/* Shared theme layer: retains ACS blue, navy and original spacing. */
:root{color-scheme:light}
:root[data-theme="dark"]{color-scheme:dark;--bg:#0d1422;--ink:#edf2fc;--muted:#b2bed1;--line:#344158;--theme-accent:#9cb6ff}
.header-controls{display:flex;align-items:center;gap:10px;order:2;margin-left:24px}header nav{order:1;margin-left:auto}header .brand{margin-right:25px}.theme-toggle{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:8px 12px;border:1px solid var(--line);background:transparent;color:var(--ink);font:500 13px 'DM Sans',sans-serif;cursor:pointer;white-space:nowrap}.theme-toggle:hover{border-color:var(--blue)}.theme-toggle span:first-child{font-size:20px;line-height:1}.menu{color:var(--ink)}
[data-theme="dark"] :is(.eyebrow,h1 em,.logo span,.card .index,.case-lines span,.case-facts a,.gs-tier,.gs-ind-num,.gs-includes li:before,.casechart .row span,.qreq,.gs-steps small,.process small,.next-steps li:before,.proof-anchor strong,.evidence-row>strong,.step:before){color:var(--theme-accent)}
[data-theme="dark"] :is(nav a:hover,nav a[aria-current=page],.capability-links a,.capability-row h3 span,.capability-example p span,.delivery-note a,.quote-steps li.is-active strong){color:var(--theme-accent)}
[data-theme="dark"] :is(.proof-section,.case,.case-ai,.delivery-note,.qsuccess){background:#18243a}
[data-theme="dark"] :is(.casechart,.quote-panel,.enquiry-panel,.qopt,.gs-popular,.gs-ps-side){background:#111c2e}
[data-theme="dark"] :is(input,textarea,select){background:#0d1728;color:var(--ink);border-color:#52617b}
[data-theme="dark"] input::placeholder,[data-theme="dark"] textarea::placeholder{color:#a6b2c6;opacity:1}
[data-theme="dark"] :is(.browser-bar){background:#202d44;color:#c3cee1;border-color:var(--line)}
[data-theme="dark"] :is(.project-screen>a,.case-visual a){background:#111c2e;border-color:var(--line)}
[data-theme="dark"] :is(.proof-stories article,.proof-footer,.proof-details,.next-project,.assistant-note,.tag){border-color:#42516c}
[data-theme="dark"] .system{box-shadow:18px 18px 0 #18243a}
[data-theme="dark"] .cta .btn,[data-theme="dark"] .gs-complete .gs-cta{color:#111726}
[data-theme="dark"] .skip:focus{background:#111c2e;color:#edf2fc}
[data-theme="dark"] .qopt:has(input:checked){background:#223654;border-color:#9cb6ff;box-shadow:inset 0 0 0 1px #9cb6ff}
@media(max-width:1100px){header{position:relative}.header-controls{margin-left:auto}header .brand{margin-right:15px}.menu{display:block;background:none;border:1px solid var(--line);padding:8px 12px;font-size:14px;min-height:44px}header nav{display:none;position:absolute;top:calc(100% - 1px);left:-6%;right:-6%;margin:0;background:var(--bg);z-index:10;padding:25px;box-shadow:0 15px 20px #0002;align-items:stretch}header nav.open{display:flex;flex-direction:column;gap:12px}header nav a{padding:8px 0}header nav .navcta{padding:10px 18px}}
@media(max-width:650px){.header-controls{gap:8px}.theme-toggle{padding:8px 10px}[data-theme="dark"] .system{box-shadow:8px 8px 0 #18243a}}

[data-theme="dark"] .biz-systems .btn{color:#111726}.biz-systems .eyebrow,.biz-grid span{color:#fff}