:root{--ink:#10223d;--muted:#71819a;--paper:#fffdf7;--navy:#07172f;--blue:#4bd6ff;--purple:#7659ed;--yellow:#ffd43f;--green:#45d2aa;--red:#ff6575;--grade-color:#45c6a6}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:#edf7ff;background:radial-gradient(circle at 12% 12%,rgba(59,144,255,.28),transparent 24%),radial-gradient(circle at 88% 70%,rgba(142,73,255,.2),transparent 25%),radial-gradient(circle,rgba(255,255,255,.42) 1px,transparent 1.5px) 0 0/36px 36px,var(--navy);font-family:"Nunito","PingFang SC","Microsoft YaHei",system-ui,sans-serif;-webkit-font-smoothing:antialiased}button,a{font:inherit;color:inherit;-webkit-tap-highlight-color:transparent}button{cursor:pointer}a{text-decoration:none}svg{width:21px;height:21px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}.svg-sprite{position:absolute;width:0;height:0;overflow:hidden}.skip-link{position:fixed;z-index:100;top:8px;left:8px;padding:9px 13px;color:var(--ink);border-radius:10px;background:#fff;transform:translateY(-150%)}.skip-link:focus{transform:none}
.math-topbar{height:72px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;padding:0 max(24px,calc((100vw - 1180px)/2));border-bottom:1px solid #213b5e;background:rgba(5,18,38,.92);backdrop-filter:blur(14px);position:sticky;top:0;z-index:30}.back-link{display:flex;align-items:center;gap:7px;width:max-content;padding:9px 10px;color:#a8bdd9;border-radius:11px;font-size: calc(14px * var(--fs, 1));font-weight:800}.back-link:hover{color:#fff;background:#153459}.math-brand{display:flex;align-items:center;gap:10px}.brand-mark{width:43px;height:43px;display:grid;place-items:center;color:#06152a;border:2px solid #06152a;border-radius:15px;background:var(--blue);box-shadow:4px 4px 0 var(--purple);font-size: calc(22px * var(--fs, 1));font-weight:950;transform:rotate(-4deg)}.math-brand>span:last-child{display:flex;flex-direction:column}.math-brand b{font-size: calc(16px * var(--fs, 1))}.math-brand small{margin-top:2px;color:#8ea5c5;font-size: calc(13px * var(--fs, 1))}.top-score{justify-self:end;display:flex;align-items:center;gap:6px;padding:8px 11px;color:#ffe18a;border:1px solid #694f23;border-radius:12px;background:#30230e}.top-score small{color:#c5a85e;font-size: calc(12.5px * var(--fs, 1))}.top-score b{font-size: calc(14.5px * var(--fs, 1))}
.math-shell{width:min(1180px,calc(100% - 48px));margin:24px auto 70px}.math-hero{min-height:285px;position:relative;display:flex;align-items:center;overflow:hidden;padding:38px 45px;border:3px solid #18365d;border-radius:30px;background:radial-gradient(circle at 85% 25%,rgba(81,221,255,.18),transparent 22%),linear-gradient(118deg,#0e315d,#19205a 58%,#54257a);box-shadow:10px 10px 0 #020914,0 24px 48px rgba(0,0,0,.3)}.math-hero:after{content:"";position:absolute;inset:0;opacity:.13;background:radial-gradient(circle,#fff 1.2px,transparent 1.7px) 0 0/20px 20px;pointer-events:none}.hero-copy{z-index:2;width:62%}.hero-kicker{display:inline-flex;padding:7px 11px;color:#06152a;border:2px solid #06152a;border-radius:10px;background:var(--yellow);box-shadow:3px 3px 0 var(--purple);font-size: calc(13.5px * var(--fs, 1));font-weight:950;transform:rotate(-1deg)}.math-hero h1{margin:16px 0 8px;font-size:clamp(30px,4vw,47px);line-height:1.1;text-shadow:3px 3px 0 #392477}.math-hero p{margin:0;color:#c4d8f3;font-size: calc(14px * var(--fs, 1))}.hero-progress{width:min(440px,100%);display:flex;align-items:center;gap:13px;margin-top:25px}.hero-progress span{font-size: calc(13.5px * var(--fs, 1))}.hero-progress strong{color:var(--yellow);font-size: calc(22px * var(--fs, 1))}.hero-progress i{height:10px;flex:1;overflow:hidden;border:1px solid rgba(255,255,255,.2);border-radius:99px;background:#09152d}.hero-progress em{height:100%;display:block;border-radius:inherit;background:linear-gradient(90deg,var(--grade-color),var(--blue),var(--yellow));transition:width .3s}.hero-orbit{z-index:2;width:300px;height:230px;position:absolute;right:6%;display:grid;place-items:center;border:2px dashed rgba(110,223,255,.35);border-radius:50%;transform:rotate(-8deg)}.hero-orbit:before{content:"";position:absolute;width:180px;height:180px;border:22px solid rgba(124,93,239,.2);border-radius:50%}.hero-orbit div{width:115px;height:115px;display:grid;place-items:center;border:5px solid #fff;border-radius:39px;background:linear-gradient(145deg,#fff5bd,#9cf5e0);box-shadow:8px 8px 0 #06152a,12px 12px 0 var(--blue);font-size: calc(66px * var(--fs, 1));transform:rotate(8deg)}.hero-orbit>span{position:absolute;width:44px;height:44px;display:grid;place-items:center;color:#07172f;border:3px solid #07172f;border-radius:13px;background:var(--yellow);box-shadow:4px 4px 0 #8e63e9;font-weight:950}.orbit-one{left:3%;top:25%}.orbit-two{right:1%;top:13%;transform:rotate(12deg)}.orbit-three{right:11%;bottom:4%;transform:rotate(-9deg)}
.section-heading{display:flex;align-items:flex-end;justify-content:space-between;margin:0 3px 15px}.section-heading>div{display:flex;flex-direction:column}.section-heading span{color:#ffbb55;font-size: calc(13.5px * var(--fs, 1));font-weight:950;letter-spacing:.1em}.section-heading h2{margin:5px 0 0;font-size: calc(22px * var(--fs, 1))}.section-heading>small{color:#94aac7;font-size: calc(13.5px * var(--fs, 1))}.grade-section{margin-top:28px}.grade-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:10px}.grade-grid button{min-width:0;display:flex;flex-direction:column;align-items:center;padding:13px 7px;border:2px solid #233f62;border-radius:17px;color:#a8bbd5;background:#0c2545;box-shadow:3px 3px 0 #020a15;transition:.17s}.grade-grid button:hover{color:#fff;border-color:#496f9e;transform:translateY(-2px)}.grade-grid button.active{color:#0a1c32;border:3px solid #07162c;background:var(--grade-color);box-shadow:4px 5px 0 var(--yellow)}.grade-grid span{font-size: calc(27px * var(--fs, 1))}.grade-grid b{margin-top:4px;font-size: calc(14.5px * var(--fs, 1))}.grade-grid small{max-width:100%;margin-top:3px;overflow:hidden;font-size: calc(12.5px * var(--fs, 1));text-overflow:ellipsis;white-space:nowrap;opacity:.8}
.math-layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:20px;margin-top:28px}.mission-panel,.daily-card,.math-stats{border:3px solid #0a1a31;border-radius:25px;box-shadow:8px 8px 0 #020914,0 17px 35px rgba(0,0,0,.22)}.mission-panel{padding:23px;background:#fffdf7;color:var(--ink)}.section-heading.compact{align-items:center}.section-heading.compact span{color:#e17031}.section-heading.compact h2{font-size: calc(20px * var(--fs, 1))}.section-heading .grade-code{width:42px;height:42px;display:grid;place-items:center;color:#07172f;border:2px solid #07172f;border-radius:13px;background:var(--grade-color);box-shadow:3px 3px 0 var(--yellow);font-size: calc(14px * var(--fs, 1))}.topic-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:11px}.topic-card{min-width:0;min-height:142px;position:relative;display:grid;grid-template-columns:auto 1fr;gap:10px;padding:15px;border:2px solid #dbe3e9;border-radius:17px;color:var(--ink);background:#fff;box-shadow:3px 3px 0 #dbe3e9;text-align:left;transition:.16s}.topic-card:hover{z-index:1;border-color:#11243f;box-shadow:5px 5px 0 var(--blue);transform:translateY(-2px)}.topic-card.active{border:3px solid #10223e;background:#fff8d9;box-shadow:5px 5px 0 var(--grade-color)}.topic-number{position:absolute;right:10px;top:9px;color:#c8d1db;font-family:Impact,sans-serif;font-size: calc(16px * var(--fs, 1))}.topic-icon{width:47px;height:47px;display:grid;place-items:center;border:2px solid #10223d;border-radius:14px;background:linear-gradient(145deg,#e9f9ff,#fff1bd);font-size: calc(24px * var(--fs, 1))}.topic-copy{min-width:0;display:flex;flex-direction:column}.topic-copy b{padding-right:26px;overflow:hidden;font-size: calc(14.5px * var(--fs, 1));text-overflow:ellipsis;white-space:nowrap}.topic-copy small{margin-top:4px;color:var(--muted);font-size: calc(13px * var(--fs, 1))}.topic-copy i{height:6px;margin-top:14px;overflow:hidden;border-radius:99px;background:#e8edf0}.topic-copy em{height:100%;display:block;border-radius:inherit;background:linear-gradient(90deg,var(--grade-color),var(--blue))}.topic-copy>span{margin-top:5px;color:#8794a6;font-size: calc(12.5px * var(--fs, 1))}.topic-card>strong{position:absolute;right:11px;bottom:11px;color:#53709b;font-size: calc(12.5px * var(--fs, 1))}.topic-card.active>strong{color:#c26423}
.daily-card{position:relative;overflow:hidden;display:flex;flex-direction:column;align-items:center;padding:27px 24px;color:#fff;background:radial-gradient(circle at 85% 8%,rgba(84,222,255,.24),transparent 25%),linear-gradient(145deg,#272064,#142b55);text-align:center}.daily-card:before{content:"";position:absolute;width:180px;height:180px;left:-105px;bottom:-100px;border:24px solid rgba(255,212,63,.1);border-radius:50%}.daily-label{align-self:flex-start;padding:5px 8px;color:#08172c;border:2px solid #08172c;border-radius:8px;background:var(--yellow);box-shadow:3px 3px 0 #9b62e9;font-size: calc(13px * var(--fs, 1));font-weight:950;transform:rotate(-2deg)}.daily-icon{width:78px;height:78px;display:grid;place-items:center;margin:17px 0 10px;border:3px solid #08172c;border-radius:25px;background:var(--grade-color);box-shadow:6px 6px 0 #061125,9px 9px 0 var(--blue);font-size: calc(39px * var(--fs, 1));transform:rotate(3deg)}.daily-card h2{margin:8px 0 5px;font-size: calc(20px * var(--fs, 1))}.daily-card>p{margin:0;color:#b9cae7;font-size: calc(13.5px * var(--fs, 1))}.daily-route{display:flex;align-items:center;gap:5px;margin:21px 0;color:#9aadd0;font-size: calc(12.5px * var(--fs, 1));font-weight:800}.daily-route span{padding:4px 6px;border-radius:7px;background:#0d2045}.daily-route .done{color:#0a2430;background:#75e1bd}.daily-route i{width:12px;border-top:2px dotted #577094}.start-button{width:100%;min-height:52px;display:flex;align-items:center;justify-content:center;gap:8px;border:2px solid #07172f;border-radius:15px;color:#07172f;background:linear-gradient(90deg,var(--yellow),#ff9c47);box-shadow:0 5px 0 #bd5b2f,4px 8px 0 #050d1d;font-weight:950}.start-button:hover{transform:translateY(-2px);box-shadow:0 7px 0 #bd5b2f,6px 11px 0 #050d1d}.start-button svg{fill:currentColor}.daily-card>small{margin-top:14px;color:#91a7c9;font-size: calc(12.5px * var(--fs, 1));line-height:1.5}
.round-meter{width:100%;margin:17px 0 0;padding:10px 12px;border:1px solid #43558b;border-radius:12px;background:rgba(5,17,44,.38);text-align:left}.round-meter span{display:flex;justify-content:space-between;color:#bcd0ec;font-size: calc(13px * var(--fs, 1));font-weight:850}.round-meter b{color:var(--yellow);font-size: calc(14.5px * var(--fs, 1))}.round-meter i{height:6px;display:block;overflow:hidden;margin-top:7px;border-radius:99px;background:#0a1837}.round-meter em{height:100%;display:block;border-radius:inherit;background:linear-gradient(90deg,var(--grade-color),var(--yellow));transition:width .25s}
.math-stats{display:grid;grid-template-columns:repeat(4,1fr);margin-top:20px;padding:12px;color:var(--ink);background:#fffdf7}.math-stats article{min-height:72px;display:flex;align-items:center;justify-content:center;gap:10px;border-right:1px dashed #dfe4e8}.math-stats article:last-child{border-right:0}.math-stats article>span{font-size: calc(25px * var(--fs, 1))}.math-stats div{display:flex;flex-direction:column}.math-stats small{color:var(--muted);font-size: calc(12.5px * var(--fs, 1))}.math-stats strong{margin-top:2px;font-size: calc(20px * var(--fs, 1))}
.quiz-view{width:min(850px,100%);margin:10px auto}.quiz-header{display:grid;grid-template-columns:auto 1fr auto;gap:14px;align-items:center}.quiz-header button{display:flex;align-items:center;gap:6px;padding:8px 10px;border:0;border-radius:11px;color:#9eb3cf;background:transparent;font-size: calc(13.5px * var(--fs, 1));font-weight:850}.quiz-header button:hover{color:#fff;background:#17365b}.quiz-track{height:10px;overflow:hidden;border:1px solid #2c4b70;border-radius:99px;background:#0b213d}.quiz-track i{height:100%;display:block;border-radius:inherit;background:linear-gradient(90deg,var(--grade-color),var(--blue),var(--yellow));transition:width .3s}.quiz-header>span{color:#a8bdd8;font-size: calc(13.5px * var(--fs, 1));font-weight:900}.quiz-stage{min-height:620px;position:relative;display:flex;flex-direction:column;align-items:center;margin-top:20px;padding:45px 50px;border:3px solid #0b1b32;border-radius:30px;color:var(--ink);background:radial-gradient(circle,rgba(22,49,79,.055) 1.2px,transparent 1.5px) 0 0/14px 14px,#fffdf7;box-shadow:10px 10px 0 #020914,0 22px 45px rgba(0,0,0,.28);text-align:center}.quiz-stage:before{content:"";position:absolute;width:190px;height:190px;right:-105px;top:-105px;border:28px solid color-mix(in srgb,var(--grade-color) 25%,transparent);border-radius:50%}.solved-badge{position:absolute;right:25px;top:22px;padding:6px 10px;color:#09182c;border:2px solid #09182c;border-radius:9px;background:var(--yellow);box-shadow:3px 3px 0 var(--purple);font-family:Impact,sans-serif;font-size: calc(14px * var(--fs, 1));transform:rotate(2deg)}.question-skill{padding:6px 10px;color:#10233d;border:2px solid #10233d;border-radius:99px;background:var(--grade-color);font-size: calc(13px * var(--fs, 1));font-weight:950}.quiz-stage h1{max-width:720px;margin:20px 0 17px;font-size:clamp(25px,4vw,40px);line-height:1.35}.question-scene{min-width:150px;min-height:105px;display:grid;place-items:center;margin-bottom:24px;padding:15px 25px;border:4px solid #11243e;border-radius:24px;background:linear-gradient(145deg,#eafbff,#fff2be);box-shadow:7px 7px 0 var(--grade-color);font-size: calc(47px * var(--fs, 1));letter-spacing:.08em}.answer-grid{width:min(650px,100%);display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.answer-grid button{min-height:69px;display:flex;align-items:center;gap:13px;padding:10px 15px;border:3px solid #132640;border-radius:16px;color:#1d304c;background:#fff;box-shadow:4px 4px 0 #d3dce4;font-weight:900;transition:.15s}.answer-grid button:hover{box-shadow:5px 6px 0 var(--blue);transform:translateY(-2px)}.answer-grid button>span{width:34px;height:34px;display:grid;place-items:center;border-radius:10px;background:#e9f1f7;font-size: calc(13.5px * var(--fs, 1))}.answer-grid button>b{font-size: calc(18px * var(--fs, 1))}.answer-grid button.correct{border-color:#164435;background:#e2f8f0;box-shadow:4px 4px 0 var(--green)}.answer-grid button.wrong{border-color:#712b36;background:#fff0f1;box-shadow:4px 4px 0 var(--red)}.answer-grid button:disabled{cursor:default;transform:none}.answer-feedback{width:min(650px,100%);display:grid;grid-template-columns:auto 1fr auto;gap:12px;align-items:center;margin-top:20px;padding:14px;border:3px solid #174536;border-radius:17px;background:#e4f8f1;box-shadow:5px 5px 0 #1b4439;text-align:left}.answer-feedback.wrong{border-color:#6c2932;background:#fff0f1;box-shadow:5px 5px 0 #6c2932}.answer-feedback>span{width:42px;height:42px;display:grid;place-items:center;color:#fff;border-radius:13px;background:var(--green);font-size: calc(20px * var(--fs, 1));font-weight:950}.answer-feedback.wrong>span{background:var(--red)}.answer-feedback h2{margin:0;font-size: calc(14px * var(--fs, 1))}.answer-feedback p{margin:4px 0 0;color:#617186;font-size: calc(13.5px * var(--fs, 1))}.answer-feedback button{min-height:42px;padding:0 16px;border:0;border-radius:12px;color:#fff;background:#2aa980;font-weight:900}.answer-feedback.wrong button{background:#e45e6c}
.result-view{width:min(680px,100%);margin:25px auto}.result-card{position:relative;overflow:hidden;padding:42px;border:3px solid #0a1b32;border-radius:31px;color:var(--ink);background:radial-gradient(circle at 90% 15%,rgba(73,218,255,.2),transparent 22%),#fffdf7;box-shadow:10px 10px 0 #020914,0 24px 50px rgba(0,0,0,.3);text-align:center}.result-burst{position:absolute;right:25px;top:23px;padding:10px;color:#07172f;border:3px solid #07172f;background:var(--yellow);clip-path:polygon(5% 20%,25% 22%,31% 2%,45% 18%,60% 0,68% 19%,91% 10%,85% 34%,100% 48%,82% 61%,94% 84%,68% 78%,56% 100%,42% 80%,18% 94%,20% 68%,0 55%,17% 40%);font-family:Impact,sans-serif;font-size: calc(14.5px * var(--fs, 1));transform:rotate(8deg)}.result-mascot{width:90px;height:90px;display:grid;place-items:center;margin:0 auto 16px;border:4px solid #10223d;border-radius:30px;background:linear-gradient(145deg,#e6fbff,#fff0b8);box-shadow:7px 7px 0 var(--grade-color);font-size: calc(50px * var(--fs, 1));transform:rotate(-3deg)}.result-card>span{color:#df6c2e;font-size: calc(13.5px * var(--fs, 1));font-weight:950;letter-spacing:.1em}.result-card h1{margin:8px 0;font-size: calc(28px * var(--fs, 1))}.result-card>p{margin:0;color:var(--muted);font-size: calc(14px * var(--fs, 1))}.result-stats{display:grid;grid-template-columns:repeat(3,1fr);margin:26px 0;border:2px solid #e1e6e9;border-radius:18px;background:#f7f9fa}.result-stats div{display:flex;flex-direction:column;padding:18px;border-right:1px dashed #d8dee3}.result-stats div:last-child{border:0}.result-stats strong{color:#315da8;font-size: calc(24px * var(--fs, 1))}.result-stats span{margin-top:3px;color:var(--muted);font-size: calc(13px * var(--fs, 1))}.result-actions{display:grid;grid-template-columns:1fr 1fr;gap:11px}.result-actions button{min-height:50px;border:2px solid #10223d;border-radius:14px;font-weight:900}.result-actions button:first-child{color:#315da8;background:#e8f2ff;box-shadow:4px 4px 0 #75b7ff}.result-actions button:last-child{color:#10223d;background:var(--yellow);box-shadow:4px 4px 0 #e59239}
.math-toast{position:fixed;z-index:60;left:50%;bottom:28px;max-width:calc(100% - 36px);padding:11px 17px;color:#fff;border-radius:12px;background:#263c59;box-shadow:0 10px 30px rgba(0,0,0,.25);font-size: calc(13.5px * var(--fs, 1));font-weight:850;opacity:0;transform:translate(-50%,15px);pointer-events:none;transition:.2s}.math-toast.show{opacity:1;transform:translate(-50%,0)}[hidden]{display:none!important}button:focus-visible,a:focus-visible{outline:3px solid rgba(75,214,255,.5);outline-offset:3px}
@media(max-width:900px){.math-shell{width:min(100% - 28px,700px);margin-top:15px}.math-hero{min-height:380px;align-items:flex-start;padding:29px}.hero-copy{width:100%}.hero-orbit{width:240px;height:185px;right:8%;bottom:5px}.hero-orbit div{width:92px;height:92px;font-size: calc(50px * var(--fs, 1))}.grade-grid{grid-template-columns:repeat(3,1fr)}.math-layout{grid-template-columns:1fr}.daily-card{min-height:350px}.math-stats{grid-template-columns:repeat(2,1fr)}.math-stats article:nth-child(2){border-right:0}.math-stats article:nth-child(-n+2){border-bottom:1px dashed #dfe4e8}}
@media(max-width:560px){.math-topbar{height:65px;padding:0 12px}.back-link span,.math-brand small,.top-score small{display:none}.back-link{padding:8px}.math-brand b{font-size: calc(14px * var(--fs, 1))}.brand-mark{width:38px;height:38px}.math-shell{width:calc(100% - 20px)}.math-hero{min-height:420px;padding:24px 20px}.math-hero h1{font-size: calc(28px * var(--fs, 1))}.hero-orbit{width:230px;right:calc(50% - 115px);bottom:8px}.grade-grid{grid-template-columns:repeat(2,1fr)}.grade-grid button{min-height:94px}.section-heading>small{display:none}.topic-grid{grid-template-columns:1fr}.mission-panel{padding:16px}.math-stats article{justify-content:flex-start;padding-left:16px}.quiz-header button span{display:none}.quiz-stage{min-height:600px;padding:35px 16px;border-radius:24px}.quiz-stage h1{font-size: calc(25px * var(--fs, 1))}.question-scene{min-height:90px;font-size: calc(38px * var(--fs, 1))}.answer-grid{grid-template-columns:1fr}.answer-grid button{min-height:58px}.answer-feedback{grid-template-columns:auto 1fr}.answer-feedback button{grid-column:1/-1;min-height:44px}.result-card{padding:38px 18px}.result-card h1{font-size: calc(24px * var(--fs, 1))}.result-actions{grid-template-columns:1fr}.result-burst{right:12px;top:12px}}

/* Keep the page heading consistent with the other learning modules. */
.math-hero h1{font-weight:900;line-height:1.15;text-shadow:none}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}

/* V2 learning diagnosis, hints and persistent mistake review. */
.recommend-reason{width:100%;margin:10px 0 0!important;padding:9px 10px;border:1px solid rgba(49,93,168,.18);border-radius:11px;color:#52657f!important;background:rgba(232,242,255,.78);font-size: calc(13px * var(--fs, 1))!important;line-height:1.55;text-align:left}
.recommend-switch{align-self:flex-start;margin-top:8px;padding:6px 9px;border:1px solid #ccd9e8;border-radius:9px;color:#315da8;background:#f3f8ff;font-size: calc(13px * var(--fs, 1));font-weight:900}
.topic-card-state{position:absolute;right:34px;top:9px;padding:3px 6px;border-radius:99px;color:#69798e;background:#eef2f4;font-size: calc(12px * var(--fs, 1));font-weight:950;letter-spacing:.03em}
.topic-card.recommended .topic-card-state{color:#805313;background:#fff0b6}
.topic-card.weak .topic-card-state{color:#923d49;background:#ffe4e7}
.topic-card.complete .topic-card-state{color:#256f58;background:#ddf5ea}
.topic-card .topic-copy>b{padding-right:72px}
.topic-card .topic-copy>i{position:relative}
.topic-card .topic-copy>i:after{content:"关卡进度";position:absolute;right:0;top:-13px;color:#9aa6b5;font-size: calc(12px * var(--fs, 1));font-style:normal}

.mistake-review{margin-top:20px;padding:22px;border:1px solid #e4e6e7;border-radius:24px;color:var(--ink);background:#fffdf8;box-shadow:0 10px 26px rgba(56,64,79,.06)}
.mistake-review-head{display:flex;align-items:center;justify-content:space-between;gap:20px}
.mistake-review-head>div>span{color:#d66e3c;font-size: calc(13px * var(--fs, 1));font-weight:950;letter-spacing:.08em}
.mistake-review-head h2{margin:4px 0 3px;font-size: calc(20px * var(--fs, 1))}
.mistake-review-head p{margin:0;color:var(--muted);font-size: calc(13.5px * var(--fs, 1));line-height:1.5}
.mistake-review-head>button{min-height:43px;padding:0 14px;border:1px solid #1f3856;border-radius:13px;color:#fff;background:#315da8;box-shadow:0 4px 0 #1f3856;font-size: calc(13.5px * var(--fs, 1));font-weight:900}
.mistake-review-head>button:disabled{color:#8793a3;border-color:#d9dee3;background:#edf0f2;box-shadow:none;cursor:default}
.mistake-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;margin-top:15px}
.mistake-list article{min-width:0;padding:11px 12px;border:1px solid #e2e6e9;border-radius:13px;background:#fff}
.mistake-list article.unresolved{border-color:#f0c8cd;background:#fff8f8}
.mistake-list article>div{display:flex;align-items:center;justify-content:space-between;gap:8px}
.mistake-list article span{color:#687a91;font-size: calc(12.5px * var(--fs, 1));font-weight:850}
.mistake-list article strong{padding:3px 6px;border-radius:99px;color:#34745f;background:#e3f5ed;font-size: calc(12px * var(--fs, 1))}
.mistake-list article.unresolved strong{color:#983f4b;background:#ffe6e9}
.mistake-list article>b{display:block;margin-top:8px;overflow:hidden;font-size: calc(13.5px * var(--fs, 1));text-overflow:ellipsis;white-space:nowrap}
.mistake-list article>small{display:block;margin-top:4px;color:#8a96a5;font-size: calc(12.5px * var(--fs, 1))}
.mistake-empty{grid-column:1/-1;margin:0;padding:16px;border:1px dashed #d9dee3;border-radius:13px;color:#7c899a;background:#f8f9f9;font-size: calc(13.5px * var(--fs, 1));text-align:center}

.quiz-stage{overflow:hidden}
.question-scene{display:flex;flex-direction:column;gap:5px;letter-spacing:0}
.question-scene .question-visual{font-size: calc(45px * var(--fs, 1));line-height:1.1}
.question-scene small{color:#53677e;font-size: calc(13px * var(--fs, 1));font-weight:900;letter-spacing:.08em}
.question-support{width:min(650px,100%);display:flex;flex-direction:column;align-items:center;margin:-8px 0 14px}
.question-support button{min-height:34px;padding:0 11px;border:1px solid #d6dfe7;border-radius:99px;color:#526982;background:#f5f8fa;font-size: calc(13px * var(--fs, 1));font-weight:900}
.question-support button:hover{color:#315da8;border-color:#9dbce0;background:#edf5ff}
.question-support p{width:100%;margin:8px 0 0;padding:10px 12px;border:1px solid #ecd99c;border-radius:12px;color:#70591b;background:#fff9df;font-size: calc(13.5px * var(--fs, 1));line-height:1.55;text-align:left}

.result-stats{grid-template-columns:repeat(4,1fr)}
.result-review{margin:0 0 18px;padding:15px;border:1px solid #e1e6e9;border-radius:16px;background:#fafbfb;text-align:left}
.result-review>div:first-child>span{color:#d66e3c;font-size: calc(12.5px * var(--fs, 1));font-weight:950;letter-spacing:.08em}
.result-review h2{margin:3px 0 10px;font-size: calc(14px * var(--fs, 1))}
.result-review>div:last-child{display:grid;gap:7px}
.result-review article{display:grid;grid-template-columns:auto 1fr;gap:9px;align-items:center;padding:8px 9px;border:1px solid #e4e7e9;border-radius:11px;background:#fff}
.result-review article>span{min-width:58px;padding:4px 6px;border-radius:99px;color:#2e755e;background:#e1f4ec;font-size: calc(12.5px * var(--fs, 1));font-weight:950;text-align:center}
.result-review article.unresolved>span{color:#9a3e4a;background:#ffe5e8}
.result-review article div{min-width:0;display:flex;flex-direction:column}
.result-review article b{overflow:hidden;font-size: calc(13.5px * var(--fs, 1));text-overflow:ellipsis;white-space:nowrap}
.result-review article small{margin-top:2px;color:#8995a4;font-size: calc(12.5px * var(--fs, 1))}
.result-next{margin:0 0 16px!important;padding:10px 12px;border-radius:12px;color:#3f5878!important;background:#eef5fb;font-size: calc(13.5px * var(--fs, 1))!important;line-height:1.55;text-align:left}
.result-actions{grid-template-columns:repeat(3,1fr)}
.result-actions button:first-child{color:#933d49;background:#fff0f2;box-shadow:4px 4px 0 #ef9ba5}
.result-actions #retryMath{color:#315da8;background:#e8f2ff;box-shadow:4px 4px 0 #75b7ff}
.result-actions #backMath{color:#10223d;background:var(--yellow);box-shadow:4px 4px 0 #e59239}

@media(max-width:700px){.mistake-review{padding:17px}.mistake-review-head{align-items:flex-start;flex-direction:column}.mistake-review-head>button{width:100%}.mistake-list{grid-template-columns:1fr}.result-stats{grid-template-columns:repeat(2,1fr)}.result-stats div:nth-child(2){border-right:0}.result-stats div:nth-child(-n+2){border-bottom:1px dashed #d8dee3}.result-actions{grid-template-columns:1fr}.topic-card .topic-copy>b{padding-right:68px}}

/* V3 interactive math labs — prediction, manipulation, answer and explanation. */
.daily-lab{width:100%;margin-top:9px!important;padding:7px 9px;border:1px solid rgba(117,225,189,.25);border-radius:10px;color:#a9efd8!important;background:rgba(13,54,69,.45);font-size: calc(13px * var(--fs, 1))!important;font-weight:850;text-align:left}
.topic-copy mark{width:max-content;max-width:100%;margin-top:7px;padding:3px 6px;overflow:hidden;border-radius:6px;color:#32644f;background:#e5f6ee;font-size: calc(12.5px * var(--fs, 1));font-weight:850;text-overflow:ellipsis;white-space:nowrap}
.topic-copy i{margin-top:9px}
.math-stats{grid-template-columns:repeat(5,1fr)}

.quiz-view{width:min(960px,100%)}
.quiz-stage{min-height:720px;padding:38px 42px}
.thinking-path{width:min(690px,100%);display:flex;align-items:center;justify-content:center;gap:6px;margin-top:14px;color:#8997a8;font-size: calc(12.5px * var(--fs, 1));font-weight:900}
.thinking-path span{padding:4px 7px;border-radius:99px;background:#edf1f3;transition:.2s}
.thinking-path span.active{color:#163a36;background:#ccefe4;box-shadow:inset 0 0 0 1px #83cfb7}
.thinking-path span.done{color:#436b5f;background:#e3f3ed}
.thinking-path i{width:18px;border-top:2px dotted #c7d0d8}
.quiz-stage h1{margin:17px 0 14px}
.math-lab{width:min(760px,100%);margin-bottom:16px;padding:15px;border:2px solid #16304d;border-radius:22px;background:linear-gradient(160deg,#f0fbff,#fff9e9);box-shadow:6px 6px 0 color-mix(in srgb,var(--grade-color) 60%,#b6c6d5);text-align:left}
.math-lab>header{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:0 2px 11px;border-bottom:1px dashed #b9cbd7}
.math-lab>header>div{display:flex;flex-direction:column}
.math-lab>header span,.answer-heading span{color:#387d67;font-size: calc(12.5px * var(--fs, 1));font-weight:950;letter-spacing:.08em}
.math-lab h2{margin:3px 0 0;font-size: calc(15px * var(--fs, 1))}
.math-lab>header button{padding:6px 9px;border:1px solid #b7c7d2;border-radius:9px;color:#526b7e;background:#fff;font-size: calc(12.5px * var(--fs, 1));font-weight:900}
.math-lab>p{margin:10px 3px 8px;color:#5f7385;font-size: calc(13px * var(--fs, 1));line-height:1.5}
.lab-canvas{min-height:190px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:14px;border:1px solid #ccdae2;border-radius:15px;background:radial-gradient(circle,rgba(61,116,148,.12) 1px,transparent 1.4px) 0 0/12px 12px,rgba(255,255,255,.8);overflow:hidden}
.math-lab>footer{display:grid;grid-template-columns:auto 1fr;gap:8px;align-items:center;margin-top:9px;padding:8px 10px;border-radius:11px;color:#53647a;background:#fff6cc}
.math-lab>footer span{font-size: calc(16px * var(--fs, 1))}
.math-lab>footer p{margin:0;font-size: calc(13px * var(--fs, 1));font-weight:750;line-height:1.45}
.lab-actions{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin-top:13px}
.lab-actions button{min-height:36px;padding:0 12px;border:1px solid #9fb3c2;border-radius:10px;color:#38536a;background:#fff;box-shadow:0 2px 0 #c7d3db;font-size: calc(13px * var(--fs, 1));font-weight:900}
.lab-actions button.primary{color:#0b332b;border-color:#3aa484;background:#c8f0e3;box-shadow:0 3px 0 #65baa1}
.lab-actions button.lab-use-answer{color:#132e4d;border:2px solid #173b60;background:#ffdc62;box-shadow:0 3px 0 #d89438}
.model-readout{margin:9px 0 0;color:#3c5d75;font-size: calc(13.5px * var(--fs, 1));font-weight:850;text-align:center}

.number-line-model{width:min(680px,95%);padding:28px 15px 0}
.number-line-track{height:54px;position:relative;border-top:5px solid #345a74}
.number-line-track:before,.number-line-track:after{content:"";position:absolute;top:-10px;border:7px solid transparent}
.number-line-track:before{left:-11px;border-right-color:#345a74}.number-line-track:after{right:-11px;border-left-color:#345a74}
.number-line-track>i{width:2px;height:12px;position:absolute;top:-4px;background:#69869a;transform:translateX(-50%)}
.number-line-track>i span{position:absolute;top:15px;left:50%;color:#637789;font-size: calc(12.5px * var(--fs, 1));font-style:normal;transform:translateX(-50%)}
.number-line-track>i.active{height:18px;background:#e47937}
.number-line-track>b{width:34px;height:34px;position:absolute;top:-48px;display:grid;place-items:center;border:2px solid #142f4d;border-radius:50%;color:#10223d;background:var(--yellow);box-shadow:3px 3px 0 #7e66db;transform:translateX(-50%)}
.number-line-track>b:after{content:"";width:8px;height:8px;position:absolute;left:11px;bottom:-5px;border-right:2px solid #142f4d;border-bottom:2px solid #142f4d;background:var(--yellow);transform:rotate(45deg)}
.jump-counter{margin-top:6px;color:#597083;font-size: calc(13px * var(--fs, 1));text-align:center}.jump-counter strong{color:#d36c30;font-size: calc(14px * var(--fs, 1))}

.lab-dots{display:flex;flex-wrap:wrap;align-content:flex-start;justify-content:center;gap:3px}
.lab-dots i{width:10px;height:10px;display:block;border:1px solid #173652;border-radius:50%;background:#f0c44c}
.lab-dots i.blue{background:#66b9ef}.lab-dots i.yellow{background:#f0c44c}
.lab-dots b{width:100%;color:#627a8e;font-size: calc(12.5px * var(--fs, 1));text-align:center}
.balance-model{width:min(560px,95%);padding:15px 10px 35px}
.balance-beam{height:112px;position:relative;display:flex;align-items:flex-end;justify-content:space-between;gap:65px;border-bottom:7px solid #37536b;transform-origin:center bottom;transition:.35s}
.balance-model.left-heavy .balance-beam{transform:rotate(-5deg)}.balance-model.right-heavy .balance-beam{transform:rotate(5deg)}
.balance-pan{width:42%;min-height:83px;display:flex;flex-direction:column;gap:7px;padding:8px;border:2px solid #31536c;border-radius:8px 8px 22px 22px;background:#fff;box-shadow:0 5px 0 #b9cad5}
.balance-pan>strong{text-align:center}.balance-pan .lab-dots{min-height:38px}
.balance-pivot{position:absolute;left:50%;bottom:-42px;color:#31536c;font-size: calc(48px * var(--fs, 1));transform:translateX(-50%) rotate(0)}

.shape-model{width:100%;display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
.shape-model button{min-height:95px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:7px;border:2px solid #b9c9d4;border-radius:14px;color:#33516a;background:#fff}
.shape-model button.selected{border-color:#285f78;background:#ddf5ef;box-shadow:3px 3px 0 #68bca3}
.shape-model i{color:#54a9d4;font-size: calc(31px * var(--fs, 1));font-style:normal}.shape-model b{font-size: calc(13px * var(--fs, 1))}

.number-cards{display:flex;align-items:center;justify-content:center;gap:14px}.number-cards b{padding:13px 17px;border:2px solid #36556d;border-radius:12px;background:#fff;box-shadow:3px 3px 0 #cad6dd;font-size: calc(22px * var(--fs, 1))}.number-cards em{color:#d56d31;font-size: calc(24px * var(--fs, 1));font-style:normal;font-weight:950}
.place-value-model{width:min(600px,100%)}.place-value-model>p{margin:10px 0 0;color:#536b80;font-size: calc(13.5px * var(--fs, 1));line-height:1.6;text-align:center}
.place-table{display:grid;gap:3px}.place-table>span,.place-table>b{display:grid;grid-auto-flow:column;grid-auto-columns:1fr;gap:3px}
.place-table i{padding:5px;color:#6b8294;border-radius:6px;background:#e7f0f4;font-size: calc(12.5px * var(--fs, 1));font-style:normal;text-align:center}
.place-table>b i{padding:9px 5px;color:#183b56;border:1px solid #aebfca;background:#fff;font-size: calc(16px * var(--fs, 1))}
.place-value-model.decimal .number-cards b{position:relative}.place-value-model.decimal .number-cards b:after{content:"先看清小数位";display:block;margin-top:3px;color:#cc6c37;font-size: calc(12px * var(--fs, 1));text-align:center}
.decimal-table{display:grid;gap:3px}.decimal-table>span,.decimal-table>b{display:grid;grid-template-columns:repeat(var(--decimal-columns),1fr);gap:3px;align-items:stretch}.decimal-table i,.decimal-table em{display:grid;place-items:center;padding:5px;border-radius:6px;color:#6b8294;background:#e7f0f4;font-size: calc(12.5px * var(--fs, 1));font-style:normal}.decimal-table>b i{padding:9px 5px;color:#183b56;border:1px solid #aebfca;background:#fff;font-size: calc(16px * var(--fs, 1))}.decimal-table>b em{color:#dc6f37;background:#fff4df;font-size: calc(19px * var(--fs, 1));font-weight:950}

.array-model{display:grid;grid-template-columns:repeat(var(--columns),22px);gap:4px;padding:10px;border:2px solid #5e7890;border-radius:13px;background:#fff}
.array-model i{width:22px;height:22px;border:2px solid #24506b;border-radius:6px;background:#8adbc3;transition:.2s}
.array-model.organized i:nth-child(2n){background:#7fc8ef}
.groups-model{width:100%;display:flex;flex-wrap:wrap;justify-content:center;gap:7px}
.groups-model>div{min-width:70px;max-width:120px;min-height:72px;display:flex;flex-direction:column;justify-content:center;gap:5px;padding:7px;border:2px dashed #7592a5;border-radius:14px;background:#fff}
.groups-model>div>b{color:#4c6a7e;font-size: calc(12.5px * var(--fs, 1));text-align:center}.groups-model .group-pile{width:min(480px,100%);max-width:none}

.clock-model{width:190px;height:190px;position:relative;border:9px solid #294d68;border-radius:50%;background:#fff;box-shadow:5px 6px 0 #9ec0d2,inset 0 0 0 4px #dceaf0}
.clock-model>i{width:22px;height:22px;position:absolute;left:calc(50% - 11px);top:calc(50% - 11px);display:grid;place-items:center;color:#47657a;font-size: calc(12.5px * var(--fs, 1));font-style:normal;transform:rotate(calc(var(--clock-index)*30deg)) translateY(-70px) rotate(calc(var(--clock-index)*-30deg))}
.clock-model .hour-hand{width:7px;height:58px;position:absolute;left:calc(50% - 3.5px);bottom:50%;border-radius:9px;background:#e2743a;transform:rotate(var(--hour-angle));transform-origin:center bottom;transition:.3s}
.clock-model>span{width:14px;height:14px;position:absolute;left:calc(50% - 7px);top:calc(50% - 7px);border-radius:50%;background:#254b67}

.ruler-model{width:min(650px,100%);text-align:center}.ruler-model>strong{color:#244e68;font-size: calc(18px * var(--fs, 1))}.ruler-model>div{height:60px;display:grid;grid-template-columns:repeat(21,1fr);margin-top:12px;border:3px solid #7a6023;border-radius:5px;background:#ffe176}.ruler-model i{height:23px;border-left:1px solid #806c3e;font-style:normal}.ruler-model i.major{height:40px;border-left-width:2px}.ruler-model i span{position:relative;top:40px;color:#735e2f;font-size: calc(12px * var(--fs, 1))}.ruler-model>b{display:block;margin-top:9px;color:#62778a;font-size: calc(13px * var(--fs, 1))}

.chart-model{width:min(520px,100%);height:160px;display:flex;align-items:flex-end;justify-content:center;gap:22px;padding:10px 20px 0;border-left:3px solid #45647b;border-bottom:3px solid #45647b}
.chart-model button{width:80px;height:100%;display:flex;flex-direction:column;justify-content:flex-end;padding:0;border:0;background:transparent}
.chart-model button>span{min-height:12px;display:flex;align-items:flex-start;justify-content:center;padding-top:4px;border:2px solid #31536d;border-bottom:0;border-radius:7px 7px 0 0;transition:.2s}.chart-model button>span.red{background:#f58b91}.chart-model button>span.blue{background:#7fc7ef}.chart-model button>span.green{background:#80d6b8}.chart-model button.selected>span{filter:saturate(1.3);box-shadow:0 0 0 4px #ffe58a}.chart-model button b{font-size: calc(13.5px * var(--fs, 1))}.chart-model button i{padding:5px;color:#4e6578;font-size: calc(12.5px * var(--fs, 1));font-style:normal}

.fraction-model{width:min(620px,100%);display:grid;gap:12px}.fraction-row{display:grid;grid-template-columns:44px 1fr;gap:9px;align-items:center}.fraction-row>b{font-size: calc(14px * var(--fs, 1));text-align:right}.fraction-row>span{display:grid;grid-template-columns:repeat(var(--fraction-columns),1fr);height:42px;border:2px solid #31526a;border-radius:8px;overflow:hidden}.fraction-row i{border-right:1px solid #7690a2;background:#fff}.fraction-row i.filled{background:#79d2b5}.fraction-row .tone-1 i.filled{background:#76bced}.fraction-model.active .fraction-row>span{box-shadow:3px 3px 0 #f0c955}.fraction-overlap{padding:7px;border-radius:9px;color:#315b50;background:#dff4ec;font-size: calc(13px * var(--fs, 1));text-align:center}

.area-decompose-model{width:min(620px,100%)}.area-whole{height:130px;display:flex;align-items:center;justify-content:center;gap:14px;border:3px solid #2e5870;border-radius:12px;background:linear-gradient(135deg,#8bd8c1,#81c6ed)}.area-whole b{font-size: calc(25px * var(--fs, 1))}.area-whole span{font-size: calc(20px * var(--fs, 1));font-weight:900}
.area-decompose-model.split{display:grid;grid-template-columns:repeat(3,minmax(75px,1fr));gap:5px}.area-decompose-model.split>i{min-height:58px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:6px;border:2px solid #46677d;border-radius:8px;background:#dff4ed;font-style:normal}.area-decompose-model.split>i:nth-child(2n){background:#dceef8}.area-decompose-model i span{font-size: calc(12.5px * var(--fs, 1))}.area-decompose-model i b{margin-top:3px;font-size: calc(14.5px * var(--fs, 1))}
.area-grid-model{text-align:center}.area-grid-model>div{max-width:100%;height:150px;position:relative;border:4px solid #31536a;background:repeating-linear-gradient(0deg,transparent 0 20px,rgba(49,83,106,.25) 21px),repeating-linear-gradient(90deg,#a6e0cd 0 20px,rgba(49,83,106,.25) 21px)}
.area-grid-model>div.shape-parallelogram{transform:skew(-15deg)}.area-grid-model>div.shape-triangle{clip-path:polygon(50% 0,100% 100%,0 100%)}.area-grid-model>div.active{background-color:#ffdf78;box-shadow:0 0 0 5px rgba(70,151,126,.22)}.area-grid-model>div.shape-perimeter.active{background:#fff;box-shadow:inset 0 0 0 7px #f2a54b}
.area-grid-model span{position:absolute;left:50%;bottom:-21px;font-size: calc(12.5px * var(--fs, 1))}.area-grid-model>div>b{position:absolute;left:-25px;top:50%;font-size: calc(12.5px * var(--fs, 1))}.area-grid-model p{margin:23px 0 0;color:#587083;font-size: calc(13px * var(--fs, 1))}

.equation-model{width:min(600px,100%);position:relative;display:grid;grid-template-columns:1fr auto 1fr;gap:20px;align-items:end;padding:20px 30px 35px}.equation-model>div{min-height:76px;display:flex;align-items:center;justify-content:center;gap:8px;padding:10px;border:3px solid #36566d;border-radius:12px 12px 25px 25px;background:#fff;box-shadow:0 5px 0 #b5c7d2}.equation-model>b{align-self:center;font-size: calc(20px * var(--fs, 1))}.x-box{width:48px;height:48px;display:grid;place-items:center;border:2px solid #224b67;border-radius:10px;color:#193b55;background:#82d8bd;font-size: calc(20px * var(--fs, 1));font-weight:950}.equation-model .balance-line{height:7px;position:absolute;left:8%;right:8%;bottom:26px;background:#34556d}.equation-model .balance-line:after{content:"▲";position:absolute;left:50%;top:0;color:#34556d;font-size: calc(36px * var(--fs, 1));transform:translateX(-50%)}.equation-model.solved>div{background:#e5f6ef}

.hundred-model{display:flex;align-items:center;gap:20px}.hundred-model>div{width:170px;height:170px;display:grid;grid-template-columns:repeat(10,1fr);border:2px solid #31536a}.hundred-model i{border:1px solid #aabdc8;background:#fff}.hundred-model i.filled{background:#73d1b3}.hundred-model p{width:150px;display:flex;flex-direction:column;margin:0}.hundred-model p b{color:#2f8067;font-size: calc(25px * var(--fs, 1))}.hundred-model p span{margin-top:6px;color:#617789;font-size: calc(13px * var(--fs, 1));line-height:1.45}

.ratio-model{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:12px}.ratio-model>div{width:min(230px,40%);min-height:90px;display:flex;flex-direction:column;justify-content:center;gap:7px;padding:8px;border:2px solid #537188;border-radius:14px;background:#fff}.ratio-model>div>b{font-size: calc(12.5px * var(--fs, 1));text-align:center}.ratio-model>span{font-size: calc(24px * var(--fs, 1));font-weight:950}.ratio-model>p{width:100%;margin:0;padding:7px;border-radius:9px;color:#3e6458;background:#ddf3eb;font-size: calc(13px * var(--fs, 1));text-align:center}

.circle-model{text-align:center}.circle-model>div{width:180px;height:180px;position:relative;border:5px solid #31546d;border-radius:50%;background:radial-gradient(circle,#fff 0 4px,transparent 5px),#dff3f8}.circle-model i{width:78px;position:absolute;left:50%;top:50%;border-top:4px solid #e4773d;transform:rotate(-25deg);transform-origin:left center}.circle-model span{position:absolute;left:54%;top:37%;padding:3px 5px;border-radius:5px;background:#fff;font-size: calc(12.5px * var(--fs, 1))}.circle-model>p{margin:10px 0 0;color:#315f51;font-size: calc(14.5px * var(--fs, 1));font-weight:950}.fallback-model{font-size: calc(50px * var(--fs, 1))}

.answer-heading{width:min(650px,100%);display:flex;align-items:center;justify-content:space-between;margin:1px 0 8px}.answer-heading small{color:#8997a7;font-size: calc(12.5px * var(--fs, 1))}
.result-stats{grid-template-columns:repeat(5,1fr)}

@media(max-width:900px){.math-stats{grid-template-columns:repeat(3,1fr)}.math-stats article{border-bottom:1px dashed #dfe4e8}.math-stats article:nth-child(3){border-right:0}.math-stats article:nth-child(n+4){border-bottom:0}.quiz-stage{padding:34px 24px}.shape-model{grid-template-columns:repeat(3,1fr)}}
@media(max-width:700px){.result-stats{grid-template-columns:repeat(2,1fr)}.result-stats div{border-bottom:1px dashed #d8dee3}.result-stats div:nth-child(2n){border-right:0}.result-stats div:last-child{grid-column:1/-1;border-bottom:0}.result-stats div:nth-child(-n+2){border-bottom:1px dashed #d8dee3}}
@media(max-width:560px){.quiz-stage{padding:27px 10px}.thinking-path{gap:2px}.thinking-path span{padding:4px;font-size: calc(12px * var(--fs, 1))}.thinking-path i{width:5px}.math-lab{padding:10px;border-radius:17px}.math-lab>header{align-items:flex-start}.lab-canvas{min-height:180px;padding:10px}.shape-model{grid-template-columns:repeat(2,1fr)}.shape-model button{min-height:78px}.balance-beam{gap:20px}.number-line-track>i span{font-size: calc(12px * var(--fs, 1))}.array-model{grid-template-columns:repeat(var(--columns),18px)}.array-model i{width:18px;height:18px}.chart-model{gap:8px;padding-left:8px;padding-right:8px}.chart-model button{width:65px}.hundred-model{flex-direction:column}.ratio-model>div{width:43%}.answer-heading{align-items:flex-start;flex-direction:column;gap:4px}.math-stats{grid-template-columns:repeat(2,1fr)}.math-stats article:nth-child(3){border-right:1px dashed #dfe4e8}.math-stats article:nth-child(2n){border-right:0}.math-stats article:nth-child(n+4){border-bottom:1px dashed #dfe4e8}.math-stats article:last-child{grid-column:1/-1;border:0}.result-stats strong{font-size: calc(20px * var(--fs, 1))}.math-quiz-active .study-tools{display:none}}

/* Separate top-level menus for practice and the embedded PhET library. */
.math-mode-nav{position:relative;z-index:2;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:22px 0 4px;padding:8px;border:2px solid #203e61;border-radius:22px;background:#0a203c;box-shadow:6px 6px 0 #020914}
.math-mode-nav button{min-width:0;display:flex;align-items:center;gap:12px;padding:14px 18px;border:2px solid transparent;border-radius:15px;color:#9fb6d0;background:transparent;text-align:left;transition:.16s}
.math-mode-nav button:hover{color:#fff;background:#133356}.math-mode-nav button.active{color:#10223d;border-color:#10223d;background:linear-gradient(115deg,#fff9cf,#a9f0de);box-shadow:4px 4px 0 var(--yellow)}
.math-mode-nav button>span:first-child{font-size: calc(28px * var(--fs, 1))}.math-mode-nav button>span:last-child{min-width:0;display:flex;flex-direction:column}.math-mode-nav b{font-size: calc(14px * var(--fs, 1))}.math-mode-nav small{margin-top:3px;font-size: calc(12.5px * var(--fs, 1));opacity:.78}
.math-stats{grid-template-columns:repeat(5,1fr)}

.phet-library{margin-top:24px}.math-phet-active .study-tools{display:none}
.phet-library-hero{display:flex;align-items:center;justify-content:space-between;gap:30px;padding:28px 30px;border:3px solid #0b1c32;border-radius:26px;color:var(--ink);background:radial-gradient(circle at 90% 10%,rgba(69,210,170,.24),transparent 28%),linear-gradient(130deg,#fffdf7,#effbff);box-shadow:8px 8px 0 #020914}
.phet-library-hero>div:first-child{max-width:700px}.phet-library-hero>div:first-child>span{color:#2b8167;font-size: calc(13.5px * var(--fs, 1));font-weight:950;letter-spacing:.08em}.phet-library-hero h2{margin:7px 0 6px;font-size: calc(28px * var(--fs, 1))}.phet-library-hero p{margin:0;color:#5c7085;font-size: calc(14.5px * var(--fs, 1));line-height:1.65}
.phet-library-stats{flex:none;display:grid;grid-template-columns:auto auto;gap:4px 11px;align-items:baseline;padding:15px 18px;border:2px solid #183452;border-radius:17px;background:#102b4a;color:#fff}.phet-library-stats strong{color:#ffe078;font-size: calc(25px * var(--fs, 1));text-align:right}.phet-library-stats span{color:#bfd0e1;font-size: calc(13.5px * var(--fs, 1))}
.phet-grade-section{margin-top:30px}.phet-grade-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:9px}
.phet-grade-grid button{min-width:0;min-height:98px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:13px 6px;border:2px solid #284465;border-radius:16px;color:#b8c9dc;background:#0c2646;box-shadow:3px 3px 0 #020a15;transition:.16s}
.phet-grade-grid button:hover{color:#fff;transform:translateY(-2px)}.phet-grade-grid button.active{color:#0d2038;border-color:#0d2038;background:var(--grade-color);box-shadow:4px 4px 0 var(--yellow)}
.phet-grade-grid button span{font-size: calc(27px * var(--fs, 1))}.phet-grade-grid button b{margin-top:4px;font-size: calc(14.5px * var(--fs, 1))}.phet-grade-grid button small{margin-top:3px;font-size: calc(13.5px * var(--fs, 1));opacity:.86}
.phet-grade-guide{position:relative;overflow:hidden;margin-top:18px;padding:24px 27px;border:2px solid #d2e0e7;border-radius:21px;color:var(--ink);background:linear-gradient(125deg,#edf9f6,#f5f2ff);box-shadow:5px 5px 0 #061426}
.phet-grade-guide:after{content:"PhET";position:absolute;right:20px;bottom:-18px;color:rgba(33,74,104,.07);font-family:Impact,sans-serif;font-size: calc(76px * var(--fs, 1));letter-spacing:.05em}.phet-grade-guide>span{color:#337b68;font-size: calc(13.5px * var(--fs, 1));font-weight:950}.phet-grade-guide h2{margin:5px 0;font-size: calc(22px * var(--fs, 1))}.phet-grade-guide p{position:relative;z-index:1;max-width:780px;margin:0;color:#536b82;font-size: calc(14px * var(--fs, 1));line-height:1.6}.phet-grade-guide strong{position:relative;z-index:1;display:inline-block;margin-top:11px;padding:6px 9px;border-radius:8px;color:#315e7c;background:#fff;font-size: calc(13.5px * var(--fs, 1))}
.phet-filter-panel{margin-top:22px;padding:20px;border:2px solid #263f5e;border-radius:21px;color:#eaf5ff;background:#0c2646;box-shadow:5px 5px 0 #020914}.phet-filter-panel>header{display:flex;align-items:flex-end;justify-content:space-between;gap:16px}.phet-filter-panel header span{color:#80dfc2;font-size: calc(13.5px * var(--fs, 1));font-weight:950;letter-spacing:.08em}.phet-filter-panel h2{margin:4px 0 0;font-size: calc(19px * var(--fs, 1))}.phet-filter-panel header p{margin:0;color:#c6d6e7;font-size: calc(14px * var(--fs, 1))}
.phet-subject-filters{display:flex;flex-wrap:wrap;gap:8px;margin-top:15px}.phet-subject-filters button{min-height:44px;display:flex;align-items:center;gap:6px;padding:7px 10px;border:1px solid #3d5877;border-radius:12px;color:#bfd0e3;background:#122f50;font-size: calc(13.5px * var(--fs, 1))}.phet-subject-filters button span{font-size: calc(18px * var(--fs, 1))}.phet-subject-filters button small{min-width:21px;padding:2px 5px;border-radius:99px;color:#b5c8dd;background:#091d36;font-size: calc(13px * var(--fs, 1));text-align:center}.phet-subject-filters button.active{color:#10223d;border-color:#10223d;background:#b7f0df;box-shadow:3px 3px 0 var(--yellow)}.phet-subject-filters button.active small{color:#fff;background:#214967}
.phet-filter-controls{display:grid;grid-template-columns:minmax(0,1fr) 190px 120px;gap:10px;align-items:end;margin-top:14px}.phet-filter-controls label{display:flex;flex-direction:column;gap:5px;color:#b9cce0;font-size: calc(13.5px * var(--fs, 1));font-weight:900}.phet-filter-controls input,.phet-filter-controls select,.phet-reset{width:100%;min-height:46px;border:1px solid #496583;border-radius:12px;color:#10223d;background:#fff;font-size: calc(14px * var(--fs, 1))}.phet-filter-controls input,.phet-filter-controls select{padding:0 12px}.phet-filter-controls input::placeholder{color:#8899aa}.phet-reset{padding:0 10px;color:#e8f4ff;background:#183b61;font-weight:900}
.phet-catalog{margin-top:24px}.phet-catalog-section{margin-top:24px}.phet-catalog-section>header{display:flex;align-items:center;justify-content:space-between;margin:0 3px 11px}.phet-catalog-section h3{margin:0;font-size: calc(18px * var(--fs, 1))}.phet-catalog-section h3 span{font-size: calc(22px * var(--fs, 1))}.phet-catalog-section header>span{color:#9fb2c8;font-size: calc(13.5px * var(--fs, 1))}
.phet-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px}
.phet-card{min-width:0;min-height:190px;display:grid;grid-template-columns:auto minmax(0,1fr);gap:13px;padding:17px;border:2px solid #ccdae2;border-radius:18px;color:#17314b;background:#fffdf8;box-shadow:4px 4px 0 #061426;text-align:left;transition:.16s}
.phet-card:hover{border-color:#244e45;box-shadow:5px 6px 0 var(--phet-subject-color,#69c7ab);transform:translateY(-2px)}
.phet-card-icon{width:50px;height:50px;display:grid;place-items:center;border:2px solid #21415e;border-radius:14px;background:color-mix(in srgb,var(--phet-subject-color,#69c7ab) 30%,#fff);font-size: calc(25px * var(--fs, 1))}
.phet-card-copy{min-width:0;display:flex;flex-direction:column}.phet-card-copy>b{font-size: calc(15px * var(--fs, 1));line-height:1.35}.phet-card-copy>em{margin-top:3px;overflow:hidden;color:#7b8da0;font-size: calc(13.5px * var(--fs, 1));font-style:normal;line-height:1.35;text-overflow:ellipsis;white-space:nowrap}.phet-card-copy>small{min-height:43px;margin-top:8px;color:#52687d;font-size: calc(14px * var(--fs, 1));line-height:1.55}
.phet-card-badges{display:flex;flex-wrap:wrap;gap:5px;margin-top:10px}.phet-card-badges i{padding:4px 6px;border-radius:7px;color:#49677c;background:#edf2f4;font-size: calc(13px * var(--fs, 1));font-style:normal}.phet-card-badges i.english{color:#895321;background:#fff0d7}
.phet-card-action{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-top:auto;padding-top:11px}.phet-card-action strong{color:#2d7a62;font-size: calc(13.5px * var(--fs, 1))}.phet-card-action b{color:#47647e;font-size: calc(13.5px * var(--fs, 1))}
.phet-empty{margin-top:24px;padding:35px 20px;border:2px dashed #58708a;border-radius:20px;color:#d9e7f4;background:#0b223e;text-align:center}.phet-empty>span{font-size: calc(34px * var(--fs, 1))}.phet-empty h3{margin:8px 0 5px;font-size: calc(18px * var(--fs, 1))}.phet-empty p{margin:0;color:#a9bdd1;font-size: calc(14px * var(--fs, 1))}.phet-empty button,.phet-load-more{min-height:46px;margin-top:15px;padding:0 18px;border:2px solid #10223d;border-radius:13px;color:#10223d;background:#b7f0df;box-shadow:4px 4px 0 var(--yellow);font-size: calc(14px * var(--fs, 1));font-weight:950}.phet-load-more{width:100%;margin-top:22px}
.phet-scope-note{margin:24px 2px 0;padding:11px 13px;border-left:4px solid #60c9aa;border-radius:8px;color:#b9cbe0;background:#102947;font-size: calc(13.5px * var(--fs, 1));line-height:1.65}.phet-license{margin:13px 2px 0;color:#9cafc3;font-size: calc(13.5px * var(--fs, 1));line-height:1.65}.phet-license a,.phet-dialog footer a{color:#8cddc6;text-decoration:underline;text-underline-offset:2px}

/* PhET stays inside the site and its single iframe is replaced when the learner returns. */
.phet-dialog{width:calc(100vw - 24px);max-width:1500px;height:calc(100vh - 24px);max-height:none;margin:auto;padding:0;border:0;border-radius:20px;background:#07172f;box-shadow:0 28px 80px rgba(0,0,0,.55);overflow:hidden}.phet-dialog::backdrop{background:rgba(3,12,27,.82);backdrop-filter:blur(5px)}
.phet-dialog-shell{height:100%;display:grid;grid-template-rows:auto minmax(0,1fr) auto;color:#eaf5ff}.phet-dialog header{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:12px 16px;border-bottom:1px solid #29445f;background:#0b203a}.phet-dialog header>div:first-child{min-width:0}.phet-dialog header>div:first-child span{color:#78d6ba;font-size: calc(13.5px * var(--fs, 1));font-weight:950;letter-spacing:.07em}.phet-dialog h2{margin:3px 0 0;font-size: calc(18px * var(--fs, 1))}.phet-dialog header p{margin:3px 0 0;color:#a9bbcc;font-size: calc(13.5px * var(--fs, 1))}
.phet-close-button{flex:none;min-height:44px;display:flex;align-items:center;gap:8px;padding:5px 7px 5px 12px;border:1px solid #4d6680;border-radius:11px;color:#d8ecf8;background:#183651;font-size: calc(13.5px * var(--fs, 1));font-weight:900}.phet-close-button b{width:30px;height:30px;display:grid;place-items:center;border-radius:8px;background:#284a68;color:#fff;font-size: calc(20px * var(--fs, 1))}
.phet-frame-wrap{min-height:0;position:relative;background:#fff}.phet-frame-wrap iframe{width:100%;height:100%;display:block;border:0;background:#fff}.phet-loading{z-index:2;position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:20px;color:#31546d;background:#f4f8fa;text-align:center;transition:.2s}.phet-dialog.is-loaded .phet-loading{opacity:0;pointer-events:none}.phet-loading>span{width:46px;height:46px;border:4px solid #cbdce5;border-top-color:#3aa784;border-radius:50%;animation:phet-spin .8s linear infinite}.phet-loading>b{margin-top:14px;font-size: calc(16px * var(--fs, 1))}.phet-loading>small{margin-top:6px;color:#718697;font-size: calc(14px * var(--fs, 1))}.phet-fallback{display:flex;flex-wrap:wrap;justify-content:center;gap:9px;margin-top:18px}.phet-fallback button,.phet-fallback a{min-height:44px;display:inline-flex;align-items:center;justify-content:center;padding:0 13px;border:1px solid #476681;border-radius:11px;color:#fff;background:#244c68;font-size: calc(13.5px * var(--fs, 1));font-weight:900}.phet-fallback a{color:#173c36;border-color:#4ba689;background:#c7f1e5;text-decoration:none}
.phet-dialog footer{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:9px 14px;color:#a7b9ca;background:#0b203a;font-size: calc(13.5px * var(--fs, 1));line-height:1.5}.phet-dialog footer p{margin:0}.phet-dialog footer p:last-child{text-align:right}
@keyframes phet-spin{to{transform:rotate(360deg)}}

@media(max-width:900px){.phet-grid{grid-template-columns:repeat(2,1fr)}.phet-grade-grid{grid-template-columns:repeat(4,1fr)}.phet-filter-controls{grid-template-columns:minmax(0,1fr) 180px}.phet-reset{grid-column:1/-1}.math-stats{grid-template-columns:repeat(3,1fr)}.math-stats article{border-bottom:1px dashed #dfe4e8}.math-stats article:nth-child(3){border-right:0}.math-stats article:nth-child(n+4){border-bottom:0}.math-stats article:last-child{border-right:0}}
@media(max-width:620px){.math-mode-nav{grid-template-columns:1fr;padding:6px}.math-mode-nav button{padding:11px 13px}.math-mode-nav button>span:first-child{font-size: calc(23px * var(--fs, 1))}.phet-library-hero{align-items:flex-start;flex-direction:column;padding:21px;gap:17px}.phet-library-hero h2{font-size: calc(24px * var(--fs, 1))}.phet-library-stats{width:100%;grid-template-columns:auto 1fr auto 1fr}.phet-library-stats strong:nth-of-type(3){grid-column:1}.phet-grade-grid{grid-template-columns:repeat(2,1fr)}.phet-grade-guide{padding:19px}.phet-filter-panel{padding:16px}.phet-filter-panel>header{align-items:flex-start;flex-direction:column}.phet-subject-filters{flex-wrap:nowrap;overflow-x:auto;margin-left:-16px;margin-right:-16px;padding:2px 16px 10px;scroll-snap-type:x proximity}.phet-subject-filters button{flex:none;scroll-snap-align:start}.phet-filter-controls{grid-template-columns:1fr}.phet-reset{grid-column:auto}.phet-grid{grid-template-columns:1fr}.phet-card{min-height:178px;padding:15px}.phet-dialog{width:100vw;height:100dvh;border-radius:0}.phet-dialog header{align-items:flex-start;padding:9px max(9px,env(safe-area-inset-right)) 9px max(9px,env(safe-area-inset-left))}.phet-dialog header p{display:none}.phet-dialog h2{font-size: calc(15px * var(--fs, 1))}.phet-close-button span{display:none}.phet-dialog footer{display:block;padding:7px max(9px,env(safe-area-inset-right)) max(7px,env(safe-area-inset-bottom)) max(9px,env(safe-area-inset-left));font-size: calc(13px * var(--fs, 1))}.phet-dialog footer p:first-child{display:none}.phet-dialog footer p:last-child{text-align:left}.math-stats{grid-template-columns:repeat(2,1fr)}.math-stats article{border-right:1px dashed #dfe4e8;border-bottom:1px dashed #dfe4e8}.math-stats article:nth-child(2n){border-right:0}.math-stats article:nth-child(n+5){border-bottom:0}.math-stats article:last-child{grid-column:1/-1;border-right:0}}
@media(max-height:500px) and (orientation:landscape){.phet-dialog{width:100vw;height:100dvh;border-radius:0}.phet-dialog header{padding-top:5px;padding-bottom:5px}.phet-dialog header p,.phet-dialog footer p:first-child{display:none}.phet-dialog footer{padding-top:4px;padding-bottom:max(4px,env(safe-area-inset-bottom))}.phet-dialog h2{font-size: calc(14px * var(--fs, 1))}}