/* Immortal Math Lab: the same glass, with a quieter work surface. */
.math-section{scroll-margin-top:28px;padding-top:80px;padding-bottom:80px}
.math-section .section-heading h2{font-size:clamp(26px,7vw,36px);text-wrap:balance}
.math-local-badge{display:inline-flex;align-items:center;gap:9px;flex-shrink:0;font-size:12px;line-height:1.8;color:var(--muted);padding:8px 13px;border-radius:999px;border:1px solid #ffffffc9;background:#ffffff4d}
.math-local-badge:before{content:"";width:6px;height:6px;border-radius:50%;background:#6b94b4}
.math-tabs{display:grid;grid-template-columns:1fr 1fr 1.45fr;gap:14px;margin-bottom:34px}
.math-tabs>button{display:flex;align-items:center;gap:16px;text-align:left;min-height:96px;padding:20px 24px;color:#465a7f;background:linear-gradient(135deg,#ffffff70,#ffffff29);border:1px solid #ffffffd9;border-radius:20px;box-shadow:inset 0 1px 0 #fff,0 7px 22px #667ba40a}
.math-tabs>button>span:first-child{display:grid;place-items:center;font:italic 36px/1 Georgia,serif;width:42px;height:48px;color:#7386be;flex-shrink:0}
.math-tabs>button>span:last-child{font-size:17px;font-weight:600;line-height:1.7}
.math-tabs small{display:block;font:9px/1.8 "Segoe UI",sans-serif;letter-spacing:1.1px;color:#61759d;margin-top:3px}
.math-tabs>button[aria-selected="true"]{background:linear-gradient(125deg,#eef9ffdd,#e1e2ffbf);border-color:#a1b4e1;box-shadow:0 9px 28px #6077b21a,inset 0 1px 0 #fff;color:#304c92}
.math-tabs>button[aria-selected="true"]>span:first-child{color:#5e70c5}
.math-tabs>button:hover{background-color:#ffffffa1;border-color:#9eafe0}
.math-stage{position:relative;isolation:isolate;margin-right:12px;margin-top:26px;perspective:1400px}
.math-backing{position:absolute;inset:0;pointer-events:none;border:1px solid #ffffffe8;border-radius:26px;transform-origin:center top;background:linear-gradient(135deg,#e0f3ff99,#e5dcff77);box-shadow:0 8px 22px #526b9910}
.math-backing-far{z-index:0;transform:translate(12px,-18px) scale(.98)}
.math-backing-near{z-index:1;transform:translate(6px,-9px) scale(.99)}
.math-panel{position:relative;z-index:3;padding:36px;border:1px solid #fffffff2;border-radius:26px;background:linear-gradient(130deg,#fbfdffc9,#f2f2ff91);box-shadow:0 18px 50px #536da615,inset 0 1px 0 #fff;transform-origin:center top;backface-visibility:hidden}
.math-panel[hidden]{display:none}
.math-stage.is-turning>.math-panel:not([hidden]){will-change:transform,opacity}
.math-panel.math-ghost{position:absolute;inset:0 0 auto;z-index:4;max-height:650px;overflow:hidden;pointer-events:none;background:linear-gradient(130deg,#f4fafff2,#eeeaffde);will-change:transform,opacity}
.math-panel-heading{display:flex;align-items:center;justify-content:space-between;gap:24px;margin-bottom:30px;padding-bottom:27px;border-bottom:1px solid var(--line)}
.math-kicker,.math-result-kicker{font-size:11px;letter-spacing:1.2px;line-height:1.8;color:#5a70a1}
.math-panel-heading h3{font-size:29px;line-height:1.5;font-weight:600;letter-spacing:-.6px;margin:7px 0 9px;color:#293e69}
.math-panel-heading p{font-size:15px;color:var(--muted);line-height:1.9;margin:0;max-width:34em}
.math-formula{font:italic 25px/1.7 Georgia,"Times New Roman",serif;color:#6b79ac;text-align:right;flex-shrink:0;max-width:40%;overflow-wrap:anywhere}
.math-workbench{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:36px;align-items:start}
.math-workbench-secondary{margin-top:34px;padding-top:34px;border-top:1px solid var(--line)}
.math-workbench form{min-width:0}
.math-workbench h4{font-size:18px;font-weight:600;margin:0 0 23px;line-height:1.6;color:#2b416d}
.math-workbench label{display:block;font-size:14px;font-weight:500;color:#3f557c;margin:16px 0 8px;line-height:1.7}
.math-workbench :is(input,textarea){display:block;width:100%;max-width:100%;min-width:0;min-height:48px;font:16px/1.7 "Segoe UI","Microsoft YaHei",sans-serif;padding:11px 13px;background:#ffffff85;color:#263e69;border:1px solid #8c9fc4;border-radius:12px;box-shadow:inset 0 1px 0 #fff}
.math-workbench textarea{resize:vertical;min-height:94px;max-height:300px;font-family:Consolas,"Microsoft YaHei",monospace}
.math-workbench [aria-invalid="true"]{border-color:#a13f50;outline-color:#a13f50}
.math-hint{font-size:12px;line-height:1.9;color:var(--muted);margin:9px 0 12px;overflow-wrap:anywhere}
.math-input-row{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:14px}
.math-form-actions{display:flex;align-items:center;gap:15px;flex-wrap:wrap;margin-top:24px}
.math-form-actions>.button{min-height:46px;font-size:14px;padding:11px 24px;line-height:1.7}
.math-reset{font-size:13px;min-height:44px;color:#4e6596;padding:8px 12px;border:1px solid #ffffffba;background:#ffffff30;border-radius:12px}
.math-reset:hover{background:#ffffffbf}
.math-error{margin:16px 0 0;padding:12px 14px;background:#fff3f4c9;border:1px solid #d3a3ac;border-radius:12px;color:#8a3448;font-size:13px;line-height:1.8}
.math-result{min-height:250px;padding:23px 25px;border:1px solid #ffffffeb;border-radius:20px;background:linear-gradient(140deg,#dfeeff70,#e9e3ff5e);box-shadow:inset 0 1px 0 #fff;overflow-wrap:anywhere}
.math-result-list{margin:10px 0 0}
.math-result-row{padding:14px 0;border-bottom:1px solid #91a4c82e}
.math-result-row:last-child{border-bottom:0;padding-bottom:0}
.math-result dt{font-size:12px;line-height:1.8;color:#52688d}
.math-result dd{font-size:16px;line-height:1.8;color:#2c4377;margin:5px 0 0;font-variant-numeric:tabular-nums}
.math-result-primary dd{font-size:23px;line-height:1.65;color:#3a51a5;font-weight:550}
.math-result-matrix dd{font:15px/1.85 Consolas,monospace;white-space:pre-wrap}
.math-empty-result{font-size:14px;line-height:1.9;color:#52688d;margin:0}
.math-precision-note{font-size:13px;color:#795825;line-height:1.8;border-bottom:1px solid #c8b38c66;padding-bottom:12px}
.math-footnote{font-size:12px;line-height:1.95;margin:28px 0 0;color:var(--muted);padding-top:20px;border-top:1px solid var(--line)}
@media(max-width:1100px){.math-tabs>button{padding:18px;gap:10px}.math-tabs>button>span:last-child{font-size:16px}.math-tabs>button>span:first-child{width:32px}.math-panel{padding:28px}.math-workbench{gap:24px}.math-formula{font-size:22px}}
@media(max-width:760px){.math-section{padding-block:54px;scroll-margin-top:78px}.math-tabs{gap:9px;grid-template-columns:1fr 1fr 1.4fr;margin-bottom:30px}.math-tabs>button{flex-direction:column;align-items:flex-start;gap:9px;padding:15px 12px;border-radius:16px;min-height:118px}.math-tabs>button>span:first-child{font-size:30px;height:33px;width:32px;justify-items:start}.math-tabs>button>span:last-child{font-size:14px;line-height:1.6}.math-tabs small{font-size:8px;letter-spacing:.4px}.math-panel{padding:23px;border-radius:22px}.math-panel-heading{display:block;padding-bottom:23px;margin-bottom:25px}.math-panel-heading h3{font-size:26px}.math-panel-heading p{font-size:15px}.math-formula{display:block;max-width:none;text-align:left;font-size:22px;margin-top:15px}.math-workbench{grid-template-columns:minmax(0,1fr);gap:24px}.math-result{min-height:180px;padding:20px}.math-panel.math-ghost{max-height:850px}.math-local-badge{margin-top:2px}.math-section .section-heading{flex-wrap:wrap;align-items:start;gap:18px}.math-stage{margin-right:8px}.math-backing-far{transform:translate(8px,-16px) scale(.98)}.math-backing-near{transform:translate(4px,-8px) scale(.99)}.math-workbench h4{font-size:18px}.math-footnote{margin-top:25px}}
@media(max-width:560px){.header nav{grid-template-columns:repeat(4,minmax(0,1fr));gap:1px}.header nav a{font-size:13px;padding-inline:0}.math-tabs small{display:none}.math-tabs>button{min-height:110px}.math-panel{padding:20px}.math-kicker{font-size:10px;letter-spacing:.8px}}
@media(max-width:390px){.header nav a{font-size:12px}.math-tabs{gap:7px}.math-tabs>button{padding:13px 10px}.math-tabs>button>span:last-child{font-size:13px}.math-panel{padding:18px}.math-panel-heading h3{font-size:24px}.math-input-row{gap:10px}.math-workbench :is(input,textarea){padding-inline:10px}.math-result-primary dd{font-size:21px}}
@media(prefers-reduced-transparency:reduce){.math-panel,.math-result{background:#f1f5ff}}
.reduce-motion .math-ghost{display:none}