/* 默认深色主题 */
:root{
  --bg:#0a0a0f;
  --fg:#ffffff;
  --muted:#a8a8b3;
  --pri:#00f0ff;
  --pri-dark:#00c4d1;
  --pri-glow:#00f0ff40;
  --card:#1a1a2e;
  --card-hover:#252544;
  --card-border:#2a2a4e;
  --line:#2a2a4e;
  --accent:#6c63ff;
  --ok:#00ff88;
  --warn:#ffb800;
  --gradient:linear-gradient(135deg,#00f0ff 0%,#6c63ff 100%);
  --gradient-hover:linear-gradient(135deg,#00c4d1 0%,#5a52e6 100%);
}

:root[data-theme="dark"]{
  --bg:#0a0a0f;
  --fg:#ffffff;
  --muted:#a8a8b3;
  --pri:#00f0ff;
  --pri-dark:#00c4d1;
  --pri-glow:#00f0ff40;
  --card:#1a1a2e;
  --card-hover:#252544;
  --card-border:#2a2a4e;
  --line:#2a2a4e;
  --accent:#6c63ff;
  --ok:#00ff88;
  --warn:#ffb800;
  --gradient:linear-gradient(135deg,#00f0ff 0%,#6c63ff 100%);
  --gradient-hover:linear-gradient(135deg,#00c4d1 0%,#5a52e6 100%);
}

:root[data-theme="light"]{
  --bg:#ffffff;
  --fg:#000000;
  --muted:#6e6e73;
  --pri:#007aff;
  --pri-dark:#0056cc;
  --pri-glow:rgba(0,122,255,0.3);
  --card:#f7f9fc;
  --card-hover:#eef2f7;
  --card-border:#d1d9e6;
  --line:#d1d9e6;
  --accent:#007aff;
  --ok:#34c759;
  --warn:#ff9500;
  --gradient:linear-gradient(135deg,#007aff 0%,#0056cc 100%);
  --gradient-hover:linear-gradient(135deg,#0056cc 0%,#0044a0 100%);
}

*{
  box-sizing:border-box
}

html{
  scroll-behavior:smooth
}

html,body{
  margin:0;
  padding:0
}

body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  background:var(--bg);
  color:var(--fg);
  line-height:1.5;
  position:relative;
  transition:background .3s ease,color .3s ease
}

/* 默认深色主题背景 */
body{
  background-image:
    radial-gradient(at 20% 30%,rgba(108,99,255,0.1) 0,transparent 50%),
    radial-gradient(at 80% 70%,rgba(0,240,255,0.1) 0,transparent 50%),
    radial-gradient(at 50% 50%,rgba(0,240,255,0.05) 0,transparent 50%);
}

:root[data-theme="dark"] body{
  background-image:
    radial-gradient(at 20% 30%,rgba(108,99,255,0.1) 0,transparent 50%),
    radial-gradient(at 80% 70%,rgba(0,240,255,0.1) 0,transparent 50%),
    radial-gradient(at 50% 50%,rgba(0,240,255,0.05) 0,transparent 50%);
}

:root[data-theme="light"] body{
  background-image:
    linear-gradient(180deg,rgba(247,249,252,0) 0%,rgba(237,242,248,0.5) 100%),
    radial-gradient(at 10% 20%,rgba(0,122,255,0.08) 0,transparent 50%),
    radial-gradient(at 90% 70%,rgba(88,101,242,0.05) 0,transparent 50%),
    radial-gradient(at 50% 100%,rgba(99,102,241,0.03) 0,transparent 70%);
}

main,footer{
  max-width:1120px;
  margin:0 auto;
  padding:24px
}

/* 为锚点定位添加偏移，避免被sticky header遮挡 */
section[id]{
  scroll-margin-top:80px
}

header{
  position:sticky;
  top:0;
  z-index:100;
  width:100%;
  backdrop-filter:blur(20px);
  background:rgba(10,10,15,0.8);
  border-bottom:1px solid var(--card-border);
  transition:background .3s ease,border-color .3s ease
}

:root[data-theme="light"] header{
  background:rgba(255,255,255,0.95);
  border-bottom:1px solid var(--card-border);
  backdrop-filter:blur(20px) saturate(180%)
}

header .nav{
  max-width:1120px;
  margin:0 auto;
  padding:0 24px
}

/* 基础排版 */
h1{
  font-size:48px;
  line-height:1.1;
  margin:0 0 16px;
  font-weight:600;
  letter-spacing:-0.003em;
  transition:color .3s ease
}

h2{
  font-size:32px;
  margin:48px 0 24px;
  font-weight:600;
  letter-spacing:-0.01em;
  transition:color .3s ease
}

h3{
  font-size:19px;
  font-weight:600;
  margin:0 0 8px;
  transition:color .3s ease
}

/* 深色模式下优化卡片标题颜色 - 使用更亮的紫色提高对比度 */
:root .card h3{
  color:#b8b0ff
}

/* 浅色模式下恢复默认颜色 */
:root[data-theme="light"] .card h3{
  color:var(--fg)
}

p{
  margin:0 0 12px;
  font-size:17px;
  transition:color .3s ease
}

.muted{
  color:var(--muted);
  font-size:14px;
  transition:color .3s ease
}

/* 组件 */
.btn{
  display:inline-block;
  padding:12px 32px;
  border-radius:8px;
  text-decoration:none;
  font-weight:500;
  font-size:15px;
  transition:all .3s ease;
  letter-spacing:0.02em;
  background:transparent;
  border:1px solid var(--card-border);
  color:var(--fg);
  position:relative;
  overflow:hidden
}

.btn::before{
  content:'';
  position:absolute;
  top:0;
  left:-100%;
  width:100%;
  height:100%;
  background:linear-gradient(90deg,transparent,rgba(255,255,255,0.1),transparent);
  transition:left .5s
}

.btn:hover::before{
  left:100%
}

.btn:hover{
  background:var(--card-hover);
  border-color:var(--pri);
  box-shadow:0 0 20px var(--pri-glow)
}

.btn-primary{
  background:var(--gradient);
  color:#fff !important;
  border:none;
  font-weight:600;
  box-shadow:0 4px 15px var(--pri-glow)
}

.btn-primary:hover{
  background:var(--gradient-hover);
  color:#fff !important;
  transform:translateY(-2px);
  box-shadow:0 6px 25px var(--pri-glow)
}

.btn-ghost{
  background:transparent;
  border:1px solid var(--pri);
  color:var(--pri);
  box-shadow:0 0 10px var(--pri-glow)
}

.btn-ghost:hover{
  background:var(--pri-glow);
  transform:translateY(-2px)
}

.nav{
  display:flex;
  justify-content:space-between;
  align-items:center;
  height:64px;
  font-size:16px
}

.nav-logo{
  display:flex;
  align-items:center;
  gap:12px;
  font-weight:800;
  font-size:18px;
  letter-spacing:0.03em;
  text-decoration:none;
  color:var(--fg);
  transition:all .3s ease
}

.nav-logo:hover{
  transform:scale(1.02);
  opacity:0.9
}

.logo-icon{
  width:36px;
  height:36px;
  display:flex;
  align-items:center;
  justify-content:center;
  border-radius:8px;
  position:relative;
  overflow:hidden
}

.logo-icon::before{
  content:'';
  position:absolute;
  top:0;
  left:0;
  right:0;
  bottom:0;
  background:linear-gradient(135deg,transparent 30%,rgba(255,255,255,0.4) 50%,transparent 70%);
  z-index:2;
  pointer-events:none;
  opacity:0.6;
  animation:shine 3s infinite ease-in-out
}

@keyframes shine{
  0%,100%{transform:translateX(-100%) translateY(-100%)}
  50%{transform:translateX(100%) translateY(100%)}
}

.logo-icon img{
  display:block;
  width:100%;
  height:100%;
  object-fit:contain;
  position:relative;
  z-index:1;
  transition:transform .3s ease
}

.nav-logo:hover .logo-icon img{
  transform:scale(1.05)
}

.nav a:not(.btn){
  color:var(--fg);
  text-decoration:none;
  transition:all .3s;
  padding:8px 16px;
  border-radius:6px;
  font-weight:500
}

.nav a:not(.btn):hover{
  background:var(--card-hover);
  color:var(--pri)
}

.nav a:not(.btn).active{
  background:var(--card);
  color:var(--pri);
  box-shadow:0 0 15px var(--pri-glow)
}

.nav a.btn-primary.active{
  background:#fff !important;
  color:var(--pri) !important;
  border:2px solid var(--pri);
  box-shadow:0 0 15px var(--pri-glow)
}

.nav a.btn-primary.active:hover{
  background:var(--pri) !important;
  color:#fff !important;
  border:2px solid var(--pri);
  transform:translateY(-2px);
  box-shadow:0 6px 25px var(--pri-glow)
}

.theme-toggle,.lang-toggle{
  background:transparent;
  border:1px solid var(--card-border);
  border-radius:50%;
  width:40px;
  height:40px;
  cursor:pointer;
  display:flex;
  align-items:center;
  justify-content:center;
  transition:all .3s ease;
  position:relative;
  overflow:hidden;
  color:var(--fg);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale
}

:root[data-theme="light"] .theme-toggle,:root[data-theme="light"] .lang-toggle{
  border-color:#d1d9e6;
  background:rgba(247,249,252,0.5);
  color:var(--fg)
}

.theme-toggle:hover,.lang-toggle:hover{
  background:var(--card-hover);
  border-color:var(--pri);
  transform:scale(1.1);
  box-shadow:0 0 15px var(--pri-glow)
}

.theme-toggle svg,.lang-toggle svg{
  transition:all .4s cubic-bezier(.68,-0.55,.27,1.55);
  pointer-events:none;
  color:inherit;
  stroke:currentColor;
  fill:none
}

.lang-toggle{
  border-radius:8px;
  font-size:14px;
  font-weight:600;
  position:relative;
  color:var(--fg)
}

.lang-dropdown{
  position:absolute;
  top:calc(100% + 8px);
  right:0;
  background:var(--card);
  border:1px solid var(--card-border);
  border-radius:8px;
  padding:4px;
  min-width:120px;
  box-shadow:0 8px 24px rgba(0,0,0,0.2);
  opacity:0;
  visibility:hidden;
  transform:translateY(-8px);
  transition:all .3s ease;
  z-index:1000
}

.lang-dropdown.open{
  opacity:1;
  visibility:visible;
  transform:translateY(0)
}

.lang-dropdown-item{
  padding:8px 12px;
  border-radius:6px;
  cursor:pointer;
  transition:all .2s ease;
  font-size:14px;
  display:flex;
  align-items:center;
  gap:8px
}

.lang-dropdown-item:hover{
  background:var(--card-hover)
}

.lang-dropdown-item.active{
  background:var(--pri-glow);
  color:var(--pri)
}

.lang-dropdown-item-flag{
  width:20px;
  height:20px;
  border-radius:3px;
  flex-shrink:0
}

.icon-moon{
  transform:rotate(0deg) scale(1);
  opacity:1;
  color:var(--fg);
  stroke:currentColor
}

.icon-sun{
  transform:rotate(90deg) scale(0);
  opacity:0;
  color:var(--fg);
  stroke:currentColor
}

:root[data-theme="light"] .icon-moon{
  transform:rotate(-90deg) scale(0);
  opacity:0
}

:root[data-theme="light"] .icon-sun{
  transform:rotate(0deg) scale(1);
  opacity:1;
  color:#ffb800;
  stroke:#ffb800
}

:root[data-theme="light"] .theme-toggle:hover{
  box-shadow:0 0 20px rgba(255,184,0,0.3)
}

.hero{
  padding:100px 0 60px;
  text-align:center
}

.hero h1{
  font-size:80px;
  line-height:1.05;
  letter-spacing:-0.015em;
  background:var(--gradient);
  -webkit-background-clip:text;
  -webkit-text-fill-color:transparent;
  background-clip:text;
  filter:drop-shadow(0 0 30px var(--pri-glow))
}

.hero p{
  color:var(--muted);
  font-size:21px;
  max-width:580px;
  margin:16px auto 32px
}

.hero .tag{
  background:var(--gradient);
  -webkit-background-clip:text;
  -webkit-text-fill-color:transparent;
  background-clip:text;
  border:1px solid var(--pri);
  background-color:transparent!important
}

.grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(260px,1fr));
  gap:20px
}

.card{
  background:var(--card);
  border-radius:12px;
  padding:32px;
  transition:all .3s ease;
  border:1px solid var(--card-border);
  position:relative
}

.card,.tag,.kpi,.btn{
  transition:background .3s ease,border-color .3s ease
}

.card::before{
  content:'';
  position:absolute;
  top:0;
  left:0;
  right:0;
  bottom:0;
  border-radius:12px;
  opacity:0;
  background:linear-gradient(135deg,var(--pri-glow),transparent);
  transition:opacity .3s;
  pointer-events:none
}

.card:hover::before{
  opacity:0.1
}

.card:hover{
  background:var(--card-hover);
  transform:translateY(-8px);
  border-color:var(--pri);
  box-shadow:0 10px 40px rgba(0,240,255,0.2)
}

.card a{
  text-decoration:none;
  display:block;
  color:inherit
}

.tag{
  display:inline-block;
  padding:8px 20px;
  background:var(--card);
  border-radius:20px;
  font-size:12px;
  font-weight:600;
  letter-spacing:0.05em;
  color:var(--pri);
  border:1px solid var(--card-border);
  text-transform:uppercase
}

.section{
  margin-top:64px
}

.kpis{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
  gap:20px
}

.kpi{
  background:var(--card);
  border:1px solid var(--card-border);
  border-radius:12px;
  padding:32px;
  text-align:center;
  transition:all .3s ease;
  position:relative;
  overflow:hidden
}

.kpi::after{
  content:'';
  position:absolute;
  top:-50%;
  left:-50%;
  width:200%;
  height:200%;
  background:radial-gradient(circle,var(--pri-glow),transparent);
  opacity:0;
  transition:opacity .3s;
  pointer-events:none
}

.kpi:hover::after{
  opacity:1
}

.kpi:hover{
  transform:scale(1.05);
  border-color:var(--pri);
  box-shadow:0 0 30px var(--pri-glow)
}

.kpi b{
  font-size:56px;
  font-weight:700;
  display:block;
  margin-bottom:8px;
  background:var(--gradient);
  -webkit-background-clip:text;
  -webkit-text-fill-color:transparent;
  background-clip:text;
  filter:drop-shadow(0 0 10px var(--pri-glow))
}

footer{
  border-top:1px solid var(--line);
  color:var(--muted);
  font-size:14px;
  text-align:center;
  padding:64px 24px 40px
}

/* 动效 */
.reveal{
  opacity:0;
  transform:translateY(30px);
  transition:all .8s cubic-bezier(.25,.46,.45,.94)
}

.reveal.on{
  opacity:1;
  transform:translateY(0)
}

/* 响应式 */
@media (max-width:768px){
  main,header,footer{
    padding:20px
  }
  
  .hero{
    padding:60px 0 40px
  }
  
  .hero h1{
    font-size:48px
  }
  
  h2{
    font-size:28px
  }
  
  .section[style*="grid-template-columns"]{
    grid-template-columns:1fr!important
  }
  
  .demo-container{
    padding:24px
  }
  
  .demo-grid{
    grid-template-columns:1fr
  }
  
  .stat-grid{
    grid-template-columns:repeat(2,1fr)
  }
  
  .stat-number{
    font-size:36px
  }
}

/* Demo容器与代码展示 */
.demo-container{
  background:var(--card);
  border-radius:16px;
  padding:40px;
  margin:40px 0;
  border:1px solid var(--card-border);
  position:relative;
  overflow:hidden;
  box-shadow:0 8px 32px rgba(0,0,0,0.1)
}

.demo-container::before{
  content:'';
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:4px;
  background:var(--gradient)
}

.demo-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(250px,1fr));
  gap:24px;
  margin:32px 0
}

.demo-item{
  background:var(--card);
  border-radius:12px;
  padding:24px;
  border:1px solid var(--card-border);
  transition:all .3s ease
}

.demo-item:hover{
  transform:translateY(-4px);
  border-color:var(--pri);
  box-shadow:0 8px 24px var(--pri-glow)
}

.demo-item-icon{
  width:48px;
  height:48px;
  border-radius:12px;
  background:var(--gradient);
  display:flex;
  align-items:center;
  justify-content:center;
  margin-bottom:16px;
  font-size:24px
}

.code-block{
  background:var(--card);
  border-radius:8px;
  padding:20px;
  margin:24px 0;
  border-left:4px solid var(--pri);
  font-family:'Courier New',monospace;
  font-size:14px;
  overflow-x:auto
}

.code-block code{
  color:var(--pri)
}

.stat-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
  gap:20px;
  margin:32px 0
}

.stat-item{
  text-align:center;
  padding:24px;
  background:var(--card);
  border-radius:12px;
  border:1px solid var(--card-border)
}

.stat-number{
  font-size:48px;
  font-weight:700;
  background:var(--gradient);
  -webkit-background-clip:text;
  -webkit-text-fill-color:transparent;
  background-clip:text;
  display:block;
  margin-bottom:8px
}

.feature-list{
  list-style:none;
  padding:0
}

.feature-list li{
  padding:16px 0;
  border-bottom:1px solid var(--card-border);
  position:relative;
  padding-left:32px
}

.feature-list li:last-child{
  border-bottom:none
}

.feature-list li::before{
  content:'✓';
  position:absolute;
  left:0;
  color:var(--ok);
  font-weight:700;
  font-size:20px
}

.badge{
  display:inline-block;
  padding:6px 12px;
  background:var(--card);
  border:1px solid var(--card-border);
  border-radius:20px;
  font-size:14px;
  color:var(--pri)
}

.badge-primary{
  background:var(--gradient);
  color:#fff;
  border:none
}

/* 返回主页按钮 - 显示在所有二级页面，悬浮在logo下方 */
.back-to-home{
  position:fixed;
  top:80px;
  left:24px;
  z-index:101;
  display:flex;
  align-items:center;
  justify-content:center;
  width:44px;
  height:44px;
  background:var(--card);
  border:1px solid var(--card-border);
  border-radius:50%;
  color:var(--fg);
  text-decoration:none;
  font-size:22px;
  transition:all .3s ease;
  box-shadow:0 4px 20px rgba(0,0,0,0.2);
  backdrop-filter:blur(10px);
  opacity:0.9
}

.back-to-home:hover{
  background:var(--card-hover);
  border-color:var(--pri);
  transform:translateY(-2px) scale(1.05);
  box-shadow:0 6px 30px var(--pri-glow);
  opacity:1
}

.back-to-home svg{
  display:none
}

@media (max-width:768px){
  .back-to-home{
    top:72px;
    left:16px;
    width:40px;
    height:40px;
    font-size:20px
  }
}