/* =====================================================================
   GIAO DIỆN NGƯỜI DÙNG  -  thuần CSS, responsive, không dùng framework
   ===================================================================== */

:root{
  --green:#0e7c66;
  --green-dark:#0a5f4e;
  --green-soft:#e6f4f0;
  --gold:#d99026;
  --gold-soft:#fdf3e3;
  --ink:#16202b;
  --ink-2:#3b4757;
  --muted:#6b7787;
  --line:#e4e8ee;
  --bg:#f6f8fa;
  --white:#fff;
  --radius:12px;
  --shadow:0 1px 2px rgba(16,32,48,.06),0 6px 20px rgba(16,32,48,.06);
  --shadow-lg:0 10px 40px rgba(16,32,48,.12);
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
  font-size:16px;line-height:1.65;color:var(--ink);background:var(--bg);
}
img{max-width:100%;height:auto;display:block}
a{color:var(--green);text-decoration:none}
a:hover{color:var(--green-dark)}
h1,h2,h3,h4{line-height:1.3;margin:0 0 .6em;color:var(--ink);font-weight:700}
h1{font-size:2rem}
h2{font-size:1.5rem}
h3{font-size:1.18rem}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em;padding-left:1.3em}
hr{border:0;border-top:1px solid var(--line);margin:2rem 0}
.container{max-width:1180px;margin:0 auto;padding:0 18px}
.site-main{min-height:60vh;padding:28px 0 56px}

/* ---------------------------- HEADER ---------------------------- */
.site-header{background:var(--white);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.header-inner{display:flex;align-items:center;gap:18px;min-height:68px;flex-wrap:wrap}
.logo{display:flex;align-items:center;gap:10px;color:var(--ink);margin-right:auto}
.logo-mark{
  width:40px;height:40px;border-radius:10px;flex:none;
  background:linear-gradient(135deg,var(--green),#12a184);
  color:#fff;font-weight:800;display:flex;align-items:center;justify-content:center;letter-spacing:.5px;
}
.logo-text strong{display:block;font-size:1.02rem;line-height:1.2}
.logo-text small{display:block;color:var(--muted);font-size:.76rem}
.site-nav{display:flex;align-items:center;gap:4px;flex-wrap:wrap}
.site-nav>a{
  padding:8px 11px;border-radius:8px;color:var(--ink-2);font-size:.94rem;font-weight:500;white-space:nowrap;
}
.site-nav>a:hover{background:var(--green-soft);color:var(--green-dark)}
.site-nav>a.active{color:var(--green-dark);background:var(--green-soft);font-weight:600}
.nav-search{display:flex;margin-left:6px}
.nav-search input{
  border:1px solid var(--line);border-right:0;border-radius:8px 0 0 8px;padding:8px 12px;
  font-size:.9rem;width:180px;outline:none;background:var(--bg);
}
.nav-search input:focus{border-color:var(--green);background:#fff}
.nav-search button{
  border:0;background:var(--green);color:#fff;padding:0 14px;border-radius:0 8px 8px 0;cursor:pointer;font-size:.9rem;
}
.nav-search button:hover{background:var(--green-dark)}
.nav-toggle,.nav-burger{display:none}

/* menu người dùng */
.nav-user{position:relative;margin-left:6px}
.nav-avatar{display:flex;align-items:center;gap:8px;padding:5px 10px;border-radius:30px;background:var(--bg);color:var(--ink)}
.avatar{
  width:30px;height:30px;border-radius:50%;background:var(--green);color:#fff;flex:none;
  display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.9rem;
}
.nav-user-name{font-size:.9rem;font-weight:600}
.nav-drop{
  position:absolute;right:0;top:calc(100% + 8px);background:#fff;border:1px solid var(--line);
  border-radius:10px;box-shadow:var(--shadow-lg);min-width:210px;padding:6px;display:none;z-index:60;
}
.nav-user:hover .nav-drop,.nav-user:focus-within .nav-drop{display:block}
.nav-drop a{display:block;padding:9px 12px;border-radius:7px;color:var(--ink-2);font-size:.92rem}
.nav-drop a:hover{background:var(--green-soft);color:var(--green-dark)}

/* ---------------------------- NÚT ---------------------------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;border-radius:9px;border:1px solid transparent;cursor:pointer;
  font-size:.96rem;font-weight:600;font-family:inherit;transition:.15s;text-align:center;
}
.btn-primary{background:var(--green);color:#fff}
.btn-primary:hover{background:var(--green-dark);color:#fff}
.btn-gold{background:var(--gold);color:#fff}
.btn-gold:hover{background:#bb7a1c;color:#fff}
.btn-ghost{background:#fff;border-color:var(--line);color:var(--ink-2)}
.btn-ghost:hover{border-color:var(--green);color:var(--green-dark)}
.btn-danger{background:#d64545;color:#fff}
.btn-danger:hover{background:#b93838;color:#fff}
.btn-sm{padding:7px 14px;font-size:.88rem}
.btn-lg{padding:14px 28px;font-size:1.05rem}
.btn-block{display:flex;width:100%}
.btn[disabled]{opacity:.55;cursor:not-allowed}

/* ---------------------------- THÔNG BÁO ---------------------------- */
.alert{padding:12px 16px;border-radius:9px;margin:0 0 16px;font-size:.95rem;border:1px solid}
.alert-success{background:#e8f7f0;border-color:#b7e4cd;color:#12603f}
.alert-error{background:#fdecec;border-color:#f5c2c2;color:#a02525}
.alert-info{background:#eaf2fd;border-color:#c3d9f5;color:#1c4e8a}

/* ---------------------------- HERO ---------------------------- */
.hero{
  background:linear-gradient(135deg,#0b5f4e 0%,#0e7c66 55%,#13a083 100%);
  color:#fff;padding:52px 0 46px;
}
.hero h1{color:#fff;font-size:2.3rem;max-width:18ch}
.hero p{color:rgba(255,255,255,.9);font-size:1.08rem;max-width:60ch}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.hero-actions .btn-ghost{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.35);color:#fff}
.hero-actions .btn-ghost:hover{background:rgba(255,255,255,.2);color:#fff}
.hero-stats{display:flex;gap:30px;flex-wrap:wrap;margin-top:32px;padding-top:22px;border-top:1px solid rgba(255,255,255,.2)}
.hero-stats div strong{display:block;font-size:1.7rem;line-height:1.1}
.hero-stats div span{font-size:.86rem;color:rgba(255,255,255,.82)}

/* ---------------------------- KHỐI / TIÊU ĐỀ ---------------------------- */
.section{padding:38px 0}
.section-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:20px}
.section-head h2{margin:0}
.section-head p{margin:4px 0 0;color:var(--muted);font-size:.95rem}
.section-head a{font-size:.92rem;font-weight:600;white-space:nowrap}
.page-head{margin-bottom:24px}
.page-head h1{margin-bottom:6px}
.page-head p{color:var(--muted);margin:0}

/* ---------------------------- LƯỚI ---------------------------- */
.grid{display:grid;gap:20px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.layout-side{display:grid;grid-template-columns:1fr 310px;gap:30px;align-items:start}

/* ---------------------------- CARD ---------------------------- */
.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
  display:flex;flex-direction:column;transition:.16s;
}
.card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}
.card-thumb{position:relative;aspect-ratio:16/9;background:#eef1f5;overflow:hidden}
.card-thumb img{width:100%;height:100%;object-fit:cover}
.card-body{padding:15px 16px 18px;display:flex;flex-direction:column;flex:1}
.card-title{font-size:1.05rem;margin:0 0 8px;font-weight:700;line-height:1.35}
.card-title a{color:var(--ink)}
.card-title a:hover{color:var(--green)}
.card-desc{color:var(--muted);font-size:.92rem;margin:0 0 12px;flex:1}
.card-meta{display:flex;align-items:center;gap:12px;color:var(--muted);font-size:.83rem;flex-wrap:wrap}
.tag{
  display:inline-block;background:var(--green-soft);color:var(--green-dark);
  padding:3px 10px;border-radius:20px;font-size:.78rem;font-weight:600;
}
.tag-gold{background:var(--gold-soft);color:#8a5c10}
.badge-play{
  position:absolute;inset:0;display:flex;align-items:center;justify-content:center;
  background:rgba(10,26,20,.28);color:#fff;font-size:2.4rem;transition:.15s;
}
.card:hover .badge-play{background:rgba(10,26,20,.45)}
.duration{
  position:absolute;right:8px;bottom:8px;background:rgba(0,0,0,.78);color:#fff;
  padding:2px 8px;border-radius:5px;font-size:.78rem;font-weight:600;
}

/* card khóa học */
.course-card .price{display:flex;align-items:baseline;gap:9px;margin:0 0 12px}
.course-card .price b{font-size:1.25rem;color:var(--gold);font-weight:800}
.course-card .price del{color:var(--muted);font-size:.9rem}
.course-card .card-meta{border-top:1px solid var(--line);padding-top:11px;margin-top:auto}

/* ---------------------------- BÀI VIẾT CHI TIẾT ---------------------------- */
.breadcrumb{font-size:.88rem;color:var(--muted);margin-bottom:16px}
.breadcrumb a{color:var(--muted)}
.breadcrumb a:hover{color:var(--green)}
.breadcrumb span{margin:0 6px}
.article{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px}
.article h1{font-size:1.9rem}
.article-meta{display:flex;gap:16px;flex-wrap:wrap;color:var(--muted);font-size:.88rem;margin-bottom:20px;
  padding-bottom:16px;border-bottom:1px solid var(--line)}
.article-thumb{border-radius:10px;overflow:hidden;margin-bottom:22px}
.content{font-size:1.04rem;color:var(--ink-2);line-height:1.8}
.content h2{font-size:1.4rem;margin-top:1.7em;color:var(--ink)}
.content h3{font-size:1.15rem;margin-top:1.4em}
.content img{border-radius:10px;margin:1.2em 0}
.content ul,.content ol{padding-left:1.4em}
.content li{margin-bottom:.5em}
.content blockquote{
  margin:1.4em 0;padding:14px 20px;background:var(--green-soft);
  border-left:4px solid var(--green);border-radius:0 8px 8px 0;color:var(--ink-2);
}
.content code{background:#f1f3f6;padding:2px 6px;border-radius:5px;font-size:.92em}
.content pre{background:#16202b;color:#e8edf3;padding:16px;border-radius:10px;overflow-x:auto}
.content table{width:100%;border-collapse:collapse;margin:1.2em 0}
.content th,.content td{border:1px solid var(--line);padding:9px 12px;text-align:left}
.content th{background:var(--bg)}

/* video nhúng */
.video-frame{position:relative;padding-top:56.25%;border-radius:10px;overflow:hidden;background:#000}
.video-frame iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.video-empty{padding:40px;text-align:center;background:#eef1f5;border-radius:10px;color:var(--muted)}

/* ---------------------------- SIDEBAR ---------------------------- */
.widget{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px;margin-bottom:20px}
.widget h3{font-size:1.02rem;margin:0 0 14px;padding-bottom:10px;border-bottom:1px solid var(--line)}
.widget-list a{display:block;padding:8px 0;color:var(--ink-2);font-size:.94rem;border-bottom:1px dashed var(--line)}
.widget-list a:last-child{border-bottom:0}
.widget-list a:hover{color:var(--green)}
.mini-item{display:flex;gap:11px;padding:9px 0;border-bottom:1px dashed var(--line)}
.mini-item:last-child{border-bottom:0}
.mini-item img{width:78px;height:52px;object-fit:cover;border-radius:7px;flex:none}
.mini-item strong{font-size:.9rem;font-weight:600;line-height:1.35;display:block}
.mini-item a{color:var(--ink)}
.mini-item a:hover{color:var(--green)}
.mini-item small{color:var(--muted);font-size:.8rem}

/* ---------------------------- BÌNH LUẬN ---------------------------- */
.comments{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:24px;margin-top:24px}
.comment{display:flex;gap:12px;padding:15px 0;border-bottom:1px solid var(--line)}
.comment:last-child{border-bottom:0}
.comment .avatar{width:40px;height:40px;font-size:1rem}
.comment-body strong{font-size:.95rem}
.comment-body time{color:var(--muted);font-size:.8rem;margin-left:8px}
.comment-body p{margin:5px 0 0;color:var(--ink-2);font-size:.96rem;white-space:pre-line}
.comment-login{background:var(--bg);border-radius:9px;padding:18px;text-align:center;color:var(--muted)}

/* ---------------------------- FORM ---------------------------- */
.form-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px}
.form-narrow{max-width:480px;margin:0 auto}
.field{margin-bottom:16px}
.field label{display:block;font-weight:600;font-size:.92rem;margin-bottom:6px;color:var(--ink-2)}
.field .hint{font-size:.83rem;color:var(--muted);margin-top:5px}
input[type=text],input[type=email],input[type=tel],input[type=password],input[type=number],input[type=search],
input[type=url],input[type=date],input[type=file],select,textarea{
  width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:9px;
  font-size:.97rem;font-family:inherit;color:var(--ink);background:#fff;outline:none;
}
input:focus,select:focus,textarea:focus{border-color:var(--green);box-shadow:0 0 0 3px rgba(14,124,102,.12)}
textarea{min-height:120px;resize:vertical;line-height:1.6}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.form-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:8px}
.radio-card{display:flex;gap:11px;align-items:flex-start;border:1px solid var(--line);
  border-radius:10px;padding:13px 15px;margin-bottom:10px;cursor:pointer}
.radio-card:hover{border-color:var(--green)}
.radio-card input{margin-top:4px;width:auto}
.radio-card strong{display:block;font-size:.96rem}
.radio-card small{color:var(--muted);font-size:.85rem}
.radio-card.disabled{opacity:.55;cursor:not-allowed}
.checkbox-inline{display:flex;align-items:center;gap:8px;font-size:.93rem}
.checkbox-inline input{width:auto}

/* ---------------------------- PHÂN TRANG ---------------------------- */
.pagination{display:flex;gap:6px;justify-content:center;margin-top:34px;flex-wrap:wrap}
.pagination a,.pagination span{
  min-width:40px;padding:9px 12px;border:1px solid var(--line);background:#fff;
  border-radius:8px;text-align:center;font-size:.92rem;color:var(--ink-2);
}
.pagination a:hover{border-color:var(--green);color:var(--green)}
.pagination .current{background:var(--green);border-color:var(--green);color:#fff;font-weight:700}
.pagination .dots{border:0;background:transparent}

/* ---------------------------- TRANG KHÓA HỌC ---------------------------- */
.course-hero{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px;margin-bottom:24px}
.course-hero h1{font-size:1.85rem;margin-bottom:10px}
.course-hero .summary{color:var(--ink-2);font-size:1.05rem}
.course-facts{display:flex;gap:22px;flex-wrap:wrap;margin-top:18px;font-size:.9rem;color:var(--muted)}
.course-facts b{color:var(--ink);font-weight:600}
.buy-box{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;position:sticky;top:88px}
.buy-box .price-now{font-size:2rem;font-weight:800;color:var(--gold);line-height:1.2}
.buy-box del{color:var(--muted)}
.buy-box ul{list-style:none;padding:0;margin:16px 0 0;font-size:.92rem;color:var(--ink-2)}
.buy-box ul li{padding:6px 0 6px 24px;position:relative}
.buy-box ul li:before{content:"✓";position:absolute;left:0;color:var(--green);font-weight:700}
.outcome-list{list-style:none;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:10px}
.outcome-list li{padding-left:26px;position:relative;color:var(--ink-2)}
.outcome-list li:before{content:"✓";position:absolute;left:0;top:0;color:var(--green);font-weight:700}

/* chương trình học */
.curriculum{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:#fff}
.cur-section{border-bottom:1px solid var(--line)}
.cur-section:last-child{border-bottom:0}
.cur-section>summary{
  padding:14px 18px;background:var(--bg);font-weight:700;cursor:pointer;display:flex;
  justify-content:space-between;gap:12px;align-items:center;
}
.cur-section>summary::-webkit-details-marker{display:none}
.cur-section>summary small{font-weight:500;color:var(--muted)}
.cur-lesson{display:flex;align-items:center;gap:10px;padding:11px 18px;border-top:1px solid var(--line);font-size:.95rem}
.cur-lesson .ico{color:var(--muted);flex:none}
.cur-lesson .t{flex:1}
.cur-lesson .free{background:var(--green-soft);color:var(--green-dark);font-size:.75rem;
  padding:2px 8px;border-radius:20px;font-weight:700}
.cur-lesson .dur{color:var(--muted);font-size:.84rem}

/* thanh tiến độ */
.progress{height:8px;background:var(--line);border-radius:20px;overflow:hidden;margin:10px 0 6px}
.progress i{display:block;height:100%;background:var(--green);border-radius:20px}

/* ---------------------------- ĐƠN HÀNG ---------------------------- */
.order-box{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.order-status{display:inline-block;padding:4px 12px;border-radius:20px;font-size:.84rem;font-weight:700}
.st-pending{background:var(--gold-soft);color:#8a5c10}
.st-paid{background:#e8f7f0;color:#12603f}
.st-cancelled{background:#f1f3f6;color:#6b7787}
.bank-info{background:var(--bg);border:1px dashed var(--line);border-radius:10px;padding:18px;margin:16px 0}
.bank-info dl{display:grid;grid-template-columns:170px 1fr;gap:8px 14px;margin:0}
.bank-info dt{color:var(--muted);font-size:.9rem}
.bank-info dd{margin:0;font-weight:600}
.bank-info .copy{font-family:monospace;font-size:1.02rem;background:#fff;border:1px solid var(--line);
  padding:3px 9px;border-radius:6px;display:inline-block}
/* vòng xoay chờ nhận tiền */
.spinner{
  width:18px;height:18px;flex:none;border-radius:50%;display:inline-block;
  border:2px solid rgba(28,78,138,.25);border-top-color:#1c4e8a;
  animation:spin .8s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}
@media (prefers-reduced-motion:reduce){.spinner{animation-duration:2.4s}}

.qr-box{text-align:center}
.qr-box img{width:230px;margin:0 auto;border:1px solid var(--line);border-radius:10px;background:#fff;padding:6px}

/* ---------------------------- BẢNG ---------------------------- */
.table-wrap{overflow-x:auto;background:#fff;border:1px solid var(--line);border-radius:var(--radius)}
table.data{width:100%;border-collapse:collapse;font-size:.93rem}
table.data th,table.data td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);vertical-align:middle}
table.data th{background:var(--bg);font-size:.85rem;text-transform:uppercase;letter-spacing:.3px;color:var(--muted);white-space:nowrap}
table.data tr:last-child td{border-bottom:0}
table.data tr:hover td{background:#fbfcfd}

/* ---------------------------- TÀI KHOẢN ---------------------------- */
.account-layout{display:grid;grid-template-columns:250px 1fr;gap:26px;align-items:start}
.account-menu{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:10px}
.account-menu a{display:block;padding:11px 14px;border-radius:8px;color:var(--ink-2);font-size:.95rem}
.account-menu a:hover{background:var(--bg)}
.account-menu a.active{background:var(--green-soft);color:var(--green-dark);font-weight:700}
.stat-row{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:24px}
.stat{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px}
.stat b{display:block;font-size:1.8rem;line-height:1.1;color:var(--green)}
.stat span{color:var(--muted);font-size:.88rem}

/* ---------------------------- TRẠNG THÁI RỖNG ---------------------------- */
.empty{background:#fff;border:1px dashed var(--line);border-radius:var(--radius);
  padding:46px 24px;text-align:center;color:var(--muted)}
.empty h3{color:var(--ink)}

/* ---------------------------- FOOTER ---------------------------- */
.site-footer{background:#101c26;color:#b9c4d0;padding:44px 0 22px;margin-top:40px}
.footer-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.2fr;gap:30px}
.site-footer h4{color:#fff;font-size:.95rem;margin-bottom:12px}
.site-footer a{display:block;color:#b9c4d0;font-size:.92rem;padding:4px 0}
.site-footer a:hover{color:#fff}
.site-footer p{font-size:.92rem;margin:0 0 8px}
.footer-logo{font-size:1.2rem;font-weight:800;color:#fff;margin-bottom:10px}
.footer-social{display:flex;gap:14px;margin-top:10px}
.footer-social a{display:inline-block}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);margin-top:26px;padding-top:16px;font-size:.86rem}

/* nút Zalo nổi */
.float-zalo{
  position:fixed;right:18px;bottom:18px;z-index:70;background:var(--green);color:#fff;
  padding:12px 18px;border-radius:30px;font-weight:700;font-size:.9rem;box-shadow:var(--shadow-lg);
}
.float-zalo:hover{background:var(--green-dark);color:#fff}

/* =====================================================================
   KHU VỰC HỌC (layout learn)
   ===================================================================== */
.learn-wrap{display:grid;grid-template-columns:330px 1fr;min-height:100vh}
.learn-side{background:#0f1a24;color:#c7d2dd;padding:0;overflow-y:auto;max-height:100vh;position:sticky;top:0}
.learn-side-head{padding:18px;border-bottom:1px solid rgba(255,255,255,.08)}
.learn-side-head a{color:#8fd9c6;font-size:.85rem}
.learn-side-head h2{color:#fff;font-size:1.05rem;margin:8px 0 6px}
.learn-side-head .progress{background:rgba(255,255,255,.15)}
.learn-side-head small{color:#8b99a8;font-size:.83rem}
.learn-sec{padding:12px 18px 4px;font-size:.8rem;text-transform:uppercase;letter-spacing:.5px;color:#7e8c9b}
.learn-lesson{display:flex;gap:10px;padding:10px 18px;color:#c7d2dd;font-size:.93rem;align-items:flex-start;
  border-left:3px solid transparent}
.learn-lesson:hover{background:rgba(255,255,255,.05);color:#fff}
.learn-lesson.active{background:rgba(19,160,131,.16);border-left-color:#13a083;color:#fff;font-weight:600}
.learn-lesson.done .ico{color:#3fcaa6}
.learn-lesson .ico{flex:none;width:18px;text-align:center}
.learn-lesson .locked{color:#6b7787}
.learn-main{padding:26px 32px 60px;background:var(--bg);max-width:100%}
.learn-main .video-frame{margin-bottom:22px}
.learn-nav{display:flex;justify-content:space-between;gap:12px;margin-top:26px;flex-wrap:wrap}
.learn-bar{display:flex;justify-content:space-between;align-items:center;gap:14px;flex-wrap:wrap;margin-bottom:18px}

/* =====================================================================
   RESPONSIVE
   ===================================================================== */
@media (max-width:1024px){
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .layout-side{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .learn-wrap{grid-template-columns:280px 1fr}
  .learn-main{padding:22px 20px 50px}
}
@media (max-width:820px){
  .nav-burger{
    display:block;width:42px;height:42px;border:1px solid var(--line);border-radius:9px;
    cursor:pointer;position:relative;
  }
  .nav-burger span,.nav-burger:before,.nav-burger:after{
    content:"";position:absolute;left:10px;right:10px;height:2px;background:var(--ink);border-radius:2px;
  }
  .nav-burger:before{top:14px}
  .nav-burger span{top:20px}
  .nav-burger:after{top:26px}
  .site-nav{display:none;width:100%;flex-direction:column;align-items:stretch;padding:10px 0 16px;gap:2px}
  .nav-toggle:checked ~ .site-nav{display:flex}
  .site-nav>a{padding:11px 12px}
  .nav-search{margin:8px 0}
  .nav-search input{width:100%}
  .nav-user{margin:8px 0 0}
  .nav-drop{position:static;display:block;box-shadow:none;border:0;padding:0;min-width:0;background:transparent}
  .nav-drop a{padding:11px 12px}
  .nav-avatar{display:none}
  .account-layout{grid-template-columns:1fr}
  .learn-wrap{grid-template-columns:1fr}
  .learn-side{max-height:none;position:static}
  .article{padding:22px 18px}
  .hero h1{font-size:1.8rem}
  .outcome-list{grid-template-columns:1fr}
  .buy-box{position:static}
}
@media (max-width:560px){
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
  .form-row{grid-template-columns:1fr}
  .stat-row{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .bank-info dl{grid-template-columns:1fr}
  .bank-info dt{margin-top:6px}
  h1{font-size:1.55rem}
  .hero{padding:38px 0 34px}
  .hero-stats{gap:18px}
  .section{padding:26px 0}
  .float-zalo{padding:10px 14px;font-size:.84rem}
}

/* in ấn */
@media print{
  .site-header,.site-footer,.float-zalo,.pagination{display:none}
  body{background:#fff}
}

/* =====================================================================
   MUA NHANH · TÀI LIỆU ĐỌC TRÊN WEB
   ===================================================================== */

/* ---------------------------- Gợi ý nhỏ dưới ô nhập ---------------------------- */
.hint{font-size:.86rem;color:var(--muted);line-height:1.55}
.help{background:var(--green-soft);border-radius:9px;padding:13px 15px;
  font-size:.89rem;color:var(--green-dark);margin:16px 0}

/* ---------------------------- Dải chuyên mục ---------------------------- */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 22px}
.chip{display:inline-block;padding:7px 15px;border-radius:999px;background:#fff;
  border:1px solid var(--line);color:var(--ink-2);font-size:.9rem}
.chip:hover{border-color:var(--green);color:var(--green)}
.chip.active{background:var(--green);border-color:var(--green);color:#fff;font-weight:600}

/* ---------------------------- Ba bước mua hàng ---------------------------- */
.buy-steps{list-style:none;display:flex;gap:8px;padding:0;margin:0 0 24px;counter-reset:s}
.buy-steps li{flex:1;counter-increment:s;font-size:.83rem;color:var(--muted);
  text-align:center;padding:9px 4px;border-radius:8px;background:var(--bg);
  border:1px solid var(--line);line-height:1.35}
.buy-steps li::before{content:counter(s);display:block;font-weight:800;font-size:1rem;color:var(--muted)}
.buy-steps li.active{background:var(--green-soft);border-color:var(--green);color:var(--green-dark);font-weight:600}
.buy-steps li.active::before{color:var(--green)}

/* ---------------------------- Khung mã học viên ---------------------------- */
.credential-box{background:var(--green-soft);border:1px dashed var(--green);
  border-radius:var(--radius);padding:22px 24px}
.credential-box h2{font-size:1.1rem;margin:0 0 10px;color:var(--green-dark)}
.credential-box dl{display:grid;grid-template-columns:200px 1fr;gap:10px 14px;margin:14px 0}
.credential-box dt{color:var(--ink-2);font-size:.9rem}
.credential-box dd{margin:0;font-weight:700}
.credential-box .copy{font-family:monospace;background:#fff;border:1px solid var(--line);
  border-radius:7px;padding:4px 10px;cursor:pointer;display:inline-block}
.cred-code{font-size:1.35rem;letter-spacing:1.5px;color:var(--green-dark)}
.cred-note{font-size:.87rem;color:var(--ink-2);margin:10px 0 0;line-height:1.6}

/* ---------------------------- Trang giới thiệu tài liệu ---------------------------- */
.doc-facts{display:flex;flex-wrap:wrap;gap:8px 18px;margin:0 0 22px;
  padding:14px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);
  font-size:.92rem;color:var(--muted)}
.doc-facts b{color:var(--ink)}
.notice-box{background:var(--gold-soft);border:1px solid #f0dcb8;border-radius:var(--radius);
  padding:18px 22px;margin:26px 0}
.notice-box h3{font-size:1.02rem;margin:0 0 8px;color:#8a5c10}
.notice-box ul{margin:0;padding-left:1.2em;font-size:.93rem;color:#6d4f14}
.notice-box li{margin-bottom:5px}
.buy-box{position:sticky;top:90px}
.buy-thumb{width:100%;border-radius:10px;border:1px solid var(--line)}

/* ---------------------------- Danh sách đã mua ---------------------------- */
.owned-list{display:flex;flex-direction:column;gap:12px}
.owned-item{display:flex;align-items:center;gap:16px;background:#fff;
  border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px}
.owned-item img{width:96px;height:64px;object-fit:cover;border-radius:8px;flex:none}
.owned-info{flex:1;min-width:0}
.owned-info strong{display:block;font-size:1rem;line-height:1.35}
.owned-info small{color:var(--muted);font-size:.86rem}
.owned-act{flex:none}

@media (max-width:760px){
  .credential-box dl{grid-template-columns:1fr;gap:4px}
  .credential-box dt{margin-top:8px}
  .buy-box{position:static}
  .owned-item{flex-wrap:wrap}
  .owned-item img{width:72px;height:50px}
  .owned-act{width:100%}
  .owned-act .btn{width:100%;text-align:center}
}