:root{--ink:#172b4d;--muted:#6d7b91;--primary:#5b5ce2;--primary-dark:#4647c7;--mint:#e7f8f1;--line:#e8ecf4;--bg:#fbfcff;--orange:#ffbd72;--shadow:0 18px 50px rgba(37,54,93,.09)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-family:'Be Vietnam Pro',system-ui,sans-serif;font-size:14px}a{color:inherit;text-decoration:none}button,input,textarea,select{font:inherit}button{cursor:pointer}.topbar{height:82px;display:flex;align-items:center;justify-content:space-between;padding:0 max(5vw,24px);background:#fff;border-bottom:1px solid #f0f2f8;gap:24px}.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:16px;letter-spacing:-.4px}.brand-mark{display:grid;place-items:center;background:#eeeeff;color:var(--primary);width:42px;height:42px;border-radius:14px;font-size:23px}.brand small{display:block;font-size:10px;font-weight:500;color:#8b96a8;letter-spacing:.1px;margin-top:2px}.topbar nav{display:flex;gap:34px;color:#617087;font-weight:600}.topbar nav a:hover{color:var(--primary)}.account-area{display:flex;align-items:center;gap:10px}.user-label{font-size:12px;color:var(--muted);max-width:180px;overflow:hidden;text-overflow:ellipsis}.btn{border:0;border-radius:12px;padding:12px 18px;font-weight:700;transition:.2s;display:inline-flex;align-items:center;justify-content:center;gap:10px}.btn-primary{background:var(--primary);color:#fff;box-shadow:0 8px 18px #5b5ce229}.btn-primary:hover{background:var(--primary-dark);transform:translateY(-1px)}.btn-outline{border:1px solid #dfe3f0;background:white;color:var(--ink)}.btn-outline:hover{border-color:var(--primary);color:var(--primary)}.btn-soft{background:#eeefff;color:var(--primary)}.hero{max-width:1180px;margin:auto;min-height:440px;padding:62px 28px 48px;display:grid;grid-template-columns:1.05fr .95fr;align-items:center;gap:40px}.eyebrow{font-size:10px;font-weight:800;letter-spacing:1.8px;color:var(--primary)}h1{font-size:clamp(38px,4.2vw,58px);line-height:1.16;letter-spacing:-2.5px;margin:18px 0;color:#172b4d}h1 span{color:var(--primary)}.hero-copy>p{max-width:480px;color:var(--muted);font-size:15px;line-height:1.9;margin-bottom:24px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap}.hero-note{display:flex;align-items:center;gap:9px;margin-top:27px;color:#8994a7;font-size:11px}.dot{width:7px;height:7px;background:#49c99b;border-radius:50%;box-shadow:0 0 0 4px #49c99b20}.hero-art{height:330px;position:relative;display:grid;place-items:center}.sun{position:absolute;width:260px;height:260px;background:#f0efff;border-radius:50%;right:13%;top:7%}.book{position:absolute;width:205px;height:230px;border-radius:13px 24px 24px 13px;transform:rotate(-9deg);box-shadow:0 24px 35px #393b8521}.book-back{background:#ffcf9a;right:25%;top:22%;transform:rotate(8deg)}.book-front{background:linear-gradient(145deg,#6c6ded,#4c4ed1);right:29%;top:17%;border-left:9px solid #4143bd;padding:70px 25px;color:#fff}.book-line{height:5px;width:105px;background:#ffffff9c;border-radius:8px;margin:12px 0}.book-line.short{width:70px}.book-star{font-size:42px;position:absolute;right:22px;bottom:23px;color:#ffcf86}.float-card{position:absolute;background:white;padding:13px 17px;border-radius:14px;box-shadow:var(--shadow);font-size:20px;color:var(--primary);font-weight:800;display:flex;align-items:center;gap:10px}.float-card span{font-size:11px;color:#40506b}.card-one{top:38px;right:1%}.card-two{bottom:40px;left:1%;color:#36b88a}.plant{position:absolute;bottom:25px;right:8%;width:38px;height:65px;border-bottom:15px solid #f2c3a3;border-radius:0 0 8px 8px}.plant i{position:absolute;width:19px;height:31px;background:#6bc7a4;border-radius:100% 0 100% 0;bottom:18px;left:0;transform:rotate(-20deg)}.plant i:nth-child(2){left:16px;bottom:27px;transform:rotate(28deg)}.plant i:nth-child(3){left:8px;bottom:40px;transform:rotate(0)}.plant b{position:absolute;width:3px;height:39px;background:#429d7d;left:18px;bottom:17px}.stats{max-width:1120px;margin:0 auto 74px;padding:25px 35px;background:white;border:1px solid #f0f2f8;border-radius:20px;display:grid;grid-template-columns:repeat(3,1fr);box-shadow:0 12px 40px #25365d08}.stats>div{display:flex;align-items:center;gap:14px;padding:5px 20px;border-right:1px solid var(--line)}.stats>div:last-child{border:0}.stats strong{width:45px;height:45px;display:grid;place-items:center;background:#f0f0ff;border-radius:14px;font-size:21px}.stats span b,.stats span small{display:block}.stats span b{font-size:12px}.stats span small{font-size:10px;color:var(--muted);margin-top:5px}.lesson-section{max-width:1120px;margin:0 auto;padding:0 24px 70px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:20px}.section-heading h2{font-size:30px;letter-spacing:-1px;margin:8px 0}.section-heading p{color:var(--muted);margin:0}.toolbar{display:flex;gap:12px;margin:28px 0 24px}.searchbox{flex:1;max-width:440px;display:flex;align-items:center;gap:10px;background:white;border:1px solid var(--line);border-radius:12px;padding:0 14px;color:#9aa5b7;font-size:24px}.searchbox input{width:100%;border:0;outline:0;padding:14px 0;font-size:12px}.toolbar select{border:1px solid var(--line);border-radius:12px;background:#fff;color:#56657b;padding:0 14px;min-width:180px;outline:0}.lesson-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.lesson-card{background:white;border:1px solid #edf0f7;border-radius:18px;overflow:hidden;transition:.2s;box-shadow:0 6px 24px #273a6306}.lesson-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}.lesson-cover{height:130px;padding:22px;display:flex;align-items:flex-start;justify-content:space-between;background:linear-gradient(135deg,#eeefff,#f7f7ff);position:relative;overflow:hidden}.lesson-cover:after{content:"";position:absolute;width:120px;height:120px;border:20px solid #ffffff70;border-radius:50%;right:-18px;bottom:-48px}.cover-icon{font-size:35px;position:relative;z-index:1}.category-pill{background:#ffffffc9;color:var(--primary);border-radius:20px;padding:7px 10px;font-size:10px;font-weight:700;position:relative;z-index:1;max-width:70%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lesson-body{padding:19px}.lesson-body h3{font-size:16px;line-height:1.5;margin:0 0 8px}.lesson-body p{font-size:12px;line-height:1.7;color:var(--muted);margin:0;min-height:42px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.lesson-meta{display:flex;align-items:center;justify-content:space-between;border-top:1px solid #f0f2f7;margin-top:17px;padding-top:14px;color:#8b96a8;font-size:10px}.lesson-meta button{border:0;background:transparent;color:var(--primary);font-weight:800}.empty-state,.status-message{text-align:center;color:var(--muted);padding:25px;font-size:13px}.teacher-banner{max-width:1072px;margin:0 auto 76px;background:#f0f0ff;border-radius:20px;padding:28px 34px;display:flex;align-items:center;gap:20px}.banner-icon{width:54px;height:54px;flex-shrink:0;border-radius:17px;background:white;display:grid;place-items:center;font-size:28px;color:var(--primary)}.teacher-banner h3{margin:0 0 6px;font-size:17px}.teacher-banner p{margin:0;color:#707b93;font-size:12px;line-height:1.7}.banner-link{margin-left:auto;white-space:nowrap;color:var(--primary);font-weight:800;font-size:12px}footer{border-top:1px solid #edf0f7;background:white;padding:25px max(5vw,24px);display:flex;align-items:center;justify-content:space-between;gap:20px}footer p{color:#8b96a8;font-size:11px}.footer-brand .brand-mark{width:35px;height:35px}.hidden{display:none!important}.modal{position:fixed;z-index:10;inset:0;background:#172b4db0;display:grid;place-items:center;padding:20px;overflow-y:auto}.modal-card{width:min(100%,430px);background:white;border-radius:22px;padding:32px;position:relative;box-shadow:0 30px 100px #09152f55;margin:auto}.modal-wide{width:min(100%,620px)}.modal-close{position:absolute;right:17px;top:13px;border:0;background:#f4f5fa;border-radius:50%;width:32px;height:32px;font-size:23px;color:#758197}.modal-symbol{width:48px;height:48px;border-radius:16px;background:#eeeefe;color:var(--primary);display:grid;place-items:center;font-size:27px;margin-bottom:17px}.modal-card h2{font-size:24px;letter-spacing:-.7px;margin:8px 0}.modal-subtitle{font-size:12px;color:var(--muted);line-height:1.7;margin:0 0 20px}.tabs{display:grid;grid-template-columns:1fr 1fr;background:#f5f6fb;padding:4px;border-radius:11px;margin:20px 0}.tab{border:0;background:transparent;padding:10px;border-radius:8px;color:#7a869a;font-weight:700;font-size:12px}.tab.active{background:white;color:var(--primary);box-shadow:0 2px 8px #1b2c4c10}form label{display:block;color:#4d5d75;font-size:11px;font-weight:700;margin:14px 0}form input,form textarea{display:block;width:100%;border:1px solid #e1e6f0;border-radius:10px;padding:12px 13px;margin-top:7px;outline:0;color:var(--ink);font-size:12px;background:white}form input:focus,form textarea:focus{border-color:#8989f1;box-shadow:0 0 0 3px #5b5ce214}form textarea{resize:vertical}.full{width:100%;margin-top:8px}.form-message{font-size:12px;line-height:1.6;color:var(--primary);min-height:16px}.fine-print{font-size:10px;line-height:1.6;color:#98a2b2;text-align:center;margin:20px 0 0}.form-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.lesson-form{margin-top:18px}.detail-category{display:inline-block;padding:7px 10px;border-radius:20px;background:#eeeefe;color:var(--primary);font-size:10px;font-weight:800;margin:10px 0}.detail-description{font-size:13px;line-height:1.9;color:#586780;white-space:pre-wrap}.detail-actions{display:flex;gap:10px;flex-wrap:wrap;margin:22px 0}.video-frame{width:100%;aspect-ratio:16/9;border:0;border-radius:12px;margin-top:12px}.delete-btn{background:#fff1f1;color:#c54d4d;border:1px solid #ffdddd}.toast{position:fixed;bottom:22px;left:50%;transform:translate(-50%,20px);background:#172b4d;color:white;padding:12px 18px;border-radius:12px;font-size:12px;opacity:0;pointer-events:none;transition:.2s;z-index:20;max-width:90vw}.toast.show{opacity:1;transform:translate(-50%,0)}
@media(max-width:850px){.topbar{padding:0 20px}.topbar nav{display:none}.hero{padding-top:42px;grid-template-columns:1fr;gap:0}.hero-art{height:280px;max-width:520px;width:100%;margin:auto}.stats{margin:0 20px 55px;padding:18px;gap:12px}.stats>div{padding:4px 8px}.stats span small{display:none}.lesson-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.teacher-banner{margin:0 20px 55px}.user-label{display:none}}
@media(max-width:560px){.topbar{height:70px}.brand{font-size:14px}.brand-mark{width:36px;height:36px}.account-area{gap:6px}.account-area .btn{padding:10px 11px;font-size:11px}.hero{padding:38px 23px 28px}.hero-copy>p{font-size:13px}.hero-actions .btn{font-size:11px;padding:12px}.hero-art{height:250px;transform:scale(.9);transform-origin:center}.stats{grid-template-columns:1fr;margin-bottom:48px;padding:15px 18px}.stats>div{border-right:0;border-bottom:1px solid var(--line);padding:10px 0}.stats>div:last-child{border:0}.stats span small{display:block}.section-heading{align-items:flex-start;flex-direction:column}.section-heading h2{font-size:25px}.toolbar{flex-direction:column}.searchbox{max-width:none}.toolbar select{height:45px}.lesson-grid{grid-template-columns:1fr}.lesson-cover{height:115px}.teacher-banner{padding:22px;align-items:flex-start;flex-wrap:wrap}.teacher-banner>div:nth-child(2){flex:1;min-width:170px}.banner-link{margin-left:74px}footer{align-items:flex-start;flex-direction:column;gap:10px}.form-row{grid-template-columns:1fr;gap:0}.modal-card{padding:27px 22px}.hero-art .card-one{right:-4%}.hero-art .card-two{left:-5%}}

.upload-hint{display:block;color:#7a869a;font-size:11px;font-weight:400;line-height:1.6;margin-top:7px}.upload-progress{display:block;width:100%;height:10px;margin:12px 0;accent-color:#5b5ce2}.video-player{display:block;width:100%;max-height:70vh;aspect-ratio:16/9;background:#111;border-radius:12px;margin-top:12px}

/* Mở rộng khung xem bài học và video MP4 */
#detail-modal .modal-card.modal-wide{width:min(96vw,1100px);padding:32px}
#detail-modal .video-player,#detail-modal .video-frame{display:block;width:100%;max-width:100%;aspect-ratio:16/9;height:auto;max-height:76vh;background:#111;border:0;border-radius:12px;margin-top:14px}
#detail-modal .video-player{object-fit:contain}
@media(max-width:600px){#detail-modal .modal-card.modal-wide{width:100%;padding:24px 16px}#detail-modal .video-player,#detail-modal .video-frame{max-height:55vh}}


/* ===== Giao diện nâng cấp: rõ ràng, hiện đại, dễ thao tác ===== */
:root{
  --ink:#17243b;
  --muted:#66758b;
  --primary:#4f46e5;
  --primary-dark:#3730a3;
  --mint:#e7f8f1;
  --line:#e5eaf3;
  --bg:#f7f9fd;
  --shadow:0 16px 42px rgba(26,42,76,.09);
}
body{background:linear-gradient(180deg,#f8faff 0%,#fff 54%,#f8faff 100%);color:var(--ink)}
.topbar{position:sticky;top:0;z-index:8;height:76px;background:rgba(255,255,255,.92);backdrop-filter:blur(16px);box-shadow:0 4px 24px rgba(30,45,80,.045);border-bottom:1px solid rgba(229,234,243,.9)}
.brand{gap:12px}
.brand-mark{background:linear-gradient(145deg,#eef0ff,#e4e8ff);border:1px solid #e1e5ff;box-shadow:0 5px 14px #4f46e510}
.topbar nav{align-items:center;gap:8px}
.topbar nav a{padding:10px 14px;border-radius:10px;transition:background .2s,color .2s}
.topbar nav a:hover{background:#f0f1ff;color:var(--primary)}
.btn{min-height:42px;border-radius:12px;transition:transform .18s,box-shadow .18s,background .18s}
.btn:focus-visible,button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #a5b4fc;outline-offset:3px}
.btn-primary{background:linear-gradient(135deg,#5b5ce2,#4945d4);box-shadow:0 7px 18px rgba(79,70,229,.2)}
.btn-primary:hover{background:linear-gradient(135deg,#4f46e5,#3730a3);box-shadow:0 10px 24px rgba(79,70,229,.25)}
.btn-outline{border-color:#dce3ef}
.hero{max-width:1240px;min-height:460px;padding:68px 38px 54px;gap:50px}
.hero-copy{position:relative;z-index:1}
.eyebrow{display:inline-flex;align-items:center;gap:8px;padding:8px 11px;border-radius:999px;background:#eeeeff;letter-spacing:1.25px}
h1{font-size:clamp(40px,4.6vw,62px);line-height:1.13;letter-spacing:-2.4px;margin:20px 0}
.hero-copy>p{max-width:510px;font-size:15px;line-height:1.95;color:#5f6e84}
.hero-actions{gap:13px}
.hero-actions .btn{padding:14px 20px}
.hero-note{margin-top:30px}
.hero-art{height:350px;border-radius:34px;background:radial-gradient(circle at 55% 45%,#f0efff 0,#f5f6ff 46%,rgba(245,247,255,0) 72%)}
.sun{background:linear-gradient(145deg,#e8e9ff,#f2f1ff);box-shadow:inset 0 0 0 1px #fff}
.book{box-shadow:0 28px 45px rgba(57,59,133,.16)}
.float-card{border:1px solid rgba(231,235,246,.9);box-shadow:0 12px 30px rgba(37,54,93,.1);border-radius:16px}
.stats{max-width:1140px;margin:0 auto 82px;padding:24px 26px;border-radius:22px;box-shadow:0 15px 42px rgba(37,54,93,.055);border-color:#edf0f7}
.stats>div{padding:8px 22px}
.stats strong{width:48px;height:48px;border-radius:15px}
.lesson-section{max-width:1180px;padding:0 28px 78px;scroll-margin-top:100px}
.section-heading{align-items:flex-end;margin-bottom:26px}
.section-heading h2{font-size:clamp(27px,3vw,34px);letter-spacing:-1.1px;margin:10px 0}
.section-heading p{font-size:13px;line-height:1.7}
.toolbar{align-items:center;gap:14px;margin:24px 0 26px}
.searchbox{max-width:none;min-height:50px;border-radius:14px;padding:0 16px;border-color:#e2e7f1;box-shadow:0 3px 12px rgba(37,54,93,.025);font-size:22px}
.searchbox:focus-within{border-color:#a5b4fc;box-shadow:0 0 0 4px #6366f115}
.searchbox input{font-size:13px;padding:15px 0}
.toolbar select{height:50px;min-width:205px;border-radius:14px;border-color:#e2e7f1;font-size:12px;box-shadow:0 3px 12px rgba(37,54,93,.025)}
.status-message{border-radius:14px;margin:12px 0;color:#64748b}
.lesson-grid{gap:22px}
.lesson-card{border:1px solid #e9edf5;border-radius:20px;box-shadow:0 8px 24px rgba(37,54,93,.045);transition:transform .22s ease,box-shadow .22s ease,border-color .22s ease}
.lesson-card:hover{transform:translateY(-5px);border-color:#d9dcff;box-shadow:0 18px 38px rgba(37,54,93,.1)}
.lesson-cover{height:150px;padding:23px}
.cover-icon{display:grid;place-items:center;width:54px;height:54px;border-radius:17px;background:#ffffffad;box-shadow:0 5px 16px #26345b0c}
.category-pill{font-size:10px;padding:8px 11px}
.lesson-body{padding:21px}
.lesson-body h3{font-size:15px;line-height:1.6;letter-spacing:-.15px}
.lesson-body p{font-size:12px;line-height:1.8;min-height:44px}
.lesson-meta{margin-top:18px;padding-top:15px;font-size:11px}
.lesson-meta button{padding:8px 0 8px 8px;border-radius:8px}
.lesson-meta button:hover{color:#3730a3;text-decoration:underline}
.empty-state{grid-column:1/-1;background:#fff;border:1px dashed #d8deec;border-radius:16px}
.teacher-banner{max-width:1124px;margin:0 auto 82px;padding:32px 36px;border:1px solid #e5e6ff;background:linear-gradient(120deg,#f0f0ff,#f3fbff);border-radius:24px;gap:22px}
.banner-icon{box-shadow:0 6px 16px #4f46e510}
.teacher-banner h3{font-size:18px}
.teacher-banner p{font-size:12px;max-width:630px}
.banner-link{padding:12px 14px;border-radius:11px;background:#fff;font-size:12px;box-shadow:0 4px 14px #4f46e50a}
.banner-link:hover{background:#eeeeff}
footer{background:rgba(255,255,255,.92);padding-top:28px;padding-bottom:28px}
.modal{background:rgba(17,29,53,.62);backdrop-filter:blur(5px)}
.modal-card{border:1px solid rgba(255,255,255,.7);box-shadow:0 28px 90px rgba(9,21,47,.25);border-radius:24px}
.modal-close{transition:background .2s,transform .2s}
.modal-close:hover{background:#e8eaff;transform:rotate(90deg)}
form label{font-size:12px;color:#40516b}
form input,form textarea{border-color:#dfe5f0;border-radius:12px;font-size:13px;padding:13px 14px}
form input:focus,form textarea:focus{border-color:#818cf8;box-shadow:0 0 0 4px #6366f116}
.toast{box-shadow:0 12px 35px #09152f30}
@media(max-width:850px){
 .topbar{height:72px}
 .hero{padding:48px 26px 38px;gap:12px}
 .stats{margin:0 20px 60px}
 .lesson-section{padding-left:22px;padding-right:22px}
 .teacher-banner{margin-left:20px;margin-right:20px}
}
@media(max-width:560px){
 .topbar{height:68px;padding:0 14px;gap:10px}
 .brand{gap:8px}
 .brand small{font-size:9px}
 .account-area .btn{min-height:38px;padding:9px 11px}
 .hero{padding:36px 21px 24px}
 h1{font-size:clamp(36px,10vw,46px);letter-spacing:-1.8px}
 .hero-copy>p{font-size:13px;line-height:1.85}
 .hero-actions{display:grid;grid-template-columns:1fr}
 .hero-actions .btn{width:100%;padding:13px 15px}
 .hero-art{height:235px;margin-top:4px}
 .stats{margin:0 14px 48px;padding:13px 16px;border-radius:18px}
 .stats>div{padding:11px 4px}
 .stats strong{width:42px;height:42px}
 .lesson-section{padding:0 16px 54px;scroll-margin-top:80px}
 .section-heading{gap:15px}
 .section-heading h2{font-size:27px}
 .section-heading .btn{width:100%}
 .toolbar{gap:10px;margin:20px 0}
 .searchbox{min-height:48px}
 .toolbar select{height:48px;width:100%}
 .lesson-grid{gap:15px}
 .lesson-card{border-radius:17px}
 .lesson-cover{height:112px;padding:14px}
 .cover-icon{width:42px;height:42px;border-radius:13px;font-size:27px}
 .category-pill{font-size:9px;padding:7px 8px}
 .lesson-body{padding:15px}
 .lesson-body h3{font-size:14px}
 .lesson-body p{font-size:11px;min-height:42px}
 .lesson-meta{align-items:flex-start;gap:8px;flex-direction:column}
 .lesson-meta button{padding:4px 0}
 .teacher-banner{margin:0 14px 50px;padding:22px;border-radius:19px}
 .teacher-banner>div:nth-child(2){min-width:0}
 .banner-link{margin-left:0}
 footer{padding:22px 18px}
 .modal{padding:12px}
 .modal-card{border-radius:20px}
}
@media(prefers-reduced-motion:reduce){
 *,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}
}


/* ===== Bảng điều khiển quản trị dành cho giáo viên ===== */
.teacher-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.teacher-dashboard{max-width:1180px;margin:0 auto 58px;padding:30px;background:#fff;border:1px solid #e4e9f4;border-radius:24px;box-shadow:0 18px 48px rgba(26,42,76,.075);scroll-margin-top:100px}
.dashboard-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;margin-bottom:24px}
.dashboard-heading h2{font-size:clamp(25px,3vw,32px);letter-spacing:-.9px;margin:12px 0 8px}
.dashboard-heading p{font-size:13px;line-height:1.7;color:#6b7890;margin:0}
.dashboard-stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px;margin-bottom:24px}
.dashboard-stats article{display:flex;align-items:center;gap:14px;padding:18px;border:1px solid #e8ecf5;border-radius:17px;background:linear-gradient(135deg,#fff,#fafbff)}
.dashboard-stats article>span{display:grid;place-items:center;flex:0 0 46px;height:46px;background:#eeeeff;border-radius:14px;font-size:22px}
.dashboard-stats article:nth-child(2)>span{background:#e7f8f1}
.dashboard-stats article:nth-child(3)>span{background:#fff1e6}
.dashboard-stats small{display:block;font-size:11px;color:#6b7890;margin-bottom:5px}
.dashboard-stats strong{font-size:25px;line-height:1.2;color:#1b2840}
.dashboard-toolbar{display:flex;align-items:center;gap:16px;margin:18px 0 14px}
.dashboard-toolbar .searchbox{flex:1}
.dashboard-count{white-space:nowrap;font-size:12px;color:#64748b}
.dashboard-list{display:grid;gap:12px}
.dashboard-item{display:grid;grid-template-columns:48px minmax(0,1fr) auto;align-items:center;gap:15px;padding:16px;border:1px solid #e7ebf4;border-radius:16px;background:#fff;transition:border-color .18s,box-shadow .18s}
.dashboard-item:hover{border-color:#cfd3ff;box-shadow:0 8px 22px rgba(35,48,90,.055)}
.dashboard-item-icon{display:grid;place-items:center;width:48px;height:48px;border-radius:15px;background:#f0f0ff;font-size:23px}
.dashboard-item-main{min-width:0}
.dashboard-item-main h3{margin:0 0 5px;font-size:14px;line-height:1.5;overflow-wrap:anywhere}
.dashboard-item-main p{margin:0 0 10px;color:#65748a;font-size:11px}
.dashboard-tags{display:flex;gap:7px;flex-wrap:wrap}
.dashboard-tags span{padding:5px 8px;border-radius:7px;background:#f5f7fb;color:#617087;font-size:10px}
.dashboard-item-actions{display:flex;align-items:center;gap:7px;flex-wrap:wrap;justify-content:flex-end}
.dashboard-item-actions .btn{min-height:34px;padding:8px 10px;font-size:11px;border-radius:9px}
.btn-danger-soft{color:#b42335;background:#fff0f1;border:1px solid #ffe0e3}
.btn-danger-soft:hover{background:#ffe2e5}
.dashboard-empty{padding:34px 18px;text-align:center;border:1px dashed #d8deec;border-radius:16px;color:#748198;font-size:13px}
.dashboard-note{margin:18px 0 0;padding-top:16px;border-top:1px solid #edf0f6;color:#7b8799;font-size:11px;line-height:1.7}
.current-video-note{padding:11px 13px;margin:2px 0 12px;border-radius:10px;background:#f4f6ff;color:#5b6480;font-size:12px;line-height:1.6}
#edit-lesson-modal .modal-card{max-height:90vh;overflow:auto}
@media(max-width:850px){
 .teacher-dashboard{margin-left:22px;margin-right:22px;padding:22px}
 .dashboard-item{grid-template-columns:44px minmax(0,1fr)}
 .dashboard-item-icon{width:44px;height:44px}
 .dashboard-item-actions{grid-column:2;justify-content:flex-start}
}
@media(max-width:560px){
 .teacher-actions{width:100%;display:grid;grid-template-columns:1fr}
 .teacher-actions .btn{width:100%}
 .teacher-dashboard{margin:0 14px 42px;padding:17px;border-radius:18px;scroll-margin-top:80px}
 .dashboard-heading{flex-direction:column;gap:14px}
 .dashboard-heading>.btn{width:100%}
 .dashboard-stats{gap:8px}
 .dashboard-stats article{padding:11px 9px;gap:8px;align-items:flex-start;flex-direction:column}
 .dashboard-stats article>span{width:36px;height:36px;flex-basis:36px;font-size:18px;border-radius:11px}
 .dashboard-stats small{font-size:10px}
 .dashboard-stats strong{font-size:22px}
 .dashboard-toolbar{align-items:stretch;flex-direction:column;gap:8px}
 .dashboard-item{padding:12px;gap:10px}
 .dashboard-item-main h3{font-size:13px}
 .dashboard-tags{gap:5px}
 .dashboard-tags span{font-size:9px}
 .dashboard-item-actions{gap:6px}
 .dashboard-item-actions .btn{padding:8px;font-size:10px}
}

/* ===== Bài trắc nghiệm và chấm điểm tự động ===== */
.quiz-editor-card,.student-quiz-card{max-height:90vh;overflow-y:auto}
.quiz-question-list,.student-quiz-questions{display:grid;gap:15px;margin:20px 0}
.quiz-question,.student-quiz-question{min-width:0;border:1px solid #e5eaf3;border-radius:16px;padding:18px;background:#fff}
.quiz-question-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:12px}
.quiz-question-head legend,.student-quiz-question legend{font-weight:700;color:#1c2b44;font-size:14px;line-height:1.65;padding:0 0 10px}
.quiz-question-head button{border:0;border-radius:9px;padding:8px 10px;font-size:11px;cursor:pointer}
.quiz-question>label{display:block;margin-bottom:14px}
.quiz-options-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.quiz-option-input{display:grid;gap:8px;padding:12px;border:1px solid #e8edf5;border-radius:12px;background:#fafbff}
.quiz-option-input>span{display:flex;align-items:center;gap:7px;font-size:12px;color:#53627a}
.quiz-option-input input[type=radio]{accent-color:#5149dd}
.quiz-option-input>input{width:100%;min-width:0}
.quiz-editor-actions{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:18px}
.student-quiz-question legend{font-size:15px}
.student-quiz-question legend span{display:inline-block;padding:5px 9px;margin-right:6px;background:#eeeeff;color:#5149dd;border-radius:8px;font-size:11px}
.student-quiz-options{display:grid;gap:9px}
.student-quiz-options label{display:flex;align-items:flex-start;gap:10px;padding:13px;border:1px solid #e7ebf4;border-radius:12px;background:#fff;cursor:pointer;transition:border-color .18s,background .18s}
.student-quiz-options label:has(input:checked){border-color:#8985f0;background:#f4f3ff}
.student-quiz-options input{margin-top:4px;accent-color:#5149dd}
.student-quiz-options label span{font-size:13px;line-height:1.6;color:#34445c}
.student-quiz-options label span b{color:#5149dd}
.quiz-result{margin-top:22px;padding:24px;text-align:center;background:linear-gradient(135deg,#f0f0ff,#effbf6);border:1px solid #e0e5ff;border-radius:18px}
.quiz-result-score{font-size:42px;font-weight:800;letter-spacing:-1px;color:#4944d2}
.quiz-result h3{margin:8px 0;color:#1d2b43}
.quiz-result p{font-size:13px;color:#65748a}
.quiz-result-track{height:9px;max-width:380px;margin:16px auto 10px;border-radius:99px;background:#e0e5f0;overflow:hidden}
.quiz-result-track span{display:block;height:100%;border-radius:99px;background:linear-gradient(90deg,#5b5ce2,#21a67a)}
.quiz-history,.quiz-attempts-admin{margin-top:22px;padding-top:18px;border-top:1px solid #edf0f6}
.quiz-history h3,.quiz-attempts-admin h3{font-size:14px;margin:0 0 12px}
.quiz-attempt-list{display:grid;gap:8px}
.quiz-attempt-row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:11px 12px;border:1px solid #e8edf5;border-radius:11px;background:#fff;font-size:12px}
.quiz-attempt-row span{display:grid;gap:4px;color:#526178}
.quiz-attempt-row small{font-size:10px;color:#8a96a8}
.quiz-attempt-row strong{white-space:nowrap;color:#4944d2}
@media(max-width:560px){
 .quiz-question,.student-quiz-question{padding:13px}
 .quiz-options-grid{grid-template-columns:1fr;gap:9px}
 .quiz-editor-actions{align-items:stretch;flex-direction:column}
 .quiz-editor-actions .btn{width:100%}
 .student-quiz-options label{padding:11px}
 .quiz-result{padding:18px}
 .quiz-attempt-row{align-items:flex-start;font-size:11px}
}

/* ===== Hoàn thiện giao diện bài trắc nghiệm ===== */
.student-quiz-card{
  width:min(100%,820px);
  max-height:calc(100dvh - 32px);
  overflow-y:auto;
  padding:clamp(20px,4vw,38px);
  border:1px solid #e7eaf4;
  border-radius:24px;
}
.student-quiz-card .eyebrow{display:inline-flex;align-items:center;gap:8px;padding:7px 11px;border-radius:999px;background:#f0f0ff;color:#5149d8;font-size:10px;font-weight:800;letter-spacing:.6px}
.student-quiz-card h2{font-size:clamp(23px,3vw,30px);line-height:1.3;margin:14px 44px 7px 0;letter-spacing:-.8px}
.student-quiz-card .modal-subtitle{font-size:13px;margin-bottom:22px}
.student-quiz-questions{display:grid;grid-template-columns:minmax(0,1fr);gap:16px;margin:20px 0 24px}
.student-quiz-question{display:block;width:100%;min-width:0;margin:0;padding:22px;border:1px solid #e4e8f2;border-radius:18px;background:linear-gradient(180deg,#fff 0%,#fcfcff 100%);box-shadow:0 5px 18px rgba(37,54,93,.035)}
.student-quiz-question legend{display:block;width:100%;max-width:100%;padding:0 0 16px;font-size:14px;font-weight:700;line-height:1.75;color:#202d46}
.student-quiz-question legend span{display:inline-flex;align-items:center;justify-content:center;vertical-align:middle;min-width:64px;padding:6px 10px;margin:0 8px 6px 0;border-radius:9px;background:#efefff;color:#5149d8;font-size:11px;letter-spacing:.2px}
.student-quiz-options{display:grid;grid-template-columns:minmax(0,1fr);gap:10px;width:100%;margin:0;padding:0}
.student-quiz-options label{display:grid;grid-template-columns:20px minmax(0,1fr);align-items:start;gap:11px;width:100%;min-width:0;margin:0;padding:14px 16px;border:1px solid #e5e9f2;border-radius:13px;background:#fff;box-sizing:border-box;cursor:pointer;transition:border-color .18s,background .18s,box-shadow .18s}
.student-quiz-options label:hover{border-color:#b5b3f6;background:#fafaff}
.student-quiz-options label:has(input:checked){border-color:#7774e9;background:#f3f2ff;box-shadow:0 0 0 2px rgba(91,92,226,.08)}
.student-quiz-options input[type=radio]{appearance:auto;display:block;width:17px;height:17px;min-width:17px;margin:3px 0 0;padding:0;border:0;box-shadow:none;accent-color:#5149d8}
.student-quiz-options label span{display:block;min-width:0;font-size:13px;line-height:1.7;color:#34445c;overflow-wrap:anywhere}
.student-quiz-options label span b{display:inline-block;min-width:20px;color:#5149d8}
#student-quiz-submit{min-height:48px;font-size:13px;border-radius:13px}
.student-quiz-card .modal-close{position:sticky;float:right;top:0;right:0;z-index:2;margin-bottom:-36px}
.quiz-history{margin-top:24px;padding-top:20px}
.quiz-history h3{font-size:14px;margin-bottom:12px}
.quiz-result{padding:28px 20px}
@media(min-width:700px){
 .student-quiz-card{width:min(100%,820px)}
 .student-quiz-options{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
 .student-quiz-options label{height:100%;align-items:start}
}
@media(max-width:560px){
 .student-quiz-card{width:100%;max-height:calc(100dvh - 16px);padding:20px 15px;border-radius:18px}
 .student-quiz-card h2{font-size:22px;margin-right:35px}
 .student-quiz-question{padding:15px 12px;border-radius:14px}
 .student-quiz-question legend{font-size:13px;padding-bottom:12px}
 .student-quiz-question legend span{margin-bottom:8px}
 .student-quiz-options{grid-template-columns:minmax(0,1fr);gap:8px}
 .student-quiz-options label{padding:12px 11px;gap:9px}
 .student-quiz-options label span{font-size:12px}
}

/* ===== Fix bố cục biểu mẫu trắc nghiệm: ghi đè CSS form toàn cục ===== */
#student-quiz-modal{z-index:1000;isolation:isolate}
#student-quiz-modal .student-quiz-card{display:block;position:relative;width:min(820px,calc(100vw - 32px));max-width:820px;max-height:calc(100dvh - 32px);overflow-x:hidden;overflow-y:auto;margin:auto;padding:clamp(18px,3.5vw,34px);box-sizing:border-box}
#student-quiz-modal .student-quiz-card form{display:block;width:100%;margin:0;padding:0}
#student-quiz-modal .student-quiz-questions{display:grid!important;grid-template-columns:minmax(0,1fr)!important;gap:16px;width:100%;margin:22px 0;padding:0}
#student-quiz-modal fieldset.student-quiz-question{display:block!important;float:none!important;position:relative;width:100%!important;min-width:0;max-width:100%;margin:0!important;padding:20px;box-sizing:border-box}
#student-quiz-modal fieldset.student-quiz-question legend{display:block!important;float:none!important;position:static;width:100%!important;max-width:100%;margin:0!important;padding:0 0 15px!important;white-space:normal;box-sizing:border-box}
#student-quiz-modal .student-quiz-options{display:grid!important;grid-template-columns:minmax(0,1fr)!important;align-items:stretch;justify-items:stretch;gap:10px;width:100%!important;max-width:100%;margin:0!important;padding:0!important}
#student-quiz-modal .student-quiz-options label{display:grid!important;grid-template-columns:20px minmax(0,1fr)!important;align-items:start!important;justify-items:stretch;float:none!important;position:relative;width:100%!important;max-width:100%;min-width:0;height:auto!important;min-height:48px;margin:0!important;padding:13px 15px!important;box-sizing:border-box;text-align:left!important;transform:none!important}
#student-quiz-modal .student-quiz-options label input[type=radio]{display:block!important;position:static!important;float:none!important;width:17px!important;height:17px!important;min-width:17px;margin:3px 0 0!important;padding:0!important;transform:none!important}
#student-quiz-modal .student-quiz-options label span{display:block!important;position:static!important;float:none!important;width:auto!important;min-width:0;max-width:100%;margin:0!important;padding:0!important;text-align:left!important;transform:none!important;white-space:normal;overflow-wrap:anywhere}
#student-quiz-modal #student-quiz-submit{display:flex;width:100%;margin:12px 0 0}
#student-quiz-modal .student-quiz-card .modal-close{position:absolute;float:none;top:14px;right:14px;margin:0}
#student-quiz-modal .quiz-result,#student-quiz-modal .quiz-history{width:100%;box-sizing:border-box}
@media(min-width:700px){
 #student-quiz-modal .student-quiz-options{grid-template-columns:minmax(0,1fr)!important}
}
@media(max-width:560px){
 #student-quiz-modal .student-quiz-card{width:calc(100vw - 16px);max-height:calc(100dvh - 16px);padding:20px 13px}
 #student-quiz-modal fieldset.student-quiz-question{padding:14px 11px}
 #student-quiz-modal .student-quiz-options label{padding:12px 10px!important;gap:9px!important}
}