:root{
--primary:#165DFF;
--primary-light:#EFF4FF;
--text-dark:#1D2129;
--text-normal:#4E5969;
--text-light:#86909C;
--bg-body:#F7F8FA;
--bg-white:#FFFFFF;
--border:#E5E6EB;
--shadow-soft:0 2px 12px rgba(0,0,0,0.06);
--shadow-card:0 8px 24px rgba(22,93,255,0.08);
}
*{margin:0;padding:0;box-sizing:border-box;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,"Microsoft YaHei"}
html{scroll-behavior:smooth; scroll-padding-top:80px;}
#home,#download,#feature,#logs,#faq{
  scroll-margin-top: 80px;
}
body{
  background:var(--bg-body);
  color:var(--text-dark);
  min-height:100vh;
  line-height:1.7;
  opacity:0;
  animation:pageFadeIn .5s ease forwards;
  will-change: opacity;
}
@keyframes pageFadeIn{to{opacity:1;}}
.navbar{
  position:sticky;
  top:0;
  z-index:999;
  background:transparent;
  transition:background .25s ease,box-shadow .25s ease;
  will-change: background, box-shadow;
}
.navbar.fixed-bg{background:rgba(255,255,255,.92);backdrop-filter:blur(10px);box-shadow:var(--shadow-soft);}
.nav-inner{max-width:1280px;margin:0 auto;padding:0 32px;height:72px;display:flex;justify-content:space-between;align-items:center;gap:20px;}
.logo{color:var(--primary);font-size:1.5rem;font-weight:700;text-decoration:none;letter-spacing:.3px}
.nav-main{display:flex;align-items:center;gap:36px;}
.nav-links{display:flex;gap:36px;list-style:none}
.nav-links a{color:var(--text-normal);text-decoration:none;font-size:.96rem;font-weight:500;transition:.24s;position:relative}
.nav-links a:hover{color:var(--primary)}
.nav-links a::after{content:"";position:absolute;left:0;bottom:-4px;width:0;height:2px;background:var(--primary);transition:.24s}
.nav-links a:hover::after{width:100%}
.lang-btn{
  padding:4px 10px;
  border:1px solid var(--primary);
  color:var(--primary);
  background:transparent;
  border-radius:6px;
  cursor:pointer;
  font-size:0.9rem;
  transition:0.24s;
  white-space:nowrap;
  flex-shrink:0;
}
.lang-btn:hover{
  background:var(--primary);
  color:#fff;
}
.menu-btn{display:none;color:var(--text-dark);font-size:28px;background:transparent;border:0;cursor:pointer;touch-action: manipulation; flex-shrink:0;}
.banner{background:linear-gradient(135deg,#165DFF,#4080FF);color:#fff;padding:100px 24px;text-align:center;position:relative;overflow:hidden}
.banner::before{content:"";position:absolute;width:700px;height:700px;border-radius:50%;background:rgba(255,255,255,.06);filter:blur(80px);top:-300px;right:-150px}
.banner-inner{max-width:800px;margin:0 auto;position:relative;z-index:1}
.banner h1,.banner p,.banner small{
  white-space:normal !important;
  word-break:break-word !important;
}
.banner h1{font-size:3.2rem;margin-bottom:20px;font-weight:700;letter-spacing:.4px}
.banner p{opacity:.92;font-size:1.2rem;margin-bottom:12px;font-weight:400}
.banner small{opacity:.76;font-size:.98rem}
.section-wrap{max-width:1280px;margin:0 auto;padding:88px 24px}
.section-head{text-align:center;margin-bottom:64px}
.section-head .sub-title{color:var(--primary);font-size:.9rem;font-weight:600;letter-spacing:1px;text-transform:uppercase;margin-bottom:12px}
.section-head h2{font-size:2.2rem;color:var(--text-dark);margin-bottom:16px;font-weight:700; word-break:break-word;}
.section-head p{color:var(--text-light);max-width:700px;margin:0 auto;font-size:1rem; word-break:break-word;}
.download-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(270px,1fr));gap:30px}
.download-card{
  background:var(--bg-white);
  border-radius:18px;
  padding:40px 28px;
  text-align:center;
  border:1px solid var(--border);
  box-shadow:var(--shadow-soft);
  transition:transform .28s ease, box-shadow .28s ease, border-color .28s ease;
  will-change: transform;
}
.download-card:hover{transform:translateY(-8px);box-shadow:var(--shadow-card);border-color:rgba(22,93,255,.16)}
.card-icon{width:58px;height:58px;margin:0 auto 20px;color:var(--primary);transition:transform .28s ease; will-change: transform;}
.download-card:hover .card-icon{transform:scale(1.08)}
.download-card h3{font-size:1.4rem;font-weight:600;margin-bottom:10px;color:var(--text-dark)}
.download-card .version{color:var(--text-light);font-size:.9rem;margin-bottom:28px}
.btn-primary{display:block;width:100%;background:var(--primary);color:#fff;text-decoration:none;padding:15px;border-radius:10px;font-weight:600;border:none;cursor:pointer;font-size:1rem;transition:background .24s ease, transform .2s ease; touch-action: manipulation;}
.btn-primary:hover{background:#0E42D2}
.btn-primary:active{transform:scale(0.97);}
.feature-section{background:var(--bg-white);padding:88px 24px}
.feature-grid{max-width:1280px;margin:0 auto;display:grid;grid-template-columns:repeat(auto-fit,minmax(290px,1fr));gap:32px}
.feature-item{padding:36px 32px;border-radius:18px;background:var(--bg-body);border:1px solid var(--border);transition:.28s ease;will-change: background, border-color;}
.feature-item:hover{border-color:rgba(22,93,255,.18);background:#FCFDFF}
.feature-item h4{font-size:1.26rem;color:var(--text-dark);margin-bottom:12px;font-weight:600; word-break:break-word;}
.feature-item p{color:var(--text-normal);font-size:.98rem; word-break:break-word;}
.log-section{padding:88px 24px}
.log-wrap{max-width:980px;margin:0 auto}
.log-item{border-left:3px solid var(--primary);padding:22px 26px;margin-bottom:26px;background:var(--bg-white);border-radius:0 14px 14px 0;box-shadow:var(--shadow-soft)}
.log-item h4{color:var(--primary);font-size:1.06rem;margin-bottom:8px;font-weight:600; word-break:break-word;}
.log-item p{color:var(--text-normal);font-size:.96rem; word-break:break-word;}
.faq-section{background:var(--bg-white);padding:88px 24px}
.faq-wrap{max-width:980px;margin:0 auto}
.faq-item{border-radius:14px;background:var(--bg-body);margin-bottom:18px;overflow:hidden;border:1px solid var(--border)}
.faq-que{padding:22px 26px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-weight:500;color:var(--text-dark);transition:.24s ease; touch-action: manipulation; word-break:break-word;}
.faq-que:hover{background:#F0F2F5}
.faq-ans{padding:0 26px;max-height:0;overflow:hidden;transition:max-height .32s ease; will-change: max-height;}
.faq-ans p{padding:0 0 22px 0;color:var(--text-normal); word-break:break-word;}
.faq-item.active .faq-ans{max-height:420px}
footer{background:#1D2129;color:#C9CDD4;padding:56px 24px;text-align:center;font-size:.9rem}
footer a{color:#86909C;text-decoration:none}
.toast{position:fixed;bottom:50px;left:50%;transform:translateX(-50%);background:rgba(29,33,41,.88);color:#fff;padding:12px 28px;border-radius:10px;display:none;z-index:9999;backdrop-filter:blur(6px)}
#backToTop{
  position:fixed;
  right:24px;
  bottom:24px;
  width:48px;height:48px;
  background:var(--primary);
  color:#fff;
  border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  cursor:pointer;
  opacity:0;visibility:hidden;
  transition:opacity .28s ease, transform .28s ease;
  will-change: opacity, transform;
  box-shadow:var(--shadow-card);
  z-index:9998;
  touch-action: manipulation;
}
#backToTop.show{opacity:1;visibility:visible}
#backToTop:hover{background:#0E42D2;transform:translateY(-4px)}
@media (hover: none) {
  .download-card:hover{
    transform:none;
  }
  .feature-item:hover{
    background:var(--bg-body);
    border-color:var(--border);
  }
  .faq-que:hover{background:transparent;}
  #backToTop:hover{transform:none;background:var(--primary);}
}
@media(max-width:768px){
.nav-inner{padding:0 16px;height:64px;}
.nav-main{
  position:static;
  display:flex;
  align-items:center;
  gap:12px;
}
.nav-links{
  position:absolute;
  top:64px;
  left:0;
  width:100%;
  background:#fff;
  flex-direction:column;
  padding:24px;
  gap:22px;
  box-shadow:var(--shadow-soft);
  display:none;
  z-index:998;
}
.nav-links.active{display:flex}
.menu-btn{display:block}
.banner h1{font-size:2.2rem}
.section-head h2{font-size:1.8rem}
.section-wrap,.feature-section,.log-section,.faq-section{padding:64px 16px}
#backToTop{right:16px;bottom:16px;width:44px;height:44px}
}