/* Math deck — clean academic style */
.deck-back{position:fixed;top:24px;left:40px;font-family:var(--font-mono);font-size:12px;color:var(--text-3);text-decoration:none;letter-spacing:.06em;z-index:30}
.deck-back:hover{color:var(--accent)}

/* MathJax inline tweaks */
.formula{font-family:'Times New Roman','Noto Serif SC',serif;font-size:18px;line-height:1.85}
.formula b{font-style:normal;color:var(--accent);font-weight:600}

.fbox{padding:16px 20px;border:1px solid var(--border);border-radius:10px;background:var(--surface);position:relative;font-family:'Times New Roman','Noto Serif SC',serif;font-size:17px;line-height:1.85}
.fbox::before{content:attr(data-tag);position:absolute;top:-9px;left:14px;background:var(--bg);padding:0 8px;font-family:var(--font-mono);font-size:11px;color:var(--accent);letter-spacing:.1em;text-transform:uppercase}
.fbox.key{border-left:3px solid var(--accent)}

table.cmp-table{width:100%;border-collapse:separate;border-spacing:0;font-size:14px}
table.cmp-table th, table.cmp-table td{padding:10px 14px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}
table.cmp-table th{font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--text-3);font-weight:600;background:var(--surface-2)}
table.cmp-table tr:hover td{background:rgba(0,0,0,.02)}
table.cmp-table td.f{font-family:'Times New Roman','Noto Serif SC',serif;font-size:15px}

/* example card */
.ex-card{padding:18px;border-radius:12px;background:var(--surface-2);border-left:3px solid var(--accent-2)}
.ex-card .lbl{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--accent);text-transform:uppercase;margin-bottom:8px}
.ex-card .q{font-family:'Times New Roman','Noto Serif SC',serif;font-size:16.5px;line-height:1.85;margin-bottom:8px}
.ex-card .s{font-family:'Times New Roman','Noto Serif SC',serif;font-size:15.5px;line-height:1.95;color:var(--text-2)}

.steps{counter-reset:s;list-style:none;padding:0;margin:0}
.steps li{counter-increment:s;padding:12px 14px 12px 50px;background:var(--surface);border:1px solid var(--border);border-radius:10px;margin-bottom:8px;position:relative;font-size:14.5px}
.steps li::before{content:counter(s);position:absolute;left:12px;top:50%;transform:translateY(-50%);width:28px;height:28px;border-radius:50%;background:var(--accent);color:#fff;display:flex;align-items:center;justify-content:center;font-family:var(--font-mono);font-weight:700;font-size:13px}

.h1.huge{font-size:96px;line-height:.98}
.label-strip{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}

.formula-row{display:flex;gap:24px;flex-wrap:wrap;font-family:'Times New Roman','Noto Serif SC',serif;font-size:17px}
.formula-row > div{padding:10px 16px;background:var(--surface-2);border-radius:8px;border:1px solid var(--border)}

/* category badge for math sub */
.sub-badge{display:inline-block;padding:3px 10px;border-radius:999px;font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;font-weight:600;text-transform:uppercase}
.sb-calc{background:#dceaff;color:#2851a3}
.sb-la{background:#ffe0d8;color:#8b3a25}
.sb-prob{background:#dff0e0;color:#1d6e3a}