footer-col a:hover{color:#fff;transform:translateX(4px)}
.footer-bottom{
  text-align:center;font-size:13px;
  border-top:1px solid rgba(255,255,255,.06);
  padding-top:28px;max-width:var(--max-w);margin:0 auto;
  color:rgba(255,255,255,.3);
}

/* Decorative orbs */
.floating-orb{position:absolute;border-radius:50%;filter:blur(80px);opacity:.06;pointer-events:none;z-index:0}
.floating-orb.orb-1{width:400px;height:400px;background:var(--c-primary);top:-100px;right:-100px;animation:float 18s ease-in-out infinite}
.floating-orb.orb-2{width:300px;height:300px;background:var(--c-accent);bottom:-80px;left:-80px;animation:float 22s ease-in-out infinite reverse}

.back-to-top{position:fixed;bottom:32px;right:32px;z-index:99;width:46px;height:46px;border-radius:50%;background:var(--c-white);border:1px solid var(--c-border);box-shadow:var(--shadow-md);display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:20px;color:var(--c-muted);transition:all var(--transition);opacity:0;visibility:hidden;transform:translateY(12px)}
.back-to-top.visible{opacity:1;visibility:visible;transform:translateY(0)}
.back-to-top:hover{background:var(--c-primary);color:#fff;border-color:var(--c-primary);box-shadow:0 8px 24px rgba(20,99,255,.3);transform:translateY(-3px)}

/* Responsive */
@media (max-width:768px){
  .nav-links{display:none}
  .hero{padding:72px 20px 56px}
  .hero-stats{gap:32px}
  .hero-stat .num{font-size:28px}
  .stats-inner{gap:36px}
  .stats-inner .item .num{font-size:28px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px}
  .pricing-card.featured{transform:none}
  .step-card + .step-card::before{display:none}
  .features-grid{grid-template-columns:1fr;max-width:400px;margin:0 auto}
}
@media (max-width:480px){
  .footer-grid{grid-template-columns:1fr}
  .hero-btns{flex-direction:column;align-items:center}
  .hero h1{font-size:28px}
  .section-header h2{font-size:24px}
  .back-to-top{bottom:20px;right:16px}
}