:root{
  --navy:#143A6B; --navy2:#0F2D54; --blue:#1D6FD1; --blue-soft:#E8F1FC;
  --yellow:#FFC107; --yellow-soft:#FFF6D6; --orange:#FF7A29; --orange-soft:#FFEEE1;
  --green:#1A9E57; --green-soft:#E2F5E9; --red:#E5484D; --red-soft:#FDECEC;
  --bg:#FFF9EC; --bg2:#FFF3D6; --card:#FFFFFF; --ink:#1E2A3A; --muted:#5B6B82;
  --line:#EADFC6; --shadow:0 10px 28px rgba(20,58,107,.13);
  --r-lg:22px; --r-md:16px; --r-sm:12px;
}
@media (prefers-color-scheme: dark){
  :root{ --bg:#101A2A; --bg2:#16253C; --card:#1B2C46; --ink:#EFF4FB; --muted:#A9BCD4; --line:#2E4462; --blue-soft:#22385A; --yellow-soft:#3A3010; --orange-soft:#3D2812; --green-soft:#173A28; --red-soft:#3D1E20; --shadow:0 10px 28px rgba(0,0,0,.4); }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:'Nunito',system-ui,sans-serif;background:var(--bg);color:var(--ink);font-size:17px;line-height:1.55}
button{font-family:inherit;cursor:pointer;min-height:44px}
h1,h2,h3{font-family:'Be Vietnam Pro','Nunito',sans-serif;line-height:1.25;margin:0}
img{max-width:100%}
.wrap{max-width:1180px;margin:0 auto;padding:0 18px 64px}

/* ===== Mockup switcher ===== */
.switcher{position:sticky;top:0;z-index:50;background:var(--navy);color:#fff;box-shadow:0 4px 18px rgba(0,0,0,.25)}
.switcher-in{max-width:1180px;margin:0 auto;padding:10px 18px;display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.switcher .brand{display:flex;align-items:center;gap:10px;font-family:'Be Vietnam Pro';font-weight:800;font-size:15px;margin-right:6px}
.switcher .brand .owl{width:38px;height:38px;border-radius:12px;background:var(--yellow);display:grid;place-items:center;font-size:22px}
.switcher .tag{font-size:11px;background:var(--orange);color:#fff;border-radius:99px;padding:3px 9px;font-weight:800;letter-spacing:.04em}
.switcher nav{display:flex;gap:6px;flex-wrap:wrap;flex:1}
.switcher nav button{border:2px solid rgba(255,255,255,.25);background:transparent;color:#fff;border-radius:99px;padding:8px 14px;font-weight:800;font-size:14px;min-height:40px}
.switcher nav button[aria-pressed="true"]{background:var(--yellow);color:var(--navy2);border-color:var(--yellow)}
.switcher nav button:focus-visible, button:focus-visible, a:focus-visible{outline:3px solid var(--orange);outline-offset:2px}

/* ===== Generic ===== */
.view{display:none;padding-top:26px}
.view.active{display:block;animation:fade .25s ease}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
@media (prefers-reduced-motion: reduce){.view.active{animation:none} html{scroll-behavior:auto}}
.card{background:var(--card);border:2px solid var(--line);border-radius:var(--r-lg);box-shadow:var(--shadow)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:none;border-radius:16px;padding:14px 22px;font-weight:900;font-size:17px;min-height:56px;text-decoration:none;box-shadow:0 5px 0 rgba(0,0,0,.18);transition:transform .08s}
.btn:active{transform:translateY(3px);box-shadow:0 2px 0 rgba(0,0,0,.18)}
.btn-blue{background:var(--blue);color:#fff}.btn-yellow{background:var(--yellow);color:var(--navy2)}
.btn-orange{background:var(--orange);color:#fff}.btn-green{background:var(--green);color:#fff}
.btn-ghost{background:var(--card);color:var(--navy);border:2px solid var(--line);box-shadow:none}
@media (prefers-color-scheme: dark){.btn-ghost{color:var(--ink)}}
.btn-sm{min-height:44px;padding:9px 16px;font-size:15px;border-radius:12px}
.pill{display:inline-block;border-radius:99px;padding:4px 12px;font-size:13px;font-weight:800}
.pill-blue{background:var(--blue-soft);color:var(--blue)} .pill-yellow{background:var(--yellow-soft);color:#8A6400}
@media (prefers-color-scheme: dark){.pill-yellow{color:var(--yellow)}}
.pill-green{background:var(--green-soft);color:var(--green)} .pill-orange{background:var(--orange-soft);color:var(--orange)}
.pill-red{background:var(--red-soft);color:var(--red)}
.muted{color:var(--muted)} .small{font-size:14px}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
@media(max-width:820px){.grid2,.grid3{grid-template-columns:1fr}}
@media(max-width:700px){.map-track{min-width:0;flex-wrap:wrap;row-gap:16px}.isle{flex:0 0 20%}.isle::before{display:none}.map-scroll{overflow:visible}}

/* ===== Login ===== */
.login-wrap{max-width:440px;margin:24px auto}
.login-card{padding:30px 26px;text-align:center}
.login-card .owl-big{width:86px;height:86px;margin:0 auto 12px;border-radius:26px;background:linear-gradient(145deg,var(--yellow),#FFD84D);display:grid;place-items:center;font-size:48px;box-shadow:var(--shadow)}
.login-card h1{font-size:26px;color:var(--navy)}
@media (prefers-color-scheme: dark){.login-card h1{color:var(--ink)}}
.field{text-align:left;margin-top:16px}
.field label{font-weight:800;font-size:14px;display:block;margin-bottom:6px}
.field input{width:100%;padding:14px 16px;border:2px solid var(--line);border-radius:14px;font-size:17px;font-family:inherit;background:var(--card);color:var(--ink);min-height:54px}
.field input:focus{border-color:var(--blue);outline:none}
.code-row{display:flex;gap:8px}.code-row input{flex:1;text-transform:uppercase;letter-spacing:.08em;font-weight:800}

/* ===== Student top bar ===== */
.stu-top{display:flex;gap:14px;align-items:center;flex-wrap:wrap;margin-bottom:18px}
.avatar{width:60px;height:60px;border-radius:20px;background:var(--orange);color:#fff;display:grid;place-items:center;font-family:'Be Vietnam Pro';font-weight:800;font-size:22px;flex:none}
.stu-top h1{font-size:24px}
.stat-chips{display:flex;gap:8px;flex-wrap:wrap;margin-left:auto}
.chip{background:var(--card);border:2px solid var(--line);border-radius:99px;padding:8px 14px;font-weight:900;font-size:15px;display:flex;gap:7px;align-items:center;min-height:44px}
.chip .dot{width:10px;height:10px;border-radius:50%}

/* Next task */
.next-task{background:linear-gradient(135deg,var(--navy),var(--blue));color:#fff;border-radius:26px;padding:26px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.next-task::after{content:"🗺️";position:absolute;right:14px;top:8px;font-size:92px;opacity:.16;transform:rotate(10deg)}
.next-task .kicker{font-weight:900;letter-spacing:.06em;font-size:13px;color:var(--yellow);text-transform:uppercase}
.next-task h2{font-size:clamp(22px,4vw,30px);margin:8px 0 6px;max-width:640px}
.next-task p{margin:0 0 18px;opacity:.92;max-width:600px}
.progress{height:16px;background:rgba(255,255,255,.25);border-radius:99px;overflow:hidden}
.progress i{display:block;height:100%;background:var(--yellow);border-radius:99px}

/* Treasure map */
.map-card{padding:22px;margin-top:18px}
.map-scroll{overflow-x:auto;padding:6px 2px}
.map-track{display:flex;align-items:flex-start;gap:0;flex-wrap:wrap;row-gap:16px;position:relative;padding-top:8px}
.isle{flex:1 1 88px}
.isle{flex:1;text-align:center;position:relative}
.isle::before{content:"";position:absolute;top:26px;left:-50%;width:100%;border-top:4px dashed var(--line);z-index:0}
.isle:first-child::before{display:none}
.isle .node{width:54px;height:54px;margin:0 auto;border-radius:50%;display:grid;place-items:center;font-size:24px;font-weight:900;position:relative;z-index:1;border:3px solid var(--line);background:var(--card)}
.isle.done .node{background:var(--green);color:#fff;border-color:var(--green)}
.isle.now .node{background:var(--yellow);border-color:var(--orange);animation:pulse 1.6s infinite}
@keyframes pulse{0%,100%{transform:scale(1)}50%{transform:scale(1.1)}}
@media (prefers-reduced-motion: reduce){.isle.now .node{animation:none}}
.isle span{display:block;font-size:12.5px;font-weight:800;margin-top:7px;color:var(--muted)}
.isle.chest .node{background:var(--yellow-soft);font-size:27px}

/* Course cards */
.course-card{padding:20px;display:flex;flex-direction:column;gap:10px}
.course-card h3{font-size:19px}
.course-head{display:flex;gap:12px;align-items:center}
.course-ic{width:52px;height:52px;border-radius:16px;display:grid;place-items:center;font-size:26px;flex:none}
.meter{height:12px;background:var(--blue-soft);border-radius:99px;overflow:hidden}.meter i{display:block;height:100%;background:var(--green);border-radius:99px}
.locked{opacity:.75}

/* Chapter accordion */
.chapter{border:2px solid var(--line);border-radius:var(--r-md);margin-bottom:12px;background:var(--card);overflow:hidden}
.chapter summary{padding:16px 18px;font-weight:900;font-size:17px;cursor:pointer;list-style:none;display:flex;gap:10px;align-items:center;min-height:56px}
.chapter summary::-webkit-details-marker{display:none}
.lesson-row{display:flex;gap:12px;align-items:center;padding:13px 18px;border-top:1.5px dashed var(--line);flex-wrap:wrap}
.lesson-row .st{margin-left:auto}

/* Video */
.video-box{aspect-ratio:16/9;background:#0B1B33;border-radius:20px;display:grid;place-items:center;color:#fff;position:relative;overflow:hidden;text-align:center;padding:20px}
.video-box .play{width:84px;height:84px;border-radius:50%;background:var(--yellow);color:var(--navy2);font-size:36px;display:grid;place-items:center;border:none;box-shadow:0 8px 0 rgba(0,0,0,.3)}
.video-box .vtag{position:absolute;left:14px;top:14px;background:rgba(0,0,0,.55);padding:5px 12px;border-radius:99px;font-size:13px;font-weight:800}
.video-bar{height:10px;background:rgba(255,255,255,.25);border-radius:99px;margin-top:16px;width:min(480px,90%)}
.video-bar i{display:block;height:100%;width:78%;background:var(--orange);border-radius:99px}
.checkpoint{border:3px solid var(--yellow);background:var(--yellow-soft);border-radius:var(--r-lg);padding:22px;margin-top:18px}
.opt-btn{width:100%;text-align:left;background:var(--card);border:2.5px solid var(--line);border-radius:16px;padding:15px 18px;font-size:18px;font-weight:800;margin-top:10px;min-height:58px;box-shadow:0 4px 0 var(--line)}
.opt-btn:hover{border-color:var(--blue)}
.opt-btn.picked{border-color:var(--blue);background:var(--blue-soft)}
.opt-btn.right{border-color:var(--green);background:var(--green-soft)}
.opt-btn.wrong{border-color:var(--red);background:var(--red-soft)}
.feedback{border-radius:14px;padding:14px 16px;font-weight:700;margin-top:14px;display:none}
.feedback.show{display:block}.feedback.ok{background:var(--green-soft);border:2px solid var(--green)}
.feedback.no{background:var(--red-soft);border:2px solid var(--red)}

/* Practice / Exam */
.q-head{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-bottom:14px}
.timer{background:var(--navy);color:#fff;border-radius:99px;padding:9px 18px;font-weight:900;font-size:18px;font-variant-numeric:tabular-nums}
.q-card{padding:26px}
.q-text{font-size:21px;font-weight:800;line-height:1.5}
.q-text-vi{font-size:16.5px;color:var(--muted);font-weight:700;margin-top:6px}
.q-fig{margin:16px 0;background:#fff;border:2px dashed var(--line);border-radius:16px;padding:18px;text-align:center;color:#143A6B}
.numpad{display:grid;grid-template-columns:repeat(3,74px);gap:10px;margin-top:14px}
.numpad button{height:60px;font-size:24px;font-weight:900;border-radius:16px;border:2px solid var(--line);background:var(--card);color:var(--ink);box-shadow:0 4px 0 var(--line)}
.numpad button:active{transform:translateY(3px);box-shadow:none}
.answer-box{font-size:30px;font-weight:900;border:3px solid var(--blue);border-radius:16px;padding:12px 20px;min-width:150px;display:inline-block;text-align:center;background:var(--blue-soft);min-height:64px}
.qnav{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}
.qnav button{width:46px;height:46px;border-radius:13px;border:2px solid var(--line);background:var(--card);font-weight:900;font-size:16px;color:var(--ink)}
.qnav button.done{background:var(--green);color:#fff;border-color:var(--green)}
.qnav button.cur{border-color:var(--blue);background:var(--blue-soft)}
.qnav button.flagged{position:relative}
.qnav button.flagged::after{content:"🚩";position:absolute;top:-9px;right:-6px;font-size:13px}
.switch-row{display:flex;align-items:center;gap:10px;font-weight:800}
.tgl{width:58px;height:34px;border-radius:99px;background:var(--line);border:none;position:relative;flex:none;min-height:34px}
.tgl::after{content:"";position:absolute;top:4px;left:4px;width:26px;height:26px;border-radius:50%;background:#fff;transition:left .15s}
.tgl[aria-pressed="true"]{background:var(--green)}.tgl[aria-pressed="true"]::after{left:28px}

/* Result */
.score-hero{text-align:center;padding:30px 22px}
.score-ring{width:150px;height:150px;margin:0 auto 10px;border-radius:50%;background:conic-gradient(var(--green) 0 80%, var(--line) 80% 100%);display:grid;place-items:center}
.score-ring b{width:118px;height:118px;border-radius:50%;background:var(--card);display:grid;place-items:center;font-size:34px;font-family:'Be Vietnam Pro'}
.bar-row{display:grid;grid-template-columns:130px 1fr 52px;gap:10px;align-items:center;margin:10px 0;font-weight:800;font-size:15px}
.bar-row .meter{height:14px}
.steps{background:var(--blue-soft);border-radius:14px;padding:16px 18px;margin-top:12px}
.steps ol{margin:8px 0 0;padding-left:20px}.steps li{margin:5px 0}

/* Admin */
.admin-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
@media(max-width:900px){.admin-grid{grid-template-columns:1fr 1fr}}
.stat-card{padding:18px}.stat-card b{font-size:30px;font-family:'Be Vietnam Pro';display:block}
table{width:100%;border-collapse:collapse;font-size:15px}
th,td{padding:11px 12px;text-align:left;border-bottom:1.5px solid var(--line);vertical-align:top}
th{font-family:'Be Vietnam Pro';font-size:13.5px;color:var(--muted)}
@media(max-width:700px){
  table,thead,tbody,tr,td{display:block} thead{display:none}
  tr{border:2px solid var(--line);border-radius:14px;margin-bottom:10px;padding:8px;background:var(--card)}
  td{border:none;padding:5px 8px} td::before{content:attr(data-l) " ";font-weight:900;color:var(--muted);font-size:12.5px;text-transform:uppercase}
}
/* ===== Logo chính thức MỚI — mặt Cú Mèo Pi (navy, sao vàng trên trán) ===== */
.logo-lockup{display:flex;align-items:center;gap:11px;text-decoration:none;color:inherit}
.logo-mark{width:46px;height:46px;flex:none;border-radius:14px;object-fit:cover;display:block;box-shadow:0 4px 0 rgba(0,0,0,.22)}
.logo-name{font-family:'Be Vietnam Pro';font-weight:800;font-size:17px;line-height:1.15;display:block}
.logo-slogan{font-size:12px;font-weight:800;color:var(--yellow);letter-spacing:.02em;display:block}
.login-logo{display:flex;flex-direction:column;align-items:center;gap:4px}
.login-logo .logo-mark{width:64px;height:64px;border-radius:20px}
.login-logo .logo-name{font-size:25px;color:var(--navy)}
@media (prefers-color-scheme: dark){.login-logo .logo-name{color:var(--ink)}}
.login-logo .logo-slogan{font-size:14.5px;color:#B07D00}
@media (prefers-color-scheme: dark){.login-logo .logo-slogan{color:var(--yellow)}}
.mascot{width:150px;height:150px;object-fit:cover;border-radius:28px;box-shadow:var(--shadow);animation:floaty 3.2s ease-in-out infinite}
@keyframes floaty{0%,100%{transform:translateY(0) rotate(-1deg)}50%{transform:translateY(-8px) rotate(1deg)}}
@media (prefers-reduced-motion: reduce){.mascot{animation:none}}

/* ===== Nút 3D gờ nổi 5px (phong cách Duolingo Math — mục FX-1) ===== */
.btn{box-shadow:0 5px 0 rgba(0,0,0,.22)}
.btn:active{transform:translateY(4px);box-shadow:0 1px 0 rgba(0,0,0,.22)}
.numpad button{box-shadow:0 5px 0 var(--line)}
.qnav button{transition:transform .1s}

/* ===== Bảng màu trạng thái bảng câu (đúng mã màu v8) ===== */
.legend{display:flex;gap:14px;flex-wrap:wrap;font-size:13.5px;font-weight:800;margin-top:10px}
.legend i{width:16px;height:16px;border-radius:5px;display:inline-block;vertical-align:-3px;margin-right:5px;border:2px solid var(--line)}

/* ===== Bong bóng thoại của Sơn — bạn học cùng, không phải thầy ===== */
.buddy{display:flex;gap:11px;align-items:flex-start;margin:14px 0}
.buddy .b-avatar{width:46px;height:46px;flex:none;border-radius:50%;background:var(--yellow);display:grid;place-items:center;font-size:23px;border:3px solid #fff;box-shadow:0 3px 8px rgba(0,0,0,.2)}
.buddy .b-bubble{background:#fff;color:var(--ink);border-radius:4px 16px 16px 16px;padding:11px 15px;font-weight:700;font-size:15.5px;box-shadow:0 4px 12px rgba(0,0,0,.13);max-width:560px}
.buddy .b-bubble b{color:var(--navy)}
@media (prefers-color-scheme: dark){.buddy .b-bubble{background:var(--blue-soft)} .buddy .b-bubble b{color:var(--yellow)}}
.buddy.on-card .b-bubble{background:var(--card)}

/* ===== Hộp xác nhận nộp bài (native dialog — giống v8) ===== */
dialog.confirm{border:none;border-radius:22px;padding:26px;max-width:420px;width:calc(100% - 32px);background:var(--card);color:var(--ink);box-shadow:0 24px 60px rgba(0,0,0,.35)}
dialog.confirm::backdrop{background:rgba(15,45,84,.55)}
dialog.confirm h3{font-size:21px;margin-bottom:8px}

/* ===== Màn hình tính năng v8 + kế hoạch FX ===== */
.feat-row{display:flex;gap:12px;padding:13px 0;border-bottom:1.5px dashed var(--line);align-items:flex-start}
.feat-row:last-child{border-bottom:none}
.feat-ic{width:44px;height:44px;flex:none;border-radius:13px;display:grid;place-items:center;font-size:21px}
.feat-row b{font-size:16.5px}
.feat-row p{margin:2px 0 0;font-size:14.5px;color:var(--muted);font-weight:700}
.fx-demo{border:2px dashed var(--line);border-radius:16px;padding:16px;text-align:center;background:var(--bg)}
.chest-anim{font-size:64px;display:inline-block;animation:chestbounce 1.8s ease-in-out infinite;cursor:pointer;background:none;border:none;min-height:0}
@keyframes chestbounce{0%,100%{transform:translateY(0) scale(1)}50%{transform:translateY(-10px) scale(1.06)}}
@media (prefers-reduced-motion: reduce){.chest-anim{animation:none}}
#confetti-canvas{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}

.note{border-left:5px solid var(--yellow);background:var(--yellow-soft);border-radius:0 14px 14px 0;padding:14px 18px;font-weight:700}
footer{margin-top:44px;text-align:center;color:var(--muted);font-size:14px;font-weight:700}
.sec-title{font-size:22px;margin:26px 0 14px;display:flex;align-items:center;gap:10px}

/* ==========================================================================
   Học Cùng Sơn — app additions
   Ghi đè nhẹ trên CSS mockup (giữ nguyên mọi class mockup để các module
   player / practice / exam / results / admin dùng chung).
   Token: nền giấy ấm #FBF9F5, chữ 19px, nút >=56px, bo 20-22px.
   ========================================================================== */
:root{ --bg:#FBF9F5; }
body{ font-size:19px; }
@media (max-width:700px){ body{ font-size:18px; } }

/* SPA screens (mockup dùng .view; app thật dùng .screen) */
.screen{ display:none; }
.screen.active{ display:block; animation:fade .25s ease; }

/* Focus rõ cho bàn phím + chuột */
:focus-visible{ outline:3px solid var(--orange); outline-offset:2px; }
a:focus-visible, summary:focus-visible, input:focus-visible{ outline:3px solid var(--orange); outline-offset:2px; }

/* Tôn trọng prefers-reduced-motion: tắt mọi animation/transition */
@media (prefers-reduced-motion: reduce){
  *, *::before, *::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    scroll-behavior:auto !important;
  }
  .screen.active{ animation:none; }
}

/* Ảnh không vỡ layout */
img{ height:auto; }
img[src=""]{ display:none; }

/* ===== Header app (dùng class logo mockup: .logo-lockup/.logo-mark/...) ===== */
.app-header{
  position:sticky; top:0; z-index:50;
  background:var(--navy); color:#fff;
  box-shadow:0 4px 18px rgba(0,0,0,.25);
}
.app-header-in{
  max-width:1180px; margin:0 auto; padding:10px 18px;
  display:flex; gap:12px; align-items:center; flex-wrap:wrap;
}
.app-header .logo-lockup{ color:#fff; }
.app-header .logo-mark{ background:var(--yellow); }
.app-header .logo-slogan{ color:var(--yellow); }
.header-spacer{ flex:1; }
.header-user{ font-weight:800; font-size:15px; }
.btn-header{
  min-height:44px; padding:9px 16px; border-radius:99px;
  border:2px solid rgba(255,255,255,.4); background:transparent; color:#fff;
  font-weight:800; font-size:14px; font-family:inherit; cursor:pointer;
  text-decoration:none; display:inline-flex; align-items:center; gap:6px;
}
.btn-header:hover{ background:rgba(255,255,255,.14); }
.btn-header.solid{ background:var(--yellow); color:var(--navy2); border-color:var(--yellow); }

/* Hàng tiêu đề màn con + nút quay lại */
.screen-head{
  display:flex; gap:12px; align-items:center; flex-wrap:wrap;
  margin:22px 0 14px;
}
.screen-head h1, .screen-head h2{ flex:1; min-width:220px; }

/* ===== Đăng nhập: rộng hơn mockup để chứa 2 thẻ demo ===== */
.login-wrap{ max-width:580px; }
.login-logo-img{
  width:96px; height:96px; border-radius:28px; object-fit:cover;
  margin:0 auto 12px; box-shadow:var(--shadow); background:var(--yellow);
  display:block;
}
.demo-accounts{ display:grid; grid-template-columns:1fr 1fr; gap:12px; margin:18px 0 4px; }
@media (max-width:560px){ .demo-accounts{ grid-template-columns:1fr; } }
.demo-card{
  border:2px solid var(--line); border-radius:var(--r-md);
  padding:16px; text-align:left; background:var(--bg);
  display:flex; flex-direction:column; gap:8px;
}
.demo-card b{ font-size:16px; color:var(--navy); }
.demo-card code{
  display:block; background:var(--card); border:1.5px solid var(--line);
  border-radius:10px; padding:8px 10px; font-size:14px; word-break:break-all;
}
.demo-card .btn{ width:100%; }
.login-note{
  margin-top:16px; font-size:14px; color:var(--muted); font-weight:700;
  text-align:center;
}
.login-error{
  display:none; margin-top:14px; padding:12px 16px; border-radius:14px;
  background:var(--red-soft); border:2px solid var(--red);
  color:var(--red); font-weight:800; font-size:15px;
}
.login-error.show{ display:block; }

/* ===== Dashboard bổ sung ===== */
.course-grid{ margin-top:8px; }
.course-card .course-meta{ font-size:15px; color:var(--muted); font-weight:700; }
.course-card .course-actions{ margin-top:auto; display:flex; gap:8px; flex-wrap:wrap; }
.course-card.is-empty{ opacity:.85; }
.course-ic.timo{ background:var(--blue-soft); }
.course-ic.hkimo{ background:var(--yellow-soft); }
.course-ic.bbb{ background:var(--green-soft); }
.empty-note{
  border:2px dashed var(--line); border-radius:var(--r-md);
  padding:18px; text-align:center; color:var(--muted); font-weight:700;
}
.topic-practice{ margin:10px 0 4px; display:flex; gap:8px; flex-wrap:wrap; align-items:center; }
.topic-title{ font-weight:900; font-size:17px; margin:14px 0 2px; color:var(--navy); }
.exam-row{
  display:flex; gap:12px; align-items:center; flex-wrap:wrap;
  padding:14px 18px; border-top:1.5px dashed var(--line);
}
.exam-row b{ flex:1; min-width:200px; }
.lesson-row .lesson-ic{ font-size:20px; flex:none; width:28px; text-align:center; }
.lesson-row.done{ background:var(--green-soft); }
.lesson-row a.lesson-link{ color:inherit; text-decoration:none; font-weight:800; }
.lesson-row a.lesson-link:hover{ color:var(--blue); text-decoration:underline; }

/* ===== Toast + modal dùng chung ===== */
#app-toast{
  position:fixed; left:50%; bottom:24px; z-index:100;
  transform:translateX(-50%) translateY(20px);
  background:var(--navy); color:#fff; padding:13px 22px; border-radius:99px;
  font-weight:800; font-size:16px; opacity:0; pointer-events:none;
  transition:opacity .2s, transform .2s;
  max-width:calc(100% - 32px); text-align:center;
  box-shadow:0 10px 28px rgba(0,0,0,.3);
}
#app-toast.show{ opacity:1; transform:translateX(-50%) translateY(0); }
#app-modal{
  border:none; border-radius:22px; padding:0;
  max-width:480px; width:calc(100% - 32px);
  background:var(--card); color:var(--ink);
  box-shadow:0 24px 60px rgba(0,0,0,.35);
}
#app-modal::backdrop{ background:rgba(15,45,84,.55); }
.modal-body{ padding:24px; }
.modal-body h3{ font-size:21px; margin-bottom:8px; }
.modal-actions{ display:flex; gap:10px; justify-content:flex-end; margin-top:18px; flex-wrap:wrap; }

/* ===== Footer ===== */
.app-footer{
  margin-top:44px; text-align:center; color:var(--muted);
  font-size:14px; font-weight:700; padding-bottom:8px;
}
.app-footer img{ width:34px; height:34px; border-radius:10px; object-fit:cover; margin:0 auto 8px; }

/* Trợ năng */
.sr-only{
  position:absolute; width:1px; height:1px; padding:0; margin:-1px;
  overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0;
}

/* ===== Thanh điều khiển video tự làm (player.js) ===== */
.video-controls{
  display:flex; align-items:center; gap:10px; flex-wrap:wrap;
  margin-top:12px; padding:10px 12px;
  background:var(--card); border:2px solid var(--line); border-radius:16px;
}
.video-controls .video-time{ font-weight:800; color:var(--muted); white-space:nowrap; }
.video-seek{ flex:1 1 160px; min-width:120px; accent-color:var(--blue); height:6px; }
.video-vol{ width:96px; accent-color:var(--blue); height:6px; }
.video-speed{
  border:2px solid var(--line); border-radius:10px; background:var(--card);
  color:var(--ink); font-weight:800; font-size:15px; padding:6px 8px;
}

/* ===== Bảng chọn câu: đã xem đáp án (practice.js) ===== */
.qnav button.viewed{ background:var(--orange); color:#fff; border-color:var(--orange); }

/* ===== Bảng quản trị (admin.js) ===== */
.admin-table{ width:100%; border-collapse:collapse; font-size:15px; }
.admin-table th, .admin-table td{ text-align:left; padding:10px 8px; border-bottom:1px solid var(--line); vertical-align:top; }
.admin-table th{ color:var(--muted); font-size:13px; text-transform:uppercase; letter-spacing:.03em; }
.admin-table tr:last-child td{ border-bottom:none; }