/* FlAi 官网落地页样式 */
:root{
  --primary:#FF5C8A;
  --primary-deep:#F03D74;
  --primary-soft:#FFE4EE;
  --deep:#2A1A3D;
  --text:#3E2C50;
  --muted:#6F5E7C;
  --bg:#FFF9FB;
  --bg-soft:#FFF0F6;
  --card:#FFFFFF;
  --border:#F4D8E5;
  --green:#2EC57E;
  --radius:18px;
  --shadow:0 10px 30px rgba(240,61,116,.08);
  --shadow-hover:0 18px 42px rgba(240,61,116,.16);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:76px}
body{font-family:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:var(--bg);color:var(--text);line-height:1.7;font-size:16px;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit}
ul{list-style:none}
button{font-family:inherit}
.container{max-width:1200px;margin:0 auto;padding:0 24px}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);transition:transform .25s,box-shadow .25s}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow-hover)}
.btn{display:inline-flex;align-items:center;justify-content:center;background:linear-gradient(90deg,var(--primary),var(--primary-deep));color:#fff;border-radius:999px;font-weight:600;border:none;cursor:pointer;transition:transform .25s,box-shadow .25s;text-align:center}
.btn:hover{transform:translateY(-3px);box-shadow:0 12px 28px rgba(240,61,116,.28)}
.btn-sm{padding:7px 18px;font-size:13px;min-height:36px}
.btn-lg{padding:14px 40px;font-size:16px;min-height:48px}

/* ===== 1 顶部导航 ===== */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);transition:box-shadow .25s}
.nav.scrolled{box-shadow:0 6px 24px rgba(42,26,61,.08)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:68px}
.logo{display:inline-flex;align-items:center;gap:10px}
.logo-icon{width:38px;height:38px;border-radius:12px;background:linear-gradient(135deg,var(--primary),var(--primary-deep));color:#fff;display:inline-flex;align-items:center;justify-content:center}
.logo-text{font-size:22px;font-weight:800;color:var(--deep);letter-spacing:.5px}
.nav-menu{display:flex;gap:6px}
.nav-menu a{padding:8px 14px;border-radius:999px;color:var(--text);font-size:15px;font-weight:500;min-height:44px;display:inline-flex;align-items:center;transition:color .2s,background .2s}
.nav-menu a:hover{color:var(--primary);background:var(--primary-soft)}

/* ===== 2 首屏 Hero ===== */
.hero{background:linear-gradient(180deg,var(--bg-soft) 0%,var(--bg) 100%);padding:130px 0 84px;overflow:hidden;position:relative}
.hero::before,.hero::after{content:"";position:absolute;border-radius:50%;filter:blur(10px);pointer-events:none}
.hero::before{width:420px;height:420px;background:radial-gradient(circle,rgba(255,92,138,.14),transparent 65%);top:-120px;left:-120px}
.hero::after{width:480px;height:480px;background:radial-gradient(circle,rgba(178,142,255,.14),transparent 65%);bottom:-160px;right:-140px}
.hero-inner{display:grid;grid-template-columns:1.05fr .95fr;gap:52px;align-items:center;position:relative;z-index:1}
.hero-badge{display:inline-flex;align-items:center;gap:8px;background:var(--primary-soft);color:var(--primary-deep);font-size:13px;font-weight:600;padding:6px 16px;border-radius:999px;margin-bottom:18px}
.hero-title{font-size:56px;font-weight:800;color:var(--deep);line-height:1.15;margin-bottom:18px}
.ver{display:inline-block;vertical-align:middle;margin-left:10px;padding:6px 14px;border-radius:999px;background:linear-gradient(90deg,var(--primary),var(--primary-deep));color:#fff;font-size:15px;font-weight:700;letter-spacing:1px}
.hero-desc{font-size:17px;color:var(--muted);max-width:480px;margin-bottom:28px}
.hero-actions{display:flex;gap:14px;margin-bottom:38px}
.personas-title{font-size:14px;color:var(--muted);font-weight:600;margin-bottom:14px}
.personas{display:grid;grid-template-columns:repeat(6,1fr);gap:12px;max-width:560px}
.persona{display:flex;flex-direction:column;align-items:center;gap:8px}
.persona img{width:64px;height:64px;border-radius:50%;border:3px solid var(--card);box-shadow:var(--shadow);object-fit:cover;transition:transform .25s,box-shadow .25s}
.persona:hover img{transform:translateY(-4px) scale(1.05);box-shadow:var(--shadow-hover)}
.persona span{font-size:13px;color:var(--text);font-weight:600}
.chat-card{background:var(--card);border:1px solid var(--border);border-radius:22px;box-shadow:0 24px 60px rgba(240,61,116,.16);overflow:hidden;max-width:420px;margin:0 auto;width:100%}
.chat-head{display:flex;align-items:center;gap:12px;padding:14px 18px;background:linear-gradient(135deg,var(--primary),var(--primary-deep));border-bottom:1px solid rgba(255,255,255,.25)}
.chat-head-avatar{width:46px;height:46px;border-radius:50%;object-fit:cover;border:2px solid #fff}
.chat-name{font-size:16px;font-weight:700;color:#fff}
.chat-status{font-size:12px;color:rgba(255,255,255,.85);display:flex;align-items:center;gap:6px}
.dot{width:8px;height:8px;border-radius:50%;background:var(--green);box-shadow:0 0 0 3px rgba(46,197,126,.18);flex-shrink:0}
.chat-body{height:340px;padding:16px;overflow-y:auto;background:var(--bg-soft);display:flex;flex-direction:column;gap:12px;scrollbar-width:none}
.chat-body::-webkit-scrollbar{display:none}
.msg{display:flex;gap:8px;max-width:82%;align-items:flex-end}
.msg.user{align-self:flex-end;flex-direction:row-reverse}
.msg-avatar{width:30px;height:30px;border-radius:50%;object-fit:cover;flex-shrink:0}
.msg-bubble{padding:10px 14px;border-radius:16px;font-size:14px;line-height:1.6;word-break:break-word}
.msg.ai .msg-bubble{background:#fff;border:1px solid var(--border);border-top-left-radius:4px}
.msg.user .msg-bubble{background:linear-gradient(135deg,var(--primary),var(--primary-deep));color:#fff;border-top-right-radius:4px}
.msg.typing .msg-bubble{display:flex;align-items:center;gap:4px;padding:13px 16px}
.msg.typing .msg-bubble i{width:6px;height:6px;border-radius:50%;background:var(--muted);animation:blink 1.1s infinite}
.msg.typing .msg-bubble i:nth-child(2){animation-delay:.2s}
.msg.typing .msg-bubble i:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,80%,100%{opacity:.3}40%{opacity:1}}
.chat-foot{display:flex;align-items:center;gap:10px;padding:12px 16px;background:#fff;border-top:1px solid var(--border)}
.chat-input{flex:1;height:44px;border:1px solid var(--border);border-radius:999px;background:var(--bg-soft);padding:0 16px;font-size:16px;color:var(--muted);outline:none;cursor:default;min-width:0}
.send-btn{width:44px;height:44px;border:none;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--primary-deep));color:#fff;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:transform .2s,box-shadow .2s;flex-shrink:0}
.send-btn:hover{transform:scale(1.06);box-shadow:0 8px 18px rgba(240,61,116,.3)}
.send-btn.disabled{background:#E2D3E4;cursor:not-allowed;box-shadow:none}
.send-btn.disabled:hover{transform:none;box-shadow:none}

/* ===== 通用区块 ===== */
.section{padding:96px 0}
.section-head{text-align:center;max-width:660px;margin:0 auto 52px}
.section-title{font-size:36px;font-weight:800;color:var(--deep);line-height:1.3}
.section-title.left{text-align:left}
.section-sub{font-size:16px;color:var(--muted);margin-top:12px}

/* ===== 3 三步上手 ===== */
.steps{background:var(--bg)}
.steps-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.step-card{padding:36px 28px}
.step-num{display:inline-flex;width:44px;height:44px;border-radius:14px;background:var(--primary-soft);color:var(--primary-deep);font-weight:800;font-size:16px;align-items:center;justify-content:center;margin-bottom:18px}
.step-card h3{font-size:19px;color:var(--deep);margin-bottom:10px}
.step-card p{font-size:15px;color:var(--muted)}

/* ===== 4 产品介绍 ===== */
.intro{background:var(--bg-soft)}
.intro-inner{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.intro-media{overflow:hidden;padding:0;border:none}
.intro-media img{width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:var(--radius)}
.intro-content h2{margin-bottom:18px}
.intro-content p{font-size:16px;color:var(--muted);margin-bottom:14px;max-width:520px}
.check-list li{position:relative;padding-left:32px;font-size:16px;color:var(--text);margin-bottom:14px;font-weight:500}
.check-list li::before{content:"✔";position:absolute;left:2px;top:0;color:var(--primary-deep);font-weight:700}

/* ===== 5 四大核心功能 ===== */
.features{background:var(--bg)}
.features-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.feature-card{padding:30px 26px}
.feature-icon{width:52px;height:52px;border-radius:16px;background:linear-gradient(135deg,var(--primary-soft),#FFD9E8);display:flex;align-items:center;justify-content:center;margin-bottom:18px;color:var(--primary-deep)}
.feature-card h3{font-size:18px;color:var(--deep);margin-bottom:10px}
.pain-tag{display:inline-block;font-size:12px;color:var(--primary-deep);background:var(--primary-soft);padding:3px 10px;border-radius:999px;margin-bottom:8px;font-weight:600}
.feature-card .pain{font-size:14px;color:var(--muted);margin-bottom:10px}
.feature-card .desc{font-size:14px;color:var(--text)}

/* ===== 6 优势对比 ===== */
.compare{background:var(--bg-soft)}
.table-wrap{overflow-x:auto;border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow);-webkit-overflow-scrolling:touch}
.compare-table{width:100%;min-width:640px;border-collapse:collapse;background:var(--card);table-layout:fixed}
.compare-table th,.compare-table td{padding:16px 18px;text-align:left;font-size:15px;border-bottom:1px solid var(--border)}
.compare-table thead th{background:var(--deep);color:#fff;font-weight:600;font-size:16px;padding:18px}
.compare-table thead th.col-best{background:linear-gradient(90deg,var(--primary),var(--primary-deep))}
.compare-table tbody tr:last-child td{border-bottom:none}
.compare-table tbody td{color:var(--muted)}
.compare-table tbody td.col-best{background:var(--primary-soft);color:var(--primary-deep);font-weight:600}
.compare-table tbody tr:hover td{background:var(--bg)}
.table-hint{display:none;text-align:center;font-size:13px;color:var(--muted);margin-top:12px}

/* ===== 7 使用场景 ===== */
.scenes{background:var(--bg)}
.scene-list{display:grid;grid-template-columns:repeat(2,1fr);gap:14px 32px;max-width:920px;margin:0 auto 60px}
.scene-list li{display:flex;gap:12px;align-items:flex-start;font-size:16px;color:var(--text);padding:14px 18px;background:var(--card);border:1px solid var(--border);border-radius:14px;box-shadow:var(--shadow)}
.scene-list li::before{content:"✔";color:var(--primary-deep);font-weight:700;flex-shrink:0}
.vs{display:grid;grid-template-columns:1fr auto 1fr;gap:24px;align-items:stretch;max-width:980px;margin:0 auto}
.vs-card{padding:32px 30px}
.vs-card h3{font-size:20px;color:var(--deep);margin-bottom:18px;text-align:center}
.vs-card.best h3{color:var(--primary-deep)}
.vs-card li{font-size:15px;color:var(--muted);margin-bottom:12px;position:relative;padding-left:26px}
.vs-card li::before{content:"✕";color:#CBBBD1;position:absolute;left:0;font-weight:700}
.vs-card.best li::before{content:"✔";color:var(--primary-deep);position:absolute;left:0;font-weight:700}
.vs-badge{width:56px;height:56px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--primary-deep));color:#fff;font-weight:800;font-size:15px;display:flex;align-items:center;justify-content:center;align-self:center;box-shadow:0 12px 26px rgba(240,61,116,.3);flex-shrink:0}

/* ===== 8 数据模块 ===== */
.stats{background:var(--deep);position:relative;overflow:hidden}
.stats::before{content:"";position:absolute;width:520px;height:520px;border-radius:50%;background:radial-gradient(circle,rgba(255,92,138,.18),transparent 65%);top:-200px;right:-160px;pointer-events:none}
.stats .section-head{margin-bottom:48px}
.stats .section-title{color:#fff}
.stats .section-sub{color:rgba(255,255,255,.6)}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;position:relative;z-index:1}
.stat{text-align:center;padding:30px 16px;border-radius:var(--radius);background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.12);transition:transform .25s,background .25s}
.stat:hover{transform:translateY(-6px);background:rgba(255,255,255,.1)}
.stat-num{display:block;font-size:44px;font-weight:800;color:#fff;line-height:1.2}
.stat-label{display:block;margin-top:8px;font-size:15px;color:rgba(255,255,255,.72)}

/* ===== 9 人设定制 ===== */
.custom{background:var(--bg-soft)}
.custom-inner{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.custom-content h2{margin-bottom:18px}
.custom-content>p{color:var(--muted);font-size:16px;margin-bottom:24px;max-width:500px}
.custom-list{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-bottom:30px;max-width:480px}
.custom-list li{display:flex;align-items:center;gap:10px;font-size:15px;color:var(--text);font-weight:600;padding:12px 16px;background:var(--card);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow)}
.custom-list li::before{content:"✔";color:var(--primary-deep);font-weight:700}
.custom-media{overflow:hidden;padding:0;border:none}
.custom-media img{width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:var(--radius)}

/* ===== 10 用户评价 ===== */
.reviews{background:var(--bg)}
.reviews-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.review-card{padding:26px}
.review-top{display:flex;align-items:center;gap:14px;margin-bottom:14px}
.review-avatar{width:46px;height:46px;border-radius:50%;color:#fff;font-weight:700;font-size:18px;display:flex;align-items:center;justify-content:center;background:var(--primary);flex-shrink:0}
.review-card:nth-child(2) .review-avatar{background:#8B7CF6}
.review-card:nth-child(3) .review-avatar{background:#FF9F4A}
.review-card:nth-child(4) .review-avatar{background:#2EC57E}
.review-card:nth-child(5) .review-avatar{background:#4A9BF6}
.review-card:nth-child(6) .review-avatar{background:#F66BA8}
.review-info{display:flex;flex-direction:column}
.review-name{font-size:16px;font-weight:700;color:var(--deep)}
.review-stars{color:#FFB400;font-size:14px;letter-spacing:2px;line-height:1.4}
.review-text{font-size:14px;color:var(--muted);line-height:1.8}

/* ===== 11 隐私安全 ===== */
.privacy{background:var(--bg-soft)}
.privacy-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.privacy-card{padding:30px 26px}
.privacy-icon{width:52px;height:52px;border-radius:16px;background:linear-gradient(135deg,var(--primary-soft),#FFD9E8);display:flex;align-items:center;justify-content:center;margin-bottom:18px;color:var(--primary-deep)}
.privacy-card h3{font-size:17px;color:var(--deep);margin-bottom:10px}
.privacy-card p{font-size:14px;color:var(--muted)}

/* ===== 12 版本更新 ===== */
.version{background:var(--bg)}
.version-card{max-width:760px;margin:0 auto;padding:36px 40px}
.version-head{display:flex;align-items:center;gap:16px;margin-bottom:24px;flex-wrap:wrap}
.version-badge{display:inline-flex;padding:8px 20px;border-radius:999px;background:linear-gradient(90deg,var(--primary),var(--primary-deep));color:#fff;font-weight:800;font-size:18px}
.version-date{font-size:14px;color:var(--muted)}
.version-list li{position:relative;padding:11px 0 11px 28px;font-size:15px;color:var(--text);border-bottom:1px dashed var(--border)}
.version-list li:last-child{border-bottom:none}
.version-list li::before{content:"";position:absolute;left:4px;top:19px;width:8px;height:8px;border-radius:50%;background:var(--primary)}

/* ===== 13 FAQ ===== */
.faq{background:var(--bg-soft)}
.faq-list{max-width:820px;margin:0 auto}
.faq-item{background:var(--card);border:1px solid var(--border);border-radius:16px;margin-bottom:14px;box-shadow:var(--shadow);overflow:hidden}
.faq-q{width:100%;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:20px 24px;background:none;border:none;cursor:pointer;font-size:16px;font-weight:600;color:var(--deep);text-align:left;min-height:44px}
.faq-icon{width:28px;height:28px;border-radius:50%;background:var(--primary-soft);position:relative;flex-shrink:0;transition:transform .3s}
.faq-icon::before,.faq-icon::after{content:"";position:absolute;background:var(--primary-deep);border-radius:2px;top:50%;left:50%;transform:translate(-50%,-50%)}
.faq-icon::before{width:12px;height:2px}
.faq-icon::after{width:2px;height:12px}
.faq-item.open .faq-icon{transform:rotate(45deg)}
.faq-a{max-height:0;overflow:hidden;transition:max-height .35s ease}
.faq-a-inner{padding:0 24px 20px;font-size:15px;color:var(--muted)}

/* ===== 14 下载区域 ===== */
.download{background:var(--bg);padding:96px 0 110px}
.download-card{max-width:860px;margin:0 auto;background:linear-gradient(135deg,#FFF0F6,#FFE4EE);border:1px solid var(--border);border-radius:28px;text-align:center;padding:64px 40px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.download-card::before{content:"";position:absolute;width:280px;height:280px;border-radius:50%;background:radial-gradient(circle,rgba(255,92,138,.14),transparent 65%);top:-90px;left:-90px;pointer-events:none}
.download-title{font-size:42px;font-weight:800;color:var(--deep);line-height:1.2}
.download-meta{font-size:14px;color:var(--muted);margin:12px 0 30px}
.download-btns{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;margin-bottom:26px}
.btn-download{padding:16px 36px;font-size:17px;min-height:52px;min-width:220px}
.download-tip{font-size:15px;color:var(--text)}

/* ===== 15 页脚 ===== */
.footer{background:var(--deep);color:rgba(255,255,255,.72);padding:40px 0;text-align:center}
.footer-copy{font-size:14px}
.footer-link{color:#fff;text-decoration:none;font-weight:700;transition:color .2s}
.footer-link:hover{color:var(--primary-soft)}

/* ===== 16 返回顶部 ===== */
.back-top{position:fixed;right:26px;bottom:30px;width:46px;height:46px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--primary-deep));color:#fff;border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:0 10px 24px rgba(240,61,116,.3);opacity:0;visibility:hidden;transform:translateY(12px);transition:all .3s;z-index:90}
.back-top.show{opacity:1;visibility:visible;transform:none}

/* ===== 响应式 ===== */
@media(max-width:1100px){
  .hero-title{font-size:46px}
  .hero-inner{grid-template-columns:1fr .95fr;gap:36px}
  .personas{grid-template-columns:repeat(3,1fr)}
  .features-grid,.privacy-grid,.stats-grid{grid-template-columns:repeat(2,1fr)}
  .reviews-grid{grid-template-columns:repeat(2,1fr)}
  .section-title{font-size:32px}
  .stat-num{font-size:38px}
}
@media(max-width:900px){
  .nav-menu{display:none}
  .hero{padding:110px 0 64px}
  .hero-inner{grid-template-columns:1fr;gap:44px}
  .hero-title{font-size:40px}
  .steps-grid{grid-template-columns:1fr}
  .intro-inner{grid-template-columns:1fr;gap:36px}
  .custom-inner{grid-template-columns:1fr;gap:36px}
  .vs{grid-template-columns:1fr}
  .vs-badge{margin:0 auto}
  .scene-list{grid-template-columns:1fr}
  .section{padding:80px 0}
}
@media(max-width:768px){
  .container{padding:0 20px}
  .section{padding:72px 0}
  .section-head{margin-bottom:40px}
  .nav-download{min-height:44px}
  .table-hint{display:block}
  .download-btns{flex-direction:column}
  .btn-download{width:100%;min-width:0}
  .download-meta{font-size:12px;white-space:nowrap}
  .download-card{padding:48px 24px}
  .download-title{font-size:34px}
  .chat-body{height:300px}
  .version-card{padding:28px 22px}
}
@media(max-width:640px){
  .features-grid,.reviews-grid,.privacy-grid{grid-template-columns:1fr}
  .stats-grid{grid-template-columns:repeat(2,1fr);gap:14px}
  .stat-num{font-size:32px}
  .custom-list{grid-template-columns:1fr}
  .hero-title{font-size:34px}
  .hero-left{text-align:center}
  .hero-desc{margin-left:auto;margin-right:auto}
  .hero-actions{justify-content:center}
  .hero-actions .btn{width:100%}
  .custom-content .btn{width:100%}
  .chat-body{height:280px}
  .personas{gap:8px}
  .back-top{right:16px;bottom:20px}
}