/* =========================================================
   深度AI线下教培系统 — 主样式
   ========================================================= */

:root{
  --ink:#0a1124;
  --ink-2:#151d33;
  --navy:#0b1430;
  --navy-soft:#111c3d;
  --brand:#2b5cff;
  --brand-2:#5b8cff;
  --cyan:#19d3c5;
  --violet:#7c5cff;
  --text:#101828;
  --text-2:#4a5568;
  --text-3:#7b869c;
  --line:#e4e9f2;
  --bg:#f5f7fb;
  --bg-2:#eef2f9;
  --white:#fff;
  --radius:18px;
  --radius-sm:12px;
  --radius-lg:28px;
  --shadow-sm:0 2px 8px rgba(16,24,40,.05);
  --shadow:0 12px 34px -12px rgba(16,24,40,.16);
  --shadow-lg:0 32px 70px -28px rgba(11,20,48,.34);
  --max:1200px;
  --ease:cubic-bezier(.22,.68,.28,1);
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  font-family:system-ui,-apple-system,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  color:var(--text);
  background:var(--bg);
  line-height:1.75;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{margin:0;line-height:1.25;font-weight:700;letter-spacing:-.01em}
p{margin:0}
ul{margin:0;padding:0;list-style:none}
button{font:inherit;cursor:pointer;border:0;background:none;color:inherit}
::selection{background:rgba(43,92,255,.18)}

/* ---------- 布局工具 ---------- */
.wrap{width:100%;max-width:var(--max);margin:0 auto;padding:0 24px}
.section{padding:96px 0}
.section--tight{padding:64px 0}
.section--bg{background:var(--white)}
.section--dark{background:var(--navy);color:#e8edfa}
.section--dark .sec-desc{color:#a9b6d4}
.center{text-align:center}

.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:13px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:var(--brand);margin-bottom:18px;
}
.eyebrow::before{content:"";width:22px;height:2px;background:linear-gradient(90deg,var(--brand),var(--cyan));border-radius:2px}
.section--dark .eyebrow{color:var(--cyan)}

.sec-title{font-size:clamp(28px,3.6vw,44px);letter-spacing:-.02em}
.sec-desc{margin-top:18px;color:var(--text-2);font-size:17px;max-width:680px;line-height:1.85}
.center .sec-desc{margin-left:auto;margin-right:auto}

.grad-text{
  background:linear-gradient(100deg,#2b5cff 0%,#19d3c5 58%,#7c5cff 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:13px 26px;border-radius:999px;font-size:15px;font-weight:600;
  transition:transform .3s var(--ease),box-shadow .3s var(--ease),background .3s,color .3s,border-color .3s;
  white-space:nowrap;
}
.btn svg{width:16px;height:16px;flex:none}
.btn--primary{background:linear-gradient(120deg,var(--brand),#4a7bff);color:#fff;box-shadow:0 10px 26px -10px rgba(43,92,255,.75)}
.btn--primary:hover{transform:translateY(-2px);box-shadow:0 16px 34px -12px rgba(43,92,255,.85)}
.btn--ghost{border:1px solid rgba(255,255,255,.28);color:#fff;background:rgba(255,255,255,.06);backdrop-filter:blur(8px)}
.btn--ghost:hover{background:rgba(255,255,255,.14);transform:translateY(-2px)}
.btn--outline{border:1px solid var(--line);color:var(--text);background:#fff}
.btn--outline:hover{border-color:var(--brand);color:var(--brand);transform:translateY(-2px)}
.btn--sm{padding:10px 20px;font-size:14px}

/* ---------- 顶部导航 ---------- */
.header{
  position:fixed;inset:0 0 auto 0;z-index:100;
  transition:background .35s var(--ease),box-shadow .35s var(--ease),border-color .35s;
  border-bottom:1px solid transparent;
}
.header.is-solid{
  background:rgba(255,255,255,.88);
  backdrop-filter:saturate(180%) blur(18px);
  -webkit-backdrop-filter:saturate(180%) blur(18px);
  border-bottom-color:rgba(16,24,40,.08);
  box-shadow:0 6px 24px -18px rgba(16,24,40,.5);
}
.header__inner{display:flex;align-items:center;gap:28px;height:72px}
.logo{display:flex;align-items:center;gap:11px;font-weight:700;font-size:17px;letter-spacing:-.01em;color:#fff;transition:color .3s}
.header.is-solid .logo{color:var(--text)}
.logo__mark{
  width:36px;height:36px;border-radius:11px;flex:none;
  background:linear-gradient(135deg,var(--brand),var(--cyan));
  display:grid;place-items:center;color:#fff;font-size:15px;font-weight:800;
  box-shadow:0 6px 16px -6px rgba(43,92,255,.8);
}
.logo__txt small{display:block;font-size:10px;font-weight:600;letter-spacing:.22em;opacity:.6;line-height:1.4}
.nav{display:flex;align-items:center;gap:4px;margin-left:auto}
.nav a{
  padding:9px 14px;border-radius:10px;font-size:14.5px;font-weight:500;
  color:rgba(255,255,255,.82);transition:color .25s,background .25s;
}
.header.is-solid .nav a{color:var(--text-2)}
.nav a:hover{color:#fff;background:rgba(255,255,255,.1)}
.header.is-solid .nav a:hover{color:var(--brand);background:rgba(43,92,255,.07)}
.nav a.is-active{color:#fff}
.header.is-solid .nav a.is-active{color:var(--brand);background:rgba(43,92,255,.09)}
.header__cta{margin-left:8px}
.header__cta .btn{padding:10px 20px;font-size:14px}
.burger{display:none;width:42px;height:42px;border-radius:11px;place-items:center;margin-left:auto;color:#fff}
.header.is-solid .burger{color:var(--text)}
.burger span{display:block;width:19px;height:2px;background:currentColor;border-radius:2px;position:relative}
.burger span::before,.burger span::after{content:"";position:absolute;left:0;width:19px;height:2px;background:currentColor;border-radius:2px;transition:.3s var(--ease)}
.burger span::before{top:-6px}
.burger span::after{top:6px}
body.nav-open .burger span{background:transparent}
body.nav-open .burger span::before{top:0;transform:rotate(45deg)}
body.nav-open .burger span::after{top:0;transform:rotate(-45deg)}

/* 移动端抽屉 */
.drawer{
  position:fixed;inset:72px 0 auto 0;z-index:99;
  background:#fff;border-bottom:1px solid var(--line);
  padding:12px 24px 26px;display:none;
  box-shadow:0 30px 40px -30px rgba(16,24,40,.5);
}
.drawer a{display:block;padding:13px 6px;font-size:16px;font-weight:500;border-bottom:1px solid #f0f3f8;color:var(--text)}
.drawer a:last-of-type{border-bottom:0}
.drawer .btn{margin-top:16px;width:100%}
body.nav-open .drawer{display:block;animation:slideDown .3s var(--ease)}
@keyframes slideDown{from{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:none}}

/* ---------- 首页 Hero ---------- */
.hero{
  position:relative;min-height:100vh;display:flex;align-items:center;
  padding:130px 0 90px;color:#fff;overflow:hidden;background:var(--navy);
}
.hero__bg{position:absolute;inset:0;z-index:0}
.hero__bg img{width:100%;height:100%;object-fit:cover;opacity:.55;transform:scale(1.04)}
.hero__bg::after{
  content:"";position:absolute;inset:0;
  background:
    radial-gradient(900px 520px at 12% 18%,rgba(43,92,255,.5),transparent 62%),
    radial-gradient(760px 460px at 88% 78%,rgba(25,211,197,.26),transparent 60%),
    linear-gradient(180deg,rgba(7,12,28,.82) 0%,rgba(7,12,28,.68) 45%,rgba(7,12,28,.94) 100%);
}
.hero__grid{
  position:absolute;inset:0;z-index:1;opacity:.16;
  background-image:linear-gradient(rgba(255,255,255,.14) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.14) 1px,transparent 1px);
  background-size:64px 64px;
  mask-image:radial-gradient(circle at 50% 40%,#000 10%,transparent 72%);
  -webkit-mask-image:radial-gradient(circle at 50% 40%,#000 10%,transparent 72%);
}
.hero .wrap{position:relative;z-index:2}
.hero__inner{max-width:860px}
.hero__badge{
  display:inline-flex;align-items:center;gap:9px;padding:7px 16px 7px 9px;border-radius:999px;
  background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);
  font-size:13.5px;font-weight:500;color:#dbe4ff;backdrop-filter:blur(10px);margin-bottom:28px;
}
.hero__badge b{
  display:inline-flex;align-items:center;padding:3px 9px;border-radius:999px;
  background:linear-gradient(120deg,var(--brand),var(--cyan));font-size:11.5px;font-weight:700;color:#fff;letter-spacing:.04em;
}
.hero h1{
  font-size:clamp(36px,5.4vw,68px);line-height:1.12;letter-spacing:-.03em;font-weight:800;
}
.hero h1 em{font-style:normal;display:block}
.hero__sub{
  margin-top:26px;font-size:clamp(15.5px,1.5vw,18.5px);line-height:1.9;color:#c3cee8;max-width:680px;
}
.hero__sub strong{color:#fff;font-weight:600}
.hero__actions{display:flex;flex-wrap:wrap;gap:14px;margin-top:40px}
.hero__metrics{
  display:grid;grid-template-columns:repeat(4,1fr);gap:1px;margin-top:64px;
  border:1px solid rgba(255,255,255,.16);border-radius:var(--radius);overflow:hidden;
  background:rgba(255,255,255,.12);backdrop-filter:blur(10px);
}
.hero__metric{background:rgba(9,15,34,.55);padding:22px 20px}
.hero__metric b{display:block;font-size:clamp(24px,2.6vw,32px);font-weight:800;letter-spacing:-.02em;line-height:1.2}
.hero__metric b i{font-style:normal;font-size:.55em;font-weight:600;color:var(--cyan);margin-left:3px}
.hero__metric > span{display:block;margin-top:6px;font-size:13px;color:#9fb0d0;letter-spacing:.02em}
.hero__metric b span{display:inline;margin:0;font-size:inherit;color:inherit;letter-spacing:inherit;font-weight:inherit}
.hero__scroll{
  position:absolute;left:50%;bottom:26px;transform:translateX(-50%);z-index:3;
  font-size:11.5px;letter-spacing:.24em;color:rgba(255,255,255,.5);text-transform:uppercase;
  display:flex;flex-direction:column;align-items:center;gap:8px;
}
.hero__scroll::after{content:"";width:1px;height:34px;background:linear-gradient(180deg,rgba(255,255,255,.6),transparent);animation:scrollLine 2.2s infinite}
@keyframes scrollLine{0%{opacity:0;transform:scaleY(.3)}50%{opacity:1}100%{opacity:0;transform:scaleY(1)}}

/* ---------- 页面头部（内页） ---------- */
.pagehead{
  position:relative;padding:150px 0 76px;color:#fff;overflow:hidden;background:var(--navy);
}
.pagehead__bg{position:absolute;inset:0;z-index:0}
.pagehead__bg img{width:100%;height:100%;object-fit:cover;opacity:.42}
.pagehead__bg::after{
  content:"";position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(8,13,30,.9),rgba(8,13,30,.72) 50%,rgba(8,13,30,.96));
}
.pagehead .wrap{position:relative;z-index:2}
.pagehead h1{font-size:clamp(32px,4.4vw,54px);letter-spacing:-.03em;font-weight:800;max-width:900px}
.pagehead p{margin-top:20px;color:#b9c6e2;font-size:17px;max-width:660px;line-height:1.85}
.crumb{display:flex;gap:8px;align-items:center;font-size:13px;color:#8ea0c2;margin-bottom:22px}
.crumb a:hover{color:#fff}
.crumb span{opacity:.5}

/* ---------- 卡片通用 ---------- */
.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:32px;transition:transform .4s var(--ease),box-shadow .4s var(--ease),border-color .4s;
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:#d3ddef}
.card h3{font-size:19px;margin-bottom:12px}
.card p{color:var(--text-2);font-size:15px;line-height:1.8}
.card__ico{
  width:48px;height:48px;border-radius:14px;display:grid;place-items:center;margin-bottom:22px;
  background:linear-gradient(140deg,rgba(43,92,255,.12),rgba(25,211,197,.14));
  color:var(--brand);
}
.card__ico svg{width:23px;height:23px}

/* ---------- 四宫格入口 ---------- */
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:26px}

.entry{
  position:relative;border-radius:var(--radius);overflow:hidden;background:#0b1430;color:#fff;
  min-height:340px;display:flex;flex-direction:column;justify-content:flex-end;padding:28px;
  transition:transform .45s var(--ease),box-shadow .45s var(--ease);
}
.entry img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;transition:transform .8s var(--ease);opacity:.72}
.entry::after{
  content:"";position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(8,13,30,.08) 0%,rgba(8,13,30,.42) 38%,rgba(8,13,30,.82) 66%,rgba(8,13,30,.97) 100%);
}
.entry:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg)}
.entry:hover img{transform:scale(1.07)}
.entry>*{position:relative;z-index:2}
.entry__no{position:absolute;top:22px;right:24px;z-index:2;font-size:12px;letter-spacing:.16em;color:rgba(255,255,255,.6);font-weight:600}
.entry h3{font-size:21px;margin-bottom:10px;text-shadow:0 2px 12px rgba(4,8,20,.55)}
.entry p{font-size:14px;color:#d3dcf0;line-height:1.75;text-shadow:0 1px 8px rgba(4,8,20,.6)}
.entry__more{
  margin-top:18px;display:inline-flex;align-items:center;gap:7px;font-size:13.5px;font-weight:600;color:var(--cyan);
}
.entry__more svg{width:15px;height:15px;transition:transform .3s var(--ease)}
.entry:hover .entry__more svg{transform:translateX(4px)}

/* ---------- 特性列表 ---------- */
.feature{display:flex;gap:18px}
.feature__ico{
  width:44px;height:44px;border-radius:13px;flex:none;display:grid;place-items:center;
  background:rgba(43,92,255,.08);color:var(--brand);
}
.feature__ico svg{width:21px;height:21px}
.feature h4{font-size:16.5px;margin-bottom:7px}
.feature p{color:var(--text-2);font-size:14.5px;line-height:1.8}
.section--dark .feature h4{color:#fff}
.section--dark .feature p{color:#a3b1cf}
.section--dark .feature__ico{background:rgba(25,211,197,.12);color:var(--cyan)}

/* ---------- 教学闭环时间轴 ---------- */
.flow{position:relative;display:grid;grid-template-columns:repeat(6,1fr);gap:0;margin-top:60px}
.flow::before{
  content:"";position:absolute;top:27px;left:8%;right:8%;height:2px;
  background:linear-gradient(90deg,rgba(43,92,255,.15),rgba(43,92,255,.55),rgba(25,211,197,.55),rgba(43,92,255,.15));
}
.flow__item{position:relative;text-align:center;padding:0 8px}
.flow__dot{
  width:54px;height:54px;border-radius:50%;margin:0 auto 20px;display:grid;place-items:center;
  background:#fff;border:2px solid #dbe4f7;color:var(--brand);font-weight:700;font-size:15px;
  position:relative;z-index:2;transition:.4s var(--ease);
}
.flow__item:hover .flow__dot{background:linear-gradient(135deg,var(--brand),var(--cyan));color:#fff;border-color:transparent;transform:scale(1.08);box-shadow:0 12px 26px -12px rgba(43,92,255,.8)}
.flow__item h4{font-size:15.5px;margin-bottom:8px}
.flow__item p{font-size:13.5px;color:var(--text-3);line-height:1.7}

/* ---------- 数据条 ---------- */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:0;border-radius:var(--radius);overflow:hidden;background:var(--white);border:1px solid var(--line)}
.stat{padding:34px 26px;border-right:1px solid var(--line)}
.stat:last-child{border-right:0}
.stat b{display:block;font-size:clamp(28px,3vw,38px);font-weight:800;letter-spacing:-.03em;line-height:1.15}
.stat b i{font-style:normal;font-size:.5em;color:var(--brand);margin-left:2px;font-weight:700}
.stat > span{display:block;margin-top:8px;font-size:13.5px;color:var(--text-3)}
.stat b span{display:inline;margin:0;font-size:inherit;color:inherit;font-weight:inherit}

/* ---------- 图片+文字分栏 ---------- */
.split{display:grid;grid-template-columns:1.05fr .95fr;gap:64px;align-items:center}
.split--rev .split__media{order:2}
.split__media{position:relative;border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--shadow-lg)}
.split__media img{width:100%;height:100%;object-fit:cover;aspect-ratio:4/3}
.split__media--tall img{aspect-ratio:3/3.4}
.split__tag{
  position:absolute;left:22px;bottom:22px;z-index:2;padding:9px 16px;border-radius:999px;
  background:rgba(11,20,48,.62);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.18);
  color:#fff;font-size:12.5px;font-weight:500;letter-spacing:.04em;
}
.split__body .sec-title{font-size:clamp(26px,3.2vw,38px)}
.split__list{margin-top:32px;display:grid;gap:22px}
.checklist{display:grid;gap:14px;margin-top:26px}
.checklist li{display:flex;gap:12px;font-size:15px;color:var(--text-2);line-height:1.75}
.checklist svg{width:20px;height:20px;flex:none;color:var(--cyan);margin-top:2px}
.section--dark .checklist li{color:#b5c2dd}

/* ---------- 规格表 ---------- */
.spec{width:100%;border-collapse:collapse;margin-top:30px;font-size:14.5px}
.spec th,.spec td{text-align:left;padding:15px 18px;border-bottom:1px solid var(--line)}
.spec th{width:34%;font-weight:600;color:var(--text-3);background:#fafbfe}
.spec td{color:var(--text)}
.spec tr:last-child th,.spec tr:last-child td{border-bottom:0}
.spec-wrap{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:#fff}

/* ---------- 标签 ---------- */
.tags{display:flex;flex-wrap:wrap;gap:10px;margin-top:26px}
.tag{padding:7px 15px;border-radius:999px;background:rgba(43,92,255,.07);color:var(--brand);font-size:13px;font-weight:500;border:1px solid rgba(43,92,255,.12)}
.section--dark .tag{background:rgba(25,211,197,.1);color:#6ce8dd;border-color:rgba(25,211,197,.2)}

/* ---------- 选项卡 ---------- */
.tabs{display:flex;flex-wrap:wrap;gap:8px;margin-top:44px;padding:6px;border-radius:999px;background:#eaeff8;width:fit-content;margin-left:auto;margin-right:auto}
.tabs button{
  padding:11px 22px;border-radius:999px;font-size:14.5px;font-weight:600;color:var(--text-2);transition:.3s var(--ease);
}
.tabs button.is-on{background:#fff;color:var(--brand);box-shadow:0 4px 14px -6px rgba(16,24,40,.28)}
.tabpanel{display:none;margin-top:48px}
.tabpanel.is-on{display:block;animation:fadeUp .45s var(--ease)}
@keyframes fadeUp{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}

/* ---------- 学员门户演示 ---------- */
.portal{
  margin-top:56px;border-radius:var(--radius-lg);overflow:hidden;background:#fff;
  border:1px solid var(--line);box-shadow:var(--shadow-lg);
}
.portal__bar{display:flex;align-items:center;gap:8px;padding:13px 18px;background:#f2f5fb;border-bottom:1px solid var(--line)}
.portal__bar i{width:11px;height:11px;border-radius:50%;background:#dbe2ef;display:block}
.portal__bar i:nth-child(1){background:#ff6058}
.portal__bar i:nth-child(2){background:#ffbd2e}
.portal__bar i:nth-child(3){background:#28c840}
.portal__url{
  margin-left:14px;flex:1;padding:5px 14px;border-radius:8px;background:#fff;border:1px solid var(--line);
  font-size:12.5px;color:var(--text-3);font-family:ui-monospace,SFMono-Regular,Menlo,monospace;
}
.portal__body{display:grid;grid-template-columns:212px 1fr}
.portal__side{background:#0d1730;padding:22px 14px;color:#fff}
.portal__user{display:flex;align-items:center;gap:11px;padding:0 8px 20px;border-bottom:1px solid rgba(255,255,255,.1);margin-bottom:16px}
.portal__avatar{width:38px;height:38px;border-radius:11px;background:linear-gradient(135deg,var(--brand),var(--cyan));display:grid;place-items:center;font-size:14px;font-weight:700;flex:none}
.portal__user b{display:block;font-size:14px;font-weight:600}
.portal__user span{font-size:11.5px;color:#8fa0c4}
.portal__nav{display:grid;gap:3px}
.portal__nav a{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:9px;font-size:13.5px;color:#a8b7d6;transition:.25s}
.portal__nav a svg{width:16px;height:16px;flex:none;opacity:.8}
.portal__nav a:hover{background:rgba(255,255,255,.07);color:#fff}
.portal__nav a.is-on{background:linear-gradient(100deg,rgba(43,92,255,.9),rgba(43,92,255,.55));color:#fff}
.portal__main{padding:28px 30px 34px;background:#fbfcff;min-height:430px}
.portal__head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:22px;flex-wrap:wrap}
.portal__head h4{font-size:18px}
.portal__head p{font-size:13px;color:var(--text-3);margin-top:3px}
.portal__kpis{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:22px}
.kpi{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 18px}
.kpi span{font-size:12px;color:var(--text-3);display:block}
.kpi b{font-size:24px;font-weight:800;letter-spacing:-.02em;display:block;margin-top:4px}
.kpi b em{font-style:normal;font-size:12px;font-weight:600;color:#0fa97f;margin-left:5px}
.portal__row{display:grid;grid-template-columns:1.35fr 1fr;gap:16px}
.pcard{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px}
.pcard h5{font-size:13.5px;margin-bottom:14px;display:flex;align-items:center;justify-content:space-between}
.pcard h5 em{font-style:normal;font-size:11.5px;color:var(--text-3);font-weight:500}
.bars{display:flex;align-items:flex-end;gap:10px;height:110px}
.bars div{flex:1;border-radius:6px 6px 3px 3px;background:linear-gradient(180deg,#4a7bff,#2b5cff);opacity:.85;position:relative;transition:height 1s var(--ease)}
.bars div::after{content:attr(data-l);position:absolute;bottom:-20px;left:0;right:0;text-align:center;font-size:10.5px;color:var(--text-3)}
.bars div:nth-child(5),.bars div:nth-child(6){background:linear-gradient(180deg,#3ee0d2,#19d3c5)}
.course-list{display:grid;gap:11px}
.course-item{display:flex;align-items:center;gap:12px;padding:11px 12px;border-radius:11px;background:#f7f9fe;transition:.25s}
.course-item:hover{background:#eef3ff}
.course-item i{width:34px;height:34px;border-radius:9px;display:grid;place-items:center;font-size:13px;font-style:normal;flex:none;color:#fff;background:linear-gradient(135deg,#2b5cff,#5b8cff)}
.course-item:nth-child(2) i{background:linear-gradient(135deg,#19d3c5,#0fb8ac)}
.course-item:nth-child(3) i{background:linear-gradient(135deg,#7c5cff,#9b7bff)}
.course-item b{font-size:13px;display:block;font-weight:600}
.course-item span{font-size:11.5px;color:var(--text-3)}
.course-item em{margin-left:auto;font-style:normal;font-size:11.5px;color:var(--brand);font-weight:600;background:rgba(43,92,255,.08);padding:4px 9px;border-radius:999px}

/* AI 对话演示 */
.chat{background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden;display:flex;flex-direction:column;height:420px}
.chat__head{display:flex;align-items:center;gap:10px;padding:13px 16px;border-bottom:1px solid var(--line);background:#fbfcff}
.chat__dot{width:8px;height:8px;border-radius:50%;background:#0fa97f;box-shadow:0 0 0 3px rgba(15,169,127,.15)}
.chat__head b{font-size:13.5px}
.chat__head span{font-size:11.5px;color:var(--text-3);margin-left:auto}
.chat__log{flex:1;overflow-y:auto;padding:18px;display:flex;flex-direction:column;gap:14px;background:linear-gradient(180deg,#fbfcff,#f7f9fe)}
.msg{max-width:82%;font-size:13.5px;line-height:1.75;padding:11px 15px;border-radius:14px}
.msg--ai{background:#fff;border:1px solid var(--line);color:var(--text);border-bottom-left-radius:5px;box-shadow:var(--shadow-sm)}
.msg--me{align-self:flex-end;background:linear-gradient(120deg,var(--brand),#4a7bff);color:#fff;border-bottom-right-radius:5px}
.msg b{font-weight:600}
.chat__input{display:flex;gap:9px;padding:12px;border-top:1px solid var(--line);background:#fff}
.chat__input input{
  flex:1;border:1px solid var(--line);border-radius:999px;padding:10px 16px;font:inherit;font-size:13.5px;outline:none;transition:.25s;background:#fafbfe;
}
.chat__input input:focus{border-color:var(--brand);background:#fff;box-shadow:0 0 0 3px rgba(43,92,255,.1)}
.chat__input button{width:40px;height:40px;border-radius:50%;background:linear-gradient(120deg,var(--brand),#4a7bff);color:#fff;display:grid;place-items:center;flex:none;transition:.25s}
.chat__input button:hover{transform:scale(1.06)}
.chat__input svg{width:16px;height:16px}

/* ---------- 时间表 ---------- */
.schedule{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:#fff}
.schedule__row{display:grid;grid-template-columns:120px 1fr 150px 120px;align-items:center;gap:16px;padding:17px 24px;border-bottom:1px solid var(--line);font-size:14px;transition:background .25s}
.schedule__row:last-child{border-bottom:0}
.schedule__row:hover{background:#fafbfe}
.schedule__row--head{background:#f5f8fe;font-size:12.5px;letter-spacing:.06em;color:var(--text-3);font-weight:600;text-transform:uppercase}
.schedule__time{font-weight:600;color:var(--text);font-variant-numeric:tabular-nums}
.schedule__row--head span{font-weight:600}
.badge{padding:4px 11px;border-radius:999px;font-size:12px;font-weight:600;background:rgba(43,92,255,.08);color:var(--brand);width:fit-content}
.badge--live{background:rgba(255,76,76,.1);color:#e04040}
.badge--done{background:rgba(15,169,127,.1);color:#0fa97f}
.badge--ai{background:rgba(124,92,255,.1);color:#6b4ce6}

/* ---------- CTA 区块 ---------- */
.cta{
  position:relative;overflow:hidden;border-radius:var(--radius-lg);padding:66px 56px;color:#fff;
  background:linear-gradient(120deg,#0b1430,#13224a 55%,#0e2a4a);
}
.cta::before{
  content:"";position:absolute;inset:0;
  background:radial-gradient(600px 340px at 85% 15%,rgba(43,92,255,.45),transparent 65%),radial-gradient(520px 300px at 10% 90%,rgba(25,211,197,.28),transparent 60%);
}
.cta>*{position:relative;z-index:2}
.cta h2{font-size:clamp(26px,3.4vw,40px);letter-spacing:-.02em;max-width:640px}
.cta p{margin-top:16px;color:#b9c6e2;font-size:16px;max-width:560px}
.cta__actions{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px}
.cta__note{margin-top:22px;font-size:12.5px;color:#8ea0c2;letter-spacing:.02em}

/* ---------- 页脚 ---------- */
.footer{background:#080e20;color:#8c9ab8;padding:70px 0 30px;font-size:14px}
.footer__grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.2fr;gap:48px;padding-bottom:46px;border-bottom:1px solid rgba(255,255,255,.08)}
.footer .logo{color:#fff;margin-bottom:20px}
.footer p{line-height:1.85;font-size:13.5px;color:#8394b4}
.footer h5{color:#fff;font-size:13.5px;font-weight:600;margin-bottom:18px;letter-spacing:.04em}
.footer li{margin-bottom:11px}
.footer li a{font-size:13.5px;color:#8394b4;transition:color .25s}
.footer li a:hover{color:var(--cyan)}
.footer__contact li{display:flex;gap:10px;font-size:13.5px;margin-bottom:13px}
.footer__contact svg{width:16px;height:16px;flex:none;margin-top:4px;color:var(--cyan);opacity:.8}
.footer__bottom{display:flex;justify-content:space-between;gap:20px;padding-top:26px;flex-wrap:wrap;font-size:12.5px;color:#66748f}
.footer__bottom a:hover{color:var(--cyan)}

/* ---------- 滚动出现动画 ---------- */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .8s var(--ease),transform .8s var(--ease)}
.reveal.is-in{opacity:1;transform:none}
.reveal[data-d="1"]{transition-delay:.08s}
.reveal[data-d="2"]{transition-delay:.16s}
.reveal[data-d="3"]{transition-delay:.24s}
.reveal[data-d="4"]{transition-delay:.32s}

/* ---------- 响应式 ---------- */
@media (max-width:1080px){
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .flow{grid-template-columns:repeat(3,1fr);gap:40px 0}
  .flow::before{display:none}
  .split{gap:40px}
  .footer__grid{grid-template-columns:1fr 1fr;gap:36px}
  .hero__metrics{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:900px){
  .nav,.header__cta{display:none}
  .burger{display:grid}
  .section{padding:72px 0}
  .split,.split--rev .split__media{grid-template-columns:1fr;order:0}
  .split__media img{aspect-ratio:16/10}
  .grid-3,.grid-2{grid-template-columns:1fr}
  .stats{grid-template-columns:repeat(2,1fr)}
  .stat{border-bottom:1px solid var(--line)}
  .stat:nth-child(2){border-right:0}
  .stat:nth-child(3),.stat:nth-child(4){border-bottom:0}
  .portal__body{grid-template-columns:1fr}
  .portal__side{display:none}
  .portal__row{grid-template-columns:1fr}
  .portal__kpis{grid-template-columns:1fr}
  .schedule__row{grid-template-columns:90px 1fr;row-gap:8px}
  .schedule__row--head{display:none}
  .schedule__row .badge:last-child{grid-column:2}
  .cta{padding:44px 28px}
}
@media (max-width:620px){
  .wrap{padding:0 18px}
  .hero{padding:120px 0 80px;min-height:auto}
  .hero__metrics{grid-template-columns:1fr 1fr;margin-top:44px}
  .hero__metric{padding:18px 16px}
  .grid-4{grid-template-columns:1fr}
  .flow{grid-template-columns:1fr 1fr}
  .stats{grid-template-columns:1fr}
  .stat{border-right:0;border-bottom:1px solid var(--line)}
  .stat:last-child{border-bottom:0}
  .tabs{width:100%;justify-content:center}
  .tabs button{padding:9px 15px;font-size:13.5px}
  .footer__grid{grid-template-columns:1fr}
  .pagehead{padding:120px 0 56px}
  .hero__scroll{display:none}
  .spec th,.spec td{padding:12px 14px;font-size:13.5px}
  .spec th{width:40%}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
  .reveal{opacity:1;transform:none}
}

/* =========================================================
   线上课堂（portal）专用组件
   ========================================================= */

/* 登录卡 */
.login{
  position:relative;z-index:5;margin:-70px auto 0;max-width:430px;
  background:#fff;border:1px solid var(--line);border-radius:var(--radius-lg);
  padding:34px 32px;box-shadow:var(--shadow-lg);
}
.login h3{font-size:20px;text-align:center}
.login p{text-align:center;font-size:13px;color:var(--text-3);margin-top:8px}
.login__field{margin-top:18px}
.login__field label{display:block;font-size:12.5px;color:var(--text-3);margin-bottom:7px;font-weight:500}
.login__field input{
  width:100%;padding:12px 15px;border:1px solid var(--line);border-radius:11px;
  font:inherit;font-size:14px;outline:none;background:#fafbfe;transition:.25s;
}
.login__field input:focus{border-color:var(--brand);background:#fff;box-shadow:0 0 0 3px rgba(43,92,255,.1)}
.login .btn{width:100%;margin-top:22px}
.login__hint{margin-top:16px;text-align:center;font-size:12px;color:var(--text-3)}
.login__hint b{color:var(--brand);font-weight:600}

/* 门户侧栏按钮 */
.portal__nav button{
  display:flex;align-items:center;gap:10px;width:100%;text-align:left;
  padding:10px 12px;border-radius:9px;font-size:13.5px;color:#a8b7d6;transition:.25s;
}
.portal__nav button svg{width:16px;height:16px;flex:none;opacity:.85}
.portal__nav button:hover{background:rgba(255,255,255,.07);color:#fff}
.portal__nav button.is-on{background:linear-gradient(100deg,rgba(43,92,255,.95),rgba(43,92,255,.55));color:#fff}

/* 进度条 */
.prog{height:7px;border-radius:99px;background:#eaeff8;overflow:hidden;margin-top:12px}
.prog__bar{height:100%;border-radius:99px;background:linear-gradient(90deg,var(--brand),var(--cyan));transition:width 1.2s var(--ease)}

/* 课程卡 */
.ccard{background:#fff;border:1px solid var(--line);border-radius:14px;padding:20px;transition:.3s var(--ease)}
.ccard:hover{box-shadow:var(--shadow);transform:translateY(-3px);border-color:#d3ddef}
.ccard__top{display:flex;align-items:flex-start;gap:12px;margin-bottom:14px}
.ccard__ico{width:40px;height:40px;border-radius:11px;display:grid;place-items:center;flex:none;color:#fff;font-size:13px;font-weight:700}
.ccard h6{margin:0;font-size:14.5px;font-weight:600}
.ccard small{display:block;font-size:11.5px;color:var(--text-3);margin-top:2px}
.ccard__meta{display:flex;justify-content:space-between;font-size:11.5px;color:var(--text-3);margin-top:9px}

/* 直播播放器 */
.player{position:relative;border-radius:14px;overflow:hidden;background:#0b1430;aspect-ratio:16/9}
.player img{width:100%;height:100%;object-fit:cover;opacity:.55}
.player__overlay{position:absolute;inset:0;display:flex;flex-direction:column;justify-content:space-between;padding:16px;background:linear-gradient(180deg,rgba(8,13,30,.35),rgba(8,13,30,.72))}
.player__top{display:flex;gap:8px;align-items:center}
.player__play{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:62px;height:62px;border-radius:50%;background:rgba(255,255,255,.92);display:grid;place-items:center;color:var(--brand);box-shadow:0 10px 30px rgba(0,0,0,.3);transition:.3s}
.player:hover .player__play{transform:translate(-50%,-50%) scale(1.08)}
.player__play svg{width:22px;height:22px;margin-left:3px}
.player__bottom{display:flex;align-items:center;gap:12px;font-size:12px;color:#cfd9ee;position:relative;z-index:2}
.player__track{flex:1;height:4px;border-radius:99px;background:rgba(255,255,255,.25);position:relative}
.player__track i{position:absolute;left:0;top:0;bottom:0;width:38%;border-radius:99px;background:var(--cyan);display:block}

/* 作业列表 */
.assign{background:#fff;border:1px solid var(--line);border-radius:13px;padding:16px 18px;display:flex;align-items:center;gap:14px;transition:.25s}
.assign:hover{border-color:#d3ddef;box-shadow:var(--shadow-sm)}
.assign__n{width:38px;height:38px;border-radius:11px;flex:none;display:grid;place-items:center;background:#f2f6ff;color:var(--brand);font-size:12.5px;font-weight:700}
.assign b{display:block;font-size:14px}
.assign span{font-size:11.5px;color:var(--text-3)}
.assign__right{margin-left:auto;text-align:right;display:grid;gap:5px;justify-items:end}

/* 代码块 */
.code{background:#0d1730;border-radius:13px;padding:18px 20px;overflow-x:auto;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px;line-height:1.9;color:#c8d4ec}
.code .k{color:#8ab4ff}
.code .s{color:#7ee2c8}
.code .c{color:#5f6f92}
.code .n{color:#ffc48a}

/* 学情热力图 */
.heat{display:grid;grid-template-columns:repeat(14,1fr);gap:5px;margin-top:14px}
.heat i{aspect-ratio:1;border-radius:3px;background:#eef2f9;display:block}
.heat i[data-l="1"]{background:#d6e2ff}
.heat i[data-l="2"]{background:#9fbcff}
.heat i[data-l="3"]{background:#5b8cff}
.heat i[data-l="4"]{background:#2b5cff}

/* 小标题 */
.mini-title{font-size:12px;letter-spacing:.1em;text-transform:uppercase;color:var(--text-3);font-weight:600;margin:24px 0 12px}

/* 建议卡 */
.tip{display:flex;gap:13px;padding:16px 18px;border-radius:13px;background:linear-gradient(120deg,rgba(43,92,255,.07),rgba(25,211,197,.08));border:1px solid rgba(43,92,255,.14)}
.tip svg{width:20px;height:20px;flex:none;color:var(--brand);margin-top:2px}
.tip b{font-size:13.5px;display:block;margin-bottom:4px}
.tip p{font-size:12.5px;color:var(--text-2);line-height:1.75}

/* 快捷提问 */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
.chips button{padding:8px 14px;border-radius:99px;background:#fff;border:1px solid var(--line);font-size:12.5px;color:var(--text-2);transition:.25s}
.chips button:hover{border-color:var(--brand);color:var(--brand);background:#f7faff}

@media (max-width:900px){
  .login{margin-top:-50px;max-width:100%}
  .heat{grid-template-columns:repeat(10,1fr)}
}

/* ---------- 细节修正 ---------- */
[id]{scroll-margin-top:92px}

@media (max-width:900px){
  /* 门户侧栏改为横向标签条，保证移动端仍可切换模块 */
  .portal__side{display:block;padding:14px 12px 16px}
  .portal__user{display:none}
  .portal__nav{grid-auto-flow:column;grid-auto-columns:max-content;overflow-x:auto;gap:6px;padding-bottom:4px}
  .portal__nav button{white-space:nowrap;padding:9px 14px;font-size:13px}
  .portal__main{padding:22px 18px 26px}
  .assign{flex-wrap:wrap;gap:10px}
  .assign__right{margin-left:0;width:100%;display:flex;justify-content:space-between;align-items:center}
}
@media (max-width:620px){
  .grid-courses{grid-template-columns:1fr!important}
  .portal__head{gap:10px}
  .chat{height:380px}
  .msg{max-width:92%}
}

/* 门户组件在深色区块内也要保持深色文字 */
.portal{color:var(--text)}
.portal__row .pcard{display:flex;flex-direction:column}
.portal__row .pcard .bars{flex:1;height:auto;min-height:120px;margin:10px 0 0;padding-bottom:26px}
.bars div::after{white-space:nowrap}

/* 移动端数据条改为两列，避免过高 */
@media (max-width:620px){
  .stats{grid-template-columns:1fr 1fr}
  .stat{padding:22px 16px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
  .stat:nth-child(2n){border-right:0}
  .stat:nth-last-child(-n+2){border-bottom:0}
  .stat b{font-size:26px}
  .stat > span{font-size:12px;margin-top:5px}
}

/* 防止门户内部内容撑破容器（移动端横向溢出修复） */
.portal__body{min-width:0}
.portal__side,.portal__main{min-width:0}
.portal__nav{min-width:0;max-width:100%}
.portal__url{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.portal__kpis,.portal__row{min-width:0}
.pcard,.kpi{min-width:0}