/* v8: khoá học theo học kì, ôn theo văn bản, đề tự chọn */
.gtabs{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:14px 0}
.gtab{display:grid;gap:2px;text-align:left;padding:12px 14px;border-radius:18px;border:2px solid color-mix(in srgb,var(--c) 35%,transparent);background:var(--card);color:var(--ink);cursor:pointer;font:inherit;transition:transform .15s,box-shadow .15s}
.gtab b{font:800 30px/1 'Baloo 2',system-ui,sans-serif;color:var(--c)}.gtab span{font-weight:700;font-size:13.5px}.gtab small{opacity:.75;font-size:12px}
.gtab:hover{transform:translateY(-2px);box-shadow:0 6px 16px #0002}.gtab.on{background:var(--c);border-color:var(--c);color:#fff}.gtab.on b{color:#fff}.gtab.is-locked{opacity:.6}
.cur-banner{display:flex;flex-wrap:wrap;gap:10px;align-items:center;padding:12px 16px;border-radius:16px;border-left:8px solid var(--c);background:color-mix(in srgb,var(--c) 14%,var(--card));color:var(--ink);margin-bottom:18px}
.cur-act{margin-left:auto;display:flex;gap:8px;flex-wrap:wrap}
.hk{margin:0 0 28px}.hk-h{display:flex;flex-wrap:wrap;gap:10px 18px;align-items:center;padding:14px 18px;border-radius:18px;background:var(--card);border:1px solid var(--line);margin-bottom:14px}
.hk-h small{font-weight:800;letter-spacing:.08em;color:var(--mut)}.hk-h h2{margin:0;font:800 24px 'Baloo 2',system-ui,sans-serif}.hk-s{margin-left:auto;color:var(--mut);font-size:14px}.hk-s b{color:var(--ink)}
.ucards{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px}
.ucard{display:grid;gap:8px;align-content:start;padding:16px 18px;border-radius:20px;background:var(--card);color:var(--ink);border:1px solid var(--line);border-top:6px solid var(--c);box-shadow:0 4px 14px #0001}
.ucard header b{color:var(--c);font-size:13px;letter-spacing:.04em}.ucard h3{margin:2px 0;font:800 19px/1.25 'Baloo 2',system-ui,sans-serif}.ucard header small{color:var(--mut)}
.ulist{list-style:none;margin:0;padding:0;display:grid;gap:5px;font-size:14px}.ulist li{line-height:1.4}.ulist small{color:var(--mut)}
.tg{display:inline-block;padding:1px 8px;border-radius:99px;font:700 11px/1.6 system-ui,sans-serif;color:#fff;background:#4b5bb0;vertical-align:1px;white-space:nowrap}
.tg-viet{background:#c0392b}.tg-noi{background:#1e8a8f}.tg-tho{background:#8a5cc7}
.uact{display:flex;gap:8px;margin-top:4px}.btn-sm{min-height:36px;padding:6px 14px;font-size:14px}
.sub{margin:14px 0 8px;font-size:15px;color:var(--mut)}
.vb-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:10px}
.vb{display:grid;gap:2px;padding:10px 14px;border-radius:14px;background:var(--card);color:var(--ink);border:1px solid var(--line);border-left:6px solid var(--c);text-decoration:none}
.vb b{font-size:14px;line-height:1.3}.vb small{color:var(--mut);font-size:12px}.vb em{font-style:normal;font-size:12px;font-weight:700;color:var(--c)}.vb0{opacity:.8}.vb:hover{transform:translateY(-2px);text-decoration:none;box-shadow:0 4px 12px #0002}
.de-box{padding:18px 20px;border-radius:20px;background:var(--card);border:1px solid var(--line);color:var(--ink)}.de-box h3{margin:14px 0 6px;font-size:15px}.de-box h3:first-child{margin-top:0}
.chips2{display:flex;flex-wrap:wrap;gap:8px}.chip2{padding:7px 14px;border-radius:99px;border:1.5px solid var(--line);background:transparent;color:var(--ink);font-weight:600;font-size:14px;font-family:inherit;cursor:pointer;min-height:38px}
.chip2:hover{border-color:var(--blue)}.chip2.on{background:#4b5bb0;border-color:#4b5bb0;color:#fff}
.de-sum{margin:16px 0 12px}
[data-theme=dark] .chip2.on,[data-theme=dark] .tg{filter:none}[data-theme=dark] .gtab.on{color:#10131f}[data-theme=dark] .gtab.on b{color:#10131f}
@media(max-width:760px){.gtabs{grid-template-columns:repeat(2,1fr)}.ucards{grid-template-columns:1fr}.cur-act{margin-left:0}.hk-s{margin-left:0}}

/* thanh tên trường nổi bật */
.schoolbar{display:flex;align-items:center;justify-content:center;gap:10px;padding:7px 12px;background:linear-gradient(90deg,#1f2a6b,#3b3fa8 50%,#1f2a6b);color:#ffd84d;font-size:14px;letter-spacing:.06em;text-align:center;flex-wrap:wrap}
.schoolbar b{font:800 16px 'Baloo 2',system-ui,sans-serif;letter-spacing:.08em;text-shadow:0 1px 0 #0006}
.schoolbar .sb-loc{color:#e8ecff;letter-spacing:.02em}.schoolbar .sb-sep{opacity:.6}.schoolbar .sb-star{color:#ffb300}
.brand-tx b{font-size:19px;letter-spacing:.01em}
@media(max-width:560px){.schoolbar{font-size:12px;gap:6px;padding:6px 8px}.schoolbar b{font-size:13px}.schoolbar .sb-sep,.schoolbar .sb-star{display:none}.schoolbar .sb-loc{flex-basis:100%}}
@media print{.schoolbar{display:none}}

/* hộp đăng nhập: tài khoản hiển thị sau khi đăng ký */
.auth-acct{margin:0;text-align:center;font:800 24px 'Baloo 2',system-ui,sans-serif;color:var(--blue-d,#35418a);background:color-mix(in srgb,#4b5bb0 12%,transparent);padding:10px 14px;border-radius:14px;word-break:break-all;user-select:all}
[data-theme=dark] .auth-acct{color:#cdd4ff}
.auth-card [hidden]{display:none!important}

/* font thống nhất: nút, ô nhập, nhãn nhỏ dùng đúng font của trang (không rơi về Arial/hệ thống) */
button,input,textarea,select{font-family:inherit}
.tg{font-family:var(--sans,'Be Vietnam Pro',system-ui,sans-serif)}

/* ô ghi suy nghĩ khi đọc: đếm từ, báo đã lưu, phản hồi; sổ suy nghĩ */
.ta-meta{display:flex;justify-content:space-between;font-size:12px;color:var(--mut);min-height:18px;margin:2px 2px 6px}.ta-meta .sv{color:var(--ok,#1f9d57);font-weight:700}
.fb2{margin-top:8px;padding:10px 12px;border-radius:12px;font-size:14px;line-height:1.55}.fb2.ok{background:color-mix(in srgb,#1f9d57 14%,var(--paper,#fff));border:1px solid color-mix(in srgb,#1f9d57 40%,transparent)}.fb2.warn{background:color-mix(in srgb,#e0901a 16%,var(--paper,#fff));border:1px solid color-mix(in srgb,#e0901a 45%,transparent)}
.notebook{display:grid;gap:12px}.nb-item{padding:14px 16px;border-radius:16px;background:var(--card);border:1px solid var(--line);border-left:6px solid var(--c,#4b5bb0);color:var(--ink)}.nb-item small{color:var(--mut)}.nb-q{margin:2px 0 6px;font-weight:700}.nb-a{margin:0;white-space:pre-wrap;font-family:var(--serif)}.nb-act{margin-top:8px;display:flex;gap:8px;flex-wrap:wrap}

/* ô lớn trên trang chủ: biểu tượng và chữ cân xứng (biểu tượng trong ô vuông bo tròn bên trái, chữ căn giữa theo chiều dọc) */
.tile,.tile:hover,.tile:focus,.tile *{text-decoration:none!important}
.tile{display:grid;grid-template-columns:72px minmax(0,1fr);grid-template-rows:1fr 1fr;column-gap:16px;align-items:center;align-content:center;min-height:128px;padding:18px 20px}
.tile .t-ic{position:static;grid-row:1/3;grid-column:1;width:72px;height:72px;display:grid;place-items:center;font-size:38px;line-height:1;border-radius:22px;background:#ffffff2b;box-shadow:inset 0 0 0 1.5px #ffffff3d,0 6px 14px #0002;filter:none;opacity:1}
.tile h3{grid-column:2;grid-row:1;align-self:end;line-height:1.15;margin:0}
.tile p{grid-column:2;grid-row:2;align-self:start;margin:4px 0 0;line-height:1.35;opacity:.92}
@media(max-width:480px){.tile{grid-template-columns:1fr;grid-template-rows:auto auto auto;row-gap:2px;min-height:136px;padding:14px;align-content:start}
  .tile .t-ic{grid-row:1;grid-column:1;width:48px;height:48px;font-size:26px;border-radius:15px;margin-bottom:6px}.tile h3{grid-column:1;grid-row:2;align-self:start;font-size:17px}.tile p{grid-column:1;grid-row:3;font-size:12px}}

/* ảnh sách giáo khoa: bìa ở trang chủ, trang mở đầu bài, phóng to */
.hero-books{position:relative;align-self:stretch;min-height:340px;display:grid;place-items:center;padding:18px 10px 8px}
.hero-books .hb{position:absolute;border:0;padding:0;background:none;cursor:zoom-in;border-radius:6px;box-shadow:0 18px 34px #0006,0 2px 0 #fff3 inset;transition:transform .25s}
.hero-books .hb img{display:block;height:100%;width:100%;border-radius:6px;object-fit:cover}
.hb-a{width:190px;aspect-ratio:520/731;left:50%;top:26px;transform:translateX(-12%) rotate(5deg);z-index:2}.hb-b{width:178px;aspect-ratio:520/731;left:50%;top:42px;transform:translateX(-96%) rotate(-7deg);z-index:1}
.hb-a:hover{transform:translateX(-12%) rotate(2deg) translateY(-6px)}.hb-b:hover{transform:translateX(-96%) rotate(-4deg) translateY(-6px)}
.hb-cap{position:absolute;bottom:6px;left:0;right:0;margin:0;text-align:center;font:600 12.5px var(--sans);color:#e6e9ff;letter-spacing:.03em}
.hb-l{position:absolute;font:800 34px 'Baloo 2',system-ui,sans-serif;color:#ffd166;text-shadow:0 3px 6px #0005;animation:hbf 5s ease-in-out infinite;z-index:3}
.hb-l1{left:6%;top:12%}.hb-l2{right:6%;top:6%;animation-delay:-1.5s}.hb-l3{left:10%;bottom:16%;animation-delay:-3s}.hb-l4{right:8%;bottom:20%;animation-delay:-2s}
@keyframes hbf{50%{transform:translateY(-9px) rotate(6deg)}}
.hero-art,.hero>svg:not(.hero-deco){display:none}
.ucard .u-open{position:relative;display:block;width:100%;height:132px;margin:-4px 0 8px;padding:0;border:0;border-radius:12px;overflow:hidden;cursor:zoom-in;background:#e8ebf8}
.ucard .u-open img{width:100%;height:100%;object-fit:cover;object-position:top;display:block;transition:transform .3s}.ucard .u-open:hover img{transform:scale(1.04)}
.ucard .u-open span{position:absolute;right:8px;bottom:8px;padding:3px 10px;border-radius:99px;background:#000a;color:#fff;font:600 12px var(--sans)}
.hk-cover{width:46px;aspect-ratio:520/731;object-fit:cover;border-radius:5px;box-shadow:0 4px 10px #0003;cursor:zoom-in;flex:none}
.unit-open{display:flex;gap:14px;align-items:center;margin:0 0 18px;padding:12px 14px;border-radius:16px;background:var(--card);border:1px solid var(--line);color:var(--ink)}
.unit-open button{flex:none;width:96px;border:0;padding:0;border-radius:8px;overflow:hidden;cursor:zoom-in;box-shadow:0 4px 12px #0003;background:none}.unit-open img{display:block;width:100%;height:auto}
.unit-open b{display:block}.unit-open small{color:var(--mut)}
.lightbox{position:fixed;inset:0;z-index:100;background:#000d;display:grid;place-items:center;padding:16px;cursor:zoom-out}
.lightbox figure{margin:0;max-height:100%;display:grid;gap:8px;justify-items:center}.lightbox img{max-height:calc(100vh - 80px);max-width:100%;width:auto;border-radius:8px;box-shadow:0 10px 40px #000}
.lightbox figcaption{color:#fff;font:600 14px var(--sans);text-align:center}.lb-x{position:absolute;right:14px;top:14px;width:44px;height:44px;border-radius:50%;border:0;background:#fff;color:#111;font-size:18px;cursor:pointer}
@media(max-width:700px){.hero-books{min-height:280px}.hb-a{width:150px}.hb-b{width:140px}}
@media(prefers-reduced-motion:reduce){.hb-l{animation:none}}

/* Sách hay */
.bk-hero{display:flex;gap:16px;align-items:center;justify-content:space-between;flex-wrap:wrap;padding:24px 26px;border-radius:24px;color:#fff;background:linear-gradient(135deg,#3b2a6b,#7a5af0 60%,#c05a8f);margin-bottom:16px}
.bk-hero h1{margin:.15em 0;font:800 clamp(28px,5vw,42px)/1.05 'Baloo 2',system-ui,sans-serif}.bk-hero p{margin:0;max-width:560px;opacity:.95}
.bk-stat{display:grid;place-items:center;padding:12px 22px;border-radius:18px;background:#ffffff26}.bk-stat b{font:800 38px/1 'Baloo 2',system-ui,sans-serif;color:#ffd166}.bk-stat small{opacity:.9}
.bk-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(330px,1fr));gap:16px}
.bk{display:grid;grid-template-columns:104px minmax(0,1fr);gap:14px;padding:14px;border-radius:20px;background:var(--card);color:var(--ink);border:1px solid var(--line);box-shadow:0 4px 14px #0001}
.bk.read{border-color:#1f9d57}
.bk-cover{position:relative;display:flex;flex-direction:column;justify-content:flex-end;gap:2px;padding:10px 8px;min-height:150px;border-radius:6px 12px 12px 6px;color:#fff;background:linear-gradient(160deg,var(--c),color-mix(in srgb,var(--c) 55%,#000));box-shadow:inset 8px 0 0 #0003,0 6px 14px #0003;font-family:'Noto Serif','Times New Roman',serif;overflow:hidden}
.bk-cover b{font-size:13px;line-height:1.25}.bk-cover small{font-size:10.5px;opacity:.85}.bk-e{position:absolute;right:8px;top:8px;font-size:30px}
.bk-body h3{margin:0 0 2px;font:800 18px/1.25 'Baloo 2',system-ui,sans-serif}.bk-m{margin:0 0 6px;font-size:12.5px;color:var(--mut)}.bk-m span{color:var(--c);font-weight:700}.bk-body p{margin:0 0 6px;font-size:14px;line-height:1.55}
.bk details{margin:6px 0}.bk summary{cursor:pointer;font-weight:700;font-size:14px;color:var(--c)}.bk-sgk{color:var(--mut)}.bk-act{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:8px}
@media(max-width:560px){.bk-grid{grid-template-columns:1fr}.bk{grid-template-columns:84px minmax(0,1fr);gap:12px;padding:12px}.bk-cover{min-height:124px}.bk-cover b{font-size:12px}.bk-hero{padding:18px}}

/* ===== Điện thoại: thanh trên cùng luôn vừa màn hình (từ 320px) ===== */
@media(max-width:560px){
  .topbar{padding:8px 8px;gap:6px}
  .gsw .gsw-l{display:none}
  .gsw{gap:3px;padding:3px}.gsw button,.gsw button.on{width:36px;min-width:36px;height:36px;min-height:36px;font-size:16px;border-radius:12px}
  .gsw button.on{transform:scale(1.06)}
  .topbar .search{width:40px}
  .login-btn{font-size:0!important;width:40px;min-width:40px;height:40px;padding:0!important;border-radius:12px}.login-btn::before{content:'👤';font-size:18px}
  .topbar .icon-btn{width:40px;min-width:40px;height:40px}
  .burger{margin-right:0}
}
@media(max-width:380px){
  .topbar{gap:4px;padding:6px}
  .gsw button,.gsw button.on{width:32px;min-width:32px;height:32px;min-height:32px;font-size:14px;border-radius:10px}
  .brand-mark{width:34px;height:34px;font-size:20px}
}
html,body{max-width:100%}body{overflow-x:clip}

/* trang chủ trên điện thoại: nút hành động cân xứng, sách xếp ngay dưới chữ */
@media(max-width:700px){
  .hero{grid-template-columns:1fr;min-height:0}
  .hero-in{padding:26px 22px 8px}
  .hero-cta{flex-direction:column;align-items:stretch}.hero-cta .btn{width:100%;justify-content:center;white-space:nowrap}
  .hero-books{min-height:270px;padding-top:6px}
  .hb-a{width:142px;top:6px}.hb-b{width:132px;top:20px}
}

/* sách ở trang chủ: to hơn, hai cuốn đặt cân đối hai bên */
.hero-books{min-height:410px;padding:10px 6px 34px}
.hero-books .hb-a{width:min(232px,49%);left:auto;right:2%;top:50px;transform:rotate(4deg)}
.hero-books .hb-b{width:min(218px,46%);right:auto;left:2%;top:68px;transform:rotate(-5deg)}
.hero-books .hb-a:hover{transform:rotate(1deg) translateY(-8px) scale(1.02)}.hero-books .hb-b:hover{transform:rotate(-2deg) translateY(-8px) scale(1.02)}
.hb-cap{bottom:8px;font-size:13px}
@media(max-width:700px){.hero-books{min-height:300px}.hero-books .hb-a{width:min(158px,47%);top:14px}.hero-books .hb-b{width:min(148px,44%);top:30px}}
.photo-edit{position:absolute;right:10px;bottom:10px;padding:6px 12px;border:0;border-radius:99px;background:#000b;color:#fff;font:600 13px var(--sans);cursor:pointer}
.school-photo{position:relative}

/* ===== Khung đầu trang chủ kiểu "văn học": nền xanh có ánh sáng, sách 3D, họa tiết, nút chuyển sắc ===== */
.hero{background:radial-gradient(ellipse at 76% 42%,#2f6fe0 0,#1d4fb0 28%,transparent 62%),radial-gradient(circle at 8% 0,#3a6fd0 0,transparent 40%),linear-gradient(135deg,#0c2566,#133a86 55%,#0f2f75);box-shadow:0 18px 40px #0a1c4d66,inset 0 0 0 1.5px #ffffff1f;isolation:isolate}
.hero .hero-deco{position:absolute;inset:0;width:100%;height:100%;z-index:0;pointer-events:none}
.hero-in,.hero-books{z-index:2}
.hero .kicker{background:#ffffff26;border:1px solid #ffffff2e;backdrop-filter:blur(2px)}
.hero h1{text-shadow:0 4px 0 #0a1c4d55,0 10px 24px #0a1c4d66}
.hero h1 em{background:linear-gradient(180deg,#fff2b3 0,#ffc83d 55%,#f5a623 100%);-webkit-background-clip:text;background-clip:text;color:transparent;-webkit-text-fill-color:transparent;text-shadow:none;filter:drop-shadow(0 4px 0 #8a4a0a88) drop-shadow(0 8px 14px #0a1c4d66);transform:rotate(-3deg)}
.hero h1 .quill{display:inline-block;vertical-align:top;margin:0 0 0 2px;transform:translateY(-4px) rotate(-6deg);filter:drop-shadow(0 4px 8px #0a1c4d77)}
.hero p{text-shadow:0 1px 6px #0a1c4d88}
.hero .btn-primary{background:linear-gradient(135deg,#ff8a3d,#ef4a1c);border-color:#ffb083;box-shadow:0 8px 20px #ef4a1c66,inset 0 1px 0 #ffffff55;border-radius:14px}
.hero .btn-ghost{background:linear-gradient(135deg,#0d3b78aa,#0b2a66aa);border:1.5px solid #4de1d0;color:#fff;border-radius:14px;box-shadow:0 0 18px #4de1d055,inset 0 0 14px #4de1d02e}
.hero .btn-ghost:hover{border-color:#8ff3e6;box-shadow:0 0 24px #4de1d088,inset 0 0 14px #4de1d03e}
.hero-stat .ring{background:radial-gradient(closest-side,#10357f 74%,transparent 76%),conic-gradient(from 0deg,#2ee6c8,#ffd166 calc(var(--p)*1%),#ffffff2e 0);box-shadow:0 0 0 3px #ffffff1a,0 6px 16px #0a1c4d66;width:76px;height:76px}
.hero-stat .ring b{font-size:18px;color:#fff}
/* sách giáo khoa 3D, to và cân đối với chữ bên trái */
.hero-books{min-height:430px;perspective:1100px}
.hero-books .hb{border-radius:5px 9px 9px 5px;box-shadow:-10px 0 0 -6px #0003,0 24px 40px #04123a99,0 3px 0 #fff4 inset;transform-style:preserve-3d}
.hero-books .hb-a{width:min(250px,52%);right:1%;top:34px;transform:rotateY(-14deg) rotateZ(3deg)}
.hero-books .hb-b{width:min(236px,49%);left:0;top:60px;transform:rotateY(14deg) rotateZ(-3deg)}
.hero-books .hb-a:hover{transform:rotateY(-6deg) rotateZ(1deg) translateY(-8px)}.hero-books .hb-b:hover{transform:rotateY(6deg) rotateZ(-1deg) translateY(-8px)}
.hb-l{color:#ffd166;text-shadow:0 2px 0 #8a4a0a66,0 6px 12px #0a1c4d88}
.hb-l5{right:20%;bottom:18%;animation-delay:-4s}.hb-l6{left:34%;bottom:12%;animation-delay:-1s;font-size:28px}
.hb-cap{color:#cfe0ff;text-shadow:0 1px 4px #0a1c4d88}
@media(max-width:700px){.hero-books{min-height:300px}.hero-books .hb-a{width:min(160px,47%);top:12px}.hero-books .hb-b{width:min(150px,44%);top:30px}.hero h1 .quill svg{width:40px;height:34px}.hero .hero-deco{top:auto;bottom:0;height:46%;opacity:.95}}

/* phân hệ quản trị nhúng trong web */
.adm-head{display:flex;gap:12px;align-items:center;justify-content:space-between;flex-wrap:wrap}.adm-head .page-t{margin:0}
.adm-frame{display:block;width:100%;height:calc(100vh - 230px);min-height:560px;border:1px solid var(--line);border-radius:18px;background:var(--card)}
.admin-btn{background:#ffd166;color:#2a1a00;border-color:#ffd166;font-weight:700;border-radius:12px}
@media(max-width:560px){.admin-btn{font-size:0!important;width:40px;min-width:40px;height:40px;padding:0!important}.admin-btn::before{content:'⚙️';font-size:18px}.adm-frame{height:calc(100vh - 200px)}}

/* ===== Nền pastel + lớp trang trí văn học hai bên rìa ===== */
body{background:linear-gradient(135deg,#fff8ee 0%,#ffeef3 32%,#e8f1ff 68%,#f7f2e9 100%) fixed}
[data-theme=dark] body{background:linear-gradient(135deg,#14172a 0%,#1d1832 48%,#101a30 100%) fixed}
.lit-bg{position:fixed;inset:0;z-index:-1;pointer-events:none;opacity:.8}
[data-theme=dark] .lit-bg{opacity:.28;filter:saturate(.75)}
@media(max-width:900px){.lit-bg{opacity:.5}[data-theme=dark] .lit-bg{opacity:.2}}
@media print{.lit-bg,.scrim,.drawer-x{display:none!important}}

/* ===== Menu trượt trên điện thoại: có nút đóng ✕ và lớp phủ bấm để đóng ===== */
.scrim,.drawer-x{display:none}
@media(max-width:900px){
  .side{inset:0 auto 0 0!important;width:min(300px,86vw)!important;padding-top:64px!important;z-index:70!important;border-radius:0 22px 22px 0}
  .side::before{content:'☰  Menu';position:absolute;left:18px;top:20px;font:800 18px 'Baloo 2',system-ui,sans-serif;color:var(--blue-d,#35418a)}
  .scrim{position:fixed;inset:0;z-index:65;background:#0008;backdrop-filter:blur(1px)}
  #drawer-toggle:checked~.shell .scrim{display:block}
  .drawer-x{position:fixed;top:10px;left:calc(min(300px,86vw) - 54px);width:44px;height:44px;border-radius:50%;background:#e8ebf8;color:#1f2340;font-size:18px;place-items:center;z-index:71;cursor:pointer;box-shadow:0 2px 8px #0003}
  #drawer-toggle:checked~.shell .drawer-x{display:grid}
  [data-theme=dark] .drawer-x{background:#2c3150;color:#fff}
  [data-theme=dark] .side::before{color:#aab5ff}
}

/* ===== Thẻ bài học: tranh minh hoạ, đầu thẻ chuyển sắc theo tập, nhãn thể loại ===== */
.bcard-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:18px;margin-top:6px}
.bcard{position:relative;display:grid;grid-template-rows:auto 1fr auto auto;min-height:214px;border-radius:22px;overflow:hidden;color:var(--ink);text-decoration:none;background:linear-gradient(160deg,color-mix(in srgb,var(--c) 11%,#fff) 0,#fff 62%);border:1px solid color-mix(in srgb,var(--c) 22%,#e6e2f2);border-top:5px solid var(--c);box-shadow:0 10px 22px color-mix(in srgb,var(--c) 18%,transparent),0 2px 0 #fff inset;transition:transform .25s,box-shadow .25s}
.bcard:hover{text-decoration:none;transform:translateY(-5px);box-shadow:0 18px 32px color-mix(in srgb,var(--c) 28%,transparent)}
.bc-head{position:relative;z-index:2;display:flex;align-items:center;gap:8px;padding:12px 16px 0}
.bc-no{padding:3px 11px;border-radius:99px;background:var(--c);color:#fff;font:800 12px/1.5 var(--sans);letter-spacing:.06em}
.bcard.vol1 .bc-vol{background:linear-gradient(90deg,#6f8cf0,#a98bff)}.bcard.vol2 .bc-vol{background:linear-gradient(90deg,#2fb59a,#7ad39a)}
.bc-vol{padding:3px 10px;border-radius:99px;color:#fff;font:700 11px/1.5 var(--sans);letter-spacing:.08em}
.bc-lock{margin-left:auto}
.bc-body{position:relative;z-index:2;padding:10px 16px 6px;max-width:60%}
.bc-body h3{margin:0 0 4px;font:800 19px/1.2 'Baloo 2',system-ui,sans-serif;color:#1f2340}.bc-body p{margin:0;font-size:13px;line-height:1.45;color:#5b6180}
.bc-art{position:absolute;right:0;bottom:30px;width:56%;height:78%;z-index:1;pointer-events:none}.bc-svg{width:100%;height:100%;display:block;transition:transform .35s}.bcard:hover .bc-svg{transform:scale(1.06) rotate(-1deg)}
.bc-foot{position:relative;z-index:2;display:flex;align-items:center;gap:6px;padding:8px 16px 12px;flex-wrap:wrap}
.bc-tag{padding:2px 10px;border-radius:99px;background:color-mix(in srgb,var(--c) 14%,#fff);border:1px solid color-mix(in srgb,var(--c) 30%,#fff);color:color-mix(in srgb,var(--c) 70%,#1f2340);font:700 12px/1.6 var(--sans)}
.bc-prog{margin-left:auto;font-size:12px;color:#5b6180}
.bc-bar{height:4px;background:#0000000f}.bc-bar i{display:block;height:100%;background:var(--c)}
[data-theme=dark] .bcard{background:linear-gradient(160deg,color-mix(in srgb,var(--c) 22%,#262b47) 0,#232844 66%);border-color:color-mix(in srgb,var(--c) 40%,#333a5e);box-shadow:0 10px 22px #0005}
[data-theme=dark] .bc-body h3{color:#f1f2ff}[data-theme=dark] .bc-body p,[data-theme=dark] .bc-prog{color:#b6bbdc}
[data-theme=dark] .bc-tag{background:color-mix(in srgb,var(--c) 22%,#232844);color:#e6e8ff;border-color:color-mix(in srgb,var(--c) 45%,#232844)}
[data-theme=dark] .bc-svg{filter:saturate(.85) brightness(.92)}
@media(max-width:560px){.bcard-grid{grid-template-columns:1fr;gap:14px}.bcard{min-height:196px}.bc-body h3{font-size:18px}.bc-art{width:50%}.bc-body{max-width:58%}}