:root{--sky-blue:#4bc8f5;--sky-blue-bright:#0877b8;--sky-blue-dark:#0877b8;--sky-blue-deep:#096bbd;--sky-blue-text:#087bc5;--link-blue:#086fba;--sunny-yellow:#ffd22e;--sunny-yellow-dark:#dda900;--sunny-yellow-ink:#684800;--cloud-white:#fff;--cloud-cream:#fff4b8;--surface:#f7fbff;--navy:#06356f;--coral:#ff735e;--coral-focus:#ff7b62;--coral-dark:#c7463b;--green:#25ad75;--green-dark:#14784e;--green-badge:#158555;--red:#f16c62;--red-dark:#ad3e3b;--red-badge:#c84440;--disabled:#596a80;--disabled-shadow:#405268;--secondary-shadow:#b9d9ea;--cloud-94:#fffffff0;--cloud-92:#ffffffeb;--cloud-90:#ffffffe6;--cloud-85:#ffffffd9;--cloud-80:#fffc;--cloud-55:#ffffff8c;--cloud-52:#ffffff85;--cloud-43:#ffffff6e;--header-shadow:#11659e38;--progress-shadow:#11659e2e;--blue-shadow-22:#033e7038;--blue-shadow-20:#03518833;--blue-shadow-18:#0351882e;--blue-shadow-15:#03518826;--blue-shadow-14:#03518824;--card-shadow:#044b792e;--mode-shadow:#04426c40;--mascot-shadow:#03406940;--coral-shadow:#4f241a33;color:var(--navy);background:var(--sky-blue);font-synthesis:none;text-rendering:optimizelegibility;font-family:ui-rounded,SF Pro Rounded,Nunito,Arial Rounded MT Bold,system-ui,sans-serif}*{box-sizing:border-box}html,body{min-height:100%}#root{min-height:100svh}body{background-color:var(--sky-blue);background-image:url(/images/backgrounds/sky-world.webp);background-position:50%;background-size:cover;background-attachment:fixed;min-width:320px;min-height:100svh;margin:0;overflow-x:hidden}button{font:inherit}button:not(:disabled){cursor:pointer}.home-button,.audio-button,.choice-card,.next-button,.secondary-button,.mic-button,.mode-card,.textbook-card{min-height:56px}.book-button{min-width:48px;min-height:48px}.skip-button{border:3px solid var(--cloud-white);background:var(--cloud-92);min-height:48px;color:var(--navy);box-shadow:0 4px 0 var(--blue-shadow-18);border-radius:16px;justify-content:center;align-items:center;gap:8px;margin:18px auto 0;padding:10px 20px;font-weight:800;display:inline-flex}.skip-button:focus-visible,.book-button:focus-visible,.home-button:focus-visible,.audio-button:focus-visible,.choice-card:focus-visible,.next-button:focus-visible,.secondary-button:focus-visible,.mic-button:focus-visible,.mode-card:focus-visible,.textbook-card:focus-visible{outline:3px solid var(--cloud-white);outline-offset:0;box-shadow:0 0 0 6px var(--navy)}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.app-shell{min-height:100svh;padding:20px clamp(16px,4vw,56px) 32px}.game-header{grid-template-columns:auto auto minmax(180px,1fr) auto;align-items:center;gap:18px;width:min(1180px,100%);min-height:72px;margin:0 auto 10px;display:grid}.home-button,.question-pill,.score-pill{border:3px solid var(--cloud-90);background:var(--cloud-90);min-height:56px;box-shadow:0 7px 0 var(--header-shadow);color:var(--navy);border-radius:999px;justify-content:center;align-items:center;gap:8px;padding:10px 20px;font-weight:800;display:inline-flex}.home-button{border:0}.home-button svg{width:24px;height:24px}.question-pill,.score-pill{color:var(--navy);font-size:1.08rem}.progress-track{border:3px solid var(--cloud-90);background:var(--cloud-55);height:16px;box-shadow:0 3px 0 var(--progress-shadow);border-radius:999px;position:relative;overflow:hidden}.progress-fill{border-radius:inherit;background:var(--sunny-yellow);height:100%;transition:width .35s;display:block}.question-screen{text-align:center;width:min(920px,100%);margin:0 auto;position:relative}.question-screen h1{letter-spacing:.03em;text-shadow:0 2px 0 var(--cloud-80);margin:8px 0 14px;font-size:clamp(1.65rem,3vw,2.4rem);line-height:1.18}.audio-button{border:6px solid var(--cloud-cream);background:var(--sky-blue-bright);min-width:142px;min-height:112px;color:var(--cloud-white);box-shadow:0 9px 0 var(--sky-blue-deep), 0 14px 24px var(--blue-shadow-22);border-radius:34px;flex-direction:column;justify-content:center;align-items:center;gap:4px;margin:0 auto 14px;padding:14px 22px;font-weight:900;display:flex}.audio-button svg{fill:currentColor;width:46px;height:46px}.audio-button:active:not(:disabled){box-shadow:0 4px 0 var(--sky-blue-deep);transform:translateY(5px)}.choice-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;width:min(700px,100%);margin:0 auto;display:grid}.choice-card{border:7px solid var(--cloud-94);background:var(--surface);min-width:0;min-height:190px;box-shadow:0 8px 0 var(--blue-shadow-20), 0 14px 26px var(--card-shadow);border-radius:34px;padding:9px;transition:transform .18s,box-shadow .18s;position:relative;overflow:hidden}.choice-card:not(:disabled):hover{transform:translateY(-4px)}.choice-card:disabled{cursor:default;opacity:1}.choice-card.is-correct{border-color:var(--green);box-shadow:0 8px 0 var(--green-dark)}.choice-card.is-wrong{border-color:var(--red);box-shadow:0 8px 0 var(--red-dark)}.choice-image{object-fit:contain;border-radius:22px;width:100%;height:100%;max-height:210px;display:block}.image-fallback{place-items:center;min-height:160px;font-size:1.5rem;font-weight:900;display:grid}.answer-badge{min-height:42px;color:var(--cloud-white);border-radius:999px;align-items:center;gap:5px;padding:8px 13px;font-weight:900;display:inline-flex;position:absolute;bottom:14px;right:14px}.correct-badge{background:var(--green-badge)}.wrong-badge{background:var(--red-badge)}.feedback-panel,.fallback-panel{border:4px solid var(--cloud-white);background:var(--cloud-92);box-shadow:0 8px 0 var(--blue-shadow-18);border-radius:24px;margin:18px auto 0;padding:16px 20px;font-weight:800}.feedback-panel p{margin:3px 0 8px}.next-button,.secondary-button,.mic-button{border:0;border-radius:18px;justify-content:center;align-items:center;gap:9px;min-height:56px;padding:12px 24px;font-weight:900;display:inline-flex}.next-button{background:var(--sunny-yellow);color:var(--sunny-yellow-ink);box-shadow:0 6px 0 var(--sunny-yellow-dark)}.secondary-button{background:var(--cloud-white);color:var(--link-blue);box-shadow:0 6px 0 var(--secondary-shadow)}.speaking-screen{width:min(960px,100%)}.gameplay-pip{display:none}.speaking-stage{border:5px solid var(--cloud-85);background:var(--cloud-43);box-shadow:0 12px 0 var(--blue-shadow-15);border-radius:42px;grid-template-columns:minmax(260px,1fr) minmax(260px,.8fr);align-items:center;gap:clamp(22px,5vw,64px);padding:clamp(20px,4vw,42px);display:grid}.speaking-image-card{aspect-ratio:1;border:8px solid var(--cloud-white);background:var(--surface);min-width:0;box-shadow:0 10px 0 var(--blue-shadow-20);border-radius:38px;padding:14px}.speaking-image-card img{object-fit:contain;border-radius:24px;width:100%;height:100%;display:block}.speech-controls{min-width:0}.speech-controls p{font-size:1.05rem;font-weight:800}.mic-button{border:7px solid var(--cloud-cream);background:var(--coral);width:min(240px,100%);min-height:150px;color:var(--navy);box-shadow:0 9px 0 var(--coral-dark), 0 16px 28px var(--coral-shadow);border-radius:44px;flex-direction:column;font-size:1.25rem}.mic-button svg{width:54px;height:54px}.mic-button:disabled{background:var(--disabled);color:var(--cloud-white);box-shadow:0 6px 0 var(--disabled-shadow)}.home-screen,.textbook-screen,.result-screen{place-items:center;width:min(1180px,100%);min-height:100svh;margin:0 auto;padding-inline:clamp(4px,2vw,16px);display:grid;position:relative}.home-hero{border:5px solid var(--cloud-80);background:var(--cloud-52);width:100%;box-shadow:0 14px 0 var(--blue-shadow-14);border-radius:48px;grid-template-columns:minmax(0,1.1fr) minmax(280px,.7fr);grid-template-areas:"eyebrow pip""title pip""intro pip""books pip""modes pip""rule pip";align-items:center;gap:0 clamp(20px,5vw,68px);padding:clamp(28px,5vw,64px);display:grid}.home-title{grid-area:title;margin:6px 0 12px;font-size:clamp(3rem,7vw,5.8rem);line-height:.98}.eyebrow{color:var(--sky-blue-text);letter-spacing:.08em;grid-area:eyebrow;margin:0;font-weight:900}.home-intro{grid-area:intro;max-width:560px;margin:0 0 24px;font-size:clamp(1rem,2vw,1.3rem);font-weight:700;line-height:1.65}.pip-mascot{width:min(390px,100%);filter:drop-shadow(0 18px 18px var(--mascot-shadow));grid-area:pip;animation:3.4s ease-in-out infinite pip-float}.book-selector{grid-area:books;margin:0 0 18px}.book-selector h2{margin:0 0 10px;font-size:1.18rem}.book-grid{grid-template-columns:repeat(6,minmax(48px,1fr));gap:9px;display:grid}.book-button{border:3px solid var(--cloud-white);background:var(--cloud-90);color:var(--navy);box-shadow:0 4px 0 var(--secondary-shadow);border-radius:16px;padding:8px 6px;font-weight:900;position:relative}.book-button[aria-pressed=true]{border-color:var(--navy);background:var(--sunny-yellow);box-shadow:0 4px 0 var(--sunny-yellow-dark)}.book-button[aria-pressed=true]:after{content:"已选";border:2px solid var(--cloud-white);background:var(--navy);width:34px;height:20px;color:var(--cloud-white);border-radius:999px;font-size:12px;line-height:16px;position:absolute;top:-8px;right:-6px}.mode-grid{grid-area:modes;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;display:grid}.mode-card{border:4px solid var(--cloud-white);min-width:0;min-height:112px;color:var(--cloud-white);text-align:left;box-shadow:0 7px 0 var(--mode-shadow);border-radius:25px;align-items:center;gap:13px;padding:18px;display:flex}.mode-listening{background:var(--sky-blue-dark)}.mode-speaking{background:var(--coral);color:var(--navy)}.mode-textbook{background:var(--sunny-yellow);color:var(--sunny-yellow-ink)}.mode-card svg{flex:none;width:36px;height:36px}.mode-card span{gap:4px;min-width:0;display:grid}.mode-card strong{font-size:1.18rem}.mode-card small{font-weight:700}.round-rule{grid-area:rule;margin:18px 0 0;font-weight:900}.result-card{z-index:1;border:6px solid var(--cloud-white);background:var(--cloud-92);width:min(560px,100%);box-shadow:0 13px 0 var(--blue-shadow-20);text-align:center;border-radius:44px;padding:44px;position:relative}.result-card h1{margin:7px 0;font-size:clamp(2.2rem,6vw,4rem)}.result-score{color:var(--sky-blue-text);margin:12px 0;font-size:clamp(5rem,14vw,8rem);font-weight:900;line-height:1}.result-message{font-size:1.5rem;font-weight:900}.result-actions{flex-wrap:wrap;justify-content:center;gap:15px;display:flex}.textbook-panel{border:5px solid var(--cloud-80);background:var(--cloud-52);width:min(1080px,100%);box-shadow:0 14px 0 var(--blue-shadow-14);border-radius:44px;padding:clamp(22px,4vw,44px)}.textbook-back-button{margin-bottom:18px}.textbook-panel h1{margin:8px 0;font-size:clamp(2.4rem,6vw,4.8rem);line-height:1}.textbook-intro{max-width:640px;margin:0 0 24px;font-size:clamp(1rem,2vw,1.22rem);font-weight:800;line-height:1.65}.textbook-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:18px;display:grid}.textbook-card{border:5px solid var(--cloud-white);background:var(--cloud-94);min-width:0;color:var(--navy);box-shadow:0 8px 0 var(--blue-shadow-18);text-align:left;border-radius:28px;gap:10px;padding:12px;transition:transform .18s,box-shadow .18s;display:grid}.textbook-card:hover{box-shadow:0 12px 0 var(--blue-shadow-18);transform:translateY(-4px)}.textbook-card img{aspect-ratio:4/5;object-fit:cover;background:var(--surface);border-radius:19px;width:100%}.textbook-card span{justify-content:space-between;align-items:baseline;gap:8px;display:flex}.textbook-card strong{font-size:1.45rem;font-weight:900}.textbook-card small{color:var(--link-blue);font-weight:900}.reader-screen{grid-template-rows:auto auto minmax(0,1fr);gap:14px;min-height:100svh;padding:16px clamp(12px,3vw,32px) 24px;display:grid}.reader-header{grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:14px;width:min(1280px,100%);margin:0 auto;display:grid}.reader-header h1{border:3px solid var(--cloud-90);background:var(--cloud-90);box-shadow:0 7px 0 var(--header-shadow);text-align:center;border-radius:999px;margin:0;padding:10px 18px;font-size:clamp(1.1rem,3vw,1.8rem)}.reader-open-link{border:3px solid var(--cloud-white);background:var(--sunny-yellow);width:min(1280px,100%);min-height:56px;color:var(--sunny-yellow-ink);box-shadow:0 6px 0 var(--sunny-yellow-dark);border-radius:18px;justify-content:center;align-items:center;gap:8px;margin:0 auto;padding:12px 22px;font-weight:900;text-decoration:none;display:inline-flex}.reader-open-link svg{width:24px;height:24px}.reader-open-link:focus-visible{outline:3px solid var(--cloud-white);outline-offset:0;box-shadow:0 0 0 6px var(--navy)}.reader-content{grid-template-columns:minmax(0,1fr) minmax(260px,320px);align-items:stretch;gap:16px;width:min(1280px,100%);min-height:0;margin:0 auto;display:grid}.textbook-frame{border:6px solid var(--cloud-white);background:var(--cloud-white);width:100%;height:calc(100svh - 112px);min-height:520px;box-shadow:0 12px 0 var(--blue-shadow-18);border-radius:28px}.textbook-audio-panel{border:5px solid var(--cloud-white);background:var(--cloud-92);max-height:calc(100svh - 112px);box-shadow:0 12px 0 var(--blue-shadow-18);border-radius:28px;padding:18px;overflow:auto}.textbook-audio-panel h2{margin:0 0 8px;font-size:1.45rem}.textbook-audio-panel p{margin:0 0 14px;font-weight:800;line-height:1.45}.textbook-audio-list{gap:10px;display:grid}.textbook-audio-button{border:3px solid var(--cloud-white);background:var(--sunny-yellow);min-height:56px;color:var(--sunny-yellow-ink);box-shadow:0 5px 0 var(--sunny-yellow-dark);text-align:left;border-radius:18px;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:10px;padding:10px 12px;font-weight:900;display:grid}.textbook-audio-button svg{fill:currentColor;width:24px;height:24px}.textbook-audio-button:focus-visible{outline:3px solid var(--cloud-white);outline-offset:0;box-shadow:0 0 0 6px var(--navy)}.celebration-layer{z-index:0;pointer-events:none;position:fixed;inset:0;overflow:hidden}.confetti-piece{--confetti-index:0;--confetti-left:50%;--confetti-delay:0s;--confetti-color:var(--sunny-yellow);top:-24px;left:var(--confetti-left);background:var(--confetti-color);width:13px;height:24px;box-shadow:0 0 14px var(--cloud-80);transform:rotate(calc(var(--confetti-index) * 19deg));animation:confetti-fall 2.9s ease-in var(--confetti-delay) infinite;border-radius:6px;position:absolute}.confetti-piece:nth-child(3n){border-radius:50%;width:18px;height:18px}.confetti-piece:nth-child(4n){width:10px;height:30px}.perfect-celebration{border:4px solid var(--sunny-yellow);background:linear-gradient(135deg, var(--cloud-white), var(--cloud-cream));box-shadow:0 7px 0 var(--sunny-yellow-dark);border-radius:24px;margin:10px auto 8px;padding:12px 16px}.celebration-label,.celebration-title{margin:0;font-weight:900}.celebration-label{color:var(--coral-dark);letter-spacing:.12em}.celebration-title{color:var(--navy);margin-top:4px;font-size:clamp(1.35rem,4vw,2rem)}@keyframes pip-float{0%,to{transform:translateY(0)}50%{transform:translateY(-12px)}}@keyframes confetti-fall{0%{opacity:0;transform:translateY(-20px)rotate(0)}10%{opacity:1}to{transform:translate3d(calc((var(--confetti-index) - 14) * 9px), 112vh, 0) rotate(calc(var(--confetti-index) * 48deg + 520deg));opacity:0}}@media (width>=901px){.question-screen{width:min(1120px,100%)}.choice-grid{gap:18px;width:min(900px,100%)}.choice-card{height:250px}.choice-image{max-height:none}.speaking-stage{width:min(960px,100%);margin-inline:auto}}@media (width>=1280px){.gameplay-pip{z-index:0;pointer-events:none;width:120px;filter:drop-shadow(0 12px 14px var(--mascot-shadow));display:block;position:fixed;bottom:20px;left:max(16px,50% - 600px)}}@media (width<=760px){.app-shell{padding:12px 12px 24px}.game-header{grid-template-columns:auto 1fr auto;gap:9px}.home-button{width:56px;padding:0}.home-button svg{margin:0}.home-button{font-size:0}.progress-track{grid-area:2/1/auto/-1}.question-pill{grid-area:1/2}.score-pill{grid-area:1/3}.speaking-stage{grid-template-columns:1fr}.speaking-image-card{width:min(360px,100%);margin:0 auto}.home-hero{text-align:center;grid-template-columns:1fr;grid-template-areas:none}.home-hero>*{grid-area:auto}.home-intro{margin-inline:auto}.pip-mascot{width:min(180px,46vw);margin:-6px auto -18px}.textbook-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.reader-screen{padding:10px 10px 220px;gap:8px;padding-bottom:220px}.reader-header{grid-template-columns:1fr}.reader-header .home-button{width:100%;font-size:1rem}.reader-header h1{padding:8px 12px;font-size:1.08rem}.reader-open-link{border-radius:16px;min-height:48px;padding:10px 16px}.reader-content{grid-template-columns:1fr}.textbook-frame{border-width:4px;border-radius:22px;width:100%;height:calc(100svh - 170px);min-height:520px}.textbook-audio-panel{z-index:5;max-height:190px;box-shadow:0 10px 0 var(--blue-shadow-18), 0 -12px 26px var(--blue-shadow-15);border-radius:24px;padding:12px;position:fixed;bottom:12px;left:12px;right:12px}.textbook-audio-panel h2{margin-bottom:4px;font-size:1.2rem}.textbook-audio-panel p{margin-bottom:10px;font-size:.92rem}.textbook-audio-list{scroll-snap-type:x proximity;gap:10px;padding:0 2px 7px;display:flex;overflow-x:auto}.textbook-audio-button{scroll-snap-align:start;min-width:min(270px,82vw)}}@media (width<=700px){.book-grid{grid-template-columns:repeat(4,minmax(48px,1fr))}}@media (width<=640px){body{background-attachment:scroll}.question-screen h1{margin-top:4px}.audio-button{border-width:4px;border-radius:26px;min-width:120px;min-height:82px}.audio-button svg{width:36px;height:36px}.choice-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.choice-card{border-width:5px;border-radius:23px;min-height:134px;padding:5px}.choice-image{border-radius:16px;max-height:145px}.answer-badge{min-height:36px;padding:6px 9px;font-size:.78rem;bottom:7px;right:7px}.home-hero{border-radius:34px;padding:24px 16px}.home-title{font-size:clamp(2.7rem,14vw,4rem)}.mode-grid{grid-template-columns:1fr}.mode-card{min-height:86px}.textbook-panel{border-radius:34px;padding:22px 14px}.textbook-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.textbook-card{border-radius:22px;padding:9px}.textbook-card img{border-radius:15px}.textbook-card span{display:grid}.textbook-card strong{font-size:1.2rem}.speaking-stage{border-radius:30px;padding:16px}.speaking-image-card{border-radius:28px;max-width:280px}.mic-button{min-height:112px}.result-card{border-radius:32px;padding:30px 18px}}@media (width<=420px){.book-grid{grid-template-columns:repeat(3,minmax(48px,1fr))}}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}