*{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#e74c3c;
  --dark:#1a1a2e;
  --darker:#0f0f1e;
  --card:#16213e;
  --text:#e0e0e0;
  --accent:#ffd700;
  --gray:#888;
}
html{scroll-behavior:smooth}
body{
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background:var(--darker);
  color:var(--text);
  line-height:1.7;
}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}

/* 顶部导航 */
.navbar{
  position:fixed;top:0;left:0;right:0;z-index:1000;
  background:rgba(15,15,30,0.95);backdrop-filter:blur(10px);
  border-bottom:1px solid rgba(231,76,60,0.3);
  padding:0 20px;
}
.nav-inner{
  max-width:1200px;margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;
  height:60px;
}
.logo{
  font-size:1.3rem;font-weight:900;
  color:var(--primary);letter-spacing:1px;
}
.logo span{color:var(--accent)}
.nav-links{display:flex;gap:20px;list-style:none}
.nav-links a{
  font-size:.9rem;padding:6px 12px;border-radius:4px;
  transition:all .3s;
}
.nav-links a:hover{background:rgba(231,76,60,0.2);color:var(--primary)}
.nav-download{
  background:var(--primary)!important;color:#fff!important;
  padding:8px 20px!important;border-radius:6px!important;font-weight:700;
}
.hamburger{display:none;font-size:1.5rem;cursor:pointer;background:none;border:none;color:var(--text)}

/* Hero 三图模块 */
.hero{
  margin-top:60px;padding:60px 20px 80px;
  text-align:center;
  background:linear-gradient(180deg,rgba(231,76,60,0.15) 0%,transparent 100%);
}
.hero h1{
  font-size:clamp(1.8rem,5vw,3rem);
  font-weight:900;margin-bottom:16px;
  background:linear-gradient(90deg,var(--primary),var(--accent));
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
}
.hero p{font-size:clamp(1rem,2.5vw,1.2rem);color:var(--gray);margin-bottom:30px;max-width:700px;margin-left:auto;margin-right:auto}
.hero-btn{
  display:inline-block;padding:14px 40px;
  background:var(--primary);color:#fff;font-size:1.1rem;font-weight:700;
  border-radius:8px;transition:transform .3s,box-shadow .3s;
  box-shadow:0 4px 20px rgba(231,76,60,0.4);
}
.hero-btn:hover{transform:translateY(-2px);box-shadow:0 6px 30px rgba(231,76,60,0.6)}
.hero-images{
  display:grid;grid-template-columns:repeat(3,1fr);gap:16px;
  max-width:900px;margin:40px auto 0;
}
.hero-img{
  aspect-ratio:16/9;border-radius:12px;overflow:hidden;
  background:var(--card);border:1px solid rgba(255,255,255,0.08);
  display:flex;align-items:center;justify-content:center;
  position:relative;
}
.hero-img::after{
  content:attr(data-label);
  position:absolute;bottom:10px;left:10px;
  background:rgba(0,0,0,0.7);padding:4px 12px;border-radius:4px;font-size:.8rem;
}
/* 图片占位 - 替换 src 为实际图片路径 */
.hero-img img{width:100%;height:100%;object-fit:cover}

/* 通用卡片 */
.section{padding:60px 20px;max-width:1200px;margin:0 auto}
.section-title{
  text-align:center;font-size:clamp(1.5rem,4vw,2rem);font-weight:900;margin-bottom:12px;
}
.section-sub{text-align:center;color:var(--gray);margin-bottom:40px;font-size:.95rem}

/* 功能卡片 */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}
.card{
  background:var(--card);border:1px solid rgba(255,255,255,0.06);
  border-radius:12px;padding:30px;transition:transform .3s,border-color .3s;
}
.card:hover{transform:translateY(-4px);border-color:rgba(231,76,60,0.4)}
.card-icon{
  width:50px;height:50px;border-radius:10px;
  background:linear-gradient(135deg,var(--primary),#c0392b);
  display:flex;align-items:center;justify-content:center;
  font-size:1.5rem;margin-bottom:16px;
}
.card h3{font-size:1.15rem;margin-bottom:8px;color:#fff}
.card p{font-size:.9rem;color:var(--gray);line-height:1.6}

/* 下载模块 */
.download-section{
  text-align:center;padding:60px 20px;
  background:linear-gradient(135deg,rgba(231,76,60,0.1),rgba(255,215,0,0.05));
  border-radius:16px;margin:0 20px 60px;
}
.download-btn{
  display:inline-block;padding:16px 50px;
  background:linear-gradient(135deg,var(--primary),#c0392b);
  color:#fff;font-size:1.2rem;font-weight:800;border-radius:10px;
  box-shadow:0 4px 25px rgba(231,76,60,0.5);transition:all .3s;
}
.download-btn:hover{transform:scale(1.05);box-shadow:0 6px 35px rgba(231,76,60,0.7)}
.download-note{margin-top:12px;color:var(--gray);font-size:.85rem}

/* 教程模块 */
.tutorial{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:24px}
.step{
  background:var(--card);border-radius:12px;padding:28px;
  border-left:4px solid var(--primary);
}
.step-num{
  display:inline-block;width:32px;height:32px;line-height:32px;
  text-align:center;border-radius:50%;background:var(--primary);
  font-weight:900;font-size:.9rem;margin-bottom:12px;
}
.step h4{margin-bottom:8px;font-size:1.05rem}
.step p{font-size:.9rem;color:var(--gray)}

/* FAQ */
.faq{max-width:800px;margin:0 auto}
.faq-item{
  background:var(--card);border-radius:10px;margin-bottom:12px;
  overflow:hidden;border:1px solid rgba(255,255,255,0.05);
}
.faq-q{
  padding:18px 24px;font-weight:700;cursor:pointer;
  display:flex;justify-content:space-between;align-items:center;
}
.faq-q::after{content:'+';font-size:1.4rem;color:var(--primary);transition:transform .3s}
.faq-item.active .faq-q::after{transform:rotate(45deg)}
.faq-a{
  padding:0 24px 18px;color:var(--gray);font-size:.9rem;
  display:none;
}
.faq-item.active .faq-a{display:block}

/* 底部 */
.footer{
  background:var(--dark);border-top:1px solid rgba(255,255,255,0.06);
  padding:40px 20px;text-align:center;
}
.footer p{color:var(--gray);font-size:.85rem;margin-bottom:6px}
.footer a{color:var(--primary)}

/* 图片占位说明 - 替换为实际图片 */
/*
  图片替换指南（全部使用本地路径或 base64）：
  1. hero-img 中：将 img src 替换为本地图片路径，如 src="img/hero1.jpg"
  2. card-icon 中：可替换为实际图标图片
  3. 底部logo等均可替换
  示例 base64 小图标（直接替换 card-icon 内的 img）：
  <img src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiNmZmYiIHN0cm9rZS13aWR0aD0iMiI+PHBhdGggZD0iTTEyIDJDNi40OCAyIDIgNi40OCAyIDEyczQuNDggMTAgMTAgMTAgMTAtNC40OCAxMC0xMFMxNy41MiAyIDEyIDJ6Ii8+PC9zdmc+" alt="icon">
*/

/* 响应式 */
@media(max-width:768px){
  .nav-links{display:none;position:absolute;top:60px;left:0;right:0;background:var(--darker);flex-direction:column;padding:20px;gap:10px;border-bottom:1px solid rgba(255,255,255,0.1)}
  .nav-links.open{display:flex}
  .hamburger{display:block}
  .hero-images{grid-template-columns:1fr;max-width:400px}
  .cards{grid-template-columns:1fr}
  .tutorial{grid-template-columns:1fr}
}