/* Lái Chuẩn – module ôn thi 600 câu (/on-thi/, /on-thi/thi-thu/, /on-thi/chuong-N/, /on-thi/cau-N/). Tiền tố lớp: ot- */
.ot-trang{padding-top:26px;padding-bottom:72px}
.ot-luoi{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:32px;margin-top:18px;align-items:start}
.ot-luoi>*{min-width:0}
.ot-nhan{display:flex;flex-wrap:wrap;gap:8px}
.ot-tag{display:inline-flex;align-items:center;font-style:normal;font-size:14px;line-height:19px;font-weight:600;padding:4px 10px;border-radius:999px;background:var(--chi-dan-nhat);color:var(--chi-dan);text-decoration:none;vertical-align:middle}
a.ot-tag:hover{background:#D3E2F8}
.ot-tag-liet{background:var(--liet-nhat);color:var(--liet)}
.ot-tag-nhat{background:#FFFFFF;border:1px solid var(--vien);color:var(--muc-phu)}
.ot-h1{font-size:30px;line-height:38px;font-weight:700;margin:14px 0 0}
.ot-h1-phu{display:block;font-family:var(--f-chu);font-size:21px;line-height:31px;font-weight:600;color:var(--muc-phu);letter-spacing:0;margin-top:4px}
.ot-the{padding:24px 26px;margin-top:18px}
.ot-hoi{font-size:20px;line-height:31px;font-weight:600;margin:0}
.ot-hoi b{color:var(--chi-dan)}
.ot-hinh{margin:16px 0 0;display:flex;flex-wrap:wrap;gap:12px;align-items:flex-start}
.ot-hinh img{display:block;width:auto;max-width:100%;max-height:380px;border:1px solid var(--vien);border-radius:var(--r,14px);background:#FFFFFF}
.ot-hinh figcaption{flex-basis:100%;font-size:13px;line-height:19px;color:var(--muc-phu)}
.ot-da{list-style:none;margin:18px 0 0;padding:0;display:grid;gap:10px}
.ot-da-nut{width:100%;display:flex;gap:12px;align-items:flex-start;text-align:left;padding:11px 14px;border:1.5px solid var(--vien-dam);border-radius:12px;background:#FFFFFF;font:inherit;font-size:17px;line-height:26px;color:var(--muc);cursor:pointer;min-height:50px}
.ot-da-nut:hover{border-color:var(--chi-dan);background:#F8FAFD}
.ot-da-so{flex:none;width:28px;height:28px;margin-top:-1px;border-radius:8px;background:var(--nen);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:15px}
.ot-da-nut.chon{border-color:var(--chi-dan);background:var(--chi-dan-nhat)}
.ot-da-nut.chon .ot-da-so{background:var(--chi-dan);color:#FFFFFF}
.ot-da-nut.dung{border-color:var(--dat);background:var(--dat-nhat)}
.ot-da-nut.dung .ot-da-so{background:var(--dat);color:#FFFFFF}
.ot-da-nut.sai{border-color:var(--liet);background:var(--liet-nhat)}
.ot-da-nut.sai .ot-da-so{background:var(--liet);color:#FFFFFF}
.ot-da-nut[aria-disabled=true]{cursor:default}
.ot-da-nut[aria-disabled=true]:hover{background:#FFFFFF;border-color:var(--vien-dam)}
.ot-da-nut.dung[aria-disabled=true]:hover{background:var(--dat-nhat);border-color:var(--dat)}
.ot-da-nut.sai[aria-disabled=true]:hover{background:var(--liet-nhat);border-color:var(--liet)}
.ot-kq{margin:12px 0 0;font-weight:600}
.ot-kq:empty{display:none}
.ot-kq.dung{color:var(--dat)}
.ot-kq.sai{color:var(--liet)}
.ot-xem{margin-top:16px;border-top:1px solid var(--vien)}
.ot-xem summary{cursor:pointer;font-weight:600;color:var(--chi-dan);padding:14px 0 10px;list-style:none;display:flex;align-items:center;gap:8px}
.ot-xem summary::-webkit-details-marker{display:none}
.ot-xem summary::before{content:"+";width:26px;height:26px;border-radius:8px;background:var(--chi-dan-nhat);display:inline-flex;align-items:center;justify-content:center}
.ot-xem[open] summary::before{content:"–"}
.ot-dung-chu{background:var(--dat-nhat);color:#14583A;border-radius:var(--r,14px);padding:12px 16px;margin:4px 0 16px}
.ot-gt h2,.ot-gt h3{font-family:var(--f-tieu-de);font-size:20px;line-height:28px;margin:0 0 6px;font-weight:600}
.ot-gt p{margin:0 0 10px}
.ot-gt .luu-y{margin-top:6px}
.ot-cho{color:var(--muc-phu);font-style:italic}
.ot-cong-cu{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.ot-ts{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:16px}
.ot-ts a{display:grid;gap:2px;padding:14px 18px;border:1px solid var(--vien);border-radius:var(--r,14px);background:#FFFFFF;text-decoration:none;font-weight:600;color:var(--muc)}
.ot-ts a:hover{border-color:var(--chi-dan);color:var(--chi-dan)}
.ot-ts small{font-size:14px;font-weight:500;color:var(--muc-phu)}
.ot-ts-sau{text-align:right}
.ot-ai{padding:22px 24px;margin-top:18px}
.ot-ai h2{font-family:var(--f-tieu-de);font-size:20px;line-height:28px;margin:0 0 12px}
.ot-ai-form{display:grid;gap:12px;justify-items:start}
.ot-ai-form .o-nhap{width:100%}
.ot-ai-form textarea{height:auto;min-height:84px;padding:10px 14px;resize:vertical}
.ot-ai-tl{margin-top:12px;white-space:pre-line}
.ot-ai-tl:empty{display:none}
.ot-ai-tb{margin:0}
.ot-ben{display:grid;gap:16px;position:sticky;top:92px}
.ot-ben-the{padding:20px 22px;display:grid;gap:10px}
.ot-ben-the>b{font-size:18px;line-height:26px}
.ot-ben-the p{margin:0;font-size:15px;line-height:23px;color:var(--muc-phu)}
.ot-ben-the .btn{width:100%}
.ot-lq a{font-size:15px;line-height:22px;text-decoration:none;padding:6px 0;border-top:1px solid #EEF1F5}
.ot-toi{background:var(--nhua);color:#C9D2DD;border-radius:20px;padding:22px;display:grid;gap:10px}
.ot-toi b,.ot-toi h2{color:#FFFFFF;font-size:19px;line-height:27px;margin:0}
.ot-toi p{margin:0;font-size:15px;line-height:23px}
.ot-toi .btn{width:100%}
.ot-nho{font-size:13px!important;line-height:19px!important;color:#8C99A9}
.ot-toi-rong{grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:24px;padding:30px 34px}
.ot-toi-rong h2{font-size:24px;line-height:32px}
.ot-toi-rong .btn{width:auto}
.ot-nguon{margin:28px 0 0;max-width:900px}
/* trang chương */
.ot-hanh-dong{display:flex;flex-wrap:wrap;gap:12px;margin-top:20px}
.ot-so3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:22px;max-width:820px}
.ot-so3 .card{padding:16px 18px;min-width:0}
.ot-so3 b{display:block;font-family:var(--f-tieu-de);font-size:30px;line-height:36px}
.ot-so3 span{font-size:14px;line-height:20px;color:var(--muc-phu)}
.ot-ds{list-style:none;padding:0;margin:22px 0 0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:32px}
.ot-ds li{border-top:1px solid #E3E8EF;min-width:0}
.ot-ds a{display:grid;grid-template-columns:78px minmax(0,1fr);gap:10px;padding:11px 2px;text-decoration:none;color:var(--muc);font-size:15px;line-height:22px}
.ot-ds a:hover span{color:var(--chi-dan)}
.ot-ds b{color:var(--chi-dan);font-variant-numeric:tabular-nums}
.ot-ds .ot-tag{font-size:14px;padding:1px 8px;margin-left:4px}
.ot-chips{display:flex;flex-wrap:wrap;gap:8px}
/* ứng dụng */
.ot-app{padding:26px;margin-top:28px;min-height:320px}
.ot-app-dau{display:flex;flex-wrap:wrap;gap:12px;align-items:center;justify-content:space-between}
.ot-app-dau h2{font-family:var(--f-tieu-de);font-size:22px;line-height:30px;margin:0}
.ot-cho-tai{color:var(--muc-phu);padding:40px 0;text-align:center}
.ot-so4{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin-top:18px}
.ot-o{border:1px solid var(--vien);border-radius:14px;padding:14px 16px;min-width:0;background:#FFFFFF}
.ot-o b{display:block;font-family:var(--f-tieu-de);font-size:26px;line-height:32px;font-variant-numeric:tabular-nums}
.ot-o span{font-size:14px;line-height:20px;color:var(--muc-phu)}
.ot-o select{margin-top:6px;height:44px;border:1.5px solid var(--vien-dam);border-radius:10px;font:inherit;font-size:14px;padding:0 8px;background:#FFFFFF;max-width:100%}
.ot-thanh{height:8px;border-radius:999px;background:#E3E8EF;overflow:hidden;margin-top:8px}
.ot-thanh i{display:block;height:100%;background:var(--vach);border-radius:999px}
.ot-thanh.xanh i{background:var(--dat)}
.ot-thanh.do i{background:var(--liet)}
.ot-db{display:grid;grid-template-columns:minmax(0,.8fr) minmax(0,1.2fr);gap:24px;margin-top:18px;padding:22px;border-radius:var(--r,14px);background:var(--chi-dan-nhat)}
.ot-db>*{min-width:0}
.ot-db-so{font-family:var(--f-tieu-de);font-size:52px;line-height:58px;font-weight:700;color:var(--chi-dan-dam);font-variant-numeric:tabular-nums}
.ot-db p{margin:6px 0 0;font-size:15px;line-height:23px}
.ot-db ul{list-style:none;margin:8px 0 0;padding:0;display:grid;gap:8px}
.ot-db li{font-size:14px;line-height:20px}
.ot-db li .ot-thanh{margin-top:4px;background:#FFFFFF}
.ot-muc{font-family:var(--f-tieu-de);font-size:18px;line-height:26px;margin:26px 0 10px;font-weight:600}
.ot-che{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.ot-che-nut{text-align:left;padding:16px 18px;border:1.5px solid var(--vien);border-radius:14px;background:#FFFFFF;cursor:pointer;font:inherit;color:var(--muc);display:grid;gap:4px;align-content:start;text-decoration:none;min-width:0}
.ot-che-nut:hover{border-color:var(--chi-dan);color:var(--muc)}
.ot-che-nut b{font-size:17px;line-height:24px}
.ot-che-nut span{font-size:14px;line-height:20px;color:var(--muc-phu)}
.ot-che-nut.noi{background:var(--nhua);border-color:var(--nhua);color:#FFFFFF}
.ot-che-nut.noi span{color:#C9D2DD}
.ot-che-nut.noi:hover{color:#FFFFFF;background:#26344A}
.ot-tim{display:flex;gap:8px;flex-wrap:wrap}
.ot-tim input{flex:1 1 240px;min-width:0;height:48px;border:1.5px solid var(--vien-dam);border-radius:999px;padding:0 14px;font:inherit;font-size:16px}
.ot-kq-tim{list-style:none;margin:10px 0 0;padding:0;max-height:420px;overflow:auto}
.ot-kq-tim li{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:10px;align-items:center;padding:10px 0;border-top:1px solid #EEF1F5;font-size:15px;line-height:22px}
.ot-kq-tim li>div{display:flex;gap:6px;flex-wrap:wrap;justify-content:flex-end}
.ot-kq-tim .chip{min-height:36px;padding:5px 12px;font-size:14px}
.ot-tien-ich{display:flex;flex-wrap:wrap;gap:8px}
.ot-tb{margin:10px 0 0;font-size:14px;line-height:21px;color:var(--muc-phu)}
.ot-tb:empty{display:none}
.ot-nut-nho{min-height:40px;padding:7px 14px;font-size:14px}
.ot-lam-dau{display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:space-between}
.ot-lam-dau b{font-size:15px}
.ot-lam-the{margin-top:14px;padding:22px 24px;border:1px solid var(--vien);border-radius:var(--r,14px);background:#FFFFFF}
.ot-gt-app{margin-top:14px;padding-top:14px;border-top:1px solid var(--vien)}
.ot-gt-app:empty{display:none}
.ot-dieu-huong{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;margin-top:16px}
.ot-phim{font-size:14px;color:var(--muc-phu);margin:10px 0 0}
.ot-tong-ket{text-align:center;padding:26px 10px}
.ot-tong-ket b{display:block;font-family:var(--f-tieu-de);font-size:44px;line-height:52px}
/* thi thử */
.ot-thi-bar{position:sticky;top:80px;z-index:5;background:#FFFFFF;border:1px solid var(--vien);border-radius:14px;display:flex;flex-wrap:wrap;gap:10px;justify-content:space-between;align-items:center;padding:10px 14px;box-shadow:0 6px 18px rgba(22,32,44,.06)}
.ot-gio{font-family:var(--f-tieu-de);font-size:26px;line-height:32px;font-weight:700;font-variant-numeric:tabular-nums}
.ot-gio.gap{color:var(--liet)}
.ot-luoi-so{display:grid;grid-template-columns:repeat(10,minmax(0,1fr));gap:6px;margin-top:14px}
.ot-luoi-so button{height:38px;min-width:0;border-radius:8px;border:1.5px solid var(--vien-dam);background:#FFFFFF;font:inherit;font-size:14px;font-weight:600;cursor:pointer;color:var(--muc);padding:0}
.ot-luoi-so button.da{background:var(--chi-dan-nhat);border-color:var(--chi-dan);color:var(--chi-dan)}
.ot-luoi-so button.hien{box-shadow:0 0 0 3px var(--vach)}
.ot-luoi-so button.dung{background:var(--dat-nhat);border-color:var(--dat);color:var(--dat)}
.ot-luoi-so button.sai{background:var(--liet-nhat);border-color:var(--liet);color:var(--liet)}
.ot-ket{border-radius:var(--r-lon,20px);padding:26px;text-align:center}
.ot-ket.dat{background:var(--dat-nhat);color:#14583A}
.ot-ket.truot{background:var(--liet-nhat);color:#7A1A12}
.ot-ket b{display:block;font-family:var(--f-tieu-de);font-size:40px;line-height:48px}
.ot-ket p{margin:6px 0 0}
.ot-xl{list-style:none;margin:14px 0 0;padding:0;display:grid;gap:12px}
.ot-xl>li{border:1px solid var(--vien);border-radius:14px;padding:16px 18px;background:#FFFFFF}
.ot-xl .ot-hoi{font-size:17px;line-height:26px}
.ot-xl .ot-da-nut{font-size:15px;line-height:22px;padding:8px 12px;min-height:40px}
.ot-xl .ot-hinh img{max-height:240px}
.ot-cau-truc{margin-top:14px}
.ot-cau-truc table{min-width:0}
.ot-cau-truc td:last-child,.ot-cau-truc th:last-child{text-align:right}
@media (max-width:900px){
 .ot-luoi{grid-template-columns:1fr}
 .ot-ben{position:static}
 .ot-h1{font-size:25px;line-height:33px}
 .ot-h1-phu{font-size:18px;line-height:27px}
 .ot-hoi{font-size:18px;line-height:28px}
 .ot-the,.ot-app,.ot-lam-the{padding:18px}
 .ot-ds{grid-template-columns:1fr}
 .ot-so4{grid-template-columns:repeat(2,minmax(0,1fr))}
 .ot-db{grid-template-columns:1fr;padding:18px}
 .ot-che{grid-template-columns:1fr 1fr}
 .ot-toi-rong{grid-template-columns:1fr;padding:24px}
 .ot-toi-rong .btn{width:100%}
 .ot-thi-bar{top:76px}
}
@media (max-width:520px){
 .ot-che{grid-template-columns:1fr}
 .ot-so3{grid-template-columns:1fr 1fr 1fr;gap:8px}
 .ot-so3 .card{padding:12px}
 .ot-so3 b{font-size:24px;line-height:30px}
 .ot-ds a{grid-template-columns:64px minmax(0,1fr)}
 .ot-kq-tim li{grid-template-columns:1fr}
 .ot-kq-tim li>div{justify-content:flex-start}
}
/* sửa giao diện 28/10 (F4): thi thử */
.ot-de-tom{font-size:16px;line-height:24px;color:var(--muc);margin-top:14px}
.ot-co-cau{margin-top:16px;border-top:1px solid var(--vien)}
.ot-co-cau summary{cursor:pointer;font-weight:600;color:var(--chi-dan);padding:12px 0 4px;min-height:44px;display:flex;align-items:center}
.ot-co-cau .ot-cau-truc{margin-top:6px}
body.dang-thi .dock,body.dang-thi .noi,body.dang-thi .om{display:none!important}
.ot-ket b{overflow-wrap:normal}
.ot-ket .ot-diem{display:block;font-family:var(--f-tieu-de);font-size:22px;line-height:30px;font-weight:600;font-variant-numeric:tabular-nums}
.ot-moi-hoc{margin-top:18px}
.ot-moi-hoc h3{color:#FFFFFF;font-family:var(--f-tieu-de);font-size:21px;line-height:29px;margin:0 0 6px;font-weight:600}
.ot-xl-dau{margin-top:22px}
.ot-xl-dau .ot-muc{margin:0}
@media (max-width:900px){
 body.dang-thi{padding-bottom:0}
 .ot-dieu-huong{position:sticky;bottom:0;z-index:4;margin:16px -18px -18px;padding:10px 18px calc(10px + env(safe-area-inset-bottom,0px));background:#FFFFFF;border-top:1px solid var(--vien);border-radius:0 0 var(--r,14px) var(--r,14px);box-shadow:0 -6px 18px rgba(22,32,44,.07);flex-wrap:nowrap}
 .ot-dieu-huong .btn{flex:1 1 0;min-height:48px}
 .ot-phim{display:none}
 .ot-luoi-so{display:flex;overflow-x:auto;gap:6px;padding:4px 2px 8px;scrollbar-width:thin;-webkit-overflow-scrolling:touch}
 .ot-luoi-so button{flex:0 0 44px;height:44px}
}
@media (max-width:760px){
 .ttp-dau>div:first-child{display:flex;flex-direction:column}
 .ttp-dau .ttp-nut{order:3;margin-top:16px}
 .ttp-dau .tra-loi{order:4}
 .ttp-nut .btn{flex:1 1 auto}
 .ttp-o3 .card{padding:12px}
 .ttp-o3 b{font-size:28px;line-height:34px}
 .ot-ket{padding:20px 16px}
 .ot-ket b{font-size:32px;line-height:40px}
}
/* sửa giao diện 28/10 (F4): trang câu – bớt lặp, đáp án lên màn hình đầu */
.ot-chinh .ot-h1{font-size:24px;line-height:32px;margin-top:10px}
.ot-chinh .ot-the{margin-top:14px}
.ot-hang-dung{margin:12px 0 0}
.ot-byline{margin:4px 0 0}
.ot-lq a{display:flex;align-items:center;min-height:44px;padding:8px 0}
@media (max-width:900px){
 .ot-chinh .ot-h1{font-size:20px;line-height:28px}
 .ot-hinh img{max-height:240px}
}
.ot-o select{width:100%}
/* sửa 28/10 (F4): ô số câu ở trang ôn, vùng bấm ≥44px */
.ot-luoi-so button{height:44px}
/* sửa sau thử người dùng 28/10/2026 (G2) */
/* chế độ ôn: ẩn thanh Gọi/Zalo, nút nổi, ô gọi lại (như thi thử) để nút "Câu tiếp" không bị che, không bấm nhầm mở popup */
body.dang-on .dock,body.dang-on .noi,body.dang-on .om{display:none!important}
@media (max-width:900px){body.dang-on{padding-bottom:0}}
/* thi thử: đồng hồ + hàng số câu cùng một khối dính, hàng số không bị che */
.ot-thi-dinh{position:sticky;top:80px;z-index:5;background:#FFFFFF;border:1px solid var(--vien);border-radius:14px;padding:10px 14px;box-shadow:0 6px 18px rgba(22,32,44,.06)}
.ot-thi-dinh .ot-thi-bar{position:static;border:0;box-shadow:none;padding:0;border-radius:0;background:transparent}
.ot-thi-dinh .ot-luoi-so{margin-top:10px}
.ot-tu-sang{display:flex;align-items:center;gap:8px;margin-top:12px;font-size:15px;line-height:22px;color:var(--muc-phu);cursor:pointer;min-height:44px}
.ot-tu-sang input{width:20px;height:20px;accent-color:var(--chi-dan)}
@media (max-width:900px){
 .ot-thi-dinh{top:76px;padding:8px 10px;margin:0 -8px}
 .ot-thi-dinh .ot-gio{font-size:22px;line-height:28px}
 .ot-thi-dinh .ot-luoi-so{margin-top:6px;padding-bottom:4px}
 .ot-thi-dinh .ot-luoi-so button{flex-basis:40px;height:40px}
}
/* máy tính: câu có hình xếp hình bên trái, đáp án bên phải (khỏi cuộn) */
@media (min-width:1100px){
 .ot-lam-the .ot-cau.co-hinh{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);column-gap:24px;align-items:start}
 .ot-lam-the .ot-cau.co-hinh>.ot-nhan,.ot-lam-the .ot-cau.co-hinh>.ot-hoi{grid-column:1/-1}
 .ot-lam-the .ot-cau.co-hinh>.ot-hinh{grid-column:1}
 .ot-lam-the .ot-cau.co-hinh>.ot-da{grid-column:2;margin-top:16px}
 .ot-lam-the .ot-cau.co-hinh .ot-hinh img{max-height:420px}
}
/* hình câu hỏi: bấm để xem to */
.ot-hinh img{cursor:zoom-in}
.ot-phong-nhac{flex-basis:100%;display:none;align-items:center;gap:6px;font-size:13px;line-height:18px;font-weight:600;color:var(--chi-dan)}
@media (max-width:900px){.ot-phong-nhac{display:inline-flex}}
.ot-phong{position:fixed;inset:0;z-index:70;background:rgba(22,32,44,.94)}
.ot-phong[hidden]{display:none}
.ot-phong-khung{position:absolute;inset:0;overflow:auto;overscroll-behavior:contain;-webkit-overflow-scrolling:touch;display:flex;align-items:safe center;justify-content:safe center;padding:64px 8px 24px}
.ot-phong-khung img{display:block;flex:none;width:min(100%,1100px);height:auto;max-width:none;margin:auto;background:#FFFFFF;border-radius:var(--r,14px);cursor:zoom-out;touch-action:pinch-zoom}
.ot-phong-dong{position:fixed;top:max(12px,env(safe-area-inset-top,0px));right:max(12px,env(safe-area-inset-right,0px));width:48px;height:48px;border-radius:50%;border:0;background:#FFFFFF;color:var(--muc);font-size:30px;line-height:1;cursor:pointer;padding:0;box-shadow:var(--bong-2)}
@media print{.ot-phong,.ot-phong-nhac{display:none!important}}
/* dự báo đỗ */
.ot-db-cho{font-size:30px;line-height:38px}
.ot-ngay-thi{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:12px}
.ot-ngay-thi label{font-weight:600;font-size:15px}
.ot-ngay-thi input{height:44px;border:1.5px solid var(--vien-dam);border-radius:10px;font:inherit;font-size:16px;padding:0 10px;background:#FFFFFF;max-width:100%}
.ot-ngay-thi .chip{min-height:40px}
.ot-kh{background:#FFFFFF;border-radius:12px;padding:10px 12px}
.ot-kh .chip{margin-top:6px;min-height:40px}
.ot-thanh.xam i{background:#C5CDD8}
/* lời mời người đang học, sắp thi */
.ot-dang-hoc{display:flex;flex-wrap:wrap;gap:12px 20px;align-items:center;justify-content:space-between;margin-top:16px;padding:16px 18px;border:1.5px solid var(--vien);border-radius:var(--r,14px);background:#FFFFFF}
.ot-dang-hoc>div{flex:1 1 320px;min-width:0;display:grid;gap:4px}
.ot-dang-hoc b{font-size:17px;line-height:24px}
.ot-dang-hoc span{font-size:15px;line-height:22px;color:var(--muc-phu)}
@media (max-width:600px){.ot-dang-hoc .btn{width:100%}}
/* kết quả thi thử: câu điểm liệt, điểm theo nhóm, giải thích ngay trong trang */
.ot-ket-ct{display:grid;gap:12px;margin-top:14px}
.ot-ket-liet{margin:0;padding:12px 16px;border-radius:12px;font-size:16px;line-height:24px}
.ot-ket-liet.dung{background:var(--dat-nhat);color:#14583A}
.ot-ket-liet.sai{background:var(--liet-nhat);color:#7A1A12}
.ot-ket-nhom table{min-width:0;width:100%}
.ot-ket-nhom caption{text-align:left;font-weight:600;padding:0 0 6px}
.ot-ket-nhom td:last-child,.ot-ket-nhom th:last-child{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap}
.ot-ket-nhom tr.thieu td:last-child{color:var(--liet);font-weight:600}
.ot-xl-gt{margin-top:8px;border-top:1px solid var(--vien)}
.ot-xl-gt summary{cursor:pointer;font-weight:600;color:var(--chi-dan);min-height:44px;display:flex;align-items:center}
.ot-xl-gt>div{padding-top:4px}
@media (min-width:901px){
 .ot-thi-dinh .ot-luoi-so{grid-template-columns:repeat(15,minmax(0,1fr));gap:5px;margin-top:8px}
 .ot-thi-dinh .ot-luoi-so button{height:36px}
}
.ot-ket-nhom caption{padding:10px 16px 6px}