:root{--bg: #0a1322;--surface: #131e33;--surface-2: #1b2944;--border: #243454;--text: #e8edf5;--text-muted: #8c97a8;--accent: #22d3ee;--accent-strong: #06b6d4;--accent-dim: rgba(34, 211, 238, .12);--result-bg: #0f1a2e;--shadow: 0 6px 24px rgba(0, 0, 0, .4);--radius: 14px;--radius-sm: 10px}*{box-sizing:border-box}html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,system-ui,Roboto,Helvetica Neue,Arial,sans-serif;font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{min-height:100vh;min-height:100dvh;display:flex;justify-content:center}main{width:100%;max-width:520px;padding:16px 16px 32px;display:flex;flex-direction:column;gap:20px}header.app-header{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:8px 0 4px}h1.app-title{font-size:20px;font-weight:600;margin:0;letter-spacing:-.01em}.lang-switch{display:inline-flex;background:var(--surface);border:1px solid var(--border);border-radius:999px;padding:3px;gap:2px}.lang-switch a{padding:6px 12px;font-size:13px;font-weight:600;text-decoration:none;color:var(--text-muted);border-radius:999px;transition:background .15s ease,color .15s ease}.lang-switch a[aria-current=page]{background:var(--accent-dim);color:var(--accent)}.lang-switch a:hover:not([aria-current=page]){color:var(--text)}section.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px 16px;display:flex;flex-direction:column;gap:14px}section.card[hidden]{display:none}h2.section-title{font-size:15px;font-weight:600;margin:0;text-transform:uppercase;letter-spacing:.06em;color:var(--text-muted)}.section-intro{margin:0;font-size:13px;color:var(--text-muted)}label.field{display:flex;flex-direction:column;gap:6px}label.field>span.label-text{font-size:14px;color:var(--text-muted)}.input-row{display:flex;align-items:stretch;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius-sm);overflow:hidden}.input-row:focus-within{border-color:var(--accent-strong);box-shadow:0 0 0 3px var(--accent-dim)}.input-row input{flex:1;background:transparent;border:0;outline:0;color:var(--text);font-size:18px;font-weight:500;padding:12px 14px;font-variant-numeric:tabular-nums;width:100%}.input-row .unit{display:inline-flex;align-items:center;padding:0 14px;font-size:14px;color:var(--text-muted);background:#00000026;border-left:1px solid var(--border)}.input-row input::-webkit-outer-spin-button,.input-row input::-webkit-inner-spin-button{-webkit-appearance:none;margin:0}.input-row input[type=number]{-moz-appearance:textfield}.segmented{display:grid;grid-template-columns:1fr 1fr;background:var(--surface);border:1px solid var(--border);border-radius:999px;padding:4px;gap:2px}.segmented-option{appearance:none;background:transparent;border:0;color:var(--text-muted);font:inherit;font-size:14px;font-weight:600;padding:10px 12px;border-radius:999px;cursor:pointer;transition:background .15s ease,color .15s ease}.segmented-option:hover:not(.is-active){color:var(--text)}.segmented-option.is-active{background:var(--accent-dim);color:var(--accent)}.segmented-option:focus-visible{outline:2px solid var(--accent-strong);outline-offset:2px}.fill-error{margin:0;font-size:13px;line-height:1.4;color:#fca5a5;background:#fca5a514;border:1px solid rgba(252,165,165,.25);border-radius:var(--radius-sm);padding:10px 12px}.fill-error[hidden]{display:none}.result{display:flex;flex-direction:column;gap:4px;background:var(--result-bg);border:1px solid var(--border);border-radius:var(--radius-sm);padding:14px 16px}.result .result-label{font-size:13px;color:var(--text-muted)}.result .result-value{font-size:32px;font-weight:700;color:var(--accent);font-variant-numeric:tabular-nums;letter-spacing:-.02em;line-height:1.1}.result .result-value .result-unit{font-size:18px;font-weight:500;color:var(--text-muted);margin-left:4px;letter-spacing:0}footer.disclaimer{font-size:12px;color:var(--text-muted);line-height:1.6;padding:0 4px}footer.disclaimer .disclaimer-title{font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--text-muted);margin-bottom:4px;font-size:11px}.tank{display:grid;grid-template-columns:120px 1fr;gap:16px;align-items:stretch;padding:4px 0}.tank-svg{width:120px;height:220px;user-select:none;touch-action:none;cursor:grab;outline:none}.tank-svg:focus-visible .tank-body{stroke:var(--accent);stroke-width:3px}.tank-svg:active{cursor:grabbing}.tank-readout{display:flex;flex-direction:column;justify-content:center;gap:8px}.tank-readout .o2-value{font-size:56px;font-weight:700;color:var(--accent);line-height:1;font-variant-numeric:tabular-nums;letter-spacing:-.03em}.tank-readout .o2-value .o2-unit{font-size:24px;font-weight:500;color:var(--text-muted);margin-left:2px}.tank-readout .o2-hint{font-size:12px;color:var(--text-muted)}.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:360px){main{padding:12px 12px 24px}.tank{grid-template-columns:100px 1fr}.tank-svg{width:100px;height:200px}.tank-readout .o2-value{font-size:48px}}