/* ============================================================
   佰分云教育 · AI未来课堂 官方网站 共享样式
   品牌色系：佰分云橙 #F26A1B / 暖米白 #FBF5EE / 墨色 #1F2430
   ============================================================ */
:root{
  --brand:#F26A1B;
  --brand-dark:#D9570F;
  --brand-soft:#FDE8D7;
  --ink:#1F2430;
  --ink-2:#4B5563;
  --ink-3:#9CA3AF;
  --bg:#FBF5EE;
  --bg-deep:#F6EDE2;
  --card:#FFFFFF;
  --line:#EFE3D5;
  --navy:#1D3A5F;
  --ok:#16A34A;
  --radius:14px;
  --shadow:0 6px 24px rgba(31,36,48,.07);
  --shadow-lg:0 16px 48px rgba(31,36,48,.12);
  --font:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,"Helvetica Neue",sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.7;font-size:16px}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
.container{max-width:1200px;margin:0 auto;padding:0 24px}

/* ---------- 顶部导航 ---------- */
.site-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.96);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:68px}
.brand{display:flex;align-items:center;gap:10px}
.brand-logo{display:flex;align-items:center;flex:none}
.brand-logo img{height:42px;width:auto;display:block}
.brand-name{font-size:18px;font-weight:800;letter-spacing:.5px}
.brand-name small{display:block;font-size:11px;font-weight:600;color:var(--ink-3);letter-spacing:2px}
.nav{display:flex;gap:4px;align-items:center}
.nav a{padding:8px 14px;border-radius:8px;font-size:15px;font-weight:500;color:var(--ink-2);transition:.2s}
.nav a:hover{color:var(--brand);background:var(--brand-soft)}
.nav a.active{color:var(--brand);font-weight:700;background:var(--brand-soft)}
.nav-cta{margin-left:10px;background:var(--brand);color:#fff !important;font-weight:600;padding:9px 18px !important;border-radius:999px}
.nav-cta:hover{background:var(--brand-dark);color:#fff !important}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:8px}
.nav-toggle svg{width:26px;height:26px;stroke:var(--ink)}

/* ---------- Hero ---------- */
.hero{position:relative;background:linear-gradient(120deg,#FFF7EF 0%,#FFE9D6 55%,#FFD9B8 100%);overflow:hidden}
.hero::after{content:"";position:absolute;right:-120px;top:-120px;width:420px;height:420px;border-radius:50%;background:radial-gradient(circle,rgba(242,106,27,.14),transparent 65%)}
.hero-inner{position:relative;z-index:2;display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center;padding-block:72px 64px}
.hero-kicker{display:inline-flex;align-items:center;gap:8px;background:#fff;border:1px solid var(--line);color:var(--brand-dark);font-size:13px;font-weight:700;padding:6px 14px;border-radius:999px;margin-bottom:18px;letter-spacing:.5px}
.hero h1{font-size:clamp(30px,4vw,46px);line-height:1.25;font-weight:900;letter-spacing:-.5px}
.hero h1 em{font-style:normal;color:var(--brand)}
.hero-sub{margin-top:18px;font-size:17px;color:var(--ink-2);max-width:560px}
.hero-actions{display:flex;gap:14px;margin-top:30px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 28px;border-radius:999px;font-size:15px;font-weight:700;transition:.2s;border:none;cursor:pointer}
.btn-primary{background:var(--brand);color:#fff;box-shadow:0 8px 24px rgba(242,106,27,.32)}
.btn-primary:hover{background:var(--brand-dark);transform:translateY(-2px)}
.btn-ghost{background:#fff;color:var(--ink);border:1.5px solid var(--line)}
.btn-ghost:hover{border-color:var(--brand);color:var(--brand)}
.hero-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:44px}
.stat{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px 16px;text-align:center;box-shadow:var(--shadow)}
.stat b{display:block;font-size:26px;font-weight:900;color:var(--brand);line-height:1.2}
.stat span{font-size:13px;color:var(--ink-2)}
.hero-visual{position:relative}
.hero-visual .img-frame{border-radius:20px;overflow:hidden;box-shadow:var(--shadow-lg);border:6px solid #fff}
.hero-visual img{width:100%;height:auto}
.hero-badge{position:absolute;left:-16px;bottom:24px;background:#fff;border-radius:12px;box-shadow:var(--shadow-lg);padding:14px 18px;display:flex;align-items:center;gap:12px;border:1px solid var(--line)}
.hero-badge svg{width:34px;height:34px;flex:none}

/* ---------- 区块通用 ---------- */
.section{padding:72px 0}
.section.bg-white{background:#fff}
.section.bg-deep{background:var(--bg-deep)}
.sec-head{text-align:center;max-width:760px;margin:0 auto 46px}
.sec-tag{display:inline-block;font-size:13px;font-weight:700;color:var(--brand-dark);background:var(--brand-soft);padding:5px 14px;border-radius:999px;letter-spacing:1px;margin-bottom:14px}
.sec-head h2{font-size:clamp(24px,3vw,34px);font-weight:900;letter-spacing:-.3px}
.sec-head p{margin-top:12px;color:var(--ink-2);font-size:16px}
.sec-head .en{display:block;font-size:12px;letter-spacing:3px;color:var(--ink-3);text-transform:uppercase;margin-top:6px}

/* ---------- 能力卡片 ---------- */
.grid{display:grid;gap:22px}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}
.g2{grid-template-columns:repeat(2,1fr)}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;transition:.25s;display:flex;flex-direction:column}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:#F5C9A8}
.card .ic{width:48px;height:48px;border-radius:12px;background:var(--brand-soft);display:flex;align-items:center;justify-content:center;margin-bottom:16px}
.card .ic svg{width:26px;height:26px;stroke:var(--brand)}
.card h3{font-size:18px;font-weight:800;margin-bottom:8px}
.card p{font-size:14.5px;color:var(--ink-2);flex:1}
.card .more{margin-top:14px;font-size:13.5px;font-weight:700;color:var(--brand)}
.card .more svg{width:14px;height:14px;vertical-align:-2px}

/* ---------- 产品卡片（图片） ---------- */
.prod-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:.25s;display:flex;flex-direction:column}
.prod-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.prod-card .pic{aspect-ratio:16/10;overflow:hidden;background:var(--bg-deep)}
.prod-card .pic img{width:100%;height:100%;object-fit:cover;transition:transform .4s}
.prod-card:hover .pic img{transform:scale(1.04)}
.prod-card .body{padding:18px 20px 20px;display:flex;flex-direction:column;flex:1}
.prod-card h3{font-size:16.5px;font-weight:800;margin-bottom:6px}
.prod-card .tag{font-size:12px;color:var(--brand-dark);font-weight:700;background:var(--brand-soft);display:inline-block;padding:2px 10px;border-radius:999px;margin-bottom:8px;align-self:flex-start}
.prod-card p{font-size:13.5px;color:var(--ink-2)}

/* ---------- 流程 / 时间轴 ---------- */
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:0;position:relative}
.step{text-align:center;padding:0 18px;position:relative}
.step .dot{width:52px;height:52px;margin:0 auto 14px;border-radius:50%;background:linear-gradient(135deg,var(--brand),var(--brand-dark));color:#fff;display:flex;align-items:center;justify-content:center;font-weight:900;font-size:18px;box-shadow:0 8px 20px rgba(242,106,27,.3)}
.step h4{font-size:16px;font-weight:800;margin-bottom:6px}
.step p{font-size:13.5px;color:var(--ink-2)}
.timeline{position:relative;padding-left:0;max-width:980px;margin:0 auto}
.tl-item{display:grid;grid-template-columns:150px 1fr;gap:20px;padding:20px 0;border-bottom:1px dashed var(--line)}
.tl-item:last-child{border-bottom:none}
.tl-year{font-weight:900;font-size:18px;color:var(--brand)}
.tl-year small{display:block;font-size:12px;color:var(--ink-3);font-weight:600}
.tl-body h4{font-size:16.5px;font-weight:800;margin-bottom:6px}
.tl-body p{font-size:14px;color:var(--ink-2)}

/* ---------- 对比 / 特性列表 ---------- */
.feature-row{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.feat{border-left:3px solid var(--brand);padding:4px 0 4px 16px}
.feat h4{font-size:16px;font-weight:800;margin-bottom:4px}
.feat p{font-size:13.5px;color:var(--ink-2)}

/* ---------- 政策/研究 ---------- */
.policy-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px}
.policy-card .num{font-size:34px;font-weight:900;color:var(--brand);line-height:1}
.policy-card h3{font-size:17px;font-weight:800;margin:10px 0 8px}
.policy-card p{font-size:14px;color:var(--ink-2)}

/* ---------- FAQ ---------- */
.faq-wrap{max-width:820px;margin:0 auto}
.faq-item{background:#fff;border:1px solid var(--line);border-radius:12px;margin-bottom:12px;overflow:hidden}
.faq-item summary{list-style:none;cursor:pointer;padding:18px 22px;font-weight:700;font-size:15.5px;display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:"+";font-size:22px;color:var(--brand);font-weight:400;flex:none;transition:.2s}
.faq-item[open] summary::after{transform:rotate(45deg)}
.faq-item .faq-a{display:none;padding:0 22px 18px;color:var(--ink-2);font-size:14.5px}
.faq-item.open .faq-a{display:block}

/* ---------- 省份/数据条 ---------- */
.data-band{background:var(--navy);color:#fff;padding:56px 0}
.data-band .grid{grid-template-columns:repeat(4,1fr)}
.data-item{text-align:center}
.data-item b{font-size:34px;font-weight:900;color:#FFB37C;display:block}
.data-item span{font-size:14px;opacity:.85}

/* ---------- CTA ---------- */
.cta-band{background:linear-gradient(120deg,var(--brand),var(--brand-dark));color:#fff;text-align:center;padding:64px 24px;border-radius:24px;position:relative;overflow:hidden}
.cta-band h2{font-size:clamp(24px,3vw,34px);font-weight:900}
.cta-band p{margin:12px auto 28px;max-width:560px;opacity:.95}
.cta-band .btn-primary{background:#fff;color:var(--brand-dark)}
.cta-band .btn-ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.6)}
.cta-band .btn-ghost:hover{border-color:#fff}

/* ---------- 页脚 ---------- */
.site-footer{background:#171C26;color:#C7CDD8;padding:56px 0 24px;margin-top:0}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr 1fr;gap:36px;padding-bottom:36px;border-bottom:1px solid rgba(255,255,255,.1)}
.footer-grid h4{color:#fff;font-size:15px;font-weight:700;margin-bottom:14px}
.footer-grid a{display:block;font-size:14px;color:#AEB6C4;padding:5px 0;transition:.2s}
.footer-grid a:hover{color:#fff}
.footer-brand p{font-size:13.5px;color:#8B93A5;margin-top:12px;max-width:300px}
.footer-seo{font-size:12px;color:#5F677A;line-height:2;padding:22px 0 0;text-align:center}
.footer-copy{text-align:center;font-size:13px;color:#7A8294;padding-top:18px}

/* ---------- 面包屑 ---------- */
.breadcrumb{font-size:13.5px;color:var(--ink-3);padding:18px 0 0}
.breadcrumb a{color:var(--brand)}
.breadcrumb span{margin:0 8px}

/* ---------- 页头横幅 ---------- */
.page-hero{background:linear-gradient(120deg,#FFF7EF,#FFE3C8);padding:52px 0 44px;border-bottom:1px solid var(--line)}
.page-hero h1{font-size:clamp(26px,3.4vw,38px);font-weight:900;letter-spacing:-.3px}
.page-hero .sub{margin-top:10px;color:var(--ink-2);max-width:720px;font-size:15.5px}

/* ---------- 响应式 ---------- */
@media (max-width:992px){
  .hero-inner{grid-template-columns:1fr;padding:48px 0 40px}
  .hero-stats{grid-template-columns:repeat(2,1fr)}
  .g4{grid-template-columns:repeat(2,1fr)}
  .g3{grid-template-columns:repeat(2,1fr)}
  .feature-row{grid-template-columns:1fr 1fr}
  .steps{grid-template-columns:repeat(2,1fr);gap:24px 0}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:640px){
  .nav{display:none;position:absolute;top:68px;left:0;right:0;background:#fff;flex-direction:column;padding:16px 24px;border-bottom:1px solid var(--line);box-shadow:var(--shadow)}
  .nav.open{display:flex}
  .nav a{width:100%;padding:12px 8px}
  .nav-cta{margin:8px 0 0;text-align:center}
  .nav-toggle{display:block}
  .card .more,.prod-card .more{display:inline-block;min-height:44px;line-height:44px}
  .btn{min-height:48px}
  .g3,.g4,.g2{grid-template-columns:1fr}
  .feature-row{grid-template-columns:1fr}
  .steps{grid-template-columns:1fr}
  .tl-item{grid-template-columns:1fr;gap:6px}
  .data-band .grid{grid-template-columns:repeat(2,1fr);gap:28px}
  .section{padding:52px 0}
}

/* ---------- 平台入口 ---------- */
.platform-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.platform-card{display:flex;flex-direction:column;gap:8px;background:#fff;border:1px solid var(--line);border-radius:16px;padding:30px 28px;transition:.25s;text-decoration:none}
.platform-card:hover{border-color:var(--brand);transform:translateY(-4px);box-shadow:0 12px 30px rgba(242,106,27,.12)}
.pf-icon{width:52px;height:52px;border-radius:14px;background:linear-gradient(135deg,var(--brand),var(--brand-dark));color:#fff;display:flex;align-items:center;justify-content:center;margin-bottom:6px}
.pf-icon svg{width:26px;height:26px}
.platform-card strong{font-size:17px;color:var(--ink);font-weight:800}
.pf-url{font-size:14px;color:var(--brand);font-weight:700;letter-spacing:.5px}
.pf-go{font-size:13.5px;color:var(--ink-3);margin-top:8px;transition:.2s}
.platform-card:hover .pf-go{color:var(--brand)}
@media(max-width:640px){.platform-grid{grid-template-columns:1fr}}