.speed-math-overlay[hidden]{display:none!important}
.speed-math-overlay{position:fixed;inset:0;z-index:1100;overflow:auto;background:#f6f4ed;color:#24352e;font-family:"PingFang SC","Microsoft YaHei",sans-serif}
.speed-math-head{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;padding:30px clamp(18px,4vw,60px);background:#233b33;color:#f7f6ed}
.speed-math-head h2{font-size:clamp(25px,3vw,38px);line-height:1.2;margin:8px 0}
.speed-math-head p{margin:0;color:#d5e1d5;font-size:15px;line-height:1.6}
.speed-math-eyebrow{font-size:13px;font-weight:800;letter-spacing:.16em;color:#d8be83}
.speed-math-head .close-exam{white-space:nowrap;background:#f6f4ed;color:#233b33}
.speed-math-layout{max-width:1320px;margin:0 auto;padding:28px clamp(18px,4vw,50px) 60px;display:grid;grid-template-columns:280px minmax(0,1fr);gap:24px}
.speed-math-sidebar,.speed-math-main{background:#fff;border:1px solid #dbe2d9;border-radius:18px;box-shadow:0 12px 40px rgba(20,47,35,.06)}
.speed-math-sidebar{padding:22px;align-self:start;position:sticky;top:20px}
.speed-math-stat{display:flex;justify-content:space-between;gap:12px;font-size:14px;color:#4a5a50}.speed-math-stat b{color:#1c624c}
.speed-math-clock{margin:12px 0 18px;padding:12px 14px;border-radius:10px;background:#eef3ee;color:#466055;font-size:14px;display:flex;justify-content:space-between}.speed-math-clock strong{font-variant-numeric:tabular-nums;color:#214d3e}
.speed-math-groups{display:grid;gap:8px;margin-bottom:20px}.speed-math-groups button{border:1px solid #d9e1d8;background:#fff;color:#34483d;border-radius:10px;text-align:left;padding:10px 12px;cursor:pointer;font-size:14px}.speed-math-groups button.active{background:#e7f2ea;border-color:#6ba182;color:#215a42;font-weight:800}
.speed-math-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.speed-math-grid button{aspect-ratio:1;border-radius:9px;border:1px solid #d6ddd4;background:#fff;color:#3f5147;cursor:pointer;font-weight:700}.speed-math-grid button.current{border-color:#2b7455;box-shadow:inset 0 0 0 2px #2b7455}.speed-math-grid button.correct{background:#dff0e4;color:#155739}.speed-math-grid button.wrong{background:#f9e4df;color:#8c3428}
.speed-math-clear{width:100%;margin-top:18px;border:1px solid #b9c9bb;background:#fff;color:#2c5b43;border-radius:10px;padding:11px 12px;cursor:pointer;font-size:14px;font-weight:700}.speed-math-clear:hover{background:#eef3ee}
.speed-math-main{padding:clamp(22px,4vw,46px);min-height:560px}.speed-math-kicker{display:flex;justify-content:space-between;align-items:center;gap:15px;color:#2d7453;font-size:14px;font-weight:800;letter-spacing:.06em}.speed-math-kicker span:last-child{color:#74867a;font-variant-numeric:tabular-nums}
.speed-math-instruction{font-size:16px;line-height:1.7;color:#546459;margin:30px 0 10px}.speed-math-expression{font-size:clamp(30px,4.7vw,58px);font-weight:800;letter-spacing:-.035em;line-height:1.28;overflow-wrap:anywhere;color:#173c2e;margin:10px 0 35px;font-variant-numeric:tabular-nums}
.speed-math-answer{max-width:480px}.speed-math-answer label{display:flex;justify-content:space-between;font-size:15px;font-weight:800;margin-bottom:10px}.speed-math-answer label span{color:#65776a;font-weight:500}.speed-math-answer input{width:100%;border:2px solid #b9cdbd;border-radius:12px;padding:16px 18px;font:700 24px "PingFang SC","Microsoft YaHei",sans-serif;color:#173c2e;background:#fff}.speed-math-answer input:focus{outline:3px solid #cfe7d3;outline-offset:2px}.speed-math-answer p{font-size:13px;color:#718073;line-height:1.5;margin:8px 0 0}
.speed-math-actions{display:flex;gap:10px;flex-wrap:wrap;margin:28px 0 0;max-width:600px}.speed-math-actions button{flex:1 1 150px;min-height:48px}.speed-math-actions .ghost{border:1px solid #b9c9bb;background:#fff;color:#2c5b43;border-radius:8px;cursor:pointer;font-weight:700}.speed-math-actions [hidden]{display:none}
.speed-math-feedback{display:none;border-radius:13px;margin-top:26px;padding:22px;border:1px solid #cbded0;background:#f0f7f1;line-height:1.7;font-size:15px}.speed-math-feedback.show{display:block}.speed-math-feedback.wrong{border-color:#e7c2b8;background:#fff2ee}.speed-math-feedback h3{margin:0 0 8px;font-size:20px}.speed-math-feedback p{margin:9px 0}.speed-math-feedback ol{margin:12px 0 0;padding-left:1.5em}.speed-math-feedback li{margin:8px 0}.speed-math-feedback .speed-math-key{font-weight:800;color:#285842}
.speed-math-feedback .speed-math-method{margin:16px 0 4px;color:#1e5b42;font-weight:800}
@media(max-width:760px){.speed-math-head{align-items:flex-start;flex-direction:column}.speed-math-layout{grid-template-columns:1fr;padding-top:16px}.speed-math-sidebar{position:static}.speed-math-groups{grid-template-columns:repeat(2,1fr)}.speed-math-main{min-height:auto}.speed-math-expression{margin-bottom:25px}}