.gas-main { max-width: 1000px; }
.gas-tool-select { display: none; margin-bottom: 24px; color: var(--muted); font-size: 16px; }
.gas-tool-select select { display: block; width: 100%; margin-top: 10px; font-size: 16px; min-height: 48px; }
.gas-hero { margin-bottom: 24px; }
.gas-hero h1 { font-size: clamp(38px, 6vw, 60px); }
.gas-picker { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-bottom: 28px; }
.gas-picker a { padding: 14px 16px; color: var(--ink); border: 1px solid var(--line); border-radius: 12px; text-decoration: none; font-size: 16px; background: rgba(14,40,45,.7); }
.gas-picker a:hover, .gas-picker a:focus-visible { border-color: var(--green); }
.gas-tool { margin-bottom: 18px; scroll-margin-top: 20px; }
.gas-tool > summary { cursor: pointer; list-style: none; }
.gas-tool > summary::-webkit-details-marker { display: none; }
.gas-tool h2 { margin: 8px 0; font-family: Georgia, serif; font-weight: 400; font-size: 27px; }
.gas-tool summary > span:last-child { color: var(--green); font-size: 14px; }
.gas-tool p, .gas-references p, .gas-references li, .gas-disclaimer p { font-size: 16px; line-height: 1.6; color: var(--muted); }
.gas-tool a, .gas-references a { color: var(--green); }
.gas-form { display: grid; gap: 18px; margin-top: 22px; }
.gas-form .field > span { font-size: 14px; line-height: 1.4; }
.gas-form input, .gas-form select { font-size: 16px; }
.gas-units { display: flex; flex-wrap: wrap; gap: 12px; border-bottom: 1px solid var(--line); padding-bottom: 18px; }
.gas-units label { flex: 1 1 130px; }
.gas-check { display: flex; align-items: flex-start; gap: 12px; font-size: 16px; line-height: 1.5; }
.gas-check input { flex: 0 0 auto; width: 22px; height: 22px; margin-top: 2px; accent-color: var(--green); }
.gas-result { margin-top: 22px; padding: 20px; border: 1px solid var(--line); border-radius: 14px; background: #0a211c; overflow-wrap: anywhere; }
.gas-result.attention { border-color: var(--amber); background: #241d0d; }
.gas-result h3 { font: 400 26px Georgia, serif; margin: 0 0 15px; color: var(--ink); }
.gas-result.attention h3 { color: var(--amber); }
.gas-metrics { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 18px; margin: 0; }
.gas-metrics dt { font-size: 14px; color: var(--faint); }
.gas-metrics dd { margin: 5px 0 0; font: 400 24px Georgia,serif; color: var(--ink); }
.gas-result ul, .gas-result ol { padding-left: 22px; color: var(--muted); font-size: 16px; line-height: 1.6; }
.gas-result .formula { margin-bottom: 0; font-size: 14px; border-top: 1px solid var(--line); padding-top: 16px; }
.gas-error { color: var(--amber); font-size: 16px; line-height: 1.5; }
.cylinder-row { border: 1px solid var(--line); border-radius: 12px; padding: 16px; margin: 0; min-width: 0; }
.cylinder-row legend { padding: 0 7px; font-size: 16px; color: var(--green); }
.cylinder-row .field-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
.cylinder-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.cylinder-actions button { border: 1px solid var(--line); background: #0a211c; color: var(--ink); border-radius: 10px; min-height: 44px; padding: 10px 15px; font-size: 16px; }
.cylinder-actions button:disabled { opacity: .45; cursor: default; }
.gas-references { margin-top: 35px; }
.gas-disclaimer { margin-top: 28px; border: 1px solid var(--line); border-radius: 14px; padding: 20px; }
@media(max-width:760px) { .gas-picker { display: none; } .gas-tool-select { display: block; } .gas-metrics, .cylinder-row .field-grid { grid-template-columns: 1fr; } .gas-tool h2 { font-size: 25px; } .gas-result { padding: 16px; } }

.gas-form .field[hidden] { display: none; }