:root{--bg:#0b0c0f;--surface:#11131a;--text:#e8ecf1;--muted:#a9b1bb;--primary:#0b5fff;--primary-600:#0a3fbf;--ring:#8ab4ff;--ok:#22c55e;--warn:#f59e0b;--err:#ef4444;--shadow:none;--radius:10px;--control-h:44px}
@media (prefers-color-scheme: light){:root{--bg:#f7f9fc;--surface:#ffffff;--text:#0b0c0f;--muted:#4b5563;--primary:#0b5fff;--primary-600:#0a3fbf;--ring:#375df1;--shadow:none;--err:#B00020}}
*{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--bg);color:var(--text);font:16px/1.5 system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Noto Sans,sans-serif;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased}a{color:inherit}img{max-width:100%;height:auto}
.container{max-width:100%;margin:0;padding:0}
.site-header{padding-top:0;padding-bottom:0}
.site-header h1{margin:.25rem 0 0;font-size:clamp(1.5rem,3vw,2rem)}
.lede{margin:.25rem 0 1rem;color:var(--muted)}
.site-footer{margin:2rem 0 0;padding:0;color:var(--muted)}

.theme-actions{display:flex;justify-content:flex-end}
.theme-toggle{display:inline-flex;align-items:center;gap:.5rem;padding:.4rem .65rem;background:transparent;border:1px solid rgba(128,128,160,.35);border-radius:0;color:var(--text);cursor:pointer}
.theme-toggle:hover{background:var(--surface)}
.theme-toggle:focus{outline:3px solid var(--ring);outline-offset:2px}

.bmc-button{display:inline-flex;align-items:center;gap:.5rem;margin-top:.5rem;padding:.625rem .9rem;background:var(--primary);color:#fff;text-decoration:none;border-radius:0;box-shadow:var(--shadow);font-weight:600}
.bmc-button:hover{background:var(--primary-600)}
.bmc-button:focus{outline:3px solid var(--ring);outline-offset:2px}

.skip-link{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}
.skip-link:focus{left:1rem;top:1rem;width:auto;height:auto;padding:.5rem 1rem;background:var(--primary);color:#fff;border-radius:var(--radius);box-shadow:var(--shadow)}

fieldset{border:none;border-radius:var(--radius);margin:1rem 0;padding:1rem 1rem 1rem 0;background:var(--surface);box-shadow:var(--shadow)}
legend{padding:0 .5rem 0 0;color:var(--muted);font-weight:600}
label{display:block;margin:.125rem 0 .25rem}
.input-unit{display:flex;align-items:stretch;gap:0}
.input-unit input[type=number]{flex:1;min-width:0;padding:.625rem .75rem;border:1px solid rgba(128,128,160,.35);border-radius:0;background:transparent;color:var(--text);height:var(--control-h)}
.input-unit select{padding:.625rem .75rem;border:1px solid rgba(128,128,160,.35);border-left:none;border-radius:0;background:transparent;color:var(--text);height:var(--control-h)}
.field>select{display:block;width:100%;padding:.625rem .75rem;border:1px solid rgba(128,128,160,.35);border-radius:0;background:transparent;color:var(--text);height:var(--control-h)}
.input-unit .segmented{border-left:none}
.prefix,.suffix{display:inline-flex;align-items:center;gap:.25rem;border:1px solid rgba(128,128,160,.35);border-radius:0;padding:.625rem .5rem;color:var(--muted);height:var(--control-h)}
.prefix{border-right:none}
.suffix{border-left:none}
.field{min-width:0}
.error{margin:.25rem 0 0;color:var(--err);font-size:.875rem}
.help{margin:.25rem 0 0;color:var(--muted);font-size:.9rem}
.small{font-size:.9rem}
.muted{color:var(--muted)}

/* Keep buttons square as requested */
button{border-radius:0}
input,select,textarea{border-radius:0}

.grid{display:grid;gap:.75rem}
.grid-gap{gap:1rem}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
@media (max-width:720px){.grid-2,.grid-3{grid-template-columns:1fr}}

.radio{display:flex;align-items:center;gap:.5rem;padding:.5rem;border:1px solid rgba(128,128,160,.35);border-radius:var(--radius)}
.radio input{margin-right:.25rem}
.segmented{display:inline-flex;border:1px solid rgba(128,128,160,.35);border-radius:var(--radius);overflow:hidden}
.segmented label{margin:0}
.segmented input{position:absolute;opacity:0;pointer-events:none}
.segmented span{display:inline-block;padding:.5rem .75rem}
.segmented input:checked+span{background:var(--primary);color:#fff}

.results-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem}
@media (max-width:720px){.results-grid{grid-template-columns:1fr}}
.result{background:var(--surface);border:1px solid rgba(128,128,160,.25);border-radius:0;padding:1rem;box-shadow:var(--shadow)}
.result .label{color:var(--muted);margin-bottom:.25rem}
.result .value{font-weight:600;font-size:1.25rem}

:focus{outline-color:var(--ring)}
:focus-visible{outline:3px solid var(--ring);outline-offset:1px;border-radius:0}

@media (prefers-reduced-motion: reduce){*{animation:none!important;transition:none!important}}

/* Explicit theme overrides via data-theme; default remains current CSS without attribute */
[data-theme="light"]{
	--bg:#CDE3F7;--surface:#ffffff;--text:#0b0c0f;--muted:#4B5563;--primary:#274E87;--primary-600:#1E3A5F;--ring:#375df1;--ok:#16a34a;--warn:#F8A23B;--err:#B00020;--shadow:none
}
[data-theme="dark"]{
	--bg:#0b2f5a;--surface:#0f1520;--text:#e8ecf1;--muted:#a9b1bb;--primary:#274E87;--primary-600:#1E3A5F;--ring:#8ab4ff;--ok:#22c55e;--warn:#F8A23B;--err:#E44B4D;--shadow:none
}
/* Split layout (flex) */
.split{display:flex;flex-direction:row;min-height:100vh;align-items:center}
.split-left{position:relative;overflow:hidden;background:#d9f2ff;flex:1 1 auto;min-width:0}
.split-image{position:sticky;top:0;left:0;width:100%;height:100vh;object-fit:cover;display:block;filter:contrast(1.05) saturate(1.05)}
.split-right{display:flex;flex-direction:column;min-width:0;background:var(--surface);color:var(--text);max-width:920px;flex:0 1 920px;padding:2rem 2rem 4rem;margin:2rem 2rem 2rem 0;width:auto;border-radius:var(--radius)}
@media (max-width:900px){
	.split{flex-direction:column}
	.split-image{height:40vh;position:relative}
	.split-right{max-width:none;width:auto;flex:0 0 auto;margin:1rem}
}

/* Remove previous page-wide background image if present */
body{background-image:none}
/* Page background colour to match the image palette */
body{background-color:#d9f2ff}