/* 爱思助手 aisi-aa —— 苹果实验室·极简大图流
   致敬 i4.cn:白底 + 浅灰分区 #f5f5f7 + iOS 蓝 #007AFF/#236EE7 + 全宽大图 + 居中大标题 + 大量留白 */

:root{
  --brand:#007AFF;
  --brand2:#236EE7;
  --bg:#FFFFFF;
  --bg2:#F5F5F7;
  --ink:#1D1D1F;
  --ink2:#6E6E73;
  --line:#D2D2D7;
  --radius:18px;
  --radius-sm:12px;
  --shadow:0 24px 60px rgba(0,0,0,.10);
  --shadow-sm:0 8px 24px rgba(0,0,0,.06);
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.7;font-size:16px;
  -webkit-font-smoothing:antialiased;
}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}
ul{list-style:none}
.wrap{max-width:1120px;margin:0 auto;padding:0 24px}
.section{padding:88px 0}
.section.bg2{background:var(--bg2)}
.kicker{display:inline-block;font-size:14px;font-weight:700;letter-spacing:.04em;color:var(--brand);margin-bottom:10px}
.sec-head{text-align:center;max-width:720px;margin:0 auto 56px}
.sec-title{font-size:44px;font-weight:800;letter-spacing:-.02em;line-height:1.15;margin-bottom:14px}
.sec-sub{color:var(--ink2);font-size:19px;line-height:1.6}
.link{display:inline-flex;align-items:center;gap:6px;color:var(--brand);font-weight:600;font-size:16px;margin-top:6px}
.link:hover{color:var(--brand2)}
.link svg{width:16px;height:16px}

/* ---------- 顶部导航 ---------- */
.topbar{position:sticky;top:0;z-index:60;background:rgba(255,255,255,.86);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{display:flex;align-items:center;gap:10px;font-size:18px;font-weight:700;color:var(--ink)}
.brand-logo{width:34px;height:34px;border-radius:9px}
.brand-sub{font-size:12px;font-weight:500;color:var(--ink2);margin-left:2px}
.nav-links{display:flex;align-items:center;gap:28px;font-size:15px;color:var(--ink)}
.nav-links a{position:relative;padding:6px 0;transition:color .2s}
.nav-links a:hover{color:var(--brand)}
.nav-links a.on{color:var(--brand);font-weight:700}
.nav-links a.on::after{content:"";position:absolute;left:0;right:0;bottom:-2px;height:2px;border-radius:2px;background:var(--brand)}
.nav-links a.nav-cta{display:inline-flex;align-items:center;gap:7px;padding:9px 20px;border-radius:980px;background:var(--brand);color:#fff !important;font-weight:600;font-size:14px;line-height:1;white-space:nowrap;transition:background .2s}
.nav-links a.nav-cta:hover{background:var(--brand2)}
.nav-links a.nav-cta svg{width:16px;height:16px;flex:none}

/* ---------- 按钮 ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:13px 26px;border-radius:980px;font-weight:600;font-size:16px;transition:all .2s;border:1px solid transparent;cursor:pointer}
.btn svg{width:18px;height:18px}
.btn-primary{background:var(--brand);color:#fff}
.btn-primary:hover{background:var(--brand2);transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--brand);border-color:var(--brand)}
.btn-ghost:hover{background:rgba(0,122,255,.06)}
.btn-light{background:#fff;color:var(--brand)}
.btn-light:hover{background:#f0f7ff}
.btn-glass{background:rgba(255,255,255,.16);color:#fff;border:1px solid rgba(255,255,255,.42);backdrop-filter:blur(8px)}
.btn-glass:hover{background:rgba(255,255,255,.28)}
.btn-lg{padding:16px 34px;font-size:17px}
.btn-block{width:100%}

/* ---------- hero 全宽大图 ---------- */
.hero{position:relative;min-height:620px;display:flex;align-items:center;color:#fff;overflow:hidden}
.hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;transform:scale(1.02)}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(15,27,51,.35) 0%,rgba(15,27,51,.62) 60%,rgba(10,18,35,.82) 100%)}
.hero-content{position:relative;text-align:center;max-width:820px;margin:0 auto;padding:72px 24px}
.hero-badge{display:inline-flex;align-items:center;gap:8px;padding:7px 16px;border-radius:980px;background:rgba(255,255,255,.14);backdrop-filter:blur(8px);font-size:13px;font-weight:600;margin-bottom:24px}
.hero-badge svg{width:15px;height:15px}
.hero h1{font-size:56px;font-weight:800;letter-spacing:-.02em;line-height:1.12;margin-bottom:20px}
.hero-sub{font-size:21px;color:rgba(255,255,255,.88);margin-bottom:32px;line-height:1.6}
.hero-actions{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.hero-note{font-size:14px;color:rgba(255,255,255,.66);margin-top:22px}

/* ---------- 产品下载卡 ---------- */
.pro-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.pro-card{background:#fff;border-radius:var(--radius);padding:40px 30px;text-align:center;box-shadow:var(--shadow-sm);border:1px solid #eee;transition:transform .25s,box-shadow .25s}
.pro-card:hover{transform:translateY(-5px);box-shadow:var(--shadow)}
.pro-icon{width:80px;height:80px;margin:0 auto 22px;border-radius:20px;display:flex;align-items:center;justify-content:center;background:var(--bg2)}
.pro-icon img{width:56px;height:56px;border-radius:14px}
.pro-icon svg{width:44px;height:44px;color:var(--brand)}
.pro-card h3{font-size:22px;font-weight:700;margin-bottom:10px}
.pro-card p{color:var(--ink2);font-size:15px;margin-bottom:24px;min-height:44px}
.pro-actions{display:flex;gap:12px;justify-content:center;align-items:center}
.pro-actions .btn{padding:10px 24px;font-size:15px}

/* ---------- 功能区块(全宽大图 + 左右图文) ---------- */
.feature{padding:104px 0}
.feature-grid{display:grid;grid-template-columns:1fr 1fr;gap:64px;align-items:center}
.feature.rev .feature-text{order:2}
.feature-text h2{font-size:38px;font-weight:800;letter-spacing:-.02em;line-height:1.18;margin-bottom:14px}
.feature-sub{font-size:19px;font-weight:600;color:var(--brand);margin-bottom:16px}
.feature-desc{font-size:16.5px;color:var(--ink2);line-height:1.85;margin-bottom:10px}
.feature-img{border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
.feature-img img{width:100%;aspect-ratio:4/3;object-fit:cover;transition:transform .5s}
.feature:hover .feature-img img{transform:scale(1.03)}

/* ---------- 平台下载 ---------- */
.dl-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.dl-card{background:#fff;border-radius:var(--radius);padding:30px 22px;text-align:center;border:1px solid #eee;transition:all .25s;box-shadow:var(--shadow-sm);display:flex;flex-direction:column;align-items:center;gap:8px}
.dl-card:hover{transform:translateY(-4px);border-color:var(--brand);box-shadow:var(--shadow)}
.dl-card .ico{width:56px;height:56px;border-radius:16px;background:var(--bg2);color:var(--brand);display:flex;align-items:center;justify-content:center;margin-bottom:6px}
.dl-card .ico svg{width:28px;height:28px}
.dl-card .name{font-weight:700;font-size:17px}
.dl-card .sub{font-size:13px;color:var(--ink2)}
.dl-card .meta{font-size:13px;font-weight:600;color:var(--brand);display:flex;align-items:center;gap:4px;margin-top:4px}
.dl-card .meta svg{width:14px;height:14px}

/* ---------- 文章/资讯列表(左图右文) ---------- */
.news-list{display:grid;grid-template-columns:1fr;gap:20px}
.news-item{display:grid;grid-template-columns:280px 1fr;gap:28px;background:#fff;border-radius:var(--radius);padding:20px;border:1px solid #eee;transition:box-shadow .25s,transform .25s}
.news-item:hover{box-shadow:var(--shadow);transform:translateY(-3px)}
.news-img{border-radius:var(--radius-sm);overflow:hidden}
.news-img img{width:100%;aspect-ratio:16/10;object-fit:cover}
.news-content{display:flex;flex-direction:column;justify-content:center}
.news-title{font-size:20px;font-weight:700;line-height:1.4;margin-bottom:10px}
.news-intro{color:var(--ink2);font-size:15px;margin-bottom:14px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.news-info{display:flex;gap:18px;color:var(--ink2);font-size:13px;align-items:center}
.news-info svg{width:14px;height:14px;vertical-align:-2px;margin-right:4px}

/* ---------- CTA ---------- */
.cta-band{background:var(--bg2);border-radius:24px;padding:64px 44px;text-align:center}
.cta-title{font-size:36px;font-weight:800;letter-spacing:-.02em;margin-bottom:14px}
.cta-band p{color:var(--ink2);font-size:17px;margin-bottom:30px}
.cta-band .btn{padding:16px 40px}

/* ---------- 内页 page-hero ---------- */
.page-hero{padding:64px 0 40px;background:var(--bg2);text-align:center}
.page-hero h1{font-size:44px;font-weight:800;letter-spacing:-.02em;margin:14px 0 16px}
.page-hero .lead{font-size:19px;color:var(--ink2);max-width:760px;margin:0 auto;line-height:1.7}
.crumb{font-size:14px;color:var(--ink2);margin-bottom:8px}
.crumb a{color:var(--brand)}
.crumb .sep{margin:0 8px;color:#b8b8c0}

/* ---------- 左右图文(内页) ---------- */
.split{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.split.rev .img-frame{order:2}
.img-frame{border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
.img-frame img{width:100%;aspect-ratio:4/3;object-fit:cover}
.split h2{font-size:30px;font-weight:800;letter-spacing:-.01em;margin-bottom:14px}
.split p{color:var(--ink2);margin-bottom:14px;font-size:16px}
.split .btn{margin-top:8px}

/* ---------- 表格 ---------- */
.table-wrap{overflow-x:auto;background:#fff;border-radius:var(--radius);border:1px solid #eee;box-shadow:var(--shadow-sm)}
table{width:100%;border-collapse:collapse;min-width:560px}
th,td{padding:16px 22px;text-align:left;font-size:15px;border-bottom:1px solid var(--line)}
th{background:var(--bg2);font-weight:700;color:var(--ink)}
tbody tr:last-child td{border-bottom:none}
tbody tr:hover td{background:#fafafc}

/* ---------- 文章双栏 ---------- */
.article-layout{display:grid;grid-template-columns:250px 1fr;gap:44px;padding:56px 0}
.toc{position:sticky;top:88px;align-self:start;background:#fff;border:1px solid #eee;border-radius:var(--radius);padding:22px;box-shadow:var(--shadow-sm)}
.toc h4{font-size:14px;font-weight:700;margin-bottom:12px;color:var(--ink)}
.toc a{display:block;font-size:14px;color:var(--ink2);padding:8px 0;border-bottom:1px dashed var(--line);transition:color .2s}
.toc a:last-child{border-bottom:none}
.toc a:hover{color:var(--brand)}
.prose{background:#fff;border:1px solid #eee;border-radius:var(--radius);padding:48px 56px;box-shadow:var(--shadow-sm)}
.prose p{font-size:16.5px;color:var(--ink);margin-bottom:20px;line-height:1.9}
.prose h2{font-size:26px;font-weight:800;margin:40px 0 18px;letter-spacing:-.01em}
.prose h3{font-size:20px;font-weight:700;margin:28px 0 12px}
.prose .lead{font-size:18px;font-weight:600;color:var(--ink)}
.prose .lead-fig{margin:8px 0 28px}
.prose .lead-fig img{width:100%;border-radius:var(--radius-sm);aspect-ratio:16/9;object-fit:cover}
.prose .lead-fig figcaption{font-size:13px;color:var(--ink2);text-align:center;margin-top:10px}
.callout{background:var(--bg2);border-radius:var(--radius-sm);padding:20px 24px;margin:28px 0}
.callout p{margin:0;font-size:15px;color:var(--ink)}
.faq-block{margin-top:28px}
.faq-block details{background:var(--bg2);border-radius:var(--radius-sm);margin-bottom:12px;overflow:hidden}
.faq-block summary{cursor:pointer;font-weight:600;font-size:15.5px;padding:16px 20px;position:relative;list-style:none}
.faq-block summary::after{content:"+";position:absolute;right:18px;top:50%;transform:translateY(-50%);font-size:22px;color:var(--brand)}
.faq-block details[open] summary::after{content:"−"}
.faq-block .a{padding:0 20px 18px;font-size:15px;color:var(--ink2);line-height:1.8}

/* ---------- 相关文章 ---------- */
.rel-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.rel-card{background:#fff;border-radius:var(--radius);padding:26px;border:1px solid #eee;transition:all .25s;box-shadow:var(--shadow-sm)}
.rel-card:hover{transform:translateY(-4px);border-color:var(--brand);box-shadow:var(--shadow)}
.rel-card .t{font-weight:700;font-size:16.5px;margin-bottom:10px;line-height:1.45}
.rel-card .d{font-size:14px;color:var(--ink2)}

/* ---------- 页脚 ---------- */
.pfoot{background:var(--bg2);padding:56px 0 36px;margin-top:20px}
.pfoot-inner{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px}
.pfoot-brand{display:flex;align-items:center;gap:10px;color:var(--ink);font-weight:700;font-size:16px}
.pfoot-brand img{width:28px;height:28px;border-radius:7px}
.pfoot-brand em{font-style:normal;font-weight:500;font-size:12.5px;color:var(--ink2)}
.pfoot-star svg{width:20px;height:20px;color:var(--brand);opacity:.55}
.pfoot-copy{font-size:13px;color:var(--ink2)}
.backtop{position:fixed;right:24px;bottom:24px;width:46px;height:46px;border-radius:50%;background:var(--brand);color:#fff;border:none;cursor:pointer;font-size:20px;box-shadow:0 10px 24px rgba(0,122,255,.4);display:none;z-index:70}

/* ---------- 工具页 ---------- */
.notfound{text-align:center;padding:40px 0}
.notfound .big{font-size:96px;font-weight:800;color:var(--brand);line-height:1}
.notfound p{margin:22px 0;color:var(--ink2);font-size:17px}
.search-box{display:flex;gap:12px;margin:24px 0;justify-content:center}
.search-input{flex:1;max-width:460px;padding:14px 20px;border:1px solid var(--line);border-radius:980px;font-size:15px;outline:none}
.search-input:focus{border-color:var(--brand)}
.search-results{text-align:left;margin-top:20px;max-width:680px;margin-left:auto;margin-right:auto}
.search-results li{background:#fff;border:1px solid #eee;border-radius:var(--radius-sm);padding:16px 20px;margin-bottom:12px;list-style:none;box-shadow:var(--shadow-sm)}
.search-results a{color:var(--brand);font-weight:600}
.search-results a:hover{color:var(--brand2)}

/* ---------- 响应式 ---------- */
@media(max-width:960px){
  .hero h1{font-size:42px}
  .sec-title{font-size:36px}
  .feature-grid,.split{grid-template-columns:1fr;gap:36px}
  .feature.rev .feature-text{order:0}
  .pro-grid{grid-template-columns:1fr}
  .dl-grid{grid-template-columns:repeat(2,1fr)}
  .news-item{grid-template-columns:1fr}
  .news-img img{aspect-ratio:16/9}
  .article-layout{grid-template-columns:1fr}
  .toc{position:static}
  .rel-grid{grid-template-columns:1fr 1fr}
  .brand-sub{display:none}
}
@media(max-width:600px){
  .hero{min-height:520px}
  .hero h1{font-size:34px}
  .hero-sub{font-size:18px}
  .sec-title{font-size:30px}
  .dl-grid,.rel-grid{grid-template-columns:1fr}
  .prose{padding:32px 22px}
  .nav-links a:not(.nav-cta){display:none}
  .feature,.section{padding:64px 0}
}