/* 91VPN 官网 · 收费版 · 移动优先 · 清新蓝主题（与 App 一致）
   字体走系统栈，不引任何外部 CDN/Google Fonts（合规 + 防供应链 + 防被墙） */
:root{
  --g1:#3D7BFF; --g2:#27C4E8; --good:#2C74E6; --soft:rgba(55,130,255,.10);
  --ink:#141B27; --muted:#5B6776; --faint:#94A0B0; --line:rgba(20,27,39,.08);
  --bg:#EEF2F8; --card:#fff; --grad:linear-gradient(135deg,#3D7BFF,#27C4E8);
  --glow:rgba(55,130,255,.28); --radius:20px;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei","Hiragino Sans GB",Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg); color:var(--ink); line-height:1.6; font-size:16px; -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none;}
img{max-width:100%;display:block;}
ul{list-style:none;}
.container{width:100%;max-width:1080px;margin:0 auto;padding:0 18px;}

/* 按钮 */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:50px;padding:0 24px;border-radius:14px;font-size:15.5px;font-weight:700;cursor:pointer;border:none;transition:transform .15s,box-shadow .15s,opacity .15s;white-space:nowrap;}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 12px 26px var(--glow);}
.btn-primary:active{transform:scale(.98);}
.btn-ghost{background:#fff;color:var(--ink);box-shadow:0 3px 12px rgba(40,55,80,.08);}
.btn-sm{height:38px;padding:0 16px;font-size:13.5px;border-radius:11px;}
.btn-lg{height:56px;font-size:17px;border-radius:16px;}
.btn-block{width:100%;}
@media(hover:hover){.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 32px var(--glow);}.btn-ghost:hover{transform:translateY(-2px);}}

/* 通用卡片 */
.card{background:var(--card);border-radius:var(--radius);box-shadow:0 8px 26px rgba(40,55,80,.07);}

/* 顶栏 */
.nav{position:sticky;top:0;z-index:50;background:rgba(238,242,248,.86);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:58px;gap:12px;}
.brand{display:flex;align-items:center;gap:9px;font-weight:800;font-size:18px;flex:none;}
.brand .logo-img{width:32px;height:32px;border-radius:9px;}
.nav-links{display:none;align-items:center;gap:24px;}
.nav-links a{font-size:14.5px;font-weight:600;color:var(--muted);}
.nav-cta{display:flex;align-items:center;gap:10px;flex:none;}
.lang-toggle{background:#fff;border:1px solid var(--line);border-radius:999px;height:34px;padding:0 13px;font-size:12.5px;font-weight:700;color:var(--muted);cursor:pointer;}
@media(min-width:780px){
  .nav-links{display:flex;}
  .nav-links a:hover{color:var(--ink);}
}

/* Hero */
.hero{position:relative;padding:40px 0 36px;overflow:hidden;}
.hero::before{content:"";position:absolute;inset:0;z-index:-2;
  background:
    radial-gradient(60% 50% at 78% 18%,rgba(39,196,232,.20),transparent 70%),
    radial-gradient(70% 60% at 12% 0%,rgba(61,123,255,.22),transparent 70%);}
.hero::after{content:"";position:absolute;inset:0;z-index:-1;opacity:.5;
  background-image:linear-gradient(rgba(55,130,255,.06) 1px,transparent 1px),linear-gradient(90deg,rgba(55,130,255,.06) 1px,transparent 1px);
  background-size:34px 34px;-webkit-mask-image:radial-gradient(70% 60% at 50% 30%,#000,transparent 75%);mask-image:radial-gradient(70% 60% at 50% 30%,#000,transparent 75%);}
.hero-grid{display:grid;gap:30px;grid-template-columns:1fr;text-align:center;}
.hero-text{display:flex;flex-direction:column;align-items:center;}
.eyebrow{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:700;letter-spacing:.04em;color:var(--good);background:rgba(255,255,255,.7);border:1px solid var(--line);box-shadow:0 4px 14px rgba(40,55,80,.06);padding:7px 15px;border-radius:999px;}
.hero h1{font-size:clamp(31px,8.5vw,50px);font-weight:800;letter-spacing:-.025em;margin:18px 0 14px;line-height:1.12;}
.hero h1 .em{background:var(--grad);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;}
.hero p{font-size:16px;color:var(--muted);max-width:560px;margin:0 0 26px;}
.hero-cta{display:flex;flex-direction:column;gap:12px;width:100%;max-width:360px;}
.trust{display:flex;flex-wrap:wrap;gap:9px 18px;justify-content:center;margin-top:26px;font-size:13px;color:var(--faint);font-weight:600;}
.trust li{display:inline-flex;align-items:center;gap:6px;}
.trust li::before{content:"";width:14px;height:14px;flex:none;background:var(--good);-webkit-mask:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M20 6 9 17l-5-5' fill='none' stroke='black' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'/></svg>") center/contain no-repeat;mask:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M20 6 9 17l-5-5' fill='none' stroke='black' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'/></svg>") center/contain no-repeat;}

/* Hero 视觉：发光球 + 玻璃信息片 */
.hero-visual{position:relative;display:flex;align-items:center;justify-content:center;min-height:190px;margin-top:4px;}
.orb{position:relative;display:grid;place-items:center;}
.orb img{width:132px;height:132px;border-radius:34px;box-shadow:0 24px 54px var(--glow);}
.orb-glow{position:absolute;inset:-55%;border-radius:50%;background:radial-gradient(closest-side,var(--glow),transparent 72%);z-index:-1;}
.hchip{position:absolute;display:inline-flex;align-items:center;gap:6px;background:rgba(255,255,255,.86);backdrop-filter:blur(6px);border:1px solid var(--line);box-shadow:0 10px 24px rgba(40,55,80,.12);color:var(--ink);font-size:12.5px;font-weight:700;padding:8px 13px;border-radius:12px;white-space:nowrap;}
.hchip::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--good);}
.hchip.c1{top:8%;left:2%;}
.hchip.c2{bottom:12%;left:6%;}
.hchip.c3{top:24%;right:2%;}
/* 手机端隐藏装饰性发光球+浮片：堆叠后显突兀，移动端以文案+CTA 为主 */
@media(max-width:879px){.hero-visual{display:none;}}
@media(min-width:600px){
  .hero{padding:64px 0 52px;}
  .hero p{font-size:17.5px;}
  .hero-cta{flex-direction:row;max-width:none;}
  .hero-cta .btn{width:auto;min-width:190px;}
}
@media(min-width:880px){
  .hero{padding:84px 0 70px;}
  .hero-grid{grid-template-columns:1.05fr .95fr;align-items:center;text-align:left;gap:24px;}
  .hero-text{align-items:flex-start;}
  .trust{justify-content:flex-start;}
  .hero-visual{min-height:330px;}
  .orb img{width:184px;height:184px;border-radius:46px;}
}

/* section 通用 */
section{padding:46px 0;}
.sec-head{text-align:center;margin-bottom:28px;}
.sec-head h2{font-size:clamp(23px,5.5vw,30px);font-weight:800;letter-spacing:-.01em;}
.sec-head p{color:var(--muted);margin-top:8px;font-size:15px;}
@media(min-width:600px){section{padding:60px 0;}.sec-head{margin-bottom:40px;}}

/* 栅格（移动 1 列，逐级展开，等高） */
.grid{display:grid;gap:14px;grid-template-columns:1fr;}
.grid-feat{}
@media(min-width:560px){.grid-feat{grid-template-columns:repeat(2,1fr);}}
@media(min-width:960px){.grid-feat{grid-template-columns:repeat(4,1fr);}}

/* 特性卡 */
.feature{padding:22px 20px;}
.feature .ic{width:48px;height:48px;border-radius:13px;background:var(--soft);display:grid;place-items:center;margin-bottom:14px;}
.feature .ic svg{width:25px;height:25px;stroke:var(--good);}
.feature h3{font-size:16.5px;font-weight:800;margin-bottom:6px;}
.feature p{font-size:14px;color:var(--muted);}

/* 套餐（flex 居中换行，避免末行错位；行内等高） */
.grid-plans{display:flex;flex-wrap:wrap;gap:14px;justify-content:center;}
.plan{position:relative;flex:1 1 260px;max-width:320px;display:flex;flex-direction:column;background:var(--card);border:2px solid transparent;border-radius:var(--radius);box-shadow:0 8px 26px rgba(40,55,80,.07);padding:24px 22px;}
.plan.pop{border-color:var(--g1);box-shadow:0 14px 34px var(--glow);}
.plan .badge{position:absolute;top:-11px;left:50%;transform:translateX(-50%);background:var(--grad);color:#fff;font-size:11px;font-weight:800;padding:4px 12px;border-radius:999px;white-space:nowrap;box-shadow:0 6px 14px var(--glow);}
.plan .pname{font-size:16px;font-weight:800;}
.plan .price{font-size:34px;font-weight:800;margin:10px 0 0;line-height:1;}
.plan .price small{font-size:14px;color:var(--faint);font-weight:700;}
.plan .per{font-size:13px;color:var(--faint);font-weight:600;margin-top:5px;}
.plan .specs{margin:18px 0 0;display:flex;flex-direction:column;gap:10px;}
.plan .specs li{font-size:13.5px;color:#39434F;font-weight:600;display:flex;gap:8px;align-items:flex-start;}
.plan .specs li svg{width:16px;height:16px;stroke:var(--good);flex:none;margin-top:2px;}
.plans-state{flex:1 1 100%;text-align:center;color:var(--faint);font-size:14px;font-weight:600;padding:28px 0;}
.plans-note{text-align:center;color:var(--faint);font-size:13px;margin-top:22px;padding:0 8px;}

/* 邀请横幅 */
.invite-bar{display:flex;align-items:center;gap:14px;background:var(--grad);padding:18px 20px;color:#fff;box-shadow:0 14px 34px var(--glow);margin-bottom:18px;flex-wrap:wrap;}
.invite-bar .ic{width:44px;height:44px;border-radius:13px;background:rgba(255,255,255,.22);display:grid;place-items:center;flex:none;}
.invite-bar .ic svg{width:23px;height:23px;stroke:#fff;}
.invite-text{display:flex;flex-direction:column;flex:1 1 180px;}
.invite-text b{font-size:15.5px;}
.invite-sub{font-size:12.5px;color:rgba(255,255,255,.9);margin-top:2px;}
.invite-bar .code{font-size:20px;font-weight:800;letter-spacing:.1em;background:rgba(255,255,255,.2);padding:5px 14px;border-radius:10px;margin-left:auto;}

/* 下载卡 */
.download{padding:38px 24px;text-align:center;display:flex;flex-direction:column;align-items:center;}
.download .dl-icon img{width:76px;height:76px;border-radius:20px;box-shadow:0 12px 28px var(--glow);}
.download h2{font-size:24px;font-weight:800;margin:18px 0 6px;}
.download p{color:var(--muted);margin-bottom:24px;font-size:15px;}

/* 下载渠道列表 */
.dl-channels{width:100%;max-width:420px;display:flex;flex-direction:column;gap:12px;}
.dl-ch{display:flex;align-items:center;gap:14px;text-align:left;padding:14px 16px;border:1px solid var(--line);border-radius:16px;background:var(--card);transition:transform .15s,box-shadow .15s,border-color .15s;}
@media(hover:hover){.dl-ch:hover{transform:translateY(-2px);box-shadow:0 12px 26px rgba(40,55,80,.10);border-color:transparent;}}
.dl-ch:active{transform:scale(.99);}
.dl-ch-ic{flex:none;width:46px;height:46px;border-radius:13px;display:flex;align-items:center;justify-content:center;}
.dl-ic-apk{background:var(--grad);color:#fff;box-shadow:0 8px 18px var(--glow);}
.dl-ic-gp{background:#F1F5FB;}
.dl-ic-ios{background:#141B27;color:#fff;}
.dl-ch-txt{flex:1;min-width:0;display:flex;flex-direction:column;gap:2px;}
.dl-ch-txt b{font-size:15.5px;font-weight:800;color:var(--ink);line-height:1.25;}
.dl-ch-txt em{font-style:normal;font-size:12.5px;color:var(--faint);font-weight:600;}
.dl-ch-act{flex:none;font-size:13.5px;font-weight:800;color:var(--good);background:var(--soft);padding:7px 14px;border-radius:10px;}
.dl-ch-act.soon{color:var(--faint);background:rgba(148,160,176,.14);}
.dl-ch.is-soon{cursor:default;opacity:.85;}
@media(hover:hover){.dl-ch.is-soon:hover{transform:none;box-shadow:none;border-color:var(--line);}}
.dl-note{font-size:12.5px;color:var(--faint);margin-top:20px;font-weight:600;max-width:420px;}

/* FAQ（原生 details 折叠，移动友好） */
.faq-wrap{max-width:780px;}
.faq-item{background:var(--card);border-radius:14px;box-shadow:0 5px 16px rgba(40,55,80,.05);margin-bottom:10px;overflow:hidden;}
.faq-item summary{list-style:none;cursor:pointer;padding:16px 46px 16px 18px;font-size:15.5px;font-weight:700;position:relative;}
.faq-item summary::-webkit-details-marker{display:none;}
.faq-item summary::after{content:"";position:absolute;right:18px;top:50%;width:9px;height:9px;border-right:2px solid var(--faint);border-bottom:2px solid var(--faint);transform:translateY(-65%) rotate(45deg);transition:transform .2s;}
.faq-item[open] summary::after{transform:translateY(-35%) rotate(-135deg);}
.faq-item p{padding:0 18px 16px;font-size:14px;color:var(--muted);}

/* Footer */
footer{padding:32px 0 92px;border-top:1px solid var(--line);text-align:center;color:var(--faint);font-size:13px;}
footer .flinks{display:flex;gap:18px;justify-content:center;margin-bottom:12px;flex-wrap:wrap;}
footer .flinks a{font-weight:600;color:var(--muted);}
@media(min-width:780px){footer{padding-bottom:40px;}}
/* 简单文档页（隐私/支持） */
.doc{background:var(--card);border-radius:var(--radius);padding:30px 22px;box-shadow:0 10px 30px rgba(40,55,80,.07);margin:28px 0;}
.doc h1{font-size:26px;font-weight:800;margin-bottom:8px;}
.doc .upd{color:var(--faint);font-size:13px;margin-bottom:24px;}
.doc h2{font-size:18px;font-weight:800;margin:24px 0 8px;}
.doc p{color:var(--muted);margin-bottom:12px;}
@media(min-width:600px){.doc{padding:42px;margin:40px 0;}.doc h1{font-size:30px;}}

/* toast */
.toast{position:fixed;left:50%;bottom:78px;transform:translateX(-50%) translateY(20px);background:var(--ink);color:#fff;padding:12px 22px;border-radius:13px;font-size:14px;font-weight:600;opacity:0;pointer-events:none;transition:all .25s;z-index:200;max-width:90vw;text-align:center;}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);}

/* 返回顶部按钮 */
.to-top{position:fixed;right:20px;bottom:24px;width:46px;height:46px;border-radius:50%;border:none;background:linear-gradient(135deg,#3D7BFF,#27C4E8);color:#fff;display:grid;place-items:center;cursor:pointer;box-shadow:0 12px 28px rgba(55,130,255,.34);opacity:0;visibility:hidden;transform:translateY(10px);transition:opacity .25s,transform .25s,visibility .25s;z-index:60;}
.to-top.show{opacity:1;visibility:visible;transform:translateY(0);}
.to-top svg{width:22px;height:22px;}
.to-top:active{transform:scale(.94);}
@media(max-width:600px){.to-top{right:14px;bottom:18px;width:42px;height:42px;}}