:root {
  --ink: #24333b;
  --muted: #708087;
  --cream: #fffaf1;
  --paper: #fffdf8;
  --yellow: #f7b84b;
  --orange: #ef8d4a;
  --teal: #43b8ad;
  --blue: #4a9ad4;
  --coral: #f17d70;
  --line: #e7e8df;
  --shadow: 0 18px 50px rgba(53, 64, 65, .09);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--cream); font-family: "Be Vietnam Pro", sans-serif; }
button, a { font: inherit; }
button { cursor: pointer; }
.page-shell { overflow: hidden; min-height: 100vh; background: radial-gradient(circle at 91% 3%, #fff1c9 0, transparent 23rem), var(--cream); }
.topbar { height: 78px; max-width: 1180px; margin: auto; display: flex; align-items: center; justify-content: space-between; padding: 0 28px; }
.brand { display: inline-flex; align-items: center; gap: 11px; color: var(--ink); text-decoration: none; font: 800 24px "Baloo 2", sans-serif; letter-spacing: -.5px; }
.brand-mark { width: 34px; height: 34px; border-radius: 13px 13px 15px 4px; display: flex; align-items: flex-end; justify-content: center; gap: 3px; padding: 7px; background: var(--yellow); transform: rotate(-8deg); }
.brand-mark span { width: 4px; border-radius: 3px; background: white; }.brand-mark span:nth-child(1) { height: 8px; }.brand-mark span:nth-child(2) { height: 14px; }.brand-mark span:nth-child(3) { height: 10px; }
.main-nav { display: flex; gap: 36px; margin-left: 90px; }.nav-link { color: var(--muted); text-decoration: none; font-size: 13px; font-weight: 700; }.nav-link:hover, .nav-link.active { color: var(--ink); }.nav-link.active::after { content: ""; display: block; width: 5px; height: 5px; margin: 6px auto 0; border-radius: 50%; background: var(--yellow); }
.topbar-actions { display: flex; align-items: center; gap: 15px; }.streak-chip { display: flex; align-items: baseline; gap: 4px; color: var(--orange); font-size: 14px; }.streak-chip span { font-size: 18px; }.streak-chip strong { font-size: 17px; }.streak-chip small { color: var(--muted); font-size: 10px; }.avatar-button { border: 0; width: 38px; height: 38px; border-radius: 50%; color: white; background: var(--teal); font-weight: 800; font-size: 11px; box-shadow: 0 5px 0 #31998f; }
.section-wrap { max-width: 1124px; margin: auto; padding: 0 26px; }.hero { min-height: 385px; display: flex; align-items: center; justify-content: space-between; }.hero-copy { max-width: 545px; padding: 42px 0 50px; animation: rise .7s ease both; }.eyebrow { color: var(--orange); text-transform: uppercase; letter-spacing: 1.8px; font-size: 10px; font-weight: 800; margin: 0 0 10px; }.sparkle { color: var(--yellow); font-size: 15px; }.hero h1 { margin: 0; font: 800 clamp(42px, 6vw, 71px)/.98 "Baloo 2", sans-serif; letter-spacing: -2.2px; }.hero h1 em { color: var(--orange); font-style: normal; position: relative; }.hero h1 em::after { content: ""; position: absolute; height: 9px; left: 4px; right: 3px; bottom: -2px; background: #ffd889; z-index: -1; border-radius: 50%; transform: rotate(-2deg); }.hero-text { max-width: 390px; margin: 20px 0 25px; color: var(--muted); font-size: 14px; line-height: 1.65; }.primary-button { display: inline-flex; align-items: center; gap: 24px; color: white; background: var(--ink); padding: 15px 18px 15px 21px; border-radius: 10px; box-shadow: 0 5px 0 #121e22; text-decoration: none; font-weight: 800; font-size: 12px; transition: transform .2s, box-shadow .2s; }.primary-button:hover { transform: translateY(-3px); box-shadow: 0 8px 0 #121e22; }.primary-button span { font-size: 21px; line-height: 10px; }
.hero-art { width: 430px; height: 300px; position: relative; margin-right: 20px; }.sun-disc { position: absolute; width: 248px; height: 248px; border-radius: 48% 52% 48% 52%; right: 57px; top: 17px; background: #ffe8a9; transform: rotate(18deg); }.number-card { position: absolute; display: grid; place-items: center; border: 5px solid var(--ink); color: var(--ink); font: 800 73px/1 "Baloo 2", sans-serif; box-shadow: 0 7px 0 var(--ink); }.number-seven { width: 120px; height: 127px; border-radius: 31px 24px 38px 20px; right: 115px; top: 63px; background: #ef8d4a; transform: rotate(8deg); }.number-three { width: 96px; height: 106px; border-radius: 23px 28px 25px 37px; right: 24px; top: 122px; background: #43b8ad; transform: rotate(-8deg); font-size: 60px; }.number-eight { width: 74px; height: 79px; border-width: 4px; border-radius: 20px; left: 104px; top: 145px; background: #f7b84b; font-size: 47px; transform: rotate(-14deg); box-shadow: 0 5px 0 var(--ink); }.number-plus { width: 63px; height: 63px; border-width: 4px; border-radius: 50%; left: 67px; top: 64px; background: #fffdf8; font-size: 44px; box-shadow: 0 4px 0 var(--ink); transform: rotate(-11deg); }.art-star { position: absolute; color: var(--coral); font-size: 26px; }.star-one { right: 7px; top: 45px; }.star-two { left: 65px; bottom: 31px; font-size: 17px; color: var(--blue); }.art-dot { position: absolute; border-radius: 50%; background: var(--teal); }.dot-one { width: 12px; height: 12px; right: 79px; top: 30px; }.dot-two { width: 8px; height: 8px; left: 76px; top: 42px; background: var(--coral); }.doodle-line { position: absolute; width: 30px; height: 30px; border: 3px solid var(--blue); border-left: 0; border-bottom: 0; border-radius: 50%; }.line-one { right: 0; bottom: 54px; transform: rotate(27deg); }.line-two { left: 35px; bottom: 90px; border-color: var(--coral); transform: rotate(-45deg); }
.dashboard, .learning-section, .achievement-section { padding-top: 48px; }.section-heading { display: flex; align-items: flex-end; justify-content: space-between; margin-bottom: 19px; }.section-heading h2, .challenge-intro h2, .parent-modal h2 { margin: 0; font: 800 32px/1 "Baloo 2", sans-serif; letter-spacing: -.7px; }.level-badge, .collection-count { border-radius: 20px; background: #fff0c9; color: #a47728; padding: 8px 13px; font-size: 11px; font-weight: 700; }.level-badge strong { color: var(--ink); font-size: 16px; margin: 0 2px; }.mini-spark { color: var(--yellow); }.progress-panel { background: var(--paper); border: 1px solid var(--line); border-radius: 15px; padding: 19px 23px 15px; box-shadow: var(--shadow); }.progress-copy, .progress-foot { display: flex; justify-content: space-between; align-items: center; font-size: 12px; }.progress-copy span { font-weight: 700; }.progress-copy strong { font-size: 12px; }.progress-copy strong span { color: var(--orange); }.progress-track, .quiz-progress { height: 9px; border-radius: 12px; overflow: hidden; background: #f1eee5; margin: 12px 0 8px; }.progress-track span, .quiz-progress span { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--yellow), var(--orange)); transition: width .5s ease; }.progress-foot { color: var(--muted); font-size: 10px; }.trophy { font-size: 21px; }.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; margin-top: 15px; }.stat-card { display: flex; align-items: center; gap: 13px; padding: 16px 18px; border-radius: 14px; }.stat-card.teal { background: #dff5ed; }.stat-card.coral { background: #ffe5dc; }.stat-card.blue { background: #e2f0fa; }.stat-icon { width: 34px; height: 34px; display: grid; place-items: center; border-radius: 10px; color: white; font-size: 20px; }.teal .stat-icon { background: var(--teal); }.coral .stat-icon { background: var(--coral); }.blue .stat-icon { background: var(--blue); }.stat-card div { display: grid; gap: 2px; }.stat-card strong { font: 800 22px "Baloo 2", sans-serif; }.stat-card small { color: var(--muted); font-size: 10px; }
.heading-with-link { align-items: center; margin-bottom: 20px; }.text-button { border: 0; background: none; color: var(--orange); font-size: 11px; font-weight: 800; }.text-button span { font-size: 18px; margin-left: 5px; }.lesson-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 15px; }.lesson-card { position: relative; min-height: 171px; border: 0; overflow: hidden; text-align: left; padding: 20px; border-radius: 14px; color: var(--ink); transition: transform .2s, box-shadow .2s; }.lesson-card:hover { transform: translateY(-5px) rotate(-1deg); box-shadow: 0 12px 22px rgba(53, 64, 65, .12); }.lesson-card::after { content: ""; position: absolute; width: 110px; height: 110px; border-radius: 50%; right: -25px; bottom: -30px; background: rgba(255,255,255,.28); }.lesson-card.orange { background: #ffdca6; }.lesson-card.green { background: #cceee2; }.lesson-card.blue { background: #cfe9f7; }.lesson-card.pink { background: #f8d6d1; }.lesson-icon { display: grid; place-items: center; width: 39px; height: 39px; border-radius: 12px; margin-bottom: 21px; color: white; background: var(--orange); font: 700 25px "Baloo 2", sans-serif; }.green .lesson-icon { background: var(--teal); }.blue .lesson-icon { background: var(--blue); }.pink .lesson-icon { background: var(--coral); }.lesson-number { position: absolute; right: 18px; top: 20px; color: rgba(36,51,59,.35); font: 700 12px "Baloo 2", sans-serif; }.lesson-card strong, .lesson-card small { position: relative; z-index: 1; display: block; }.lesson-card strong { font: 800 19px "Baloo 2", sans-serif; }.lesson-card small { margin-top: 1px; color: #637278; font-size: 10px; }.lesson-arrow { position: absolute; right: 19px; bottom: 17px; z-index: 2; font-size: 22px; font-weight: 700; }
.advanced-pill { display: inline-block; transform: translateY(-1px); margin-left: 7px; padding: 4px 7px; border-radius: 12px; color: #9c6820; background: #ffe4a3; font-size: 8px; letter-spacing: .7px; }
.question-visual { min-height: 0; margin: -3px 0 15px; display: grid; place-items: center; color: #f9f3db; }.visual-svg { width: min(100%, 360px); height: 120px; overflow: visible; }.grid-shape line { stroke: #f7b84b; stroke-width: 3; }.circle-shape { fill: #43b8ad; stroke: #dff5ed; stroke-width: 3; }.square-shape { fill: #ef8d4a; stroke: #ffe5dc; stroke-width: 3; }.visual-svg text { fill: #fff4cf; font: 800 17px "Baloo 2", sans-serif; }.cut-shape { fill: #4a9ad4; stroke: #d8effb; stroke-width: 3; }.cut-line { stroke: #f7b84b; stroke-width: 3; stroke-dasharray: 5 4; fill: none; }.dot-pattern { display: flex; align-items: center; justify-content: center; gap: 12px; min-height: 65px; color: #f7b84b; font: 800 18px "Baloo 2", sans-serif; }.dot-pattern span { padding: 9px 11px; border-radius: 10px; color: #fff4cf; background: #2e4144; letter-spacing: 2px; }.dot-pattern b { color: #ef8d4a; }
.picture-model, .number-road, .digit-cards, .tournament-visual, .coin-visual, .machine-visual, .share-visual, .icon-sequence, .place-value-visual, .clue-visual, .combination-visual, .map-visual, .array-visual, .number-line-visual, .thinking-visual { width: min(100%, 520px); min-height: 68px; display: flex; align-items: center; justify-content: center; gap: 9px; flex-wrap: wrap; color: #ffe08a; font: 800 18px "Baloo 2", sans-serif; }
.picture-caption, .number-road small, .tournament-visual small, .coin-visual small, .icon-sequence small, .place-value-visual small, .clue-visual small, .map-visual small, .array-visual small, .number-line-visual small, .thinking-visual small { flex-basis: 100%; color: #9fc8c0; font-size: 10px; font-weight: 700; text-align: center; }.picture-groups { display: flex; justify-content: center; gap: 7px; flex-wrap: wrap; }.picture-group, .picture-bag { padding: 7px 9px; border: 1px solid #75b7ad; border-radius: 10px; color: #fff4cf; background: linear-gradient(145deg, #244f56, #315c62); font-size: 14px; letter-spacing: 1px; }.picture-bag { color: #ffe5dc; background: linear-gradient(145deg, #704e59, #3e5265); }.number-road { position: relative; gap: 8px; padding: 8px 12px; border-radius: 12px; background: linear-gradient(90deg, #244f56, #3a4e65); }.number-road span, .digit-card, .place-value-visual span { min-width: 39px; padding: 5px 9px; border-radius: 9px; color: #fff4cf; background: #2e4144; text-align: center; }.number-road span:last-of-type { color: #2e4144; background: #ffe08a; }.number-road b, .digit-cards b, .machine-visual b, .combination-visual b, .map-visual b { color: #ef8d4a; }.digit-cards strong { padding: 6px 12px; border: 2px dashed #f7b84b; border-radius: 9px; color: #f7b84b; }.digit-card { display: grid; gap: 0; font-size: 25px; }.digit-card small { color: #9fc8c0; font-size: 8px; }.tournament-cup { font-size: 34px; }.tournament-visual i { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; color: #214a58; background: #ffe08a; font-style: normal; font-size: 13px; }.coin-visual span { font-size: 29px; }.machine-visual strong { padding: 6px 10px; border-radius: 9px; color: #214a58; background: #9ddfd3; font-size: 14px; }.share-visual span { padding: 6px 9px; border-radius: 10px; background: #244f56; letter-spacing: 2px; }.share-visual b { color: #fff4cf; }.icon-sequence span, .clue-visual span, .combination-visual span, .map-visual span { padding: 7px 10px; border-radius: 11px; background: #244f56; font-size: 26px; }.place-value-visual span { color: #214a58; background: #ffe08a; font-size: 25px; }.place-value-visual { gap: 6px; }.clue-visual b { color: #f7b84b; }.combination-visual strong { color: #fff4cf; font-size: 28px; }.array-visual { max-width: 280px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 3px; padding: 9px; border: 1px solid #75b7ad; border-radius: 10px; background: #244f56; font-size: 15px; }.array-visual small { grid-column: 1 / -1; }.number-line-visual { gap: 4px; }.number-line-visual i { width: 38px; height: 7px; border-radius: 5px; background: linear-gradient(90deg, #f7b84b, #ef8d4a); }.thinking-visual span { padding: 8px 12px; border-radius: 12px; background: #244f56; font-size: 28px; }
.solid-facts { display: flex; align-items: center; justify-content: center; gap: 10px; min-height: 56px; color: #ffe08a; font: 800 17px "Baloo 2", sans-serif; }.solid-facts span { padding: 8px 13px; border: 1px solid #75b7ad; border-radius: 12px; background: #244f56; }
.bar-model { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; min-height: 56px; color: #ffe08a; font: 800 18px "Baloo 2", sans-serif; }.bar-model span { padding: 7px 10px; border: 1px solid #75b7ad; border-radius: 9px; background: #244f56; letter-spacing: 3px; }
.english-translation { display: grid; gap: 8px; margin: 10px 0; padding: 10px; border-radius: 9px; background: #1c454b; }.english-translation span, .english-vietnamese-solution span { color: #ffe08a; font-size: 9px; font-weight: 800; text-transform: uppercase; letter-spacing: .04em; }.english-translation p, .english-vietnamese-solution p { margin: 2px 0 0 !important; color: #f2fbf5 !important; font: 500 11px/1.55 "Be Vietnam Pro", sans-serif !important; }.english-translation > div + div { padding-top: 8px; border-top: 1px solid rgba(141,182,173,.35); }.english-card .correct-answer em { margin-left: auto; color: #fff4cf; font-size: 11px; font-style: normal; }.english-vietnamese-solution { margin-top: 9px; padding-top: 9px; border-top: 1px solid rgba(141,182,173,.35); }.english-card .explanation-panel > p::before { content: "Explanation: "; }
.clock-hand { stroke: #fff4cf; stroke-width: 4; stroke-linecap: round; }.clock-dot { fill: #f7b84b; }.triangle-shape { fill: #ef8d4a; stroke: #ffe5dc; stroke-width: 3; }.point-lines { stroke: #526f75; stroke-width: 2; opacity: .8; }.point-dots circle { fill: #f7b84b; stroke: #fff4cf; stroke-width: 2; }.match-pattern { display: flex; align-items: center; justify-content: center; gap: 13px; min-height: 65px; color: #fff4cf; font: 800 31px "Baloo 2", sans-serif; }.match-pattern b { color: #ef8d4a; font-size: 21px; }
.package-switcher { position: relative; z-index: 1; display: flex; align-items: center; flex-wrap: wrap; gap: 7px; margin: 15px 0 16px; color: #aec0c0; font-size: 9px; line-height: 1.3; }.package-tab { min-width: 50px; border: 1px solid #526466; border-radius: 20px; padding: 6px 10px; color: #dce8e2; background: transparent; font-size: 9px; line-height: 1.2; font-weight: 700; white-space: nowrap; }.package-tab:hover, .package-tab.active { border-color: var(--yellow); color: var(--ink); background: var(--yellow); }.question-area { position: relative; z-index: 0; }
.games-section { padding-top: 76px; }.game-note { color: var(--muted); font-size: 10px; }.game-layout { display: grid; grid-template-columns: 245px 1fr; gap: 16px; }.game-picker { display: grid; gap: 9px; align-content: start; }.game-tab { display: grid; grid-template-columns: 37px 1fr; grid-template-rows: 1fr 1fr; column-gap: 11px; min-height: 72px; padding: 12px; border: 1px solid var(--line); border-radius: 13px; color: var(--ink); text-align: left; background: var(--paper); transition: .2s; }.game-tab:hover { transform: translateX(3px); }.game-tab.active { border-color: var(--yellow); background: #fff2c9; box-shadow: 4px 4px 0 #f5dfa8; }.game-tab span { grid-row: span 2; display: grid; place-items: center; width: 37px; height: 37px; border-radius: 11px; background: #dff5ed; font-size: 20px; }.game-tab:nth-child(2) span { background: #ffe3dc; }.game-tab:nth-child(3) span { background: #e2f0fa; }.game-tab strong { align-self: end; font: 700 13px "Baloo 2", sans-serif; }.game-tab small { align-self: start; color: var(--muted); font-size: 9px; }.game-stage { min-height: 244px; border-radius: 16px; padding: 25px 28px; color: white; background: var(--ink); box-shadow: 0 10px 0 #dfe6dc; }.game-stage h3 { margin: 0 0 5px; font: 800 25px "Baloo 2", sans-serif; }.game-stage p { margin: 0; color: #bbcccc; font-size: 11px; line-height: 1.5; }.game-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; }..game-reward { flex: 0 0 auto; color: var(--yellow); font-size: 10px; font-weight: 800; }.game-action-row { display: flex; align-items: center; gap: 9px; margin-top: 24px; }.game-input { width: 104px; border: 1px solid #526466; border-radius: 9px; padding: 12px; outline: none; color: white; background: #2e4144; font: 800 18px "Baloo 2", sans-serif; }.game-input:focus { border-color: var(--yellow); }.game-button { border: 0; border-radius: 9px; padding: 12px 16px; color: var(--ink); background: var(--yellow); font-size: 11px; font-weight: 800; }.game-button.secondary { color: white; background: #405457; }.game-feedback { min-height: 17px; margin-top: 12px !important; color: var(--yellow) !important; }.missing-equation { display: flex; align-items: center; gap: 11px; margin-top: 23px; color: white; font: 800 30px "Baloo 2", sans-serif; }.missing-box { display: grid; place-items: center; width: 55px; height: 48px; border: 2px dashed var(--yellow); border-radius: 10px; color: var(--yellow); }.missing-answers { display: flex; gap: 8px; margin-top: 18px; }.missing-choice { min-width: 58px; border: 1px solid #526466; border-radius: 8px; padding: 9px; color: white; background: #2e4144; font: 700 17px "Baloo 2", sans-serif; }.missing-choice:hover { border-color: var(--yellow); }.missing-choice.correct { background: #247c76; border-color: var(--teal); }.missing-choice.wrong { background: #9d4e4a; border-color: var(--coral); }.order-board { display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; margin-top: 22px; max-width: 490px; }.order-number { border: 1px solid #526466; border-radius: 8px; padding: 9px 5px; color: white; background: #2e4144; font: 700 17px "Baloo 2", sans-serif; }.order-number:hover { border-color: var(--yellow); }.order-number.done { color: #9ddfd3; background: #247c76; border-color: var(--teal); }.order-number.mistake { animation: shake .25s ease; background: #9d4e4a; border-color: var(--coral); }.order-status { margin-top: 11px !important; color: var(--yellow) !important; }
.game-heading-actions { display: flex; align-items: center; gap: 14px; }.arcade-link { display: inline-flex; align-items: center; padding: 9px 12px; border-radius: 10px; color: var(--ink); background: var(--yellow); box-shadow: 0 3px 0 #e2a73e; font-size: 10px; font-weight: 800; text-decoration: none; transition: transform .2s; }.arcade-link:hover { transform: translateY(-2px); }
.game-launch-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; }
.game-launch-card { position: relative; display: grid; grid-template-columns: 58px 1fr; gap: 14px; min-height: 166px; padding: 20px; overflow: hidden; border-radius: 20px; color: var(--ink); text-decoration: none; transition: transform .2s, box-shadow .2s; }
.game-launch-card::after { content: ""; position: absolute; right: -32px; bottom: -42px; width: 135px; height: 135px; border-radius: 50%; background: rgba(255,255,255,.33); }
.game-launch-card:hover { transform: translateY(-5px); box-shadow: 0 13px 22px rgba(45,70,75,.14); }
.game-launch-icon { position: relative; z-index: 1; display: grid; place-items: center; width: 58px; height: 58px; border-radius: 17px; background: rgba(255,255,255,.72); font-size: 29px; }
.game-launch-copy { position: relative; z-index: 1; display: flex; min-width: 0; flex-direction: column; }.game-launch-copy strong { font: 800 20px/1.12 "Baloo 2", sans-serif; }.game-launch-copy small { max-width: 185px; margin-top: 7px; color: #607278; font-size: 10px; line-height: 1.45; }.game-launch-copy b { margin-top: auto; color: #607278; font-size: 10px; }.game-launch-copy i { margin-left: 4px; font-style: normal; font-size: 15px; }.launch-orange { background: #ffdca6; }.launch-green { background: #cceee2; }.launch-blue { background: #cfe9f7; }.launch-pink { background: #f8d6d1; }.launch-purple { background: #dfd8f8; }.launch-city { color: white; background: linear-gradient(135deg, #285466, #398c83); }.launch-city small, .launch-city b { color: #dcf0e8; }
.standalone-game { min-height: 100%; overflow-x: hidden; overflow-y: auto; background: #f5fbf7; }.standalone-game .topbar, .standalone-game footer, .standalone-game main > section:not(.games-section), .standalone-game .games-section > .section-heading, .standalone-game .game-launch-grid, .standalone-game .leaderboard-card { display: none; }.standalone-game .page-shell { display: flex; min-height: 100vh; max-width: 1120px; flex-direction: column; }.standalone-game main { display: flex; min-height: 0; flex: 1; }.standalone-game .games-section { display: flex; width: 100%; min-height: 100vh; height: auto; padding-top: 12px; flex-direction: column; }.standalone-game .standalone-game-stage { display: block; min-height: calc(100vh - 12px); height: auto; padding: 24px 32px; overflow: hidden; border-radius: 24px; }.standalone-game .game-stage h3 { font-size: 34px; }.standalone-game .game-stage p { font-size: 13px; }.standalone-game .game-input { font-size: 22px; }.standalone-game .game-button { font-size: 13px; }
.standalone-document, .standalone-document body { min-height: 100%; overflow-x: hidden; overflow-y: auto; }
.standalone-game-stage { display: none; }
.game-start-screen { display: grid; min-height: 520px; place-content: center; justify-items: center; gap: 8px; padding: 35px 20px; border-radius: 20px; color: #f4fbf5; text-align: center; background: radial-gradient(circle at 50% 15%, #3b7775, transparent 42%), linear-gradient(145deg, #253b4a, #285962); }.game-start-icon { display: grid; place-items: center; width: 86px; height: 86px; border: 3px solid #ffe08a; border-radius: 27px; background: rgba(255,255,255,.12); box-shadow: 0 8px 0 rgba(17,43,57,.45), 0 0 30px rgba(255,224,138,.18); font-size: 45px; animation: start-float 2s ease-in-out infinite; }.game-start-kicker { margin-top: 15px; color: #9ddfd3; font-size: 10px; font-weight: 800; letter-spacing: 2px; }.game-start-screen h3 { margin: 0; color: #fff2c9; font: 800 clamp(28px, 5vw, 44px) "Baloo 2", sans-serif; }.game-start-screen p { max-width: 480px; margin: 0; color: #c8e3dc; font-size: 12px; line-height: 1.6; }.game-start-button { margin-top: 14px; border: 0; border-radius: 14px 14px 14px 5px; padding: 15px 25px; color: var(--ink); background: var(--yellow); box-shadow: 0 5px 0 #dca94a; font-size: 14px; font-weight: 800; cursor: pointer; transition: transform .16s ease, box-shadow .16s ease; }.game-start-button:hover { transform: translateY(-3px); box-shadow: 0 8px 0 #dca94a; }.game-start-screen small { color: #9ebbb5; font-size: 9px; }
@keyframes start-float { 0%, 100% { transform: translateY(0) rotate(-3deg); } 50% { transform: translateY(-8px) rotate(3deg); } }
@media (max-width: 820px) { .game-launch-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 480px) { .game-launch-grid { grid-template-columns: 1fr; gap: 10px; }.game-launch-card { min-height: 130px; padding: 16px; }.game-launch-copy strong { font-size: 18px; }.standalone-game .standalone-game-stage { min-height: calc(100vh - 34px); padding: 22px 16px; }.standalone-game .game-stage h3 { font-size: 27px; } }
.game-reward { flex: 0 0 auto; color: var(--yellow); font-size: 10px; font-weight: 800; }
.leaderboard-card { margin-top: 18px; padding: 22px 24px 18px; border: 1px solid var(--line); border-radius: 17px; background: var(--paper); box-shadow: var(--shadow); }
.leaderboard-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 15px; }
.leaderboard-head .eyebrow { margin-bottom: 4px; }
.leaderboard-head h3 { margin: 0; font: 800 26px/1 "Baloo 2", sans-serif; }
.leaderboard-head p:last-child { margin: 5px 0 0; color: var(--muted); font-size: 10px; }
.leaderboard-badge { padding: 7px 10px; border-radius: 20px; color: #986c20; background: #fff0c9; font-size: 10px; font-weight: 800; }
.leaderboard-entry { display: flex; align-items: center; gap: 9px; margin-top: 16px; padding: 10px 12px; border-radius: 11px; background: #f5f7ef; }
.leaderboard-entry label { color: var(--muted); font-size: 10px; font-weight: 700; }
.leaderboard-entry input { width: 150px; border: 1px solid #d9e4da; border-radius: 8px; padding: 8px 10px; color: var(--ink); background: white; font-size: 11px; outline: none; }
.leaderboard-entry input:focus { border-color: var(--yellow); }
.leaderboard-entry span { margin-left: auto; color: var(--muted); font-size: 10px; }
.leaderboard-list { display: grid; gap: 6px; margin: 14px 0 0; padding: 0; list-style: none; }
.leaderboard-row { display: grid; grid-template-columns: 32px 1fr auto; align-items: center; gap: 8px; min-height: 34px; padding: 5px 9px; border-radius: 9px; color: var(--ink); background: #f6f8f2; font-size: 11px; }
.leaderboard-row.podium { background: #fff6d9; }
.leaderboard-rank { font-size: 16px; text-align: center; }
.leaderboard-row strong { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.leaderboard-score { color: #b57822; font: 800 13px "Baloo 2", sans-serif; }
.leaderboard-empty { padding: 13px; border-radius: 9px; color: var(--muted); background: #f6f8f2; font-size: 10px; text-align: center; }
.explanation-panel { margin-top: 14px; padding: 13px 14px; border: 1px solid #f0c767; border-radius: 11px; color: #fff8df; background: #3a4f4f; text-align: left; animation: explain-in .25s ease both; }.explanation-panel[hidden] { display: none; }.explanation-heading { display: flex; align-items: center; gap: 7px; color: var(--yellow); font-size: 11px; }.explanation-heading span { font-size: 17px; }.correct-answer { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin: 9px 0 7px; padding: 8px 10px; border-radius: 8px; background: #247c76; }.correct-answer span { color: #bce9df; font-size: 9px; }.correct-answer strong { color: white; font: 800 20px "Baloo 2", sans-serif; }.explanation-panel > p { margin: 0 !important; color: #e7f0e7 !important; font: 500 11px/1.55 "Be Vietnam Pro", sans-serif !important; }.explanation-panel > p::before { content: "Cách làm: "; color: var(--yellow); font-weight: 800; }@keyframes explain-in { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: translateY(0); } }
@keyframes shake { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }
.achievement-section { padding-bottom: 61px; }.collection-count { background: none; color: var(--muted); padding-right: 0; }.collection-count strong { color: var(--orange); }.badge-row { display: flex; justify-content: space-between; gap: 12px; }.badge { display: flex; align-items: center; gap: 10px; min-width: 150px; color: var(--ink); }.badge span { width: 53px; height: 53px; flex: 0 0 auto; display: grid; place-items: center; border-radius: 50%; font-size: 25px; background: #ffdda0; border: 2px solid #f2bd5e; }.badge strong { font: 700 12px/1.1 "Baloo 2", sans-serif; }.badge.locked { opacity: .42; }.badge.locked span { color: var(--muted); background: #e9e9e1; border-color: #d5d8ce; font: 800 19px "Be Vietnam Pro", sans-serif; }footer { display: flex; justify-content: space-between; align-items: center; max-width: 1124px; margin: auto; padding: 23px 26px 30px; border-top: 1px solid var(--line); color: var(--muted); font-size: 10px; }footer b { color: var(--yellow); margin: 0 5px; }footer button { padding: 0; border: 0; color: var(--muted); background: none; font-size: 10px; }
.modal-backdrop { position: fixed; inset: 0; z-index: 5; display: grid; place-items: center; padding: 20px; background: rgba(25, 39, 42, .45); backdrop-filter: blur(4px); }.modal-backdrop[hidden] { display: none; }.parent-modal { position: relative; width: min(100%, 410px); border-radius: 20px; padding: 34px; background: var(--paper); box-shadow: 0 25px 80px rgba(20, 30, 30, .24); }.parent-modal h2 { margin-bottom: 8px; font-size: 34px; }.parent-modal > p:not(.eyebrow) { color: var(--muted); font-size: 12px; line-height: 1.6; }.close-button { position: absolute; top: 13px; right: 16px; border: 0; color: var(--muted); background: none; font-size: 25px; }.parent-summary { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin: 22px 0; }.parent-summary div { display: grid; grid-template-columns: 25px 1fr; align-items: center; padding: 12px; border-radius: 11px; background: #fff4d9; }.parent-summary span { grid-row: span 2; font-size: 18px; }.parent-summary strong { font: 800 20px "Baloo 2", sans-serif; }.parent-summary small { color: var(--muted); font-size: 9px; }.reset-button { width: 100%; border: 1px solid #f1c3b9; border-radius: 9px; padding: 11px; color: #b85d51; background: #fff7f3; font-size: 11px; font-weight: 700; }
@keyframes rise { from { opacity: 0; transform: translateY(15px); } to { opacity: 1; transform: translateY(0); } }
.catch-hud { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 17px; color: #c9ded9; font-size: 10px; }.catch-hud strong { color: var(--yellow); font: 800 17px "Baloo 2", sans-serif; }.catch-canvas { display: block; width: 100%; max-width: 720px; height: auto; margin-top: 14px; border: 2px solid #4a8586; border-radius: 13px; background: #173b42; cursor: crosshair; touch-action: none; outline: none; }.catch-canvas:focus { border-color: var(--yellow); }.catch-controls { display: flex; justify-content: center; align-items: center; gap: 10px; margin-top: 12px; }.catch-control { min-width: 52px; border: 1px solid #526466; border-radius: 9px; padding: 9px 14px; color: white; background: #2e4144; font: 800 16px "Baloo 2", sans-serif; }.catch-control:hover { border-color: var(--yellow); }.catch-control.catch-start { color: var(--ink); background: var(--yellow); font-size: 11px; }.catch-feedback { text-align: center; }
.game-stage h3 { text-shadow: 0 0 16px rgba(255, 224, 138, .18); }.game-hud strong { text-shadow: 0 0 12px rgba(255, 224, 138, .25); }.secret-range { position: relative; overflow: hidden; }.secret-range::after { content: "✦  ✧  ✦"; position: absolute; right: 12px; color: rgba(255, 224, 138, .32); letter-spacing: 7px; animation: drift-stars 2.4s ease-in-out infinite; }.missing-choice, .order-number { transition: transform .16s ease, border-color .16s ease, background .16s ease; }.missing-choice:hover, .order-number:hover:not(:disabled) { transform: translateY(-3px) scale(1.03); }.missing-choice.correct, .order-number.done { animation: game-pop .35s ease both; }.advanced-sequence span { animation: sequence-in .35s ease both; }.advanced-sequence span:nth-child(2) { animation-delay: .04s; }.advanced-sequence span:nth-child(4) { animation-delay: .08s; }.advanced-sequence span:nth-child(6) { animation-delay: .12s; }.advanced-sequence span:nth-child(8) { animation-delay: .16s; }
.order-mission { position: relative; margin-top: 18px; padding: 13px 16px 12px 19px; overflow: hidden; border: 1px solid #5b7f7d; border-radius: 12px; background: linear-gradient(110deg, #254e55, #2f3f52); box-shadow: inset 4px 0 0 var(--yellow); }.order-mission::after { content: "✦  ✧  ✦"; position: absolute; right: 16px; top: 14px; color: rgba(255, 224, 138, .35); letter-spacing: 8px; animation: drift-stars 2.2s ease-in-out infinite; }.order-mission-label { display: block; margin-bottom: 2px; color: #9ddfd3; font-size: 9px; font-weight: 800; letter-spacing: 1.4px; }.order-mission strong { display: block; color: #fff2c9; font: 800 19px "Baloo 2", sans-serif; }.order-mission p { margin: 1px 86px 0 0; color: #d8ebe4; font-size: 11px; line-height: 1.4; }.order-action-row { display: flex; align-items: center; gap: 12px; margin-top: 14px; }.order-tip { color: #9ebbb5; font-size: 10px; }.order-number { position: relative; min-height: 51px; font-size: 19px; font-weight: 800; }.order-number.done { position: relative; color: #d9fff0; background: linear-gradient(145deg, #247c76, #1e625f); box-shadow: 0 4px 0 #164e50; }.order-number.mistake { animation: race-shake .35s ease; background: #9d4e4a; border-color: var(--coral); }.order-burst { position: absolute; top: -7px; right: 4px; color: var(--yellow); font: 800 10px "Baloo 2", sans-serif; pointer-events: none; animation: score-float .7s ease forwards; }.race-track.race-finished { border-color: var(--yellow); box-shadow: 0 0 18px rgba(255, 224, 138, .35); }
@keyframes game-pop { 0% { transform: scale(.86); } 70% { transform: scale(1.1); } 100% { transform: scale(1); } } @keyframes sequence-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } } @keyframes drift-stars { 0%, 100% { transform: translateX(0); opacity: .55; } 50% { transform: translateX(-10px); opacity: 1; } }
@keyframes race-shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-7px) rotate(-2deg); } 75% { transform: translateX(7px) rotate(2deg); } } @keyframes score-float { from { opacity: 1; transform: translateY(0) scale(1); } to { opacity: 0; transform: translateY(-22px) scale(1.15); } }
.game-tab:nth-child(4) span { background: #fff0c9; }
.game-hud { display: flex; flex-wrap: wrap; gap: 17px; margin-top: 17px; color: #c9ded9; font-size: 10px; }.game-hud strong { color: var(--yellow); font: 800 17px "Baloo 2", sans-serif; }.secret-range { margin-top: 22px; padding: 12px 15px; border: 1px solid #4e7777; border-radius: 10px; color: #fff2c9; background: #254e55; font: 800 15px "Baloo 2", sans-serif; text-align: center; }.game-restart { display: block; margin-top: 10px; }.advanced-sequence { flex-wrap: wrap; gap: 7px !important; }.advanced-sequence span { min-width: 33px; padding: 4px 7px; border-radius: 7px; background: #2e4144; }.advanced-sequence .missing-box { min-width: 48px; padding: 0; }.advanced-order-board { grid-template-columns: repeat(5, 1fr); max-width: 540px; }.race-track { position: relative; height: 32px; margin-top: 17px; border-bottom: 3px dashed #5a8580; color: #ffe08a; }.race-track::before { content: ""; position: absolute; left: 0; right: 0; bottom: -3px; height: 3px; background: linear-gradient(90deg, #f7b84b, #43b8ad); transform: scaleX(var(--race-progress, 0)); transform-origin: left; }.race-track span { position: absolute; left: 0; bottom: 2px; z-index: 1; font-size: 24px; transform: translateX(-50%); transition: left .25s ease; }.race-track i { position: absolute; right: 0; bottom: 0; font-size: 21px; font-style: normal; }.catch-rule { color: var(--yellow); }.catch-rule-help { color: #bbcccc; font-size: 10px; } .catch-mission { margin-top: 13px; padding: 10px 12px; border: 1px solid #5e8583; border-radius: 10px; color: #fff2c9; background: linear-gradient(90deg, #315b63, #3c5262); font-size: 11px; font-weight: 800; }
@media (max-width: 800px) { .game-picker { grid-template-columns: repeat(4, 1fr); } }
@media (max-width: 480px) { .game-picker { grid-template-columns: repeat(2, 1fr); }.advanced-order-board { grid-template-columns: repeat(4, 1fr); }.game-hud { gap: 10px; }.secret-range { font-size: 13px; } }
.sound-toggle { flex: 0 0 auto; border: 1px solid #526466; border-radius: 20px; padding: 5px 8px; color: #dce8e2; background: transparent; font-size: 9px; font-weight: 700; }.sound-toggle:hover, .sound-toggle[aria-pressed="false"] { color: #aec0c0; background: #2e4144; }.sound-toggle[aria-pressed="false"] { opacity: .65; }
.mixed-mode-button { border: 0; padding: 5px 4px; color: #ffd982; background: transparent; font-size: 9px; font-weight: 700; }.mixed-mode-button:hover { color: white; text-decoration: underline; }
.english-section { padding-top: 78px; }.english-layout { display: grid; grid-template-columns: .7fr 1.3fr; gap: 42px; align-items: stretch; }.english-intro { position: relative; overflow: hidden; min-height: 300px; padding: 29px; border-radius: 17px; color: #f5fbf5; background: linear-gradient(135deg, #2b6d70, #24494e); box-shadow: 0 10px 0 #dfe6dc; }.english-intro::after { content: "∑  π  3.14"; position: absolute; right: -8px; bottom: 19px; color: rgba(255,255,255,.1); font: 800 40px "Baloo 2", sans-serif; transform: rotate(-10deg); }.english-stamp { display: grid; place-items: center; width: 44px; height: 44px; border: 2px solid #f7d67f; border-radius: 50%; color: #f7d67f; font: 800 14px "Baloo 2", sans-serif; }.english-intro h3 { margin: 23px 0 12px; font: 800 32px/1 "Baloo 2", sans-serif; }.english-intro h3 em { color: #f7d67f; font-style: normal; }.english-intro p { max-width: 275px; color: #c8ded9; font-size: 11px; line-height: 1.7; }.english-topics { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 24px; }.english-topics span { padding: 5px 8px; border: 1px solid rgba(255,255,255,.25); border-radius: 12px; color: #e7f5e7; font-size: 9px; }.english-card { background: #253f45; }.english-card .quiz-label strong { color: #f7d67f; }.english-card .quiz-progress span { background: #f7d67f; }.english-card .next-button { background: #f7d67f; }.english-card .answer-button:hover:not(:disabled) { border-color: #f7d67f; }.english-card .answer-button.correct { border-color: #67c8af; background: #247c76; }.english-card .explanation-panel { border-color: #f7d67f; }.english-card .correct-answer { background: #2f887b; }
.quiz-top { flex-wrap: wrap; gap: 8px; }.quiz-top .quiz-topic { margin-left: auto; }.sound-toggle { margin-left: 0; }
@media (max-width: 480px) { .quiz-top .quiz-topic { margin-left: 0; }.quiz-top { justify-content: flex-start; } }
@media (max-width: 800px) { .topbar { padding: 0 18px; }.main-nav { gap: 17px; margin-left: 0; }.hero { min-height: 570px; align-items: flex-start; flex-direction: column; padding-top: 25px; }.hero-copy { padding-bottom: 10px; }.hero-art { align-self: center; transform: scale(.8); transform-origin: top center; margin: 0; }.stats-grid { grid-template-columns: 1fr; }.lesson-grid { grid-template-columns: repeat(2, 1fr); }.challenge-section { grid-template-columns: 1fr; gap: 25px; padding-top: 55px; }.challenge-intro { padding-left: 0; }.game-layout { grid-template-columns: 1fr; }.game-picker { grid-template-columns: repeat(3, 1fr); }.game-tab { grid-template-columns: 1fr; grid-template-rows: auto auto auto; min-height: 112px; }.game-tab span { grid-row: auto; }.game-tab strong { align-self: auto; }.game-tab small { align-self: auto; }.badge-row { overflow-x: auto; justify-content: flex-start; padding-bottom: 8px; }.badge { min-width: 170px; } }
@media (max-width: 480px) { .topbar { height: 68px; }.brand { font-size: 21px; }.main-nav { display: none; }.streak-chip { margin-left: auto; }.section-wrap { padding-left: 18px; padding-right: 18px; }.hero h1 { font-size: 48px; }.hero { min-height: 505px; }.hero-art { transform: scale(.66); margin-top: -18px; margin-left: -55px; }.section-heading h2 { font-size: 28px; }.lesson-grid { gap: 10px; }.lesson-card { min-height: 155px; padding: 15px; }.lesson-card strong { font-size: 17px; }.lesson-number { right: 13px; top: 15px; }.lesson-arrow { right: 14px; bottom: 12px; }.challenge-section { padding-top: 50px; }.challenge-intro h2 { font-size: 37px; }.quiz-card { padding: 18px 15px 15px; }.question-area > p:first-child { font-size: 17px; }.answer-grid { grid-template-columns: repeat(2, 1fr); }.heading-with-link .text-button { max-width: 100px; text-align: right; }.game-note { max-width: 100px; text-align: right; }.game-picker { gap: 6px; }.game-tab { min-height: 102px; padding: 9px; }.game-tab strong { font-size: 11px; }.game-tab small { font-size: 8px; }.game-stage { padding: 21px 16px; }.game-stage h3 { font-size: 23px; }.game-action-row { flex-wrap: wrap; }.missing-equation { gap: 7px; font-size: 25px; }.missing-answers { flex-wrap: wrap; }.order-board { grid-template-columns: repeat(4, 1fr); }.parent-modal { padding: 29px 23px; }footer { padding-left: 18px; padding-right: 18px; }.game-heading-actions { align-items: flex-end; flex-direction: column; gap: 7px; }.arcade-link { font-size: 9px; padding: 8px 9px; } }
.leaderboard-entry { flex-wrap: wrap; }
@media (max-width: 480px) { .leaderboard-card { padding: 18px 14px 14px; }.leaderboard-head h3 { font-size: 22px; }.leaderboard-entry span { flex-basis: 100%; margin-left: 0; }.leaderboard-entry input { flex: 1; min-width: 0; } }

/* Experimental adventure skin: scoped to the separate preview folder. */
.adventure-version { --ink: #253b4a; --muted: #667d86; --cream: #f4fbf5; --paper: #ffffff; --yellow: #ffc857; --orange: #ff815e; --teal: #39bda8; --blue: #568fe8; --coral: #f16f8d; --line: #dcebe3; }
.adventure-version .page-shell { background: radial-gradient(circle at 8% 8%, #fff0bc 0 9rem, transparent 20rem), radial-gradient(circle at 93% 34%, #d7f3ee 0 11rem, transparent 22rem), #f4fbf5; }
.adventure-version .topbar { position: relative; z-index: 5; }
.adventure-version .brand-mark { border-radius: 50% 50% 38% 38%; background: var(--orange); transform: rotate(-10deg); box-shadow: 0 4px 0 #d95c59; }
.adventure-version .avatar-button { background: var(--blue); box-shadow: 0 5px 0 #3d6fc0; }
.adventure-version .hero { position: relative; min-height: 420px; padding-top: 20px; }
.adventure-version .hero::before { content: ""; position: absolute; right: -8%; top: 27px; width: 57%; height: 250px; border-radius: 48% 52% 38% 62%; background: linear-gradient(135deg, #dff6ec, #cfe9fa); transform: rotate(-5deg); }
.adventure-version .hero-copy { position: relative; z-index: 1; }
.adventure-version .hero h1 { letter-spacing: -1.5px; }
.adventure-version .hero h1 em { color: var(--blue); }
.adventure-version .hero h1 em::after { background: #bdebdc; }
.adventure-version .hero-text { max-width: 425px; }
.adventure-version .primary-button { border-radius: 18px 18px 18px 5px; background: var(--blue); box-shadow: 0 5px 0 #3d6fc0; }
.adventure-version .primary-button:hover { box-shadow: 0 8px 0 #3d6fc0; }
.adventure-version .hero-art { z-index: 1; }
.adventure-version .sun-disc { background: #ffe8a9; box-shadow: 12px 12px 0 rgba(255, 200, 87, .12); }
.adventure-version .number-card { border-width: 4px; border-radius: 26px; }
.adventure-version .number-card::after { content: ""; position: absolute; inset: 9px; border: 2px dashed rgba(37, 59, 74, .22); border-radius: inherit; pointer-events: none; }
.adventure-version .hero-compass { position: absolute; right: 12px; bottom: 19px; display: grid; place-items: center; width: 68px; height: 68px; border: 4px solid var(--ink); border-radius: 50%; color: var(--orange); background: #fff5c9; font-size: 28px; box-shadow: 0 5px 0 var(--ink); transform: rotate(12deg); }
.adventure-version .hero-compass span { display: block; margin-top: -8px; color: var(--ink); font: 800 10px "Baloo 2", sans-serif; }
.adventure-version .dashboard { padding-top: 25px; }
.adventure-version .progress-panel { border: 2px solid #d4e8df; border-radius: 22px 22px 22px 7px; box-shadow: 0 8px 0 #dceee5; }
.adventure-version .progress-track { height: 13px; border: 3px solid #d4e8df; background: #eef7f0; }
.adventure-version .progress-track span { background: linear-gradient(90deg, var(--teal), var(--blue)); }
.adventure-version .stat-card { border-radius: 18px 18px 18px 6px; border: 1px solid rgba(37,59,74,.05); }
.adventure-version .learning-section, .adventure-version .games-section, .adventure-version .achievement-section { padding-top: 68px; }
.adventure-version .adventure-map { padding-top: 20px; }
.map-status { padding: 8px 12px; border-radius: 99px; color: #238575; background: #d7f3e8; font-size: 10px; font-weight: 800; }
.map-route { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr; align-items: center; gap: 10px; padding: 22px 20px; border: 2px solid #d6ebe1; border-radius: 26px 26px 26px 8px; background: rgba(255,255,255,.82); box-shadow: 0 10px 0 #deeee7; }
.map-node { position: relative; min-height: 137px; display: flex; flex-direction: column; align-items: flex-start; justify-content: flex-end; padding: 14px; overflow: hidden; border-radius: 18px 18px 18px 6px; color: var(--ink); text-decoration: none; transition: transform .2s, box-shadow .2s; }
.map-node:hover { transform: translateY(-7px) rotate(-1deg); box-shadow: 0 9px 0 rgba(37,59,74,.12); }
.map-node::before { content: ""; position: absolute; right: -22px; top: -28px; width: 90px; height: 90px; border-radius: 50%; background: rgba(255,255,255,.3); }
.map-node-icon { position: absolute; top: 12px; left: 14px; font-size: 31px; }
.map-node strong { position: relative; z-index: 1; font: 800 18px/1.02 "Baloo 2", sans-serif; }
.map-node small { position: relative; z-index: 1; margin-top: 6px; color: #597078; font-size: 9px; }
.map-node i { position: absolute; right: 13px; top: 13px; color: rgba(37,59,74,.35); font: 800 11px "Baloo 2", sans-serif; font-style: normal; }
.map-node-orange { background: #ffddb0; }.map-node-teal { background: #c8efe2; }.map-node-blue { background: #cfe2fb; }.map-node-coral { background: #ffd5dd; }
.map-connector { color: var(--orange); font-size: 23px; animation: map-hop 1.5s ease-in-out infinite; }.map-connector:nth-of-type(2) { animation-delay: .15s; }.map-connector:nth-of-type(3) { animation-delay: .3s; }
.adventure-version .lesson-card { border-radius: 19px 19px 19px 6px; box-shadow: 0 5px 0 rgba(37,59,74,.07); }
.adventure-version .lesson-card:hover { box-shadow: 0 12px 22px rgba(53,64,65,.14), 0 5px 0 rgba(37,59,74,.08); }
.adventure-version .challenge-section { position: relative; }
.adventure-version .challenge-section::before { content: "✦  ✧  ✦"; position: absolute; left: 20px; top: 31px; color: #b9dfd1; font-size: 21px; letter-spacing: 8px; }
.adventure-version .quiz-card { border: 2px solid #314c5a; border-radius: 24px 24px 24px 8px; box-shadow: 0 9px 0 #c8ddd4; }
.adventure-version .game-stage { border-radius: 24px 24px 24px 8px; box-shadow: 0 10px 0 #c8ddd4; background: linear-gradient(145deg, #253b4a, #285962); }
.adventure-version .game-tab { border-radius: 17px 17px 17px 6px; }
.adventure-version .badge { border-radius: 18px 18px 18px 6px; }
@keyframes map-hop { 0%, 100% { transform: translateX(0); opacity: .55; } 50% { transform: translateX(4px); opacity: 1; } }
@media (max-width: 800px) { .adventure-version .hero::before { width: 85%; right: -25%; opacity: .7; }.map-route { grid-template-columns: 1fr 1fr; }.map-connector { display: none; } }
@media (max-width: 480px) { .adventure-version .hero { min-height: 570px; }.adventure-version .hero-art { margin-top: 0; }.map-route { gap: 8px; padding: 12px; }.map-node { min-height: 125px; padding: 11px; }.map-node strong { font-size: 16px; }.map-node-icon { left: 10px; top: 9px; }.map-node i { right: 9px; top: 9px; } }

/* Preview refinements: a consistent learning map and larger, easier-to-tap answers. */
.adventure-version .learning-section { padding-top: 72px; }
.adventure-version .learning-section .section-heading { margin-bottom: 25px; }
.adventure-version .learning-section .section-heading h2 { font-size: 38px; }
.adventure-version .lesson-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.adventure-version .lesson-card { min-height: 184px; display: grid; grid-template-columns: 55px 1fr auto; grid-template-rows: auto 1fr auto; column-gap: 13px; align-items: start; padding: 20px 22px; border: 2px solid rgba(37, 59, 74, .08); text-align: left; }
.adventure-version .lesson-card::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 7px; border-radius: inherit; background: rgba(255,255,255,.6); }
.adventure-version .lesson-icon { grid-row: 1 / span 2; width: 55px; height: 55px; margin: 0; border-radius: 17px; font-size: 32px; box-shadow: 0 4px 0 rgba(37,59,74,.12); }
.adventure-version .lesson-number { top: 20px; right: 22px; padding: 4px 8px; border-radius: 10px; color: rgba(37,59,74,.52); background: rgba(255,255,255,.4); }
.adventure-version .lesson-card strong { align-self: center; padding-right: 32px; font-size: 23px; line-height: 1.02; }
.adventure-version .lesson-card small { grid-column: 2 / span 2; margin-top: 3px; color: #526b73; font-size: 11px; line-height: 1.45; }
.adventure-version .lesson-arrow { right: 21px; bottom: 17px; display: grid; place-items: center; width: 31px; height: 31px; border-radius: 50%; color: var(--ink); background: rgba(255,255,255,.58); }
.adventure-version .lesson-card.orange { background: linear-gradient(135deg, #ffdda9, #ffe9c9); }.adventure-version .lesson-card.green { background: linear-gradient(135deg, #c6eee0, #e1f7e9); }.adventure-version .lesson-card.blue { background: linear-gradient(135deg, #cce3fb, #e3f2ff); }.adventure-version .lesson-card.pink { background: linear-gradient(135deg, #ffd4dd, #ffe7dc); }
.adventure-version .answer-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 13px; margin: 20px 0 8px; }
.adventure-version .answer-button { min-height: 64px; width: 100%; padding: 12px 16px; border: 2px solid #b9d5cc; border-radius: 15px 15px 15px 5px; color: var(--ink); background: #f8fffb; box-shadow: 0 4px 0 #d9e9e1; font: 800 20px/1.2 "Baloo 2", sans-serif; transition: transform .15s, border-color .15s, background .15s, box-shadow .15s; }
.adventure-version .answer-button:hover:not(:disabled) { transform: translateY(-3px); border-color: var(--blue); background: #eaf4ff; box-shadow: 0 7px 0 #c7ddec; }
.adventure-version .answer-button.correct { border-color: var(--teal); color: #fff; background: #2d9888; box-shadow: 0 4px 0 #1f756b; }.adventure-version .answer-button.wrong { border-color: var(--coral); color: #fff; background: #bd615f; box-shadow: 0 4px 0 #914c4f; }
.adventure-version .question-area > p:first-child { font-size: 20px; line-height: 1.55; }
.adventure-version .quiz-card .next-button { min-height: 52px; border-radius: 14px 14px 14px 5px; font-size: 14px; }
@media (max-width: 620px) { .adventure-version .lesson-grid { grid-template-columns: 1fr; }.adventure-version .lesson-card { min-height: 164px; }.adventure-version .answer-grid { gap: 10px; }.adventure-version .answer-button { min-height: 60px; font-size: 18px; padding: 10px; } }
@media (max-width: 400px) { .adventure-version .answer-grid { grid-template-columns: 1fr; }.adventure-version .answer-button { min-height: 56px; } }

/* The challenge panel needs its own layout so the 10-minute activity never collapses into browser defaults. */
.adventure-version .challenge-section { display: grid; grid-template-columns: minmax(220px, .72fr) minmax(0, 1.28fr); gap: 28px; align-items: start; padding-top: 76px; }
.adventure-version .challenge-intro { padding: 28px 0 0 24px; }
.adventure-version .challenge-intro h2 { margin: 0 0 14px; color: var(--ink); font: 800 clamp(34px, 4vw, 48px)/.98 "Baloo 2", sans-serif; }
.adventure-version .challenge-intro > p:not(.eyebrow) { max-width: 320px; margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.adventure-version .challenge-meta { display: grid; gap: 9px; margin-top: 24px; color: #557079; font-size: 10px; font-weight: 700; }
.adventure-version .challenge-meta span { width: fit-content; padding: 8px 11px; border-radius: 9px; background: #e7f5ef; }
.adventure-version .quiz-card { width: 100%; min-width: 0; padding: 22px 24px 20px; color: #f4fbf5; background: #253f45; }
.adventure-version .quiz-top { display: flex; align-items: center; gap: 10px; min-height: 27px; color: #d7e9e2; }
.adventure-version .quiz-label { font-size: 10px; font-weight: 800; letter-spacing: .8px; }
.adventure-version .quiz-label strong { color: var(--yellow); font: 800 19px "Baloo 2", sans-serif; }
.adventure-version .quiz-topic { max-width: 42%; overflow: hidden; padding: 5px 9px; border: 1px solid #6b9e95; border-radius: 99px; color: #d9f3e9; font-size: 9px; font-weight: 700; text-overflow: ellipsis; white-space: nowrap; }
.adventure-version .sound-toggle { margin-left: auto; padding: 6px 9px; border: 1px solid #6b9e95; border-radius: 99px; color: #d9f3e9; background: transparent; font-size: 9px; font-weight: 700; }
.adventure-version .sound-toggle:hover { border-color: var(--yellow); color: var(--yellow); }
.adventure-version .package-switcher { padding: 8px 10px; border-radius: 12px; background: rgba(255,255,255,.05); }
.adventure-version .package-switcher > span { margin-right: auto; color: #b8d5cc; font-size: 10px; font-weight: 800; }
.adventure-version .quiz-progress { height: 10px; margin: 4px 0 19px; border-radius: 99px; background: #456268; }
.adventure-version .question-area { padding: 1px 0; }
.adventure-version .question-area > p:first-child { min-height: 62px; margin: 0; color: #ffffff; font: 700 19px/1.5 "Be Vietnam Pro", sans-serif; }
.adventure-version .question-visual { min-height: 95px; padding: 8px 0; }
.adventure-version .feedback { min-height: 20px; margin: 10px 0 0; color: #ffe08a; font-size: 11px; font-weight: 700; }
.adventure-version .next-button { width: 100%; margin-top: 14px; border: 0; padding: 13px 16px; border-radius: 14px 14px 14px 5px; color: var(--ink); background: var(--yellow); font-size: 13px; font-weight: 800; box-shadow: 0 4px 0 #dca94a; }
.adventure-version .next-button:hover:not(:disabled) { transform: translateY(-2px); box-shadow: 0 6px 0 #dca94a; }
.adventure-version .next-button:disabled { cursor: not-allowed; opacity: .42; }
.adventure-version .challenge-section .answer-button { color: var(--ink); background: #ffffff; }
.adventure-version .english-card .answer-button { color: #ffffff; background: #315861; }
@media (max-width: 800px) { .adventure-version .challenge-section { grid-template-columns: 1fr; gap: 18px; padding-top: 55px; }.adventure-version .challenge-intro { padding: 0; }.adventure-version .challenge-intro > p:not(.eyebrow) { max-width: 590px; }.adventure-version .challenge-meta { display: flex; flex-wrap: wrap; }.adventure-version .challenge-meta span { flex: 1 1 180px; } }
@media (max-width: 480px) { .adventure-version .quiz-card { padding: 17px 15px 16px; }.adventure-version .quiz-top { align-items: flex-start; flex-wrap: wrap; }.adventure-version .quiz-topic { max-width: 100%; order: 3; }.adventure-version .sound-toggle { margin-left: auto; }.adventure-version .question-area > p:first-child { min-height: 0; font-size: 17px; }.adventure-version .challenge-meta { gap: 6px; }.adventure-version .challenge-meta span { width: 100%; flex-basis: 100%; } }

/* A clearer, child-friendly finish line and a car facing the finish flag. */
.race-track { height: 58px; overflow: hidden; border: 1px solid #4d7777; border-radius: 13px; background: linear-gradient(180deg, #214a58 0 42%, #31505b 43% 74%, #243f48 75%); box-shadow: inset 0 7px 12px rgba(126, 224, 191, .08), 0 5px 0 #182e35; }
.race-track::after { content: ""; position: absolute; left: 0; right: 0; bottom: 8px; height: 4px; opacity: .85; background: repeating-linear-gradient(90deg, #ffe08a 0 22px, transparent 22px 43px); animation: road-dash .8s linear infinite; }
.race-track::before { bottom: 4px; height: 5px; z-index: 1; border-radius: 8px; background: linear-gradient(90deg, #f7b84b, #ff7c68 45%, #43b8ad); transition: transform .25s ease; }
.race-track span { bottom: 13px; z-index: 2; display: block; font-size: 29px; line-height: 1; filter: drop-shadow(0 4px 2px rgba(0, 0, 0, .35)); transform: translateX(-50%) scaleX(-1); }
.race-track span::after { content: "💨"; position: absolute; right: 20px; top: 8px; z-index: -1; font-size: 14px; opacity: .72; transform: scaleX(-1); animation: exhaust-puff .55s ease-in-out infinite alternate; }
.race-track i { right: 8px; bottom: 10px; z-index: 2; padding: 4px 6px; border-radius: 8px; background: rgba(255, 224, 138, .12); }
@keyframes road-dash { from { background-position: 0 0; } to { background-position: -43px 0; } }
@keyframes exhaust-puff { from { opacity: .35; transform: scaleX(-1) translateX(0); } to { opacity: .9; transform: scaleX(-1) translateX(4px); } }
@media (max-width: 800px) { .english-layout { grid-template-columns: 1fr; gap: 25px; } }
@media (max-width: 480px) { .english-intro { min-height: 260px; padding: 22px; }.english-intro h3 { font-size: 28px; }.english-topics { margin-top: 17px; } }
.english-card { color: #ffffff; background: #173b42; }.english-card .quiz-top, .english-card .quiz-label, .english-card .question-area, .english-card .question-area > p:first-child { color: #ffffff; }.english-card .quiz-label strong { color: #ffe08a; }.english-card .quiz-topic { color: #e8f5ef; border-color: #8db6ad; }.english-card .quiz-progress span { background: #f7d67f; }.english-card .answer-button { color: #ffffff; border-color: #8db6ad; background: #315861; }.english-card .answer-button:hover:not(:disabled) { border-color: #ffe08a; background: #416d73; }.english-card .answer-button.correct { border-color: #7ee0bf; color: #ffffff; background: #237b70; }.english-card .answer-button.wrong { border-color: #ff9e91; color: #ffffff; background: #9b4e4a; }.english-card .feedback { color: #ffe08a; }.english-card .next-button { color: #173b42; background: #f7d67f; }.english-card .explanation-panel { color: #ffffff; border-color: #f7d67f; background: #254f55; }.english-card .explanation-panel > p { color: #f2fbf5 !important; }.english-card .correct-answer { background: #2f887b; }
/* Chinh phục tháp số: a readable 2D battle board with large touch targets. */
.game-stage { position: relative; overflow: hidden; }
.tower-canvas { display: block; width: 100%; max-width: 720px; height: auto; margin: 17px auto 0; border: 2px solid #4d8585; border-radius: 16px; background: #173b42; box-shadow: inset 0 0 28px rgba(255, 224, 138, .08), 0 7px 0 #162e35; }
.tower-round-overlay { position: absolute; inset: 0; z-index: 8; display: grid; place-content: center; justify-items: center; gap: 4px; padding: 24px; color: #fff7d6; text-align: center; background: radial-gradient(circle at center, rgba(48, 124, 122, .93), rgba(17, 43, 57, .97) 68%); backdrop-filter: blur(5px); pointer-events: auto; }
.tower-round-overlay[hidden] { display: none; }
.tower-round-overlay.is-showing { animation: tower-screen-in .55s cubic-bezier(.2,.8,.2,1) both; }
.tower-round-kicker { color: #9ff5dc; font-size: 11px; font-weight: 800; letter-spacing: 2px; animation: tower-screen-rise .55s .08s both; }
.tower-round-overlay strong { color: #ffe08a; font: 800 clamp(42px, 9vw, 78px)/.95 "Baloo 2", sans-serif; text-shadow: 0 5px 0 rgba(79, 45, 37, .45), 0 0 30px rgba(255, 224, 138, .42); animation: tower-screen-rise .6s .16s both; }
.tower-round-name { color: #ffffff; font: 800 22px "Baloo 2", sans-serif; animation: tower-screen-rise .6s .24s both; }
.tower-round-overlay small { margin-top: 6px; color: #d1ebe2; font-size: 11px; animation: tower-screen-rise .6s .32s both; }
.tower-finish-card { margin-top: 17px; padding: 20px 18px; border: 2px solid #ffe08a; border-radius: 18px; color: #fff7d6; text-align: center; background: radial-gradient(circle at 50% 0, #3d7774, #214853 70%); box-shadow: 0 0 26px rgba(255, 224, 138, .24); animation: tower-finish-in .55s cubic-bezier(.2,.8,.2,1) both; }
.tower-finish-card[hidden] { display: none; }
.tower-finish-kicker { display: block; color: #ffe08a; font-size: 11px; font-weight: 800; letter-spacing: 2px; }
.tower-finish-card > strong { display: block; margin-top: 3px; color: #ffffff; font: 800 28px "Baloo 2", sans-serif; }
.tower-finish-card > p { margin: 3px 0 13px !important; color: #d1ebe2 !important; font-size: 11px; }
.tower-finish-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.tower-finish-stats span { display: grid; gap: 1px; padding: 8px 5px; border-radius: 10px; color: #ffe08a; background: rgba(255,255,255,.1); font-size: 16px; }
.tower-finish-stats b { color: #ffffff; font: 800 22px "Baloo 2", sans-serif; }
.tower-finish-stats small { color: #b8d7ce; font-size: 8px; }
@keyframes tower-screen-in { from { opacity: 0; transform: scale(1.08); } to { opacity: 1; transform: scale(1); } }
@keyframes tower-screen-rise { from { opacity: 0; transform: translateY(15px); } to { opacity: 1; transform: translateY(0); } }
@keyframes tower-finish-in { from { opacity: 0; transform: translateY(12px) scale(.97); } to { opacity: 1; transform: translateY(0) scale(1); } }
.tower-audio-row { display: flex; align-items: center; flex-wrap: wrap; gap: 9px; margin-top: 10px; color: #a8cbc5; font-size: 9px; }
.tower-audio-button { border: 1px solid #6d9e98; border-radius: 18px; padding: 7px 11px; color: #fff2c9; background: #254d58; font-size: 10px; font-weight: 800; transition: transform .16s ease, border-color .16s ease, background .16s ease; }
.tower-audio-button:hover { transform: translateY(-2px); border-color: #ffe08a; background: #326875; }
.tower-audio-button[aria-pressed="false"] { color: #adc5c0; opacity: .75; }
.tower-mission { position: relative; margin-top: 17px; padding: 15px 18px; overflow: hidden; border: 1px solid #5b8581; border-radius: 14px; background: linear-gradient(120deg, #214e58, #2c3f56); box-shadow: inset 5px 0 0 #ffe08a; }
.tower-mission::after { content: "✦  ✧  ✦"; position: absolute; right: 17px; top: 14px; color: rgba(255, 224, 138, .35); letter-spacing: 8px; animation: drift-stars 2.2s ease-in-out infinite; }
.tower-mission span { display: block; margin-bottom: 3px; color: #9ddfd3; font-size: 9px; font-weight: 800; letter-spacing: 1.4px; }
.tower-mission strong { display: block; max-width: 82%; color: #fff2c9; font: 800 21px/1.35 "Baloo 2", sans-serif; }
.tower-mission small { display: block; margin-top: 4px; color: #c8e2dc; font-size: 10px; line-height: 1.4; }
.tower-answer-row { display: flex; flex-wrap: wrap; align-items: center; gap: 9px; margin-top: 15px; }
.tower-answer-row .game-input { width: 155px; min-height: 48px; font-size: 20px; }
.tower-answer-row .game-button { min-height: 48px; }
.tower-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 16px; }
.tower-choice { position: relative; min-height: 105px; padding: 13px 10px 11px; border: 2px solid #557a7d; border-radius: 15px; color: #f7fff7; background: linear-gradient(160deg, #2e515b, #243d4c); box-shadow: 0 5px 0 #172f3a; font: 800 16px "Baloo 2", sans-serif; transition: transform .16s ease, border-color .16s ease, box-shadow .16s ease, opacity .16s ease; }
.tower-choice b { display: block; margin: 4px 0 1px; color: #ffe08a; font: 800 31px/1 "Baloo 2", sans-serif; }
.tower-choice small { display: block; min-height: 15px; color: #a9d4ca; font: 700 9px/1.3 "Be Vietnam Pro", sans-serif; }
.tower-choice:not(:disabled):hover { transform: translateY(-5px); border-color: #ffe08a; box-shadow: 0 9px 0 #172f3a, 0 0 22px rgba(255, 224, 138, .24); }
.tower-choice:disabled { cursor: default; opacity: .52; }
.tower-choice.too-strong { border-color: #a16a67; background: linear-gradient(160deg, #543f4b, #3b3947); }
.tower-choice.too-strong:not(:disabled) { opacity: .84; }
.tower-choice.captured { border-color: #7ee0bf; color: #d8fff1; background: linear-gradient(160deg, #247c76, #1b5c61); animation: game-pop .35s ease both; }
.tower-choice.wrong { border-color: #ff9e91; background: #9d4e4a; animation: race-shake .35s ease; }
.tower-grid.boss-grid { grid-template-columns: minmax(260px, 390px); justify-content: center; }.tower-choice.boss-choice { min-height: 118px; border-color: #55c7e8; background: linear-gradient(160deg, #245f78, #243d5a); }.tower-choice.boss-choice b { color: #9ef5ff; }.tower-choice.boss-hit { border-color: #ffe08a; background: linear-gradient(160deg, #4a6871, #35465b); animation: boss-shake .35s ease; }
@keyframes boss-shake { 0%, 100% { transform: translateX(0) rotate(0); } 25% { transform: translateX(-7px) rotate(-2deg); } 75% { transform: translateX(7px) rotate(2deg); } }
.tower-grid + .game-feedback { min-height: 31px; }
@media (max-width: 600px) { .tower-mission strong { max-width: 100%; font-size: 18px; }.tower-mission::after { display: none; }.tower-grid { gap: 8px; }.tower-choice { min-height: 100px; padding: 10px 5px; font-size: 14px; }.tower-choice b { font-size: 27px; }.tower-choice small { font-size: 8px; }.tower-answer-row .game-input { width: 100%; }.tower-answer-row .game-button { flex: 1; } }
/* Link to the separate TIMO practice room. */
.timo-link-card { position: relative; z-index: 2; display: flex; align-items: center; gap: 10px; max-width: 290px; margin-top: 20px; padding: 10px 12px; border: 1px solid rgba(255,255,255,.28); border-radius: 13px 13px 13px 4px; color: #f7fff8; background: rgba(255,255,255,.1); text-decoration: none; transition: transform .2s, background .2s; }.timo-link-card:hover { transform: translateY(-3px); background: rgba(255,255,255,.18); }.timo-link-badge { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 11px; color: #173b42; background: #f7d67f; font: 800 11px "Baloo 2", sans-serif; }.timo-link-card strong, .timo-link-card small { display: block; }.timo-link-card strong { font: 800 14px "Baloo 2", sans-serif; }.timo-link-card small { margin-top: 2px; color: #c8e4db; font-size: 9px; }