.stats{grid-template-columns:repeat(4,1fr)}
.depth-stat small{display:block;margin-top:6px;color:var(--accent);font-size:.68rem;font-weight:700;text-transform:uppercase;letter-spacing:.055em}
.calculations{margin:-42px 0 70px;border:1px solid var(--line);border-radius:14px;background:rgba(251,250,246,.58);overflow:hidden}
.calculations summary{list-style:none;cursor:pointer;padding:15px 18px;display:flex;align-items:center;justify-content:space-between;gap:16px;font-size:.8rem;font-weight:760}
.calculations summary::-webkit-details-marker{display:none}
.calculations summary:after{content:'+';font:400 1.2rem Georgia,serif;color:var(--muted)}
.calculations[open] summary:after{content:'−'}
.calculations summary small{color:var(--muted);font-size:.72rem;font-weight:500;margin-left:auto}
.calc-body{border-top:1px solid var(--line);padding:22px 22px 24px}
.calc-intro{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin-bottom:22px;color:#504e48;font-size:.82rem;line-height:1.6}
.calc-intro p{margin:0}.calc-intro strong{color:var(--ink)}
.calc-grid{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid var(--line);border-radius:11px;overflow:hidden;background:rgba(255,255,255,.3)}
.calc{padding:16px;min-height:104px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.calc:nth-child(4n){border-right:0}.calc:nth-last-child(-n+4){border-bottom:0}
.calc span{display:block;color:var(--muted);font-size:.7rem;text-transform:uppercase;letter-spacing:.055em;font-weight:760}
.calc b{display:block;margin-top:8px;font:400 1.45rem Georgia,serif;letter-spacing:-.025em}
.calc b.method{font:650 .86rem/1.3 Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;letter-spacing:0}
.calc small{display:block;margin-top:6px;color:var(--muted);font-size:.66rem;line-height:1.35}
.formula{display:flex;align-items:flex-start;gap:14px;margin-top:16px;padding:13px 15px;border-radius:10px;background:#ebe7df;font-size:.72rem}
.formula span{font-weight:800;white-space:nowrap}.formula code{font:500 .72rem/1.45 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;color:#47453f;white-space:normal}
.calc-note{margin:15px 2px 0;color:var(--muted);font-size:.72rem;line-height:1.55}
@media(max-width:820px){.stats{grid-template-columns:repeat(2,1fr)}.stat:nth-child(3){border-left:0;border-top:1px solid var(--line)}.stat:nth-child(4){border-top:1px solid var(--line)}.calculations{margin-top:-24px}.calc-grid{grid-template-columns:repeat(2,1fr)}.calc:nth-child(4n){border-right:1px solid var(--line)}.calc:nth-child(2n){border-right:0}.calc:nth-last-child(-n+4){border-bottom:1px solid var(--line)}.calc:nth-last-child(-n+2){border-bottom:0}.calc-intro{grid-template-columns:1fr;gap:8px}}
@media(max-width:560px){.stats{grid-template-columns:1fr}.stat+.stat,.stat:nth-child(3),.stat:nth-child(4){border-left:0;border-top:1px solid var(--line)}.calculations summary small{display:none}.calc-grid{grid-template-columns:1fr}.calc,.calc:nth-child(2n),.calc:nth-child(4n){border-right:0;border-bottom:1px solid var(--line)}.calc:last-child{border-bottom:0}.formula{display:block}.formula span{display:block;margin-bottom:7px}}