.page-hero{background:linear-gradient(135deg,#0b1f3a 0%,#0a66c2 100%);color:#fff;padding:50px 0 60px}
.page-hero h1{color:#fff;font-size:2.4rem;margin-bottom:8px}
.page-hero p{color:#cfd8e6;font-size:1.05rem;margin:0;max-width:720px}
.breadcrumb{color:#a9b6c9;font-size:.88rem;margin-bottom:10px}
.breadcrumb a{color:#cfd8e6}

.filter-bar{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:30px;justify-content:center}
.filter{background:#fff;border:1px solid var(--border);padding:8px 18px;border-radius:24px;font-weight:500;cursor:pointer;font-size:.9rem;color:var(--text);transition:all .2s}
.filter:hover{border-color:var(--brand);color:var(--brand)}
.filter.active{background:var(--brand);color:#fff;border-color:var(--brand)}

/* Course detail layout */
.course-detail{padding:50px 0}
.course-layout{display:grid;grid-template-columns:1fr 360px;gap:40px;align-items:start}
.course-main h2{margin-top:30px;border-bottom:2px solid var(--bg-alt);padding-bottom:10px}
.course-main h2:first-child{margin-top:0}

.course-aside{position:sticky;top:90px;background:#fff;border-radius:12px;box-shadow:var(--shadow);overflow:hidden}
.aside-thumb{height:180px;background:linear-gradient(135deg,#0a66c2,#3aa0ff);background-size:cover;background-position:center}
.aside-body{padding:24px}
.price{font-size:1.6rem;font-weight:700;color:var(--text);margin-bottom:4px}
.price-old{color:var(--muted);text-decoration:line-through;font-size:1rem;font-weight:500;margin-left:8px}
.aside-body .btn{width:100%;margin-top:8px}
.aside-list{list-style:none;padding:0;margin:18px 0 0;border-top:1px solid var(--border);padding-top:18px}
.aside-list li{padding:6px 0;font-size:.92rem;color:var(--text);display:flex;justify-content:space-between}
.aside-list li span:last-child{color:var(--muted)}

.module{background:#fff;border:1px solid var(--border);border-radius:8px;margin-bottom:10px;overflow:hidden}
.module summary{padding:14px 18px;cursor:pointer;font-weight:600;list-style:none;display:flex;justify-content:space-between;align-items:center}
.module summary::after{content:"+";font-size:1.3rem;color:var(--brand)}
.module[open] summary::after{content:"−"}
.module-body{padding:0 18px 16px;color:var(--muted)}
.module-body ul{padding-left:18px;margin:8px 0}

.batch-list{display:grid;gap:10px;margin:10px 0 20px}
.batch{background:#fff;border:1px solid var(--border);border-radius:8px;padding:14px 18px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px}
.batch strong{display:block}
.batch span{color:var(--muted);font-size:.9rem}

.faq{margin-bottom:10px}

@media (max-width: 960px){
  .course-layout{grid-template-columns:1fr}
  .course-aside{position:static}
}