.guide[data-astro-cid-ipdb5bjo]{container:guide/inline-size}.guide-hero[data-astro-cid-ipdb5bjo],.guide-section[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-white)}.guide-hero[data-astro-cid-ipdb5bjo]{grid-template-columns:minmax(0,1.25fr) minmax(12rem,.75fr);gap:1.25rem;padding:clamp(1.3rem,2.5vw,2rem);display:grid}.eyebrow[data-astro-cid-ipdb5bjo]{color:var(--color-blue-600);font-size:var(--type-caption);font-weight:var(--weight-bold);letter-spacing:.085em;text-transform:uppercase;margin:0;line-height:1.4}.guide[data-astro-cid-ipdb5bjo] h1[data-astro-cid-ipdb5bjo],.guide[data-astro-cid-ipdb5bjo] h2[data-astro-cid-ipdb5bjo],.guide[data-astro-cid-ipdb5bjo] h3[data-astro-cid-ipdb5bjo]{font-family:var(--font-heading);color:var(--color-navy-950)}.guide[data-astro-cid-ipdb5bjo] h1[data-astro-cid-ipdb5bjo]{letter-spacing:-.035em;margin:.55rem 0 .75rem;font-size:clamp(1.8rem,3.2vw,2.7rem);line-height:1.1}.guide[data-astro-cid-ipdb5bjo] h1[data-astro-cid-ipdb5bjo] span[data-astro-cid-ipdb5bjo]{color:var(--color-navy-700)}.guide-hero__meta[data-astro-cid-ipdb5bjo]{color:var(--color-muted);font-size:var(--type-caption);flex-wrap:wrap;gap:.35rem;margin:-.35rem 0 .8rem;line-height:1.4;display:flex}.guide-hero__lead[data-astro-cid-ipdb5bjo]{max-width:57ch;color:var(--color-navy-700);font-size:var(--type-body);margin:0;line-height:1.65}.guide-hero__answer[data-astro-cid-ipdb5bjo]{background:var(--color-blue-50);border-radius:var(--radius-sm);margin-top:1.1rem;padding:.85rem 1rem}.guide-hero__answer[data-astro-cid-ipdb5bjo] strong[data-astro-cid-ipdb5bjo]{color:var(--color-blue-700);font-size:var(--type-small)}.guide-hero__answer[data-astro-cid-ipdb5bjo] p[data-astro-cid-ipdb5bjo]{color:var(--color-navy-800);font-size:var(--type-small);margin:.25rem 0 0;line-height:1.55}.guide-hero__media[data-astro-cid-ipdb5bjo]{border-radius:var(--radius-sm);background:var(--color-surface);min-height:16rem;margin:0;position:relative;overflow:hidden}.guide-hero__media[data-astro-cid-ipdb5bjo] img[data-astro-cid-ipdb5bjo]{object-fit:cover;width:100%;height:100%}.guide-hero__media[data-astro-cid-ipdb5bjo] figcaption[data-astro-cid-ipdb5bjo]{color:var(--color-white);font-size:var(--type-caption);background:linear-gradient(#0000,#041326c7);padding:1.6rem .8rem .6rem;line-height:1.4;position:absolute;inset:auto 0 0}.guide-section[data-astro-cid-ipdb5bjo]{margin-top:1rem;padding:clamp(1.25rem,2.25vw,1.8rem)}.section-heading[data-astro-cid-ipdb5bjo]{margin-bottom:1rem}.section-heading[data-astro-cid-ipdb5bjo] h2[data-astro-cid-ipdb5bjo]{letter-spacing:-.02em;margin:.3rem 0 0;font-size:clamp(1.35rem,2vw,1.8rem);line-height:1.2}.section-heading[data-astro-cid-ipdb5bjo]>p[data-astro-cid-ipdb5bjo]:last-child:not(.eyebrow){color:var(--color-muted);font-size:var(--type-small);margin:.45rem 0 0;line-height:1.6}.guide-diagram[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-white);margin:0 0 1.25rem;overflow:hidden}.guide-diagram[data-astro-cid-ipdb5bjo] a[data-astro-cid-ipdb5bjo]{overscroll-behavior-inline:contain;display:block;overflow-x:auto}.guide-diagram[data-astro-cid-ipdb5bjo] img[data-astro-cid-ipdb5bjo]{width:100%;max-width:100%;height:auto;display:block}.guide-diagram[data-astro-cid-ipdb5bjo] figcaption[data-astro-cid-ipdb5bjo]{border-top:1px solid var(--color-line);color:var(--color-muted);font-size:var(--type-caption);padding:.55rem .75rem;line-height:1.5}.comparison-scroll[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);overflow-x:auto}.comparison-scroll[data-astro-cid-ipdb5bjo] table[data-astro-cid-ipdb5bjo]{border-collapse:collapse;width:100%;font-size:var(--type-small);line-height:1.4}.comparison-scroll[data-astro-cid-ipdb5bjo] th[data-astro-cid-ipdb5bjo],.comparison-scroll[data-astro-cid-ipdb5bjo] td[data-astro-cid-ipdb5bjo]{text-align:left;vertical-align:top;border-bottom:1px solid var(--color-line);padding:.62rem .7rem}.comparison-scroll[data-astro-cid-ipdb5bjo] th[data-astro-cid-ipdb5bjo]+th[data-astro-cid-ipdb5bjo],.comparison-scroll[data-astro-cid-ipdb5bjo] th[data-astro-cid-ipdb5bjo]+td[data-astro-cid-ipdb5bjo],.comparison-scroll[data-astro-cid-ipdb5bjo] td[data-astro-cid-ipdb5bjo]+td[data-astro-cid-ipdb5bjo]{border-left:1px solid var(--color-line)}.comparison-scroll[data-astro-cid-ipdb5bjo] thead[data-astro-cid-ipdb5bjo] th[data-astro-cid-ipdb5bjo]{background:var(--color-blue-100);color:var(--color-navy-950);font-weight:var(--weight-bold)}.comparison-scroll[data-astro-cid-ipdb5bjo] tbody[data-astro-cid-ipdb5bjo] th[data-astro-cid-ipdb5bjo]{width:32%;color:var(--color-navy-900);font-weight:var(--weight-semibold)}.comparison-scroll[data-astro-cid-ipdb5bjo] tbody[data-astro-cid-ipdb5bjo] td[data-astro-cid-ipdb5bjo]{width:34%;color:var(--color-navy-800)}.comparison-scroll[data-astro-cid-ipdb5bjo] tbody[data-astro-cid-ipdb5bjo] tr[data-astro-cid-ipdb5bjo]:last-child>[data-astro-cid-ipdb5bjo]{border-bottom:0}.comparison-key[data-astro-cid-ipdb5bjo]>[data-astro-cid-ipdb5bjo]{background:var(--color-blue-50)}.comparison-key[data-astro-cid-ipdb5bjo] td[data-astro-cid-ipdb5bjo]:last-child{font-weight:var(--weight-bold)}.table-note[data-astro-cid-ipdb5bjo],.chemistry-caveat[data-astro-cid-ipdb5bjo],.verification-note[data-astro-cid-ipdb5bjo]{color:var(--color-muted);font-size:var(--type-caption);margin:.65rem 0 0;line-height:1.55}.chemistry-grid[data-astro-cid-ipdb5bjo],.grade-grid[data-astro-cid-ipdb5bjo],.practical-grid[data-astro-cid-ipdb5bjo],.verification-grid[data-astro-cid-ipdb5bjo]{grid-template-columns:repeat(2,minmax(0,1fr));gap:.85rem;display:grid}.chemistry-grade[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);grid-template-columns:3.5rem minmax(0,1fr);gap:.75rem;padding:1rem;display:grid}.chemistry-grade--316[data-astro-cid-ipdb5bjo]{background:var(--color-blue-50);border-color:var(--color-blue-100)}.chemistry-grade__number[data-astro-cid-ipdb5bjo]{color:var(--color-navy-800);font-size:2rem;font-weight:var(--weight-bold);letter-spacing:-.05em;line-height:1}.chemistry-grade--316[data-astro-cid-ipdb5bjo] .chemistry-grade__number[data-astro-cid-ipdb5bjo]{color:var(--color-blue-600)}.chemistry-grade[data-astro-cid-ipdb5bjo] h3[data-astro-cid-ipdb5bjo],.practical[data-astro-cid-ipdb5bjo] h3[data-astro-cid-ipdb5bjo],.application-notes[data-astro-cid-ipdb5bjo] h3[data-astro-cid-ipdb5bjo]{font-size:var(--type-body);margin:0;line-height:1.3}.chemistry-grade[data-astro-cid-ipdb5bjo] p[data-astro-cid-ipdb5bjo],.practical[data-astro-cid-ipdb5bjo] p[data-astro-cid-ipdb5bjo],.application-notes[data-astro-cid-ipdb5bjo] p[data-astro-cid-ipdb5bjo]{color:var(--color-muted);font-size:var(--type-small);margin:.35rem 0 0;line-height:1.6}.decision-grid[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);grid-template-columns:repeat(4,minmax(0,1fr));display:grid;overflow:hidden}.decision[data-astro-cid-ipdb5bjo]{border-right:1px solid var(--color-line);flex-direction:column;min-width:0;padding:.95rem;display:flex}.decision[data-astro-cid-ipdb5bjo]:last-child{border-right:0}.decision__step[data-astro-cid-ipdb5bjo]{color:var(--color-blue-600);font-size:.7rem;font-weight:var(--weight-bold);letter-spacing:.04em;text-transform:uppercase}.decision[data-astro-cid-ipdb5bjo] h3[data-astro-cid-ipdb5bjo]{font-size:var(--type-small);margin:.55rem 0 0;line-height:1.3}.decision[data-astro-cid-ipdb5bjo] p[data-astro-cid-ipdb5bjo]{color:var(--color-muted);font-size:var(--type-label);margin:.45rem 0 .9rem;line-height:1.5}.decision[data-astro-cid-ipdb5bjo] strong[data-astro-cid-ipdb5bjo],.decision[data-astro-cid-ipdb5bjo] a[data-astro-cid-ipdb5bjo]{border-top:1px solid var(--color-line);color:var(--color-blue-700);font-size:var(--type-label);margin-top:auto;padding-top:.6rem;line-height:1.4;text-decoration:none;display:block}.decision[data-astro-cid-ipdb5bjo] a[data-astro-cid-ipdb5bjo]:hover{text-decoration:underline}.rule-of-thumb[data-astro-cid-ipdb5bjo]{border-radius:var(--radius-sm);background:var(--color-blue-50);color:var(--color-navy-800);font-size:var(--type-small);margin:.85rem 0 0;padding:.7rem .8rem;line-height:1.5}.grade-card[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);overflow:hidden}.grade-card[data-astro-cid-ipdb5bjo]>img[data-astro-cid-ipdb5bjo]{object-fit:cover;width:100%;height:9.5rem}.grade-card__body[data-astro-cid-ipdb5bjo]{padding:1rem}.grade-card__label[data-astro-cid-ipdb5bjo]{color:var(--color-blue-600);font-size:var(--type-caption);font-weight:var(--weight-bold);letter-spacing:.07em;text-transform:uppercase}.grade-card[data-astro-cid-ipdb5bjo] h3[data-astro-cid-ipdb5bjo]{font-size:var(--type-lead);margin:.2rem 0 .4rem;line-height:1.25}.grade-card[data-astro-cid-ipdb5bjo] p[data-astro-cid-ipdb5bjo]{color:var(--color-muted);font-size:var(--type-small);margin:0;line-height:1.55}.grade-card[data-astro-cid-ipdb5bjo] ul[data-astro-cid-ipdb5bjo]{grid-template-columns:repeat(2,minmax(0,1fr));gap:.35rem .7rem;margin:.8rem 0;padding:0;list-style:none;display:grid}.grade-card[data-astro-cid-ipdb5bjo] li[data-astro-cid-ipdb5bjo]{color:var(--color-navy-800);font-size:var(--type-label);padding-left:.8rem;line-height:1.4;position:relative}.grade-card[data-astro-cid-ipdb5bjo] li[data-astro-cid-ipdb5bjo]:before{color:var(--color-blue-600);content:"•";position:absolute;left:0}.grade-card[data-astro-cid-ipdb5bjo] a[data-astro-cid-ipdb5bjo]{font-size:var(--type-small);font-weight:var(--weight-semibold)}.application-notes[data-astro-cid-ipdb5bjo]{border-top:1px solid var(--color-line);grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin-top:1rem;padding-top:1rem;display:grid}.practical-grid[data-astro-cid-ipdb5bjo]>div[data-astro-cid-ipdb5bjo]{background:var(--color-surface);border-radius:var(--radius-sm);padding:1rem}.verification-grid[data-astro-cid-ipdb5bjo] figure[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);margin:0;overflow:hidden}.verification-grid[data-astro-cid-ipdb5bjo] img[data-astro-cid-ipdb5bjo]{width:100%;height:auto;display:block}.verification-grid[data-astro-cid-ipdb5bjo] figcaption[data-astro-cid-ipdb5bjo]{font-size:var(--type-label);gap:.15rem;padding:.65rem .8rem;line-height:1.45;display:grid}.verification-grid[data-astro-cid-ipdb5bjo] figcaption[data-astro-cid-ipdb5bjo] b[data-astro-cid-ipdb5bjo]{color:var(--color-navy-900)}.verification-grid[data-astro-cid-ipdb5bjo] figcaption[data-astro-cid-ipdb5bjo] span[data-astro-cid-ipdb5bjo]{color:var(--color-muted)}.specification[data-astro-cid-ipdb5bjo]{background:#f8faff}.spec-list[data-astro-cid-ipdb5bjo]{grid-template-columns:repeat(4,minmax(0,1fr));gap:.45rem;margin:1rem 0;padding:0;list-style:none;display:grid}.spec-list[data-astro-cid-ipdb5bjo] li[data-astro-cid-ipdb5bjo]{border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-white);gap:.15rem;padding:.7rem;display:grid}.spec-list[data-astro-cid-ipdb5bjo] span[data-astro-cid-ipdb5bjo]{color:var(--color-blue-600);font-size:.68rem;font-weight:var(--weight-bold)}.spec-list[data-astro-cid-ipdb5bjo] strong[data-astro-cid-ipdb5bjo]{color:var(--color-navy-900);font-size:var(--type-label);line-height:1.3}.spec-list[data-astro-cid-ipdb5bjo] small[data-astro-cid-ipdb5bjo]{color:var(--color-muted);font-size:.7rem;line-height:1.35}.example[data-astro-cid-ipdb5bjo]{border-left:2px solid var(--color-blue-500);background:var(--color-white);margin:1rem 0;padding:.8rem 1rem}.example[data-astro-cid-ipdb5bjo]>p[data-astro-cid-ipdb5bjo]:last-child{color:var(--color-navy-800);font-size:var(--type-small);margin:.35rem 0 0;line-height:1.6}.visually-hidden[data-astro-cid-ipdb5bjo]{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}@container guide (width<=48rem){.guide-hero[data-astro-cid-ipdb5bjo]{grid-template-columns:1fr}.guide-hero__media[data-astro-cid-ipdb5bjo]{min-height:12rem;max-height:16rem}.decision-grid[data-astro-cid-ipdb5bjo]{grid-template-columns:repeat(2,minmax(0,1fr))}.decision[data-astro-cid-ipdb5bjo]:nth-child(2){border-right:0}.decision[data-astro-cid-ipdb5bjo]:nth-child(-n+2){border-bottom:1px solid var(--color-line)}.spec-list[data-astro-cid-ipdb5bjo]{grid-template-columns:repeat(2,minmax(0,1fr))}}@container guide (width<=37rem){.chemistry-grid[data-astro-cid-ipdb5bjo],.grade-grid[data-astro-cid-ipdb5bjo],.practical-grid[data-astro-cid-ipdb5bjo],.verification-grid[data-astro-cid-ipdb5bjo],.application-notes[data-astro-cid-ipdb5bjo]{grid-template-columns:1fr}.comparison-scroll[data-astro-cid-ipdb5bjo] table[data-astro-cid-ipdb5bjo]{min-width:34rem}.grade-card[data-astro-cid-ipdb5bjo]>img[data-astro-cid-ipdb5bjo]{height:11rem}.rule-of-thumb[data-astro-cid-ipdb5bjo] span[data-astro-cid-ipdb5bjo]{display:none}}@container guide (width<=25rem){.decision-grid[data-astro-cid-ipdb5bjo]{grid-template-columns:1fr}.decision[data-astro-cid-ipdb5bjo]{border-right:0;border-bottom:1px solid var(--color-line)}.decision[data-astro-cid-ipdb5bjo]:last-child{border-bottom:0}.grade-card[data-astro-cid-ipdb5bjo] ul[data-astro-cid-ipdb5bjo]{grid-template-columns:1fr}}