:root{--bg:#fafbfc;--card:#fff;--bd:#eef0f3;--tx:#1a1f2e;--mt:#6a7280;--ac:#ff8b3d;--ac2:#ff6b2b;--dark:#1a1f2e}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;background:var(--bg);color:var(--tx);line-height:1.7}
.wrap{max-width:1200px;margin:0 auto;padding:0 24px}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;border-radius:12px;margin:14px 0}
/* 导航 */
.nav{background:#fff;border-bottom:1px solid var(--bd);position:sticky;top:0;z-index:50}
.nav .wrap{display:flex;align-items:center;height:64px;gap:28px}
.logo{font-weight:800;font-size:19px;display:flex;align-items:center;gap:8px}
.logo i{width:22px;height:22px;border-radius:6px;background:var(--ac);display:inline-block}
.nav-links{display:flex;gap:22px;font-size:14px;color:#5b6472}
.nav-links a:hover{color:var(--ac)}
.nav-right{margin-left:auto;display:flex;gap:10px;align-items:center}
.btn-solid{background:var(--ac);color:#fff;font-weight:600;padding:8px 18px;border-radius:8px;font-size:14px}
.burger{display:none;background:none;border:none;font-size:22px;color:var(--tx)}
.nav-mobile{display:none;background:#fff;border-top:1px solid var(--bd);padding:12px 24px}
.nav-mobile a{display:block;padding:10px 0;color:#5b6472;font-size:15px}
/* Hero */
.hero{background:linear-gradient(135deg,#fff,#f5f7fa);border-bottom:1px solid var(--bd);padding:56px 0 48px;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-60px;right:-60px;width:280px;height:280px;border-radius:50%;background:radial-gradient(circle,rgba(255,139,61,.08),transparent 70%)}
.hero h1{font-size:40px;font-weight:800;text-align:center;line-height:1.2;letter-spacing:-.5px;position:relative}
.hero .orange{color:var(--ac)}
.hero p{text-align:center;color:var(--mt);font-size:15px;margin:14px 0 26px;position:relative}
.search{max-width:560px;margin:0 auto;display:flex;background:#fff;border:1px solid #e2e6eb;border-radius:12px;overflow:hidden;box-shadow:0 2px 12px rgba(0,0,0,.04);position:relative}
.search input{flex:1;border:none;padding:14px 18px;font-size:15px;outline:none}
.search button{background:var(--ac);color:#fff;border:none;padding:14px 26px;font-weight:600;font-size:15px;cursor:pointer}
.hero-tags{display:flex;gap:10px;justify-content:center;margin-top:22px;flex-wrap:wrap;position:relative}
.htag{font-size:12px;color:#5b6472;background:#fff;border:1px solid #e2e6eb;padding:6px 14px;border-radius:9999px}
/* 通用区块 */
.section{padding:52px 0}
.sec-head{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:26px}
.sec-head h2{font-size:23px;font-weight:800}
.sec-head .more{color:var(--ac);font-size:14px;font-weight:600}
/* 学习路径 */
.path{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.path-step{background:#fff;border:1px solid var(--bd);border-radius:16px;padding:22px;position:relative}
.path-step .num{position:absolute;top:-14px;left:20px;width:28px;height:28px;border-radius:50%;background:var(--ac);color:#fff;font-weight:800;font-size:14px;display:flex;align-items:center;justify-content:center;box-shadow:0 2px 8px rgba(255,139,61,.3)}
.path-step h3{font-size:15px;font-weight:700;margin:8px 0 8px}
.path-step p{color:var(--mt);font-size:13px;line-height:1.6}
.path-step .bar{height:4px;background:#f0f1f4;border-radius:4px;margin-top:14px;overflow:hidden}
.path-step .bar i{display:block;height:100%;background:linear-gradient(90deg,#ffb27d,#ff8b3d);border-radius:4px}
/* 课程卡 */
.course-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.course{background:#fff;border:1px solid var(--bd);border-radius:16px;padding:24px;transition:box-shadow .2s,transform .2s}
.course:hover{box-shadow:0 8px 24px rgba(0,0,0,.06);transform:translateY(-3px)}
.course .ic{width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:22px;margin-bottom:16px}
.course h3{font-size:16px;font-weight:700;margin-bottom:8px}
.course .level{font-size:11px;color:#9aa1ab;float:right}
.course p{color:var(--mt);font-size:13px;line-height:1.6}
.course .n{font-size:12px;color:var(--ac);font-weight:600;margin-top:14px}
/* 教程卡 */
.tut-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.tut{background:#fff;border:1px solid var(--bd);border-radius:16px;padding:22px;transition:box-shadow .2s,transform .2s}
.tut:hover{box-shadow:0 8px 24px rgba(0,0,0,.06);transform:translateY(-3px)}
.tut .tag{display:inline-block;font-size:11px;color:var(--ac);background:#fff2e8;padding:4px 10px;border-radius:9999px;font-weight:600}
.tut h3{font-size:15px;font-weight:700;margin:14px 0 8px;line-height:1.5}
.tut p{color:var(--mt);font-size:13px;line-height:1.6}
.tut .meta{display:flex;justify-content:space-between;color:#9aa1ab;font-size:12px;margin-top:16px}
.tut .len{color:var(--ac);font-weight:600}
/* 数据/CTA */
.stats{background:var(--dark);border-radius:20px;padding:40px;display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.stat{text-align:center}
.stat .v{font-size:30px;font-weight:800;color:var(--ac)}
.stat .l{color:#9aa1ab;font-size:13px;margin-top:6px}
.cta{background:linear-gradient(135deg,#ff8b3d,#ff6b2b);border-radius:20px;padding:40px;text-align:center;color:#fff;margin-top:24px}
.cta h2{font-size:26px;font-weight:800;margin-bottom:8px}
.cta p{opacity:.9;font-size:14px;margin-bottom:24px}
.cta .btn{background:#fff;color:var(--ac);font-weight:700;padding:13px 34px;border-radius:10px;font-size:15px;display:inline-block}
/* 分类页 */
.cat-head{background:#fff;border-bottom:1px solid var(--bd);padding:36px 0}
.cat-head h1{font-size:28px;font-weight:800}
.cat-head p{color:var(--mt);font-size:14px;margin-top:8px}
.crumb{font-size:13px;color:#9aa1ab;margin-bottom:12px}
.crumb a:hover{color:var(--ac)}
.c-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:20px;padding:36px 0}
.c-card{background:#fff;border:1px solid var(--bd);border-radius:16px;padding:24px;transition:box-shadow .2s,transform .2s}
.c-card:hover{box-shadow:0 8px 24px rgba(0,0,0,.06);transform:translateY(-3px)}
.c-card .c-tag{font-size:11px;color:var(--ac);background:#fff2e8;padding:4px 10px;border-radius:9999px;font-weight:600}
.c-card .c-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}
.c-card time{font-size:12px;color:#9aa1ab}
.c-card h3{font-size:17px;font-weight:700;margin-bottom:8px}
.c-card p{color:var(--mt);font-size:13px;line-height:1.6}
.c-card .c-foot{margin-top:14px}
.c-card .c-go{color:var(--ac);font-weight:600;font-size:13px}
.pager{display:flex;gap:8px;justify-content:center;padding-bottom:36px}
.pager a{width:36px;height:36px;display:flex;align-items:center;justify-content:center;border:1px solid var(--bd);border-radius:8px;font-size:14px;color:#5b6472;background:#fff}
.pager a.cur{background:var(--ac);color:#fff;border-color:var(--ac)}
/* 文章页 */
.art-top{background:#fff;border-bottom:1px solid var(--bd);padding:36px 0}
.art-top h1{font-size:26px;font-weight:800;line-height:1.4}
.art-top .meta{display:flex;gap:20px;color:#9aa1ab;font-size:13px;margin-top:12px}
.art-main{padding:36px 0}
.art-body{background:#fff;border:1px solid var(--bd);border-radius:16px;padding:32px;font-size:15px;line-height:1.9;color:#2a3140}
.art-body h2{font-size:20px;font-weight:700;margin:28px 0 14px;color:var(--tx);padding-left:12px;border-left:3px solid var(--ac)}
.art-body p{margin:12px 0}
.art-rel{margin-top:24px}
.art-rel h3{font-size:17px;font-weight:700;margin-bottom:14px}
.r-li{display:flex;justify-content:space-between;background:#fff;border:1px solid var(--bd);border-radius:10px;padding:14px 18px;margin-bottom:10px;font-size:14px;color:var(--tx)}
.r-li time{color:#9aa1ab;font-size:12px}
.art-nav{display:flex;justify-content:space-between;margin:24px 0}
.art-nav a{background:#fff;border:1px solid var(--bd);border-radius:10px;padding:14px 18px;font-size:13px;color:var(--tx);max-width:45%}
.art-nav span{color:var(--ac);font-weight:600;display:block;margin-bottom:4px}
.art-back{display:inline-block;color:var(--ac);font-weight:600;font-size:14px}
/* 页脚 */
footer{background:var(--dark);color:#9aa1ab;margin-top:48px;padding:48px 0 0}
.foot-grid{display:grid;grid-template-columns:2fr repeat(3,1fr);gap:24px;padding-bottom:32px}
.foot-brand .logo{color:#fff}
.foot-brand p{font-size:13px;line-height:1.8;margin-top:12px;max-width:260px}
.foot-col h4{color:#fff;font-size:14px;margin-bottom:16px}
.foot-col a{display:block;font-size:13px;margin-bottom:10px}
.foot-col a:hover{color:var(--ac)}
.foot-bar{border-top:1px solid #2a3140;padding:18px 0;display:flex;justify-content:space-between;font-size:12px}
/* 响应式 */
@media(max-width:900px){
  .nav-links{display:none}
  .burger{display:block}
  .nav-mobile.show{display:block}
  .hero h1{font-size:28px}
  .course-grid{grid-template-columns:repeat(2,1fr)}
  .tut-grid{grid-template-columns:1fr}
  .path{grid-template-columns:repeat(2,1fr)}
  .stats{grid-template-columns:repeat(2,1fr)}
  .foot-grid{grid-template-columns:repeat(2,1fr)}
  .c-grid{grid-template-columns:1fr}
  .art-body{padding:20px}
}