:root{
  --primary:#22d3ee;
  --accent:#fb923c;
  --bg:#0f172a;
  --text:#e2e8f0;
  --card-bg:#1e293b;
  --radius:20px;
  --radius-lg:24px;
  --shadow:0 12px 40px rgba(0,0,0,0.45);
}
*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  background:var(--bg);
  color:var(--text);
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
  line-height:1.7;
  overflow-x:hidden;
}
/* 噪点纹理 */
body::before{
  content:"";
  position:fixed;
  top:0;left:0;width:100%;height:100%;
  background-image:url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.05'/%3E%3C/svg%3E");
  pointer-events:none;
  z-index:0;
}
a{text-decoration:none;color:var(--text);transition:color 0.3s ease;}
a:hover{color:var(--primary);}
img{max-width:100%;height:auto;}

/* 导航 */
.navbar-custom{
  background:rgba(15,23,42,0.85);
  backdrop-filter:blur(20px);
  -webkit-backdrop-filter:blur(20px);
  border-bottom:1px solid rgba(255,255,255,0.06);
  padding:18px 0;
  position:sticky;
  top:0;
  z-index:1000;
}
.navbar-brand{
  font-size:1.65rem;
  font-weight:800;
  letter-spacing:-0.02em;
  color:var(--primary) !important;
  display:flex;
  align-items:center;
  gap:10px;
}
.navbar-brand i{font-size:1.5rem;color:var(--accent);}
.nav-link{
  font-weight:500;
  font-size:0.98rem;
  margin:0 8px;
  color:var(--text) !important;
  opacity:0.85;
  transition:opacity 0.3s,color 0.3s;
}
.nav-link:hover{opacity:1;color:var(--primary) !important;}
.navbar-toggler{
  border:1px solid rgba(255,255,255,0.2);
  background:transparent;
}
.navbar-toggler:focus{box-shadow:none;}
.navbar-toggler i{color:var(--text);font-size:1.4rem;}

/* 通用 */
.section-padding{padding:120px 0;}
.container{max-width:1140px;}
.section-label{
  display:inline-flex;
  align-items:center;
  gap:8px;
  font-size:0.85rem;
  font-weight:600;
  letter-spacing:0.08em;
  text-transform:uppercase;
  color:var(--accent);
  margin-bottom:18px;
}
.section-label i{font-size:1rem;}
.section-title{
  font-size:2.8rem;
  font-weight:800;
  letter-spacing:-0.03em;
  line-height:1.15;
  margin-bottom:24px;
  color:#f8fafc;
}
.section-subtitle{
  font-size:1.1rem;
  color:rgba(226,232,240,0.7);
  max-width:680px;
  margin-bottom:50px;
  font-weight:400;
}

/* Hero */
.hero{
  padding:140px 0 120px;
  position:relative;
}
.hero-badge{
  display:inline-flex;
  align-items:center;
  gap:8px;
  background:rgba(34,211,238,0.12);
  border:1px solid rgba(34,211,238,0.3);
  color:var(--primary);
  padding:8px 20px;
  border-radius:50px;
  font-size:0.85rem;
  font-weight:600;
  margin-bottom:30px;
  letter-spacing:0.03em;
}
.hero-badge i{font-size:0.9rem;}
.hero-title{
  font-size:4rem;
  font-weight:900;
  letter-spacing:-0.04em;
  line-height:1.1;
  margin-bottom:28px;
  color:#f8fafc;
  min-height:1.2em;
}
.hero-title .typing{
  color:var(--primary);
  border-right:3px solid var(--primary);
  animation:blink 0.8s step-end infinite;
}
@keyframes blink{50%{border-color:transparent;}}
.hero-desc{
  font-size:1.15rem;
  color:rgba(226,232,240,0.75);
  max-width:620px;
  margin-bottom:40px;
  font-weight:300;
  line-height:1.8;
}
.btn-custom{
  display:inline-flex;
  align-items:center;
  gap:10px;
  padding:16px 36px;
  border-radius:50px;
  font-weight:600;
  font-size:1rem;
  transition:all 0.3s ease;
  border:none;
  cursor:pointer;
}
.btn-primary-custom{
  background:var(--primary);
  color:#0f172a;
  box-shadow:0 8px 30px rgba(34,211,238,0.25);
}
.btn-primary-custom:hover{
  background:#0ea5c9;
  color:#0f172a;
  transform:translateY(-3px);
  box-shadow:0 12px 40px rgba(34,211,238,0.35);
}
.btn-outline-custom{
  background:transparent;
  color:var(--text);
  border:1.5px solid rgba(226,232,240,0.25);
  margin-left:15px;
}
.btn-outline-custom:hover{
  border-color:var(--accent);
  color:var(--accent);
  transform:translateY(-3px);
}

/* 数据统计 */
.stats-section{
  padding:80px 0;
  border-top:1px solid rgba(255,255,255,0.06);
  border-bottom:1px solid rgba(255,255,255,0.06);
  background:rgba(30,41,59,0.3);
}
.stat-item{
  text-align:center;
  padding:30px 20px;
}
.stat-number{
  font-size:3.2rem;
  font-weight:900;
  color:var(--primary);
  letter-spacing:-0.03em;
  line-height:1.1;
}
.stat-label{
  font-size:0.95rem;
  color:rgba(226,232,240,0.65);
  margin-top:10px;
  font-weight:400;
  letter-spacing:0.02em;
}

/* 使用说明-步骤条 */
.steps-section{
  position:relative;
}
.step-card{
  background:rgba(30,41,59,0.5);
  border-radius:var(--radius-lg);
  padding:40px 32px;
  height:100%;
  border:1px solid rgba(255,255,255,0.05);
  transition:all 0.4s ease;
  position:relative;
  overflow:hidden;
}
.step-card:hover{
  background:rgba(30,41,59,0.8);
  transform:translateY(-6px);
  box-shadow:var(--shadow);
  border-color:rgba(34,211,238,0.15);
}
.step-number{
  width:48px;
  height:48px;
  border-radius:50%;
  background:rgba(34,211,238,0.15);
  border:1px solid rgba(34,211,238,0.3);
  display:flex;
  align-items:center;
  justify-content:center;
  font-weight:800;
  font-size:1.2rem;
  color:var(--primary);
  margin-bottom:24px;
}
.step-icon{
  position:absolute;
  top:30px;
  right:30px;
  font-size:1.8rem;
  color:rgba(226,232,240,0.08);
}
.step-title{
  font-size:1.25rem;
  font-weight:700;
  color:#f8fafc;
  margin-bottom:12px;
}
.step-desc{
  font-size:0.95rem;
  color:rgba(226,232,240,0.65);
  line-height:1.7;
  font-weight:300;
}

/* 特色-卡片网格 */
.features-section{
  position:relative;
}
.feature-card{
  background:rgba(30,41,59,0.5);
  border-radius:var(--radius-lg);
  padding:38px 30px;
  height:100%;
  border:1px solid rgba(255,255,255,0.05);
  transition:all 0.4s ease;
  overflow:hidden;
  position:relative;
}
.feature-card::after{
  content:"";
  position:absolute;
  top:0;
  left:0;
  width:100%;
  height:3px;
  background:linear-gradient(90deg,var(--primary),var(--accent));
  transform:scaleX(0);
  transform-origin:left;
  transition:transform 0.4s ease;
}
.feature-card:hover::after{transform:scaleX(1);}
.feature-card:hover{
  transform:translateY(-8px);
  box-shadow:var(--shadow);
  background:rgba(30,41,59,0.85);
}
.feature-icon{
  width:56px;
  height:56px;
  border-radius:16px;
  background:rgba(34,211,238,0.12);
  border:1px solid rgba(34,211,238,0.2);
  display:flex;
  align-items:center;
  justify-content:center;
  font-size:1.4rem;
  color:var(--primary);
  margin-bottom:24px;
  transition:all 0.3s ease;
}
.feature-card:hover .feature-icon{
  background:var(--primary);
  color:#0f172a;
  transform:scale(1.05);
}
.feature-title{
  font-size:1.2rem;
  font-weight:700;
  color:#f8fafc;
  margin-bottom:12px;
}
.feature-desc{
  font-size:0.93rem;
  color:rgba(226,232,240,0.65);
  line-height:1.7;
  font-weight:300;
}

/* FAQ */
.faq-section{
  position:relative;
}
.faq-item{
  background:rgba(30,41,59,0.4);
  border-radius:var(--radius);
  border:1px solid rgba(255,255,255,0.05);
  margin-bottom:18px;
  overflow:hidden;
  transition:all 0.3s ease;
}
.faq-item:hover{
  border-color:rgba(34,211,238,0.15);
  background:rgba(30,41,59,0.6);
}
.faq-question{
  padding:24px 30px;
  font-size:1.05rem;
  font-weight:600;
  color:#f8fafc;
  cursor:pointer;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:15px;
  user-select:none;
}
.faq-question i{
  color:var(--primary);
  font-size:0.9rem;
  transition:transform 0.3s ease;
  flex-shrink:0;
}
.faq-item.active .faq-question i{
  transform:rotate(45deg);
}
.faq-answer{
  max-height:0;
  overflow:hidden;
  transition:max-height 0.4s ease;
}
.faq-answer-inner{
  padding:0 30px 24px;
  color:rgba(226,232,240,0.65);
  font-size:0.95rem;
  line-height:1.8;
  font-weight:300;
}
.faq-item.active .faq-answer{
  max-height:300px;
}

/* CTA */
.cta-section{
  padding:120px 0;
}
.cta-box{
  background:linear-gradient(135deg,rgba(34,211,238,0.12) 0%,rgba(251,146,60,0.12) 100%);
  border:1px solid rgba(255,255,255,0.08);
  border-radius:calc(var(--radius-lg) + 8px);
  padding:70px 60px;
  text-align:center;
  position:relative;
  overflow:hidden;
}
.cta-box::before{
  content:"";
  position:absolute;
  top:-50%;
  right:-20%;
  width:300px;
  height:300px;
  background:radial-gradient(circle,rgba(34,211,238,0.15),transparent 70%);
  border-radius:50%;
  pointer-events:none;
}
.cta-box::after{
  content:"";
  position:absolute;
  bottom:-40%;
  left:-10%;
  width:250px;
  height:250px;
  background:radial-gradient(circle,rgba(251,146,60,0.12),transparent 70%);
  border-radius:50%;
  pointer-events:none;
}
.cta-title{
  font-size:2.5rem;
  font-weight:800;
  color:#f8fafc;
  letter-spacing:-0.03em;
  margin-bottom:20px;
  position:relative;
  z-index:1;
}
.cta-desc{
  font-size:1.1rem;
  color:rgba(226,232,240,0.7);
  max-width:560px;
  margin:0 auto 40px;
  font-weight:300;
  position:relative;
  z-index:1;
}

/* 友情链接 */
.friend-links{
  padding:60px 0;
  border-top:1px solid rgba(255,255,255,0.06);
}
.friend-title{
  font-size:1rem;
  font-weight:600;
  color:rgba(226,232,240,0.5);
  margin-bottom:20px;
  letter-spacing:0.05em;
  text-transform:uppercase;
}
.friend-links-content{
  font-size:0.9rem;
  color:rgba(226,232,240,0.45);
  line-height:2.2;
}

/* 页脚 */
.footer{
  background:rgba(15,23,42,0.9);
  border-top:1px solid rgba(255,255,255,0.06);
  padding:50px 0 30px;
}
.footer-brand{
  font-size:1.4rem;
  font-weight:800;
  color:var(--primary) !important;
  display:flex;
  align-items:center;
  gap:8px;
  margin-bottom:16px;
}
.footer-brand i{color:var(--accent);}
.footer-desc{
  font-size:0.9rem;
  color:rgba(226,232,240,0.55);
  font-weight:300;
  max-width:300px;
}
.footer-links{
  list-style:none;
  padding:0;
}
.footer-links li{margin-bottom:10px;}
.footer-links a{
  font-size:0.92rem;
  color:rgba(226,232,240,0.6);
  font-weight:400;
  transition:color 0.3s;
}
.footer-links a:hover{color:var(--primary);}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,0.06);
  padding-top:25px;
  margin-top:40px;
  font-size:0.85rem;
  color:rgba(226,232,240,0.4);
  text-align:center;
}

/* 滚动渐显 */
.reveal{
  opacity:0;
  transform:translateY(40px);
  transition:opacity 0.8s ease,transform 0.8s ease;
}
.reveal.visible{
  opacity:1;
  transform:translateY(0);
}
.reveal-delay-1{transition-delay:0.1s;}
.reveal-delay-2{transition-delay:0.2s;}
.reveal-delay-3{transition-delay:0.3s;}

/* 图片占位 */
.img-placeholder{
  background:linear-gradient(135deg,#1e293b 0%,#334155 100%);
  border-radius:var(--radius);
  min-height:180px;
  display:flex;
  align-items:center;
  justify-content:center;
  color:rgba(226,232,240,0.2);
  font-size:2rem;
  position:relative;
  overflow:hidden;
}

/* 响应式 */
@media (max-width: 992px){
  .hero{padding:100px 0 80px;}
  .hero-title{font-size:3rem;}
  .section-title{font-size:2.2rem;}
  .cta-box{padding:50px 30px;}
  .cta-title{font-size:2rem;}
}
@media (max-width: 768px){
  .section-padding{padding:80px 0;}
  .hero-title{font-size:2.4rem;}
  .stat-number{font-size:2.4rem;}
  .navbar-nav{padding-top:15px;}
  .btn-outline-custom{margin-left:0;margin-top:12px;}
  .hero-desc{font-size:1rem;}
  .section-title{font-size:1.9rem;}
  .cta-box{padding:40px 20px;}
  .cta-title{font-size:1.6rem;}
}
@media (max-width: 480px){
  .hero-title{font-size:1.9rem;}
  .step-card{padding:30px 20px;}
  .feature-card{padding:28px 20px;}
}

/* --- 子页面追加 --- */
/* 保证 Bootstrap 组件不破坏深色风格 */
    .card, .card-body, .card-title, .card-text {
      background: var(--card-bg) !important;
      color: var(--text) !important;
      border-color: rgba(255,255,255,0.08) !important;
    }
/* 页面内自定义小组件 */
    .about-hero {
      background: linear-gradient(145deg, rgba(34, 211, 238, 0.08) 0%, rgba(251, 146, 60, 0.03) 100%);
      border-bottom: 1px solid rgba(255,255,255,0.04);
    }
.about-grid-item {
      background: rgba(30, 41, 59, 0.5);
      border-radius: var(--radius);
      padding: 1.8rem 1.5rem;
      height: 100%;
      transition: all 0.2s ease;
      border: 1px solid rgba(255,255,255,0.03);
    }
.about-grid-item:hover {
      background: rgba(30, 41, 59, 0.8);
      transform: translateY(-4px);
      border-color: rgba(34, 211, 238, 0.3);
    }
.about-icon {
      width: 48px;
      height: 48px;
      background: rgba(34, 211, 238, 0.15);
      border-radius: 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }
.about-icon.orange {
      background: rgba(251, 146, 60, 0.12);
      color: var(--accent);
    }
.about-icon.green {
      background: rgba(52, 211, 153, 0.12);
      color: #34d399;
    }
.about-quote {
      border-left: 3px solid var(--primary);
      padding-left: 1.2rem;
      color: var(--text);
      opacity: 0.9;
    }
.about-stats {
      background: rgba(15, 23, 42, 0.6);
      border-radius: var(--radius);
      padding: 2rem 1.5rem;
      border: 1px solid rgba(255,255,255,0.04);
    }
.about-stats .stat-number {
      font-size: 2.5rem;
      font-weight: 800;
      color: var(--primary);
    }
.about-stats .stat-label {
      color: var(--text);
      opacity: 0.7;
    }
/* 保证标题带品牌色 */
    .section-title span {
      color: var(--primary);
    }

/* --- 子页面追加 --- */
/* 页面专属微调 */
        .privacy-section { max-width: 960px; margin: 0 auto; }
.privacy-card { background: var(--card-bg); border-radius: var(--radius); padding: 2.2rem; margin-bottom: 1.8rem; box-shadow: var(--shadow); }
.privacy-card h3 { color: var(--primary); font-weight: 700; margin-bottom: 1.2rem; font-size: 1.4rem; }
.privacy-card p, .privacy-card li { color: var(--text); line-height: 1.8; }
.privacy-card ul { padding-left: 1.2rem; }
.privacy-card li { margin-bottom: .5rem; }
.privacy-card a { color: var(--accent); }
.privacy-card .highlight { color: var(--accent); font-weight: 600; }
.last-updated { color: rgba(226,232,240,.6); font-size: .9rem; font-style: italic; margin-bottom: 2rem; }
.divider { border-top: 1px solid rgba(34,211,238,.2); margin: 2.5rem 0; }
.fa-icon-accent { color: var(--accent); margin-right: .5rem; }
.fa-icon-primary { color: var(--primary); margin-right: .5rem; }

/* --- 子页面追加 --- */
/* 本页专属微调 */
        .terms-section {
            background: var(--card-bg);
            border-radius: var(--radius-lg);
            padding: 40px;
            margin-bottom: 24px;
            box-shadow: var(--shadow);
            border: 1px solid rgba(34, 211, 238, 0.08);
        }
.terms-section h2 {
            color: var(--primary);
            font-weight: 800;
            font-size: 1.6rem;
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            gap: 12px;
        }
.terms-section h2 i {
            color: var(--accent);
            font-size: 1.3rem;
        }
.terms-section h3 {
            color: var(--text);
            font-weight: 600;
            font-size: 1.15rem;
            margin: 18px 0 10px;
        }
.terms-section p, .terms-section li {
            color: rgba(226, 232, 240, 0.85);
            line-height: 1.8;
            font-size: 0.95rem;
        }
.terms-section ul {
            padding-left: 1.2rem;
        }
.terms-section ul li {
            margin-bottom: 8px;
        }
.terms-section strong {
            color: var(--primary);
        }
.terms-section .highlight-box {
            background: rgba(34, 211, 238, 0.06);
            border-left: 3px solid var(--primary);
            padding: 16px 20px;
            border-radius: 0 12px 12px 0;
            margin: 16px 0;
        }
.terms-section .highlight-box p {
            margin: 0;
        }
.terms-section {
                padding: 24px 18px;
            }
.terms-section h2 {
                font-size: 1.3rem;
            }