:root{font-family:system-ui,-apple-system,'Segoe UI',sans-serif;color:#302653;background:#f7f4ff}*{box-sizing:border-box}body{margin:0}header{display:flex;justify-content:space-between;align-items:center;padding:14px max(20px,calc((100vw - 1100px)/2));background:#fff;box-shadow:0 2px 12px #7766b71b;gap:12px;flex-wrap:wrap}.brand{font-weight:900;color:#6b49c7;font-size:1.25rem}a{text-decoration:none;color:#6749c4}nav{display:flex;gap:15px;align-items:center;flex-wrap:wrap}main{max-width:1100px;margin:auto;padding:24px 18px 60px}footer{text-align:center;padding:25px;color:#766b90}.hero{text-align:center;border-radius:30px;padding:38px 15px;background:linear-gradient(135deg,#d7f5ff,#f7e1ff,#fff2bd)}h1{font-size:clamp(1.6rem,4vw,2.5rem);margin:12px 0}h2{font-size:1.35rem}.mascot{font-size:3.3rem}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:18px}.world{min-height:210px;display:flex;align-items:center;flex-direction:column;justify-content:center;gap:9px;border-radius:25px;background:#fff;box-shadow:0 7px 22px #66539b19;padding:20px;text-align:center;transition:transform .15s}.world:hover{transform:translateY(-5px)}.world:nth-child(4n+1){background:#e5f9e8}.world:nth-child(4n+2){background:#fff1e1}.world:nth-child(4n+3){background:#e4f4ff}.world:nth-child(4n){background:#f4e8ff}.emoji{font-size:3.7rem}.world strong{color:#3d3166}.pill{background:#fff;padding:7px 14px;border-radius:50px;color:#6c46b7;font-weight:700}.bar,.playtop{display:flex;gap:15px;align-items:center;justify-content:space-between;flex-wrap:wrap;margin:24px 0}.panel{background:#fff;padding:24px;border-radius:25px;box-shadow:0 6px 25px #66539b14;margin:20px 0}.narrow{max-width:460px;margin:60px auto}.two{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}.two .panel{margin:0}label{display:block;font-weight:600;margin:12px 0}input,select{display:block;width:100%;padding:12px;border:2px solid #e2dcf4;border-radius:12px;margin-top:6px;font:inherit;background:#fff}button,.button{border:0;background:#7655d7;color:white;border-radius:16px;padding:13px 20px;font:inherit;font-weight:800;cursor:pointer;display:inline-block;margin:8px 5px 8px 0}button:hover,.button:hover{background:#5737b9;color:white}.notice{background:#fff4c9;padding:15px;border-radius:14px;margin:16px 0}.row{display:flex;align-items:end;gap:14px;flex-wrap:wrap}.row label{flex:1;min-width:150px}.table-wrap{overflow:auto}table{border-collapse:collapse;width:100%}td,th{padding:12px;border-bottom:1px solid #ece8f7;text-align:left}.game{text-align:center;max-width:760px;margin:20px auto;min-height:440px}.objects{font-size:clamp(2.2rem,7vw,4.5rem);min-height:90px;display:flex;justify-content:center;align-items:center;gap:10px;flex-wrap:wrap;margin:18px 0}.choices{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.choices button{font-size:clamp(1.4rem,4vw,2rem);background:#f3ebff;color:#47357e;border:3px solid #d7c5ff;min-height:75px;margin:0}.choices button:disabled{opacity:.6}.choices button.correct{background:#a5f0bd}.choices button.wrong{background:#ffd3d8}.progress{height:12px;background:#ece5fc;border-radius:20px;overflow:hidden}.progress div{height:100%;background:#69c994;width:0;transition:width .2s}#feedback{font-size:1.2rem;font-weight:700;min-height:30px}@media(max-width:480px){.panel{padding:17px}.choices{gap:7px}.choices button{min-height:65px;padding:8px}.hero{padding:25px 10px}}

.inline-form{display:inline-flex;margin:0}.nav-button{background:#fff;color:#5a36a5;padding:8px 12px;border:1px solid #ddd}.game-controls{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;margin:12px 0}.game-controls button{font-size:15px;padding:9px 14px}.objects{overflow-wrap:anywhere;line-height:1.8}.choices button{min-height:65px;touch-action:manipulation}button:focus-visible,a:focus-visible{outline:3px solid #ff9d00;outline-offset:3px}

/* V1.2: trẻ thao tác cảm ứng và thả hình */
.drag-hint{font-size:1rem;color:#604a95}.drop-zone{border:4px dashed #a78bfa;background:#f7f0ff;border-radius:24px;min-height:90px;display:flex;align-items:center;justify-content:center;font-size:2rem;margin:15px auto;max-width:330px;cursor:pointer}.drop-zone[hidden],.drag-hint[hidden]{display:none!important}.choices button.selected{outline:5px solid #ffb648;background:#fff0ba}.world .emoji{filter:drop-shadow(0 6px 5px #0001)}@media(hover:none){button,.world{min-height:55px}}

/* V1.3: giao diện thân thiện với trẻ */
.world{position:relative;transition:transform .2s,box-shadow .2s;border:3px solid transparent;border-radius:24px;background:linear-gradient(145deg,#fff,#f1faff);box-shadow:0 7px 20px #b1c7dc55}.world:nth-child(5n+1){background:linear-gradient(145deg,#e6ffe6,#fff8d9)}.world:nth-child(5n+2){background:linear-gradient(145deg,#fff0e2,#ffe9f5)}.world:nth-child(5n+3){background:linear-gradient(145deg,#e4f5ff,#e9eaff)}.world:nth-child(5n+4){background:linear-gradient(145deg,#f5eaff,#fff2da)}.world:hover,.world:focus-within{transform:translateY(-5px);box-shadow:0 12px 24px #8aa9cc66}.world .emoji{font-size:3.6rem;display:block;animation:bob 3s ease-in-out infinite}.mascot{animation:bob 4s ease-in-out infinite}@keyframes bob{0%,100%{transform:translateY(0)}50%{transform:translateY(-9px)}}.choices button{min-height:72px;min-width:88px;font-size:1.35rem;border-radius:18px;touch-action:manipulation}.drop-zone{min-height:85px;border:3px dashed #719fe8;border-radius:18px}.button{display:inline-block;text-decoration:none;margin:6px}.world p{line-height:1.5}@media(max-width:600px){.choices{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.choices button{min-width:0}.world .emoji{font-size:3rem}}

/* V1.4: trò chơi giỏ táo và báo cáo in */
.basket-game{margin:18px auto;padding:18px;border-radius:24px;background:#fff5dc;max-width:700px;text-align:center}.basket-game[hidden],.choices[hidden]{display:none!important}.basket-items{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin-bottom:20px}.fruit{font-size:2.3rem;min-width:64px;min-height:64px;background:white;border:2px solid #ffcf82;border-radius:18px;cursor:grab;touch-action:manipulation}.fruit.in-basket{opacity:.24;pointer-events:none}.basket-target{font-size:3.5rem;border:4px dashed #ecaa45;border-radius:24px;background:#fff;min-height:120px;max-width:280px;margin:0 auto;display:flex;align-items:center;justify-content:center;gap:20px;cursor:pointer}.basket-target span{font-size:2.3rem;font-weight:bold;color:#925a20}.reward{font-size:1.4rem;font-weight:bold;color:#7b3bb8}@media print{header,footer,nav,button{display:none!important}main{max-width:none}.panel{box-shadow:none;border:0}table{width:100%;border-collapse:collapse}th,td{border:1px solid #999;padding:8px}}

/* V1.4 nâng cấp: trò chơi nhìn thấy và chạm được */
.game-kind{font-size:.86rem;font-weight:700;color:#60458b;background:#ffffffb9;border-radius:14px;padding:7px 10px}.world{min-height:240px}.world:hover .pill{background:#ffe28c}.play-label{color:#7a50c7;font-weight:800}.memory-game,.sort-game{background:linear-gradient(145deg,#e8f8ff,#fff1d6);padding:20px;border-radius:24px;margin:15px auto}.memory-game[hidden],.sort-game[hidden]{display:none!important}.memory-board{display:grid;grid-template-columns:repeat(3,minmax(75px,120px));justify-content:center;gap:14px}.memory-card{height:100px;margin:0;font-size:3rem;border:3px solid #a6c9f3;background:#fff;box-shadow:0 5px 0 #b8a4db}.memory-card.flipped{background:#e3f4ff}.memory-card.matched{background:#bff4cf;box-shadow:none}.sort-numbers{display:flex;justify-content:center;gap:12px;flex-wrap:wrap}.sort-numbers button{font-size:2.2rem;background:#fff;color:#53368c;border:3px solid #b8a4ec;min-width:70px;min-height:80px}.sort-numbers button:disabled{opacity:.35}.sort-picked{font-size:1.35rem;font-weight:800;min-height:55px;padding:12px}.basket-items .fruit{transition:transform .2s}.fruit:active{transform:scale(.9)}@media(max-width:550px){.memory-board{gap:8px;grid-template-columns:repeat(3,minmax(70px,1fr))}.memory-card{height:80px;font-size:2.3rem}.game{min-height:unset}}

/* V1.5: trò chơi thao tác trực tiếp */
.train-game,.shape-game{margin:20px auto;padding:20px;border-radius:25px;background:linear-gradient(120deg,#fff6da,#e7f8ff);max-width:720px;text-align:center}.train-numbers,.shape-options{display:flex;justify-content:center;flex-wrap:wrap;gap:14px;margin:20px 0}.train-number,.shape-option{min-width:76px;min-height:78px;font-size:2.2rem;border:3px solid #b8a6fa;border-radius:22px;background:#fff;cursor:pointer;touch-action:manipulation}.shape-option{font-size:3.2rem}.train-track,.shape-target{font-size:1.7rem;padding:20px;min-height:76px;background:white;border-radius:20px}.train-number:disabled{opacity:.4}.train-game button:focus-visible,.shape-game button:focus-visible{outline:4px solid #ff9d33}#basket-undo{margin-right:12px}@media(max-width:600px){.train-number,.shape-option{min-width:58px;min-height:65px;font-size:1.8rem}.train-game,.shape-game{padding:12px}}

/* Bố cục tối ưu cho điện thoại */
button, a, input, select {touch-action:manipulation;}
@media(max-width:640px){header{padding:12px 14px}nav{gap:9px}main{padding:14px 10px 48px}.grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.world{min-height:165px;padding:12px 6px;border-radius:20px}.hero{padding:24px 10px;border-radius:22px}button,.btn{min-height:44px}input,select{max-width:100%}}
@media(max-width:360px){.grid{grid-template-columns:1fr}}

/* V1.9.1: Đáp án luôn rõ trên thiết bị cảm ứng, không phụ thuộc hover. */
#choices button,.train-number,.sort-numbers button,.shape-option,.memory-card,#fish-board button,#pair-board button {color:#27164f!important;-webkit-text-fill-color:#27164f!important;opacity:1!important;visibility:visible!important;text-shadow:none!important;font-weight:900!important;}
#choices button:disabled,.train-number:disabled,.sort-numbers button:disabled {opacity:.85!important;}
#choices button.correct {background:#baf2c8!important;color:#164628!important;-webkit-text-fill-color:#164628!important;}
#choices button.wrong {background:#ffd3d8!important;color:#722033!important;-webkit-text-fill-color:#722033!important;}
#choices button{font-size:clamp(1.55rem,5vw,2.2rem)!important;min-height:84px!important;}
#audio-status{font-size:.9rem;color:#534278;background:#f1edff;padding:10px;border-radius:12px;}
@media(hover:none){#choices button:hover,.train-number:hover,.shape-option:hover{transform:none!important;filter:none!important;}}

/* V1.9.2: quả táo phải xuất hiện TRONG giỏ sau khi chạm */
#basket-target{max-width:100%;min-height:145px;flex-wrap:wrap;gap:7px;padding:14px;touch-action:manipulation;}
#basket-target .basket-apple{font-size:2rem;display:inline-flex;animation:popIn .2s ease-out;}
#basket-items .fruit{min-width:66px;min-height:70px;font-size:2.5rem;touch-action:manipulation;-webkit-tap-highlight-color:transparent;}
#basket-items .fruit.in-basket{opacity:.22;background:#e5e5e5;}
@keyframes popIn{from{transform:scale(.4)}to{transform:scale(1)}}
#audio-status{font-weight:700;}
/* V2: Xưởng bài tập động */
.studio-panel{background:white;border:2px solid #e8dfff;border-radius:22px;padding:22px;margin:18px 0;box-shadow:0 7px 25px #6352aa12}.studio-panel label{display:block;font-weight:700;margin:12px 0}.studio-panel input,.studio-panel textarea{display:block;width:100%;padding:13px;margin-top:7px;border:2px solid #d6c8f6;border-radius:13px;font:inherit;box-sizing:border-box}.studio-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:15px}.studio-btn,.answer-btn{background:#7250d5;color:white;border:0;border-radius:16px;padding:14px 20px;font-weight:800;cursor:pointer;display:inline-block;text-decoration:none}.studio-top{display:flex;justify-content:space-between;gap:10px;align-items:center}.object-stage{display:flex;justify-content:center;align-items:center;gap:14px;flex-wrap:wrap;min-height:150px;padding:15px;background:#fff7dc;border-radius:18px;font-size:clamp(26px,6vw,46px)}.moving-objects{max-width:100%;overflow-wrap:anywhere;animation:floatObjects 2s ease-in-out infinite alternate}.choice-row{display:flex;justify-content:center;gap:14px;flex-wrap:wrap;margin:20px}.answer-btn{font-size:28px;min-width:80px;min-height:75px}.answer-btn.right{background:#139c5b}.answer-btn.wrong{background:#d95555}@keyframes floatObjects{to{transform:translateY(-9px)}}@media(max-width:600px){.studio-panel{padding:14px}.studio-top{flex-wrap:wrap}}

/* V2.1: phong cảnh hoạt hình dựa trên mô tả của giáo viên */
.scene-world{position:relative;isolation:isolate;min-height:310px;border-radius:24px;overflow:hidden;padding:12px;background:linear-gradient(#c9eeff 0%,#f5fcff 65%,#b4e69b 66%,#79bf72 100%)}
.scene-forest{background:linear-gradient(#b9e5e4 0%,#d8f1d1 58%,#8dc47d 59%,#4f9a5c 100%)}
.scene-ocean{background:linear-gradient(#a4efff,#52bfe3 55%,#1688bb 100%)}
.scene-space{background:linear-gradient(#182251,#4a3b82 75%,#69559a)}
.scene-castle{background:linear-gradient(#fbe3ff,#e7e7ff 65%,#b5dc95 66%,#8bc478)}
.scene-sky{text-align:center;font-size:32px;letter-spacing:25px;white-space:nowrap;animation:sceneDrift 7s ease-in-out infinite alternate;min-height:45px}
.scene-decor{display:flex;justify-content:space-around;align-items:end;gap:4px;min-height:95px;flex-wrap:wrap;pointer-events:none}
.scene-item{font-size:clamp(32px,5vw,60px);animation:sceneBob 2.8s ease-in-out infinite alternate;filter:drop-shadow(0 5px 3px #0002)}
.scene-world .object-stage{position:relative;z-index:2;background:#ffffffc9;border:2px solid #ffffff99;min-height:95px;margin:12px auto;max-width:850px}
.scene-ground{text-align:center;font-size:24px;letter-spacing:9px;min-height:30px}
@keyframes sceneBob{to{transform:translateY(-12px) rotate(5deg)}}
@keyframes sceneDrift{to{transform:translateX(16px)}}
@media(prefers-reduced-motion:reduce){.scene-item,.scene-sky{animation:none}}
@media(max-width:600px){.scene-world{min-height:260px}.scene-sky{letter-spacing:7px}.scene-item{font-size:32px}}

/* V2.2: tap-to-collect game, accessible on phones and tablets */
.collect-game{width:100%;text-align:center;font-size:21px}.collect-items{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;padding:16px}.collect-item{font-size:clamp(36px,7vw,64px);min-width:68px;min-height:70px;border:2px solid #d5b873;border-radius:18px;background:#fffdf6;cursor:pointer;touch-action:manipulation}.collect-item.picked{opacity:.15;transform:translateY(-18px) scale(.6);transition:transform .3s,opacity .3s}.collect-basket{border:3px dashed #c7a05c;border-radius:18px;background:#fff9e6;padding:16px;margin:8px auto;max-width:260px;font-weight:800;font-size:30px}
/* Trang chủ chọn lớp - tách ngân hàng theo độ tuổi */
.grade-hero{border-radius:30px;background:linear-gradient(115deg,#dceffc,#f5e5ff 55%,#fff0c4);padding:38px 30px;text-align:center;margin:18px 0 25px}.grade-hero h1{font-size:clamp(27px,4vw,43px);margin:12px 0;color:#31265c}.grade-hero p{max-width:650px;margin:auto;line-height:1.6}.grade-hero-label,.eyebrow{font-size:13px;font-weight:800;letter-spacing:.05em;color:#6c4cc6}.grade-section{margin:24px 0 34px}.grade-section h2{margin:12px 0 18px}.grade-cards{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:13px}.grade-card{background:#fff;border:2px solid #e9e3fb;border-radius:19px;text-decoration:none;color:#352658;padding:18px 10px;display:flex;align-items:center;flex-direction:column;gap:4px;transition:.15s}.grade-card:hover{transform:translateY(-3px);border-color:#9376df}.grade-card.selected{background:#f1eafe;border-color:#7753d5;box-shadow:0 4px 15px #8064bd24}.grade-icon{font-size:31px}.grade-card strong{font-size:18px}.grade-card small{color:#6f6785}.grade-section-head{display:flex;align-items:center;justify-content:space-between;gap:20px;flex-wrap:wrap}.grade-section-head h2{margin:6px 0}.grade-section-head p{margin:4px 0 14px;color:#655c7b}.learner-bar{display:flex;align-items:center;gap:12px;flex-wrap:wrap;background:#fff;border:1px solid #e8e1fa;border-radius:18px;padding:15px 18px;margin:12px 0 20px}.learner-bar select{max-width:390px;flex:1;min-width:190px}.grade-info{background:#fff8d9;border-radius:13px;padding:15px 18px}.lesson-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.lesson-card{background:#fff;border:1px solid #e7dffa;border-radius:19px;padding:19px;display:flex;flex-direction:column;min-height:205px;box-shadow:0 4px 14px #6b53a00b}.lesson-top{display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:13px;color:#7253bb;font-weight:700}.lesson-tag{background:#f2edfd;padding:5px 8px;border-radius:10px;font-size:11px}.lesson-card h3{margin:14px 0 8px;font-size:19px}.lesson-card p{font-size:14px;color:#605873;line-height:1.5;flex:1}.lesson-bottom{margin-top:12px}.lesson-play{display:inline-block;border:0;border-radius:12px;padding:10px 15px;background:#7652d8;color:white;text-decoration:none;font-weight:750;cursor:pointer;font-size:14px}.grade-actions{background:#fff;border:1px solid #e7dffa;border-radius:20px;padding:23px}.grade-action-links{display:flex;gap:12px;flex-wrap:wrap}.grade-action-links a{background:#f0eafd;padding:12px 15px;border-radius:12px;text-decoration:none;font-weight:700;color:#6243bb}@media(max-width:850px){.grade-cards{grid-template-columns:repeat(4,minmax(0,1fr))}.lesson-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:550px){.grade-hero{padding:28px 15px}.grade-cards{grid-template-columns:repeat(2,minmax(0,1fr))}.lesson-grid{grid-template-columns:1fr}.grade-card{padding:12px 6px}.grade-section-head .button{width:100%;text-align:center}}

/* Trang chào cho khách trên laptop và Android */
.welcome-screen{max-width:680px;margin:28px auto;padding:clamp(20px,5vw,48px);background:#fff;border-radius:24px;box-shadow:0 8px 30px rgba(58,36,114,.10);text-align:center}
.welcome-screen h1{font-size:clamp(28px,6vw,44px);margin:8px 0;color:#6345bb}
.welcome-emoji{font-size:clamp(36px,9vw,60px);line-height:1.4}
.welcome-lead{font-size:clamp(17px,3vw,22px);font-weight:650}
.welcome-actions{display:grid;gap:14px;margin:28px auto;max-width:420px}
.welcome-button{display:block;text-decoration:none;border-radius:14px;padding:16px 20px;font-size:18px;font-weight:700;min-height:52px;box-sizing:border-box}
.welcome-primary{background:#7856d8;color:white}
.welcome-secondary{background:#f2edff;color:#5534a4;border:2px solid #7856d8}
.welcome-note{font-size:14px;color:#606070}
@media(max-width:600px){.welcome-screen{margin:12px auto;padding:22px 16px}.welcome-actions{margin:22px auto}}