/* Phần mới: câu trả lời của nhóm (trang chủ) và trò chơi. Dùng lại biến màu của giao diện cũ. */
.quick-resource-section{grid-template-columns:repeat(4,1fr)}
.muted-s{color:var(--muted);font-size:14px;margin:0 0 4px}

/* ----- câu trả lời trên trang chủ ----- */
.answer-section{padding-top:20px}
.answer-grid{display:grid;grid-template-columns:repeat(3,1fr);border:1px solid var(--line);border-radius:5px;overflow:hidden}
.answer-card{padding:26px 28px;border-right:1px solid var(--line);background:var(--surface,var(--white))}
.answer-card:last-child{border-right:0}
.answer-card span{font-size:14px;color:var(--warm)}
.answer-card h3{font:400 24px var(--serif);margin:6px 0 8px}
.answer-card p{margin:0;color:var(--muted);font-size:15px}
.answer-card.hot{background:var(--accent);color:var(--paper)}
.answer-card.hot span,.answer-card.hot p{color:inherit;opacity:.85}
.answer-lab{display:grid;grid-template-columns:1fr 1fr;gap:40px;margin-top:26px;align-items:center}
.answer-controls h3{font:400 22px var(--serif);margin-bottom:4px}
.answer-hint{color:var(--muted);font-size:14px}
.answer-controls label,.rng{display:block;font-size:14px;font-weight:500;margin:14px 0 4px}
.answer-controls output,.rng output{float:right;color:var(--warm);font-weight:600}
input[type=range]{width:100%;accent-color:var(--accent)}
.split-bar{display:flex;height:44px;border-radius:5px;overflow:hidden;margin:14px 0;font-size:13px;font-weight:600;color:#fff}
.split-bar>div{display:flex;align-items:center;justify-content:center;white-space:nowrap;overflow:hidden;transition:flex .35s}
.s-chia{background:#7b837c}.s-tieu{background:#8a6f9e}.s-tich{background:#315947}
.answer-stats{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.answer-stats div{border:1px solid var(--line);border-radius:5px;padding:10px 14px}
.answer-stats span{display:block;font-size:12px;color:var(--muted)}
.answer-stats strong{font:400 26px var(--serif)}
.answer-chart{color:var(--ink)}
.answer-chart svg{width:100%;height:auto}
.answer-chart p{font-size:14px;color:var(--muted);margin:6px 0 0}
.answer-foot{margin:22px 0 0;color:var(--muted)}

/* ----- trò chơi ----- */
.game-main{padding-top:50px;padding-bottom:70px}
.game-heading{margin-bottom:30px}
.game-heading h1{font-size:clamp(42px,6vw,72px);margin-bottom:14px}
.game-heading p{color:var(--muted);max-width:560px}
.game-tabs{display:flex;gap:10px;margin-bottom:26px;border-bottom:1px solid var(--line)}
.game-tabs button{background:none;border:0;border-bottom:2px solid transparent;padding:10px 4px;margin-right:18px;color:var(--muted);font-size:16px}
.game-tabs button.on{color:var(--ink);border-color:var(--accent)}
.pane{display:none}.pane.on{display:block}
.panel{background:var(--surface,var(--white));border:1px solid var(--line);border-radius:5px;padding:22px}
.panel h3{font:400 24px var(--serif);margin-bottom:8px}
.panel h4,.ctl h4{margin:16px 0 6px;font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);font-weight:600}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(110px,1fr));gap:10px;margin-top:12px}
.stat{border:1px solid var(--line);border-radius:5px;padding:8px 12px}
.stat span{display:block;font-size:12px;color:var(--muted)}
.stat b{font:400 22px var(--serif)}
.game-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:18px;align-items:center}
.sim{display:grid;grid-template-columns:1.05fr .95fr;gap:26px;align-items:start}
.scene-box{background:var(--soft,#eceee3);border:1px solid var(--line);border-radius:5px;overflow:hidden}
.scene-box svg{display:block;width:100%;height:auto}
.meter{margin:8px 0}
.meter .lab{display:flex;justify-content:space-between;font-size:13px;font-weight:500}
.meter .tr{height:8px;background:var(--line);border-radius:8px;overflow:hidden}
.meter .tr i{display:block;height:100%;transition:width .6s,background .4s}
.choice{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.choice.two{grid-template-columns:1fr 1fr;margin-top:10px}
.choice label{border:1px solid var(--line);border-radius:5px;padding:9px 6px;text-align:center;font-size:14px;cursor:pointer;line-height:1.3}
.choice label:hover{border-color:var(--accent)}
.choice input{position:absolute;opacity:0;pointer-events:none}
.choice label:has(input:checked){border-color:var(--accent);background:var(--soft,#eceee3);font-weight:600}
.choice small{display:block;color:var(--muted);font-size:12px;font-weight:400}
.report{margin-top:16px}
.news{padding:9px 13px;border-radius:5px;margin:6px 0;font-size:14px;border-left:3px solid var(--line);background:var(--soft,#eceee3)}
.news.g{border-color:var(--accent)}.news.r{border-color:#b5483a;background:var(--warning-surface,#f4e1da)}.news.y{border-color:var(--warm)}
.report table,.panel table{width:100%;border-collapse:collapse;font-size:14px;margin:10px 0}
.report th,.report td{padding:8px 10px;border-bottom:1px solid var(--line);text-align:center}
.report th{font-size:12px;color:var(--muted);font-weight:600}
.sim-end{display:none;margin-top:16px}
.res{text-align:center;padding:14px 6px}
.res .big{font:400 60px var(--serif);color:var(--accent)}
.smoke{animation:rise 3s linear infinite}
.strike{animation:shake .6s 2}

/* quiz */
.quiz{max-width:760px}
.q-meta{display:flex;justify-content:space-between;font-size:14px;color:var(--muted);margin-bottom:10px}
.q-prog{height:4px;background:var(--line);margin-bottom:16px}
.q-prog i{display:block;height:100%;background:var(--accent);transition:width .4s}
.scene{display:flex;gap:14px;align-items:center;background:var(--soft,#eceee3);border-radius:5px;padding:12px 16px;font-size:15px;color:var(--muted);margin:14px 0}
.scene svg{flex:none;width:60px;height:45px}
.q-text{font:400 26px/1.35 var(--serif);margin-bottom:16px}
.opts{display:grid;gap:10px}
.opt{text-align:left;background:var(--surface,var(--white));border:1px solid var(--line);border-radius:5px;padding:12px 15px;display:flex;gap:12px;color:var(--ink);transition:border-color .15s,transform .15s}
.opt b{flex:none;width:26px;height:26px;border-radius:50%;border:1px solid var(--line);display:grid;place-items:center;font-size:13px}
.opt:hover:not([disabled]){border-color:var(--accent);transform:translateX(3px)}
.opt.right{background:var(--success-surface,#e1ece1);border-color:var(--accent);animation:pop .45s}
.opt.right b{background:var(--accent);color:var(--paper);border-color:var(--accent)}
.opt.wrong{background:var(--warning-surface,#f4e1da);border-color:#b5483a;animation:shake .45s}
.opt.wrong b{background:#b5483a;color:#fff;border-color:#b5483a}
.opt[disabled]{cursor:default}
.fb{margin-top:16px;border-radius:5px;padding:15px 17px;display:none}
.fb.ok{display:block;background:var(--success-surface,#e1ece1);border:1px solid var(--accent)}
.fb.no{display:block;background:var(--warning-surface,#f4e1da);border:1px solid #b5483a}
.fb .eff{display:flex;gap:10px;align-items:center;font-weight:600;margin-bottom:6px}
.fb .eff svg{width:32px;height:32px;flex:none}
.fb p{margin:0;font-size:15px}
.weak{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin:12px 0 20px}
.weak span{background:var(--warning-surface,#f4e1da);padding:3px 12px;border-radius:99px;font-size:13px}
.fx{position:fixed;inset:0;pointer-events:none;z-index:99;overflow:hidden}
.fx i{position:absolute;top:-12px;width:9px;height:13px;border-radius:2px;animation:fall 1.4s ease-in forwards}
.fx.bad{background:radial-gradient(circle,transparent 55%,rgba(181,72,58,.35));animation:flash .6s}
@keyframes pop{0%{transform:scale(.98)}50%{transform:scale(1.02)}100%{transform:none}}
@keyframes shake{0%,100%{transform:none}20%{transform:translateX(-7px)}40%{transform:translateX(7px)}60%{transform:translateX(-5px)}80%{transform:translateX(5px)}}
@keyframes fall{to{transform:translateY(105vh) rotate(540deg)}}
@keyframes flash{from{opacity:1}to{opacity:0}}
@keyframes rise{from{transform:translateY(0);opacity:.7}to{transform:translateY(-26px);opacity:0}}

@media(max-width:820px){
  .answer-grid{grid-template-columns:1fr}
  .answer-card{border-right:0;border-bottom:1px solid var(--line)}
  .answer-card:last-child{border-bottom:0}
  .answer-lab,.sim{grid-template-columns:1fr;gap:22px}
  .quick-resource-section{grid-template-columns:1fr 1fr}
  .q-text{font-size:22px}
}
@media(prefers-reduced-motion:reduce){.fx,.smoke,.strike,.opt{animation:none!important}}
.practice-button{border:1px solid var(--line);border-radius:5px;background:transparent;color:var(--ink);padding:11px 17px;font-size:14px;min-height:44px;transition:background .2s,border-color .2s}
.practice-button:hover{border-color:var(--accent);background:var(--soft,#eceee3)}
@media(max-width:1000px){.sim{grid-template-columns:1fr}}

/* khái niệm dẫn đến kết luận (trang chủ) */
.concept-steps{list-style:none;margin:0;padding:0;border-top:1px solid var(--line)}
.concept-steps li{display:grid;grid-template-columns:70px 1fr auto;gap:22px;align-items:start;padding:26px 4px;border-bottom:1px solid var(--line)}
.cs-num{font:italic 34px var(--serif);color:var(--warm)}
.concept-steps h3{font:400 26px var(--serif);margin:0 0 6px}
.concept-steps p{margin:0 0 10px;color:var(--muted);max-width:640px}
.cs-chip{font:400 20px var(--serif);border:1px solid var(--line);border-radius:5px;padding:8px 14px;background:var(--surface,var(--white));white-space:nowrap}
.conclusion-box{margin-top:26px;border:1px solid var(--accent);border-radius:5px;padding:24px 28px;background:var(--surface,var(--white))}
.conclusion-box h3{font:400 24px var(--serif);margin-bottom:8px}
.conclusion-box ol{margin:0 0 14px;padding-left:20px}
.conclusion-box li{margin:.45em 0}
.credit-names{display:block;font-size:14px}
.credit-names a:hover{color:var(--warm)}
@media(max-width:820px){.concept-steps li{grid-template-columns:44px 1fr}.cs-chip{grid-column:2;justify-self:start}.cs-num{font-size:26px}}
.slide-inner .opts{max-width:820px}
.slide-inner .opt{font-size:1.1rem;padding:14px 18px}
.slide-inner .fb{max-width:820px;font-size:1.02rem}

/* ===== Thuyết trình: thanh công cụ mới ===== */
.pres-top{display:flex;align-items:center;gap:18px;padding:12px 28px;border-bottom:1px solid var(--line);background:var(--header-bg,rgba(245,244,236,.96));flex-shrink:0;position:relative;z-index:5}
.pres-brand{display:flex;align-items:center;gap:12px}
.pres-logo{width:38px;height:38px;border:1px solid var(--accent);border-radius:50%;display:grid;place-items:center;font:italic 27px var(--serif);padding-right:2px;color:var(--accent)}
.pres-brand strong{display:block;font-size:15px;line-height:1.2;font-weight:600}
.pres-brand small{display:block;font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted)}
.pres-chip{margin:0 auto;font-size:12px;letter-spacing:.14em;text-transform:uppercase;font-weight:600;color:var(--warm);background:var(--soft,#eceee3);padding:8px 18px;border-radius:99px;max-width:46vw;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.pres-tools{display:flex;gap:8px;align-items:center}
.pres-btn,.pres-icon{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--surface,var(--white));color:var(--ink);border-radius:99px;height:40px;padding:0 16px;font-size:14px;cursor:pointer;transition:background .2s,color .2s,border-color .2s}
.pres-icon{width:40px;padding:0;justify-content:center}
.pres-btn:hover,.pres-icon:hover{background:var(--accent);color:var(--paper);border-color:var(--accent)}
.pres-menu-wrap{position:relative}
.pres-menu{position:absolute;right:0;top:48px;width:min(430px,86vw);max-height:62vh;overflow:auto;background:var(--surface,var(--white));border:1px solid var(--line);border-radius:12px;box-shadow:0 18px 50px -16px rgba(0,0,0,.35);padding:8px;z-index:10;animation:pxRise .25s both}
.pres-menu[hidden]{display:none}
.pres-menu button{display:flex;gap:12px;width:100%;text-align:left;background:none;border:0;border-radius:8px;padding:9px 12px;color:var(--ink);font-size:14px;line-height:1.4;cursor:pointer}
.pres-menu button span{color:var(--warm);font-variant-numeric:tabular-nums;flex:none}
.pres-menu button:hover{background:var(--soft,#eceee3)}
.pres-menu button.on{background:var(--accent);color:var(--paper)}
.pres-menu button.on span{color:inherit}
@media(max-width:760px){.pres-top{padding:10px 14px;gap:10px}.pres-brand small,.pres-btn span{display:none}.pres-btn{padding:0 12px}.pres-chip{display:none}.pres-tools{margin-left:auto}}

/* ===== Thuyết trình: hoạt ảnh ===== */
.presentation-v3 .slide-stage{position:relative;overflow-x:hidden}
.presentation-v3 .slide-stage::before{content:"m";position:absolute;right:3vw;bottom:-6vh;font:italic 38vh/1 var(--serif);color:var(--accent);opacity:.05;pointer-events:none;animation:pxFloat 9s ease-in-out infinite}
.presentation-v3[data-dir=next] .slide-inner.slide-enter{animation:pxInR .55s cubic-bezier(.2,.7,.2,1) both}
.presentation-v3[data-dir=prev] .slide-inner.slide-enter{animation:pxInL .55s cubic-bezier(.2,.7,.2,1) both}
.slide-enter .slide-heading>*{animation:pxRise .6s cubic-bezier(.2,.7,.2,1) both}
.slide-enter .slide-heading>:nth-child(1){animation-delay:.05s}
.slide-enter .slide-heading>:nth-child(2){animation-delay:.14s}
.slide-enter .slide-heading>:nth-child(3){animation-delay:.24s}
.slide-enter .slide-block,.slide-enter .slide-flow li,.slide-enter .slide-comparison-panel,.slide-enter .slide-points li,.slide-enter .slide-example-case,.slide-enter .slide-table-block,.slide-enter .slide-conclusion,.slide-enter .slide-note,.slide-enter .opt,.slide-enter .iq-actions{animation:pxRise .6s cubic-bezier(.2,.7,.2,1) both;animation-delay:calc(var(--i,0)*95ms + .3s)}
.slide-enter .slide-equation{animation:pxPop .7s cubic-bezier(.2,.9,.3,1.2) both;animation-delay:.35s}
.slide-flow li{position:relative}
.slide-enter .slide-block-number{display:inline-block;animation:pxPop .6s both;animation-delay:calc(var(--i,0)*95ms + .45s)}
.slide-enter .fb{animation:pxRise .4s both}
@keyframes pxInR{from{opacity:0;transform:translateX(60px)}to{opacity:1;transform:none}}
@keyframes pxInL{from{opacity:0;transform:translateX(-60px)}to{opacity:1;transform:none}}
@keyframes pxRise{from{opacity:0;transform:translateY(22px)}to{opacity:1;transform:none}}
@keyframes pxPop{0%{opacity:0;transform:scale(.88)}100%{opacity:1;transform:none}}
@keyframes pxFloat{0%,100%{transform:translateY(0) rotate(-2deg)}50%{transform:translateY(-3vh) rotate(2deg)}}
.slide-inner .opt{animation-fill-mode:both}
.slide-inner .opt.right{animation:pop .5s}
.slide-inner .opt.wrong{animation:shake .5s}
@media(prefers-reduced-motion:reduce){.presentation-v3 .slide-stage::before{animation:none}.slide-enter *,.slide-enter{animation:none!important}}

/* ===== Trang chủ: banner câu hỏi ===== */
.question-banner{display:flex;gap:28px;align-items:center;background:var(--accent);color:var(--paper);border-radius:5px;padding:34px 40px;margin-bottom:30px;position:relative;overflow:hidden}
.question-banner::after{content:"";position:absolute;right:-60px;top:-60px;width:220px;height:220px;border-radius:50%;border:1px solid currentColor;opacity:.18}
.qb-mark{flex:none;width:76px;height:76px;border:1.5px solid currentColor;border-radius:50%;display:grid;place-items:center;font:italic 48px var(--serif);padding-bottom:6px}
.qb-label{display:block;font-size:13px;letter-spacing:.16em;text-transform:uppercase;font-weight:600;opacity:.85;margin-bottom:8px}
.question-banner p{margin:0;font:400 clamp(22px,2.6vw,32px)/1.4 var(--serif);color:inherit}
@media(max-width:700px){.question-banner{flex-direction:column;align-items:flex-start;padding:26px 24px;gap:16px}.qb-mark{width:56px;height:56px;font-size:36px}}

/* ===== Màn hình lớn (16:9 full HD trở lên): phóng nội dung để không bị thưa ===== */
:root{--z:1}
@media(min-width:
px){:root{--z:1}}
@media(min-width:
px){:root{--z:1}}
@media(min-width:
px){:root{--z:1}}
@media(min-width:
px){:root{--z:1}}
/* màn hình rộng: giữ cỡ chữ, chỉ thu hẹp khung nội dung còn 70% để hai bên có khoảng trống */
@media(min-width:1700px){.container{width:70%}}

.presentation-v3{zoom:calc(var(--z) * 1);width:calc(100vw / (var(--z) * 1));height:calc(100vh / (var(--z) * 1));max-width:none;max-height:none}
.slide-inner .opt.done{pointer-events:none}

.pres-tools{margin-left:auto}
/* thẻ ví dụ trang chủ: chừa chỗ để nhãn công thức không che chú thích */
.hero-visual{padding-bottom:84px!important}
.formula-stamp{bottom:8px!important;right:-6px!important}
.visual-caption{bottom:0!important}
.compact-points details.hl{outline:2px solid var(--warm);outline-offset:4px;border-radius:4px;animation:hlFade 3s 1.5s forwards}
@keyframes hlFade{to{outline-color:transparent}}

/* ===== Bài học: câu hỏi khán giả có âm thanh ===== */
.aud{margin:22px 0 8px;display:grid;gap:12px}
.aud .eyebrow{margin:0 0 2px}
.aud-item{background:var(--surface,var(--white));border:1px solid var(--line);border-left:3px solid var(--warm);border-radius:5px;padding:14px 18px}
.aud-top{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:6px}
.aud-n{font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--warm);font-weight:700}
.aud-play{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:transparent;color:var(--ink);border-radius:99px;padding:6px 14px;font-size:13px;cursor:pointer;transition:.2s}
.aud-play:hover,.aud-play.playing{background:var(--accent);color:var(--paper);border-color:var(--accent)}
.aud-q{font:400 19px/1.45 var(--serif);margin:0 0 8px}
.aud-item details summary{cursor:pointer;color:var(--accent);font-size:14px;font-weight:500}
.aud-item details p{margin:8px 0 0;font-size:15px;color:var(--muted)}
.aud-item details strong{color:var(--ink)}

.pres-icon.muted{color:var(--muted);background:transparent}
.slide-inner .opt.picked{background:var(--soft,#eceee3);border-color:var(--accent)}
.slide-inner .opt.picked b{background:var(--accent);color:var(--paper);border-color:var(--accent)}

/* bấm vào câu hỏi để nghe lại */
.aud-click,.aud-play{cursor:pointer}
.aud-click:hover,.aud-play:hover{color:var(--accent)}
.aud-play.playing{color:var(--accent)}
.aud-hint{font-size:12px;color:var(--muted)}
.qd-close.muted{color:var(--muted)}

/* Slide kết luận: câu hỏi là trọng tâm, câu trả lời đứng sau */
.presentation-v3 .slide-layout-closing .slide-heading h2{font-size:34px;margin-bottom:16px}
.presentation-v3 .slide-layout-closing .slide-lead{position:relative;max-width:none;background:var(--accent);color:var(--paper);border-radius:6px;padding:46px 36px 28px;font:400 38px/1.35 var(--serif);letter-spacing:-.005em;margin:0 0 26px}
.presentation-v3 .slide-layout-closing .slide-lead::before{content:"CÂU HỎI CỦA CHỦ ĐỀ";position:absolute;left:36px;top:18px;font:600 12px var(--sans);letter-spacing:.16em;opacity:.8}
.presentation-v3 .slide-layout-closing .slide-points li{font-size:21px}
.presentation-v3 .slide-layout-closing .slide-lead{font-size:34px;padding:40px 32px 22px;margin-bottom:18px}
.presentation-v3 .slide-layout-closing .slide-lead::before{left:32px;top:15px}
.presentation-v3 .slide-layout-closing .slide-points{margin:0 0 14px}
.presentation-v3 .slide-layout-closing .slide-points li{font-size:19px;margin:.3em 0}
.presentation-v3 .slide-layout-closing .slide-conclusion{font-size:27px;margin-top:10px}
.presentation-v3 .slide-layout-closing .slide-heading h2{font-size:30px;margin-bottom:12px}
.presentation-v3 .slide-stage::before{bottom:auto;top:30vh;right:3vw}
.presentation-v3 .slide-layout-closing .slide-lead::before{content:none;display:none}
.presentation-v3 .slide-layout-closing .slide-lead{padding:30px 32px}