/* ==========================================================================
   CloseAI — 企业级 AI API 中转站官网样式
   纯 CSS，无任何 JS 依赖。移动端 / 平板 / 桌面自适应。
   ========================================================================== */

/* ---------- 设计令牌 ---------- */
:root{
  --bg:            #070A12;
  --bg-alt:        #0A0F1C;
  --surface:       rgba(255,255,255,.035);
  --surface-2:     rgba(255,255,255,.055);
  --line:          rgba(255,255,255,.09);
  --line-strong:   rgba(255,255,255,.16);

  --text:          #E9EDF8;
  --text-soft:     #A7B0C6;
  --text-dim:      #78829C;

  --brand-1:       #8FB0FF;
  --brand-2:       #7C6BFF;
  --brand-3:       #C77DFF;
  --accent:        #FF9166;

  --grad-brand:    linear-gradient(120deg,var(--brand-1),var(--brand-2) 55%,var(--brand-3));
  --grad-text:     linear-gradient(100deg,#FFFFFF 15%,#C9D4F5 60%,#B8A6FF);

  --radius:        18px;
  --radius-sm:     12px;
  --shadow:        0 18px 50px -22px rgba(0,0,0,.85);
  --shadow-lg:     0 40px 90px -40px rgba(70,60,180,.65);

  --wrap:          1200px;
  --pad:           clamp(20px,5vw,40px);
  --sec-y:         clamp(64px,9vw,120px);

  --font: "Inter","HarmonyOS Sans SC","PingFang SC","Hiragino Sans GB",
          "Microsoft YaHei","Noto Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  --mono: "JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;
}

/* ---------- 基础重置 ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:88px;
}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--font);
  font-size:clamp(15px,.42vw + 14px,17px);
  line-height:1.78;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
/* 页面底纹：细网格 + 顶部光晕 */
body::before{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:
    radial-gradient(900px 480px at 50% -12%,rgba(124,107,255,.20),transparent 70%),
    radial-gradient(700px 400px at 88% 8%,rgba(199,125,255,.12),transparent 70%),
    linear-gradient(rgba(255,255,255,.022) 1px,transparent 1px) 0 0/64px 64px,
    linear-gradient(90deg,rgba(255,255,255,.022) 1px,transparent 1px) 0 0/64px 64px;
}
img,svg{max-width:100%;display:block;}
h1,h2,h3,h4{margin:0;line-height:1.28;letter-spacing:-.01em;font-weight:700;}
p{margin:0;}
a{color:inherit;text-decoration:none;transition:color .2s ease,opacity .2s ease;}
ul{margin:0;padding:0;list-style:none;}
code{font-family:var(--mono);font-size:.92em;}
strong,b{color:#fff;font-weight:650;}

.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0;}
.skip-link{
  position:absolute;left:-9999px;top:0;z-index:999;
  background:var(--brand-2);color:#fff;padding:10px 18px;border-radius:0 0 10px 0;
}
.skip-link:focus{left:0;}
:focus-visible{outline:2px solid var(--brand-1);outline-offset:3px;border-radius:6px;}

/* ---------- 布局容器 ---------- */
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--pad);}
.narrow{max-width:860px;}
.center{text-align:center;}
.section{padding-block:var(--sec-y);position:relative;}
.section.alt{background:
  linear-gradient(180deg,transparent,rgba(255,255,255,.022) 18%,rgba(255,255,255,.022) 82%,transparent);
  border-block:1px solid var(--line);
}

/* ---------- 顶部导航 ---------- */
.site-header{
  position:sticky;top:0;z-index:80;
  background:rgba(7,10,18,.72);
  backdrop-filter:saturate(160%) blur(16px);
  -webkit-backdrop-filter:saturate(160%) blur(16px);
  border-bottom:1px solid var(--line);
}
.nav{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:68px;}
.brand{display:inline-flex;align-items:center;gap:11px;}
.brand-mark{border-radius:10px;box-shadow:0 6px 18px -8px rgba(124,107,255,.9);flex:none;}
.brand-text{
  font-size:21px;font-weight:800;letter-spacing:-.02em;
  background:var(--grad-text);-webkit-background-clip:text;background-clip:text;color:transparent;
}
.nav-links{display:flex;align-items:center;gap:clamp(14px,1.6vw,28px);}
.nav-links a{color:var(--text-soft);font-size:15px;font-weight:500;white-space:nowrap;}
.nav-links a:hover{color:#fff;}
.nav-burger{display:none;}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 24px;border-radius:999px;
  font-size:15px;font-weight:600;white-space:nowrap;
  border:1px solid var(--line-strong);
  transition:transform .22s cubic-bezier(.2,.7,.3,1),box-shadow .22s ease,background .22s ease,border-color .22s ease;
}
.btn:hover{transform:translateY(-2px);}
.btn-primary{
  background:var(--grad-brand);border-color:transparent;color:#0B0716;font-weight:700;
  box-shadow:0 14px 34px -14px rgba(124,107,255,.9);
}
.btn-primary:hover{box-shadow:0 20px 44px -14px rgba(124,107,255,1);}
.btn-ghost{background:var(--surface);color:var(--text);}
.btn-ghost:hover{background:var(--surface-2);border-color:var(--line-strong);}
.btn-sm{padding:9px 18px;font-size:14px;}
.btn.lg{padding:16px 36px;font-size:17px;}
.btn.full{width:100%;margin-top:auto;}
.nav-links .btn{background:var(--surface);color:#fff;}
.nav-links .btn:hover{background:var(--surface-2);}

/* ---------- 首屏 ---------- */
.hero{position:relative;padding-block:clamp(64px,11vw,132px) clamp(56px,8vw,104px);overflow:hidden;}
.glow{position:absolute;border-radius:50%;filter:blur(90px);opacity:.5;pointer-events:none;}
.glow-a{width:min(620px,85vw);height:min(620px,85vw);left:-14%;top:-24%;background:radial-gradient(circle,rgba(124,107,255,.55),transparent 66%);}
.glow-b{width:min(560px,80vw);height:min(560px,80vw);right:-12%;top:2%;background:radial-gradient(circle,rgba(255,145,102,.30),transparent 66%);}
.hero-inner{position:relative;z-index:1;}
.hero-inner h1{max-width:16ch;}

.eyebrow{
  display:inline-flex;align-items:center;gap:9px;
  padding:7px 16px 7px 12px;margin-bottom:26px;
  border:1px solid var(--line-strong);border-radius:999px;
  background:var(--surface);color:var(--text-soft);
  font-size:13.5px;letter-spacing:.02em;
}
.eyebrow .dot{width:7px;height:7px;border-radius:50%;background:#54E3A5;box-shadow:0 0 0 4px rgba(84,227,165,.16);flex:none;}

h1{font-size:clamp(38px,7.2vw,76px);font-weight:800;letter-spacing:-.035em;line-height:1.06;}
h1 .h1-sub{
  display:block;margin-top:14px;
  font-size:clamp(19px,3vw,34px);font-weight:700;letter-spacing:-.015em;
  background:var(--grad-text);-webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero-sub{margin-top:26px;font-size:clamp(16px,1.5vw,20px);color:var(--text-soft);max-width:62ch;}
.hero-sub code{
  background:var(--surface-2);border:1px solid var(--line);
  padding:2px 8px;border-radius:7px;color:var(--brand-1);
}
.hero-desc{margin-top:16px;font-size:clamp(14.5px,1.1vw,16.5px);color:var(--text-dim);max-width:66ch;}

.cta-row{display:flex;flex-wrap:wrap;gap:14px;margin-top:36px;}

.stat-strip{
  display:grid;grid-template-columns:repeat(4,1fr);gap:1px;
  margin-top:52px;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;background:var(--line);
}
.stat-strip li{
  background:rgba(10,14,26,.85);padding:22px 18px;text-align:center;
}
.stat-strip b{
  display:block;font-size:clamp(22px,2.6vw,30px);font-weight:800;letter-spacing:-.02em;
  background:var(--grad-brand);-webkit-background-clip:text;background-clip:text;color:transparent;
}
.stat-strip span{display:block;margin-top:4px;font-size:13px;color:var(--text-dim);}

.trust{margin-top:26px;font-size:14px;color:var(--text-dim);}
.trust b{color:var(--text-soft);font-weight:600;}

/* ---------- 区块标题 ---------- */
.sec-title{
  font-size:clamp(26px,3.6vw,44px);letter-spacing:-.025em;
  background:var(--grad-text);-webkit-background-clip:text;background-clip:text;color:transparent;
}
.sec-lead{margin-top:16px;color:var(--text-soft);font-size:clamp(15px,1.2vw,17.5px);max-width:70ch;}
.sec-lead.center{margin-inline:auto;}
.sec-title.center + .sec-lead{margin-bottom:8px;}
.note{margin-top:28px;font-size:13.5px;color:var(--text-dim);}
.note a{color:var(--brand-1);text-decoration:underline;text-underline-offset:3px;}

/* ---------- 卡片网格 ---------- */
.grid{display:grid;gap:clamp(16px,1.8vw,24px);margin-top:44px;}
.grid-3{grid-template-columns:repeat(auto-fit,minmax(300px,1fr));}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(380px,1fr));}

.card{
  position:relative;display:flex;flex-direction:column;
  padding:clamp(22px,2.4vw,30px);
  background:linear-gradient(180deg,rgba(255,255,255,.05),rgba(255,255,255,.02));
  border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);
  transition:transform .3s cubic-bezier(.2,.7,.3,1),border-color .3s ease,box-shadow .3s ease;
}
.card::before{
  content:"";position:absolute;inset:0;border-radius:inherit;padding:1px;
  background:linear-gradient(140deg,rgba(143,176,255,.5),transparent 42%,transparent 62%,rgba(199,125,255,.35));
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);
          mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);
  -webkit-mask-composite:xor;mask-composite:exclude;
  opacity:0;transition:opacity .3s ease;pointer-events:none;
}
.card:hover{transform:translateY(-5px);border-color:var(--line-strong);box-shadow:var(--shadow-lg);}
.card:hover::before{opacity:1;}
.card h3{font-size:clamp(17px,1.5vw,20px);margin-bottom:12px;}
.card p{color:var(--text-soft);font-size:15px;}

.ico{
  width:46px;height:46px;border-radius:13px;margin-bottom:18px;
  display:grid;place-items:center;
  background:linear-gradient(140deg,rgba(143,176,255,.20),rgba(199,125,255,.14));
  border:1px solid var(--line-strong);
}
.ico svg{width:22px;height:22px;fill:none;stroke:var(--brand-1);stroke-width:1.7;}

/* ---------- 模型卡 ---------- */
.model-card{padding-top:26px;}
.model-card h3{display:flex;align-items:center;flex-wrap:wrap;gap:10px;}
.tag{
  font-size:11.5px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;
  padding:4px 10px;border-radius:999px;
  background:var(--surface-2);border:1px solid var(--line-strong);color:var(--text-soft);
}
.accent-claude .tag{color:#FFB08C;border-color:rgba(255,145,102,.45);background:rgba(255,145,102,.12);}
.accent-openai .tag{color:#7CE0C0;border-color:rgba(84,227,165,.42);background:rgba(84,227,165,.12);}
.accent-gemini .tag{color:#9DBBFF;border-color:rgba(143,176,255,.45);background:rgba(143,176,255,.12);}
.accent-cn    .tag{color:#D6AEFF;border-color:rgba(199,125,255,.45);background:rgba(199,125,255,.12);}

.chip-list{display:flex;flex-wrap:wrap;gap:8px;margin-top:20px;}
.chip-list li{
  font-size:13px;color:var(--text-soft);
  padding:6px 13px;border-radius:999px;
  background:var(--surface);border:1px solid var(--line);
}

/* ---------- 代码卡 ---------- */
.code-grid{align-items:stretch;}
.code-card{gap:0;}
.code-desc{font-size:14px;color:var(--text-dim);margin-bottom:16px;}
.code-card pre{
  margin:0;padding:18px;border-radius:var(--radius-sm);
  background:#05070E;border:1px solid var(--line);
  overflow-x:auto;
  font-size:13px;line-height:1.75;
  -webkit-overflow-scrolling:touch;
}
.code-card pre code{color:#B9C6EC;white-space:pre;}
/* 暗色细滚动条，避免默认白色滚动条破坏暗色调 */
.code-card pre,.table-scroll{scrollbar-width:thin;scrollbar-color:rgba(143,176,255,.34) transparent;}
.code-card pre::-webkit-scrollbar,.table-scroll::-webkit-scrollbar{height:7px;width:7px;}
.code-card pre::-webkit-scrollbar-track,.table-scroll::-webkit-scrollbar-track{background:transparent;}
.code-card pre::-webkit-scrollbar-thumb,.table-scroll::-webkit-scrollbar-thumb{
  background:rgba(143,176,255,.28);border-radius:99px;
}
.code-card pre::-webkit-scrollbar-thumb:hover,.table-scroll::-webkit-scrollbar-thumb:hover{background:rgba(143,176,255,.5);}
.code-tip{margin-top:16px;font-size:13px;color:var(--text-dim);}
.code-tip code,.faq-body code,.code-desc code{
  background:var(--surface-2);border:1px solid var(--line);
  padding:1px 6px;border-radius:6px;color:var(--brand-1);
}

/* ---------- 价格卡 ---------- */
.price-card{padding-top:32px;}
.price-card.featured{
  background:linear-gradient(180deg,rgba(124,107,255,.14),rgba(255,255,255,.02));
  border-color:rgba(143,176,255,.34);
  box-shadow:0 30px 70px -34px rgba(124,107,255,.75);
}
.badge{
  position:absolute;top:-13px;left:50%;transform:translateX(-50%);
  padding:5px 15px;border-radius:999px;white-space:nowrap;
  background:var(--grad-brand);color:#0B0716;
  font-size:12px;font-weight:800;letter-spacing:.03em;
}
.price{margin-top:14px;display:flex;align-items:baseline;gap:8px;flex-wrap:wrap;}
.price b{
  font-size:clamp(38px,4.6vw,54px);font-weight:800;letter-spacing:-.04em;line-height:1;
  background:var(--grad-brand);-webkit-background-clip:text;background-clip:text;color:transparent;
}
.price span{font-size:14px;color:var(--text-dim);}
.price-note{margin-top:8px;font-size:13.5px;color:var(--text-dim);}
.tick-list{margin:22px 0 26px;display:grid;gap:11px;}
.tick-list li{
  position:relative;padding-left:26px;font-size:14.5px;color:var(--text-soft);line-height:1.6;
}
.tick-list li::before{
  content:"";position:absolute;left:0;top:.52em;
  width:15px;height:8px;border-left:2px solid var(--brand-1);border-bottom:2px solid var(--brand-1);
  transform:rotate(-45deg) translateY(-2px);border-radius:1px;
}
.tick-list b{color:#fff;}

/* ---------- 对比表 ---------- */
.table-scroll{
  margin-top:44px;overflow-x:auto;-webkit-overflow-scrolling:touch;
  border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(180deg,rgba(255,255,255,.045),rgba(255,255,255,.015));
}
table.cmp{width:100%;min-width:720px;border-collapse:collapse;font-size:14.5px;}
table.cmp th,table.cmp td{padding:16px 20px;text-align:left;border-bottom:1px solid var(--line);}
table.cmp thead th{
  font-size:13px;letter-spacing:.05em;color:var(--text-dim);font-weight:600;
  background:rgba(255,255,255,.03);white-space:nowrap;
}
table.cmp tbody th{color:var(--text);font-weight:600;white-space:nowrap;}
table.cmp td{color:var(--text-dim);}
table.cmp tbody tr:last-child th,table.cmp tbody tr:last-child td{border-bottom:0;}
table.cmp .hl{color:#fff;font-weight:600;background:rgba(124,107,255,.10);}
table.cmp thead .hl{color:var(--brand-1);background:rgba(124,107,255,.16);}
table.cmp tbody tr:hover td,table.cmp tbody tr:hover th{background:rgba(255,255,255,.022);}
table.cmp tbody tr:hover .hl{background:rgba(124,107,255,.16);}

/* ---------- 场景卡 ---------- */
.scene h3{
  padding-left:16px;position:relative;
}
.scene h3::before{
  content:"";position:absolute;left:0;top:.24em;bottom:.24em;width:3px;border-radius:3px;
  background:var(--grad-brand);
}

/* ---------- FAQ ---------- */
.faq{
  margin-top:14px;border:1px solid var(--line);border-radius:var(--radius-sm);
  background:linear-gradient(180deg,rgba(255,255,255,.042),rgba(255,255,255,.015));
  overflow:hidden;transition:border-color .25s ease;
}
.faq:hover{border-color:var(--line-strong);}
.faq summary{
  cursor:pointer;list-style:none;
  padding:19px 56px 19px 22px;position:relative;
  font-size:16px;font-weight:600;color:var(--text);
}
.faq summary::-webkit-details-marker{display:none;}
.faq summary::after{
  content:"";position:absolute;right:24px;top:50%;
  width:9px;height:9px;margin-top:-6px;
  border-right:2px solid var(--text-dim);border-bottom:2px solid var(--text-dim);
  transform:rotate(45deg);transition:transform .25s ease,border-color .25s ease;
}
.faq[open] summary::after{transform:rotate(-135deg);margin-top:-2px;border-color:var(--brand-1);}
.faq[open] summary{color:#fff;}
.faq-body{padding:0 22px 22px;color:var(--text-soft);font-size:15px;border-top:1px solid var(--line);padding-top:18px;}
.faq-body p{color:var(--text-soft);}

/* ---------- 底部 CTA ---------- */
.cta-band{
  position:relative;overflow:hidden;
  padding-block:clamp(60px,8vw,104px);
  border-top:1px solid var(--line);
  background:
    radial-gradient(760px 320px at 50% 118%,rgba(124,107,255,.32),transparent 70%),
    linear-gradient(180deg,rgba(255,255,255,.02),transparent);
}
.cta-band h2{font-size:clamp(24px,3.4vw,40px);letter-spacing:-.025em;}
.cta-band p{margin-top:16px;color:var(--text-soft);}
.cta-band .btn{margin-top:32px;}

/* ---------- 页脚 ---------- */
.site-footer{border-top:1px solid var(--line);background:var(--bg-alt);padding-top:clamp(48px,6vw,72px);}
.foot-grid{
  display:grid;gap:clamp(28px,3vw,40px);
  grid-template-columns:1.6fr repeat(3,1fr);
}
.foot-brand p{margin-top:16px;color:var(--text-dim);font-size:14px;max-width:38ch;}
.foot-col h3{font-size:14px;color:var(--text);margin-bottom:14px;letter-spacing:.02em;}
.foot-col{display:flex;flex-direction:column;gap:11px;}
.foot-col a{color:var(--text-dim);font-size:14px;}
.foot-col a:hover{color:var(--brand-1);}
.foot-bottom{
  margin-top:clamp(36px,4vw,56px);padding-block:24px;
  border-top:1px solid var(--line);
}
.foot-bottom p{font-size:13px;color:var(--text-dim);}
.foot-bottom a{color:var(--brand-1);}
.disclaim{margin-top:8px !important;font-size:12.5px !important;color:#5C6580 !important;line-height:1.7;}

/* ==========================================================================
   响应式
   ========================================================================== */

/* 平板 */
@media (max-width:900px){
  .foot-grid{grid-template-columns:1fr 1fr;}
  .foot-brand{grid-column:1 / -1;}
  .stat-strip{grid-template-columns:repeat(2,1fr);}
}

/* 移动端导航（纯 CSS 汉堡菜单） */
@media (max-width:860px){
  html{scroll-padding-top:76px;}
  .nav{flex-wrap:wrap;min-height:62px;}
  .nav-burger{
    display:flex;flex-direction:column;justify-content:center;gap:5px;
    width:42px;height:42px;padding:0 9px;cursor:pointer;
    border:1px solid var(--line-strong);border-radius:11px;background:var(--surface);
  }
  .nav-burger span{
    display:block;height:2px;width:100%;border-radius:2px;background:var(--text-soft);
    transition:transform .28s ease,opacity .22s ease;
  }
  .nav-links{
    flex-basis:100%;flex-direction:column;align-items:stretch;gap:0;
    max-height:0;overflow:hidden;
    transition:max-height .38s cubic-bezier(.2,.7,.3,1);
  }
  .nav-links a{padding:13px 2px;font-size:15.5px;border-top:1px solid var(--line);}
  .nav-links .btn{
    margin:16px 0 18px;justify-content:center;border-top:1px solid var(--line-strong);
    background:var(--grad-brand);color:#0B0716;font-weight:700;
  }
  .nav-toggle:checked ~ .nav-links{max-height:520px;}
  .nav-toggle:checked ~ .nav-burger span:nth-child(1){transform:translateY(7px) rotate(45deg);}
  .nav-toggle:checked ~ .nav-burger span:nth-child(2){opacity:0;}
  .nav-toggle:checked ~ .nav-burger span:nth-child(3){transform:translateY(-7px) rotate(-45deg);}
}

/* 手机 */
@media (max-width:560px){
  :root{--radius:15px;}
  .grid-2,.grid-3{grid-template-columns:1fr;}
  .cta-row{flex-direction:column;align-items:stretch;}
  .cta-row .btn{width:100%;}
  .stat-strip li{padding:18px 10px;}
  .stat-strip span{font-size:12px;}
  .hero-sub br{display:none;}
  .faq summary{font-size:15px;padding:17px 46px 17px 18px;}
  .faq summary::after{right:18px;}
  .faq-body{padding-inline:18px;}
  .code-card pre{font-size:12.2px;padding:15px;}
  .foot-grid{grid-template-columns:1fr;}
  .price b{font-size:40px;}
}

/* 大屏 */
@media (min-width:1500px){
  :root{--wrap:1280px;}
}

/* 降低动效偏好 */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{animation-duration:.001ms !important;transition-duration:.001ms !important;}
  .card:hover,.btn:hover{transform:none;}
}

/* 打印 */
@media print{
  body{background:#fff;color:#000;}
  body::before,.glow,.site-header,.cta-band,.nav-burger{display:none !important;}
  .card,.faq{border:1px solid #ccc;box-shadow:none;background:#fff;}
  .sec-title,.brand-text,h1 .h1-sub,.price b,.stat-strip b{
    -webkit-text-fill-color:#000;color:#000;background:none;
  }
  a{color:#000;text-decoration:underline;}
  .faq-body{display:block !important;}
}