:root{--bg:#101822;--panel:#192434;--panel-2:#111d2b;--border:#233248;--text:#fff;--muted:#9bb0ce;--primary:#1973f0;--primary-soft:#78adff;--warning:#f59e0b;--success:#34d399;--max:1040px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:Lexend,Arial,sans-serif;line-height:1.7;-webkit-font-smoothing:antialiased}img,svg{max-width:100%;height:auto}a{color:var(--primary-soft);text-decoration:none}a:hover{text-decoration:underline}.skip-link{position:absolute;left:-9999px;top:8px;background:#fff;color:#111;padding:10px 14px;z-index:100}.skip-link:focus{left:8px}.site-header{position:sticky;top:0;z-index:20;background:rgba(16,24,34,.94);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}.header-inner,.page,.footer-inner{max-width:var(--max);margin:auto;padding-left:20px;padding-right:20px}.header-inner{min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{color:#fff;font-weight:800;letter-spacing:-.02em}.nav{display:flex;gap:18px;flex-wrap:wrap;font-size:14px}.nav a{color:#cfe0f8}.hero{padding:58px 0 28px}.eyebrow{color:var(--primary-soft);font-size:13px;font-weight:700;letter-spacing:.14em;text-transform:uppercase}.hero h1{font-size:clamp(32px,6vw,54px);line-height:1.1;margin:12px 0 16px;letter-spacing:-.035em}.lead{font-size:18px;color:var(--muted);max-width:800px}.content{padding:18px 0 72px}.card{background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:24px;margin:18px 0}.card h2,.card h3{margin-top:0;line-height:1.25}.muted{color:var(--muted)}.notice{border-left:4px solid var(--primary);background:#132238;padding:16px 18px;border-radius:8px;margin:22px 0}.warning{border-left-color:var(--warning);background:#2a2212}.success{border-left-color:var(--success);background:#10251f}.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.pill-list{display:flex;flex-wrap:wrap;gap:10px;padding:0;list-style:none}.pill-list li,.pill{background:var(--panel-2);border:1px solid var(--border);border-radius:999px;padding:7px 12px;color:#d7e5fa;font-size:14px}.table-wrap{overflow-x:auto}.data-table{width:100%;border-collapse:collapse}.data-table th,.data-table td{text-align:left;border-bottom:1px solid var(--border);padding:12px 10px;vertical-align:top}.data-table th{color:#cfe0f8}.breadcrumbs{font-size:13px;color:var(--muted);padding-top:20px}.breadcrumbs ol{display:flex;flex-wrap:wrap;gap:8px;list-style:none;margin:0;padding:0}.breadcrumbs li:not(:last-child)::after{content:'›';margin-left:8px;color:#667b99}.molecule-hero{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(260px,.75fr);gap:28px;align-items:center}.formula-panel{background:linear-gradient(145deg,#182b43,#101822);border:1px solid #315172;border-radius:18px;padding:28px;text-align:center;box-shadow:0 18px 50px rgba(0,0,0,.22)}.formula-large{font-size:clamp(46px,9vw,78px);font-weight:800;letter-spacing:.02em}.lewis-ascii{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;white-space:pre;display:inline-block;text-align:left;color:#eaf3ff;font-size:clamp(16px,3vw,24px);line-height:1.35;margin:16px auto}.facts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:24px 0}.fact{background:var(--panel-2);border:1px solid var(--border);border-radius:12px;padding:15px}.fact strong{display:block;font-size:13px;color:#cfe0f8;margin-bottom:4px}.fact span{color:#fff}.steps{counter-reset:step;list-style:none;padding:0;margin:0}.steps li{counter-increment:step;position:relative;padding:0 0 22px 52px}.steps li::before{content:counter(step);position:absolute;left:0;top:0;width:34px;height:34px;border-radius:10px;background:var(--primary);color:#fff;display:grid;place-items:center;font-weight:800}.steps li+li{border-top:1px solid transparent}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.related-card{display:block;background:var(--panel-2);border:1px solid var(--border);border-radius:12px;padding:16px;color:#fff}.related-card:hover{border-color:#416992;text-decoration:none;transform:translateY(-1px)}.related-card small{display:block;color:var(--muted);margin-top:4px}.cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:22px}.button{display:inline-flex;align-items:center;justify-content:center;background:var(--primary);color:#fff;border-radius:10px;padding:11px 16px;font-weight:700}.button.secondary{background:transparent;border:1px solid #3d5878}.button:hover{text-decoration:none;filter:brightness(1.08)}details{background:var(--panel-2);border:1px solid var(--border);border-radius:10px;margin:10px 0}summary{cursor:pointer;font-weight:700;padding:16px}details>div{padding:0 16px 16px;color:var(--muted)}.updated{font-size:13px;color:#758aa7}.site-footer{border-top:1px solid var(--border);background:#0b1119;padding:30px 0;color:var(--muted);font-size:13px}.footer-inner{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}.footer-links{display:flex;gap:14px;flex-wrap:wrap}@media(max-width:820px){.molecule-hero{grid-template-columns:1fr}.facts{grid-template-columns:repeat(2,minmax(0,1fr))}.grid-3,.related-grid{grid-template-columns:1fr 1fr}}@media(max-width:700px){.header-inner{align-items:flex-start;flex-direction:column;padding-top:14px;padding-bottom:14px}.nav{gap:12px}.hero{padding-top:42px}.grid,.grid-3,.related-grid{grid-template-columns:1fr}.card{padding:20px}.facts{grid-template-columns:1fr 1fr}.formula-panel{padding:22px 16px}}