/* Học viện Dovapu Academy — giao diện theo Brand Guidelines v1.0 */
:root{
  --flame:#F78C26;--ember:#E0370A;--leaf:#44961F;--green:#1F6E3B;--deep:#0A5A30;
  --night:#0C0907;--char:#1A1A1C;--soft:#FAF7F2;--ash:#8A817C;--line:rgba(12,9,7,.09);
  --grad-flame:linear-gradient(90deg,#F78C26,#E0370A);--grad-leaf:linear-gradient(90deg,#44961F,#0A5A30);
  --radius:18px;--shadow:0 18px 50px rgba(12,9,7,.10);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:'Be Vietnam Pro',system-ui,sans-serif;color:var(--night);background:var(--soft);line-height:1.6;font-size:17px}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{font-family:'Montserrat',sans-serif;line-height:1.12;letter-spacing:-.01em}
h1{font-weight:900;font-size:clamp(38px,5.4vw,68px)}
h2{font-weight:800;font-size:clamp(28px,3.4vw,44px)}
h3{font-weight:800;font-size:21px}
em.hl{font-style:normal;color:var(--flame)}
.wrap{max-width:1200px;margin:0 auto;padding:0 24px}
.eyebrow{font-weight:700;font-size:13px;letter-spacing:.2em;text-transform:uppercase;color:var(--flame);margin-bottom:14px;display:block}
.muted{color:#655d57}
section{padding:88px 0}
.dark{background:var(--night);color:var(--soft)}
.dark .muted{color:#bdb5ad}

/* nút */
.btn{display:inline-flex;align-items:center;gap:10px;font-weight:700;font-size:16px;padding:14px 26px;border-radius:999px;border:0;cursor:pointer;transition:transform .15s,box-shadow .15s}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--grad-flame);color:#fff;box-shadow:0 10px 30px rgba(224,55,10,.28)}
.btn-ghost{background:transparent;border:2px solid currentColor}
.btn-leaf{background:var(--grad-leaf);color:#fff}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(250,247,242,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:72px;gap:16px}
.site-header .logo img{height:44px}
.nav{display:flex;gap:26px;align-items:center;font-weight:600;font-size:15px}
.nav a:hover,.nav a.on{color:var(--flame)}
.nav .btn{padding:10px 20px;font-size:14px}
.burger{display:none;background:none;border:0;font-size:28px;cursor:pointer}

/* hero */
.hero{background:radial-gradient(900px 600px at 80% 20%,rgba(247,140,38,.22),transparent 70%),radial-gradient(700px 500px at 0 100%,rgba(68,150,31,.18),transparent 70%),var(--night);color:var(--soft);padding:96px 0 110px}
.hero .wrap{display:grid;grid-template-columns:1.15fr .85fr;gap:56px;align-items:center}
.hero p.lead{font-size:20px;color:#d9d3cc;margin:22px 0 32px;max-width:560px}
.hero .ctas{display:flex;gap:14px;flex-wrap:wrap}
.hero .stats{display:flex;gap:34px;margin-top:40px;flex-wrap:wrap}
.hero .stats b{display:block;font-family:'Montserrat';font-weight:900;font-size:34px;color:var(--flame)}
.hero .stats span{font-size:14px;color:#bdb5ad}
.hero-card{background:var(--char);border:1px solid rgba(255,255,255,.08);border-radius:24px;overflow:hidden;box-shadow:0 30px 80px rgba(0,0,0,.45)}
.hero-card img{width:100%;aspect-ratio:16/9;object-fit:cover}
.hero-card .in{padding:22px 24px}
.hero-card .tag{display:inline-block;background:var(--grad-flame);color:#fff;font-weight:700;font-size:12px;padding:5px 12px;border-radius:999px;letter-spacing:.06em}

/* lưới & thẻ */
.grid{display:grid;gap:24px}
.g2{grid-template-columns:repeat(2,1fr)}.g3{grid-template-columns:repeat(3,1fr)}.g4{grid-template-columns:repeat(4,1fr)}.g5{grid-template-columns:repeat(5,1fr)}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;transition:transform .15s,box-shadow .15s}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.dark .card{background:var(--char);border-color:rgba(255,255,255,.08)}
.icon{font-size:34px;margin-bottom:12px}
.step-n{width:46px;height:46px;border-radius:50%;background:var(--grad-flame);color:#fff;display:grid;place-items:center;font-family:'Montserrat';font-weight:900;font-size:20px;margin-bottom:14px}

/* thẻ khóa học */
.course{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:transform .15s,box-shadow .15s}
.course:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.course .top{height:150px;position:relative;display:grid;place-items:center;background:radial-gradient(260px 160px at 70% 30%,rgba(247,140,38,.35),transparent 70%),var(--night);color:#fff}
.course .top .em{font-size:54px}
.course .top img.cover{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.course .badge{position:absolute;top:12px;left:12px;font-weight:700;font-size:12px;padding:5px 11px;border-radius:999px;letter-spacing:.04em;z-index:2}
.badge.mo{background:var(--leaf);color:#fff}.badge.sap{background:rgba(255,255,255,.9);color:var(--night)}
.course .body{padding:20px 22px 22px;display:flex;flex-direction:column;flex:1}
.course .meta{display:flex;gap:14px;flex-wrap:wrap;font-size:13px;color:var(--ash);font-weight:600;margin-bottom:8px}
.course h3{font-size:19px;margin-bottom:8px}
.course p{font-size:15px;color:#655d57;flex:1}
.course .go{margin-top:16px;font-weight:700;color:var(--flame);font-size:15px}
.free{display:inline-block;background:rgba(68,150,31,.12);color:var(--green);font-weight:700;font-size:12px;padding:4px 10px;border-radius:999px}

/* bộ lọc */
.filters{display:flex;gap:10px;flex-wrap:wrap;margin:26px 0 30px}
.chip{border:1.5px solid var(--line);background:#fff;border-radius:999px;padding:9px 16px;font-weight:600;font-size:14px;cursor:pointer}
.chip.on{background:var(--night);color:#fff;border-color:var(--night)}

/* trang khóa học */
.course-hero{background:radial-gradient(800px 500px at 85% 20%,rgba(247,140,38,.2),transparent 70%),var(--night);color:var(--soft);padding:72px 0}
.course-hero .wrap{display:grid;grid-template-columns:1.3fr .7fr;gap:48px;align-items:center}
.info{display:flex;gap:26px;flex-wrap:wrap;margin:22px 0 28px;color:#d9d3cc;font-weight:600}
.syllabus .part{margin-bottom:26px}
.syllabus .part h4{font-size:15px;letter-spacing:.14em;text-transform:uppercase;color:var(--ash);margin-bottom:10px}
.lesson-row{display:flex;align-items:center;gap:16px;background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 18px;margin-bottom:8px}
.lesson-row .n{width:36px;height:36px;border-radius:50%;background:#efe9e2;display:grid;place-items:center;font-family:'Montserrat';font-weight:800;font-size:15px;flex-shrink:0}
.lesson-row.open .n{background:var(--grad-flame);color:#fff}
.lesson-row.done .n{background:var(--leaf);color:#fff}
.lesson-row .t{flex:1;font-weight:600}
.lesson-row .m{font-size:13px;color:var(--ash);font-weight:600;white-space:nowrap}
.lesson-row.lock{opacity:.6}

/* trang bài học */
.player{display:grid;grid-template-columns:1fr 340px;gap:28px;padding:34px 0 80px}
.video-box{background:#000;border-radius:16px;overflow:hidden;box-shadow:var(--shadow)}
.video-box video{width:100%;display:block;aspect-ratio:16/9;background:#000}
.side-list{background:#fff;border:1px solid var(--line);border-radius:16px;padding:16px;max-height:calc(100vh - 120px);overflow:auto;position:sticky;top:90px}
.side-list a{display:flex;gap:10px;padding:10px;border-radius:10px;font-size:14px;font-weight:600;align-items:flex-start}
.side-list a:hover{background:#f4efe9}
.side-list a.on{background:rgba(247,140,38,.12);color:var(--ember)}
.side-list a .n{min-width:24px;font-family:'Montserrat';font-weight:800;color:var(--ash)}
.tabs{display:flex;gap:6px;border-bottom:1px solid var(--line);margin:24px 0 18px;flex-wrap:wrap}
.tab{padding:12px 16px;font-weight:700;font-size:15px;cursor:pointer;border-bottom:3px solid transparent}
.tab.on{border-color:var(--flame);color:var(--flame)}
.pane{display:none}.pane.on{display:block}
.pane ul{padding-left:20px}.pane li{margin-bottom:8px}
.done-btn.ok{background:var(--leaf)}

/* quiz & chứng nhận */
.q{background:#fff;border:1px solid var(--line);border-radius:16px;padding:22px;margin-bottom:14px}
.q h4{font-family:'Be Vietnam Pro';font-weight:700;font-size:17px;margin-bottom:12px}
.q label{display:flex;gap:10px;padding:9px 12px;border-radius:10px;cursor:pointer;font-size:15px}
.q label:hover{background:#f4efe9}
.q.right{border-color:var(--leaf)}.q.wrong{border-color:var(--ember)}
input[type=text],input[type=email],input[type=tel],select,textarea{width:100%;padding:14px 16px;border-radius:12px;border:1.5px solid var(--line);font:inherit;background:#fff}
input:focus,select:focus,textarea:focus{outline:2px solid var(--flame);border-color:transparent}
.form-row{margin-bottom:16px}.form-row label{display:block;font-weight:700;font-size:14px;margin-bottom:6px}
canvas#cert{width:100%;max-width:900px;border-radius:12px;box-shadow:var(--shadow);display:none;margin:24px auto 0}
.note{background:rgba(247,140,38,.1);border-left:4px solid var(--flame);padding:14px 18px;border-radius:0 12px 12px 0;font-size:15px}

/* chân trang */
.site-footer{background:var(--night);color:#bdb5ad;padding:64px 0 30px;font-size:15px}
.site-footer .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px}
.site-footer h4{color:var(--soft);font-size:15px;margin-bottom:14px}
.site-footer a{display:block;margin-bottom:8px}.site-footer a:hover{color:var(--flame)}
.site-footer .logo img{height:60px;margin-bottom:16px}
.site-footer .copy{border-top:1px solid rgba(255,255,255,.08);margin-top:40px;padding-top:22px;font-size:13px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* điện thoại */
@media (max-width:960px){
  .hero .wrap,.course-hero .wrap,.player{grid-template-columns:1fr}
  .g3,.g4,.g5{grid-template-columns:repeat(2,1fr)}
  .site-footer .cols{grid-template-columns:1fr 1fr}
  .side-list{position:static;max-height:none}
}
@media (max-width:720px){
  section{padding:64px 0}
  .wrap{padding:0 16px}
  .g2,.g3,.g4,.g5{grid-template-columns:1fr}
  .nav{display:none;position:absolute;top:72px;left:0;right:0;flex-direction:column;background:var(--soft);padding:18px 16px 24px;border-bottom:1px solid var(--line);gap:16px;align-items:flex-start}
  .nav.open{display:flex}
  .burger{display:block}
  .hero{padding:64px 0 72px}
  .site-footer .cols{grid-template-columns:1fr}
}

/* bài bị khóa: cần đăng ký hoặc mua */
.gate{aspect-ratio:16/9;display:grid;place-items:center;text-align:center;color:#fff;padding:24px}
.gate h3{color:#fff;margin:10px 0 8px;font-size:clamp(20px,2.4vw,28px)}
.gate p{color:#d9d3cc;max-width:520px;margin:0 auto 20px;font-size:15px}
.gate-btns{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
@media (max-width:600px){.gate{aspect-ratio:auto;min-height:300px}.gate p{font-size:14px}}
.lesson-row .lk{font-size:12px;font-weight:700;padding:3px 8px;border-radius:20px;background:rgba(247,140,38,.12);color:var(--ember);white-space:nowrap}
/* trang mua khóa & tài khoản */
.pay-box{display:grid;grid-template-columns:260px 1fr;gap:28px;align-items:center}
.pay-box img{width:100%;border-radius:14px;background:#fff;border:1px solid var(--line)}
.pay-row{display:flex;justify-content:space-between;gap:12px;padding:10px 0;border-bottom:1px dashed var(--line);font-size:15px}
.pay-row b{font-family:Montserrat,sans-serif}.copy{cursor:pointer;color:var(--ember);font-weight:700;font-size:13px;margin-left:8px}
.pack{display:flex;gap:14px;padding:14px 0;border-bottom:1px solid var(--line)}.pack .i{font-size:26px}.pack p{margin:2px 0 0;font-size:14px}
.tabs-acc{display:flex;gap:8px;margin-bottom:22px}.tabs-acc button{flex:1;padding:12px;border-radius:12px;border:1px solid var(--line);background:#fff;font:inherit;font-weight:700;cursor:pointer}
.tabs-acc button.on{background:var(--night,#0C0907);color:#fff;border-color:transparent}
@media (max-width:700px){.pay-box{grid-template-columns:1fr}.pay-box img{max-width:280px;margin:0 auto}}