.formula-guide{display:grid;gap:18px;margin-top:16px}
.formula-intro{margin:0;color:var(--muted);font-size:13px;line-height:1.8}
.formula-card{min-width:0;padding:20px;background:#f8fafc;border:1px solid #e0e7ee;border-radius:8px;scroll-margin-top:24px}
.formula-heading{display:flex;align-items:center;gap:10px}
.formula-heading h3{margin:0;font-size:15px;line-height:1.5;color:#253747}
.formula-number{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;flex-shrink:0;border-radius:7px;background:#e1efed;color:var(--accent);font-size:12px;font-weight:800}
.formula-equation{margin:16px 0;padding:18px;background:#fff;border:1px solid #e5eaf0;border-radius:6px;color:#163c42}
.formula-result{font-size:16px;font-weight:750;margin-bottom:12px}
.formula-expression{display:flex;align-items:center;gap:12px;font-size:17px;line-height:1.8}
.formula-rhs{display:flex;align-items:center;flex-wrap:wrap;gap:8px 12px;min-width:0}
.formula-term{max-width:100%;overflow-wrap:anywhere}
.formula-link{color:var(--accent);text-decoration:underline;text-decoration-style:dotted;text-underline-offset:5px;text-decoration-thickness:1px;border-radius:3px}
.formula-link:hover{color:#064e49;background:#e7f4f0;text-decoration-style:solid}
.formula-op{flex-shrink:0;font-family:"Cambria Math",serif;font-size:23px;font-weight:400;line-height:1.2}
.formula-fraction{display:inline-flex;flex-direction:column;align-items:stretch;min-width:0;max-width:100%;text-align:center;vertical-align:middle}
.formula-numerator,.formula-denominator{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:5px 10px;padding:4px 8px}
.formula-numerator{border-bottom:1.5px solid #45656b;padding-bottom:7px}
.formula-denominator{padding-top:7px}
.formula-note{margin:0;color:#506070;font-size:13px;line-height:1.9}
.formula-definition{display:block;scroll-margin-top:24px;border-radius:4px}
.formula-note .formula-definition{margin-bottom:5px}
.formula-card:focus,.formula-definition:focus{outline:3px solid #56b8b0;outline-offset:3px}
.formula-link:focus-visible,.formula-back:focus-visible{outline:3px solid #56b8b0;outline-offset:4px}
.formula-back{display:inline-block;margin-top:14px;color:var(--accent);font-size:12px;text-underline-offset:3px}
@media(max-width:600px){.formula-card{padding:14px}.formula-equation{padding:14px 12px}.formula-heading h3{font-size:14px}.formula-result{font-size:15px}.formula-expression{font-size:15px;gap:8px}.formula-rhs{gap:6px 8px}.formula-op{font-size:21px}.formula-numerator,.formula-denominator{padding-left:2px;padding-right:2px}}
.formula-overview{min-width:0;padding:20px;background:linear-gradient(145deg,#eef8f6,#f7fafc 72%);border:1px solid #b7d8d1;border-radius:9px;box-shadow:0 5px 16px rgba(11,122,117,.08)}
.formula-sigma-inline{display:inline-flex;vertical-align:middle;flex-direction:column;align-items:center;justify-content:center;line-height:.95;color:#0b615c}
.formula-sigma-inline>span{font-family:"Cambria Math","Times New Roman",serif;font-size:27px;line-height:.9}
.formula-sigma-inline small{font-size:8px;line-height:1.1;white-space:nowrap;color:#506070}
.formula-math-frame{margin-top:16px;padding:24px 20px;background:#fff;border:1px solid #b9d9d2;border-radius:7px;overflow-x:auto;scrollbar-width:thin;box-shadow:0 2px 8px rgba(11,122,117,.06)}
.formula-math-frame math{width:max-content;min-width:100%;margin:0;color:#123e42;font-size:22px;font-family:"Cambria Math", "STIX Two Math", serif}
.formula-math-frame mtable{margin:0}
.formula-math-hint{display:none;margin:8px 0 0;color:#647082;font-size:11px}
.formula-notation{margin-top:12px;padding:8px 12px;background:#f9fcfb;border-color:#d5e6e2;box-shadow:none}
.formula-notation summary{font-size:12px;color:#0b6661}
.formula-notation dl{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px 18px;margin:14px 0 6px}
.formula-notation dl>div{display:grid;grid-template-columns:minmax(105px,auto) 1fr;gap:8px;font-size:12px;line-height:1.6}
.formula-notation dt{font-family:"Cambria Math",serif;font-size:14px;font-weight:700;color:#164c4b}
.formula-notation dd{margin:0;color:#506070}
.formula-notation p{margin:8px 0 2px;color:#506070;font-size:12px;line-height:1.7}
.formula-simple{min-width:0;padding:20px;background:#f8fafc;border:1px solid #e0e7ee;border-radius:8px}
.formula-simple .formula-equation{margin-bottom:10px}
.formula-overview:focus{outline:3px solid #56b8b0;outline-offset:3px}
@media(max-width:600px){.formula-math-frame{padding:18px 12px}.formula-math-frame math{font-size:19px}.formula-math-hint{display:block}.formula-notation dl{grid-template-columns:1fr}.formula-simple{padding:14px}}
.formula-math-frame:focus-visible{outline:3px solid #56b8b0;outline-offset:3px}
.formula-level-intro{margin:16px 0;padding:12px 14px;border-left:3px solid var(--accent);background:#eaf6f2;color:#27534d;font-size:13px;line-height:1.8}
.formula-level-table{width:100%;min-width:0;border:1px solid #dbe5ea;border-radius:7px;border-collapse:separate;border-spacing:0;overflow:hidden;background:#fff;font-size:13px}
.formula-level-table caption{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.formula-level-table th,.formula-level-table td{padding:8px 14px;border-bottom:1px solid #e6ecf0;white-space:normal}
.formula-level-table thead th{position:static;background:#e7f2f0;color:#184f4b;cursor:default;font-size:12px;font-weight:800;text-align:left}
.formula-level-table thead th:last-child,.formula-level-table td:last-child{text-align:right;width:100px;font-weight:800}
.formula-level-table .level-group th{position:static;padding:8px 14px;background:#f1f5f7;color:#506070;text-align:left;font-size:11px;font-weight:800;cursor:default}
.formula-level-table tbody:last-child tr:last-child td{border-bottom:0}
.formula-level-table .level-best td{background:#e6f7ec;color:#117442;font-weight:900}
.formula-level-table .level-even td{background:#f4faf8}
.formula-level-source{margin:12px 0 0;color:#647082;font-size:12px;line-height:1.7}
.formula-level-source a{color:var(--accent);text-underline-offset:3px}
@media(prefers-color-scheme:dark){
.formula-card,.formula-simple{background:#1a222c;border-color:#2c3744}
.formula-heading h3{color:#dbe4ee}
.formula-number{background:#16332f}
.formula-equation,.formula-math-frame,.formula-level-table{background:#10161d;border-color:#2c3744;color:#cfe9e5}
.formula-link:hover{color:#8fe3d9;background:#16332f}
.formula-numerator{border-bottom-color:#7d9ea3}
.formula-note,.formula-notation dd,.formula-notation p,.formula-sigma-inline small,.formula-level-source,.formula-math-hint{color:#9aa7b7}
.formula-overview{background:linear-gradient(145deg,#132a27,#171e27 72%);border-color:#24514b;box-shadow:none}
.formula-sigma-inline,.formula-notation summary,.formula-notation dt{color:#7fd6cc}
.formula-math-frame math{color:#d6efeb}
.formula-notation{background:#131b23;border-color:#24514b}
.formula-level-intro{background:#15302b;color:#b9e3dc}
.formula-level-table th,.formula-level-table td{border-bottom-color:#26313d}
.formula-level-table thead th{background:#16332f;color:#bfe9e3}
.formula-level-table .level-group th{background:#1d2631;color:#9aa7b7}
.formula-level-table .level-best td{background:#13281d;color:#6fdc98}
.formula-level-table .level-even td{background:#141d25}
}