:root{--bg-base:#060911;--card-bg:#0f172ac7;--card-border:#ffffff24;--card-glow:#38bdf81f;--text-primary:#f8fafc;--text-secondary:#94a3b8;--accent-cyan:#38bdf8;--accent-emerald:#34d399;--accent-amber:#fbbf24;--dropdown-bg:#0d1527;--dropdown-border:#334155;--dropdown-optgroup-bg:#070c18;--input-bg:#00000073;--radius-2xl:24px;--radius-xl:18px;--radius-lg:14px;--radius-sm:8px;--font-mono:ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent;margin:0;padding:0}body{background-color:var(--bg-base);color:var(--text-primary);justify-content:center;align-items:center;min-height:100vh;padding:16px;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;transition:background-color .8s;display:flex;position:relative;overflow-x:hidden}.wallpaper-layer{z-index:0;pointer-events:none;background-position:50%;background-size:cover;transition:opacity .8s cubic-bezier(.4,0,.2,1),background .8s cubic-bezier(.4,0,.2,1);position:fixed;inset:0}.ambient-glow{z-index:0;pointer-events:none;background:radial-gradient(circle at 50% 25%, var(--card-glow), transparent 70%);transition:background .8s;position:fixed;inset:0}body.cat-length{--card-glow:#38bdf838}body.cat-length .wallpaper-layer{background:radial-gradient(circle at 80% 20%,#38bdf826,#0000 50%),radial-gradient(circle at 20% 80%,#10b9811f,#0000 50%),linear-gradient(#ffffff08 1px,#0000 1px) 0 0/40px 40px,linear-gradient(90deg,#ffffff08 1px,#0000 1px) 0 0/40px 40px,#060913}body.cat-mass{--card-glow:#f9731633}body.cat-mass .wallpaper-layer{background:radial-gradient(circle at 70% 30%,#f9731629,#0000 55%),radial-gradient(circle at 30% 70%,#d9770624,#0000 60%),radial-gradient(circle,#78350f1f,#0000 70%),#0c0a08}body.cat-time{--card-glow:#f59e0b38}body.cat-time .wallpaper-layer{background:radial-gradient(circle at 50% 15%,#f59e0b2e,#0000 50%),radial-gradient(circle at 80% 85%,#b4530926,#0000 55%),radial-gradient(circle,#0000 60%,#f59e0b0a 62%,#0000 64%),radial-gradient(circle,#0000 80%,#f59e0b0a 82%,#0000 84%),#0b0a06}body.cat-frequency{--card-glow:#ec489938}body.cat-frequency .wallpaper-layer{background:radial-gradient(circle at 85% 20%,#ec48992e,#0000 50%),radial-gradient(circle at 15% 80%,#8b5cf629,#0000 55%),linear-gradient(0deg,#ec48990a 1px,#0000 1px) 0 0/100% 24px,#0c0612}body.cat-temperature{--card-glow:#ef44443d}body.cat-temperature .wallpaper-layer{background:radial-gradient(circle at 20% 20%,#38bdf829,#0000 45%),radial-gradient(circle at 80% 20%,#ef444433,#0000 50%),radial-gradient(circle at 50% 90%,#f9731629,#0000 60%),#0d0707}body.cat-area{--card-glow:#10b98138}body.cat-area .wallpaper-layer{background:radial-gradient(circle at 75% 25%,#10b9812e,#0000 50%),radial-gradient(circle at 25% 75%,#05966924,#0000 60%),linear-gradient(45deg,#ffffff05 25%,#0000 25% 75%,#ffffff05 75%,#ffffff05) 0 0/30px 30px,#060e0a}body.cat-volume{--card-glow:#0ea5e940}body.cat-volume .wallpaper-layer{background:radial-gradient(circle at 50% 10%,#38bdf838,#0000 50%),radial-gradient(circle at 85% 70%,#0369a12e,#0000 55%),radial-gradient(circle at 15% 85%,#0ea5e926,#0000 50%),#050b14}body.cat-speed{--card-glow:#a855f73d}body.cat-speed .wallpaper-layer{background:radial-gradient(circle at 20% 30%,#a855f733,#0000 50%),radial-gradient(circle at 80% 70%,#38bdf82e,#0000 50%),linear-gradient(135deg,#ffffff08 1px,#0000 1px) 0 0/32px 32px,#090614}body.cat-energy{--card-glow:#eab3083d}body.cat-energy .wallpaper-layer{background:radial-gradient(circle at 50% 20%,#eab30838,#0000 50%),radial-gradient(circle at 80% 80%,#f59e0b29,#0000 55%),#0d0b05}body.cat-power{--card-glow:#f43f5e3d}body.cat-power .wallpaper-layer{background:radial-gradient(circle at 75% 25%,#f43f5e33,#0000 50%),radial-gradient(circle at 25% 75%,#e11d4826,#0000 55%),#0e0508}body.cat-pressure{--card-glow:#3b82f63d}body.cat-pressure .wallpaper-layer{background:radial-gradient(circle at 50% 25%,#3b82f633,#0000 50%),radial-gradient(circle,#0000 40%,#3b82f60d 42%,#0000 44%),radial-gradient(circle,#0000 65%,#3b82f60a 67%,#0000 69%),#060a14}body.cat-fuel_economy{--card-glow:#22c55e3d}body.cat-fuel_economy .wallpaper-layer{background:radial-gradient(circle at 30% 30%,#22c55e33,#0000 50%),radial-gradient(circle at 70% 70%,#10b98129,#0000 55%),#060e08}body.cat-digital_storage{--card-glow:#06b6d440}body.cat-digital_storage .wallpaper-layer{background:radial-gradient(circle at 80% 20%,#06b6d438,#0000 50%),radial-gradient(circle at 20% 80%,#3b82f629,#0000 55%),linear-gradient(#06b6d40a 1px,#0000 1px) 0 0/24px 24px,linear-gradient(90deg,#06b6d40a 1px,#0000 1px) 0 0/24px 24px,#050d12}body.cat-data_transfer{--card-glow:#6366f140}body.cat-data_transfer .wallpaper-layer{background:radial-gradient(circle at 50% 20%,#6366f138,#0000 50%),radial-gradient(circle at 80% 80%,#8b5cf62e,#0000 55%),#070714}body.cat-electricity{--card-glow:#38bdf847}body.cat-electricity .wallpaper-layer{background:radial-gradient(circle at 30% 25%,#38bdf840,#0000 50%),radial-gradient(circle at 70% 75%,#eab30829,#0000 55%),#050a14}body.cat-angles{--card-glow:#8b5cf63d}body.cat-angles .wallpaper-layer{background:radial-gradient(circle at 50% 25%,#8b5cf633,#0000 50%),radial-gradient(circle at 80% 80%,#a855f729,#0000 55%),#0a0614}body.cat-radiation{--card-glow:#a3e63542}body.cat-radiation .wallpaper-layer{background:radial-gradient(circle at 50% 20%,#a3e63538,#0000 50%),radial-gradient(circle at 80% 80%,#eab30829,#0000 55%),#090d05}body.cat-typography{--card-glow:#e2e8f029}body.cat-typography .wallpaper-layer{background:radial-gradient(circle at 50% 20%,#f8fafc1f,#0000 50%),linear-gradient(#ffffff0a 1px,#0000 1px) 0 0/16px 16px,#08090c}#zen-converter-wrapper{z-index:10;width:100%;max-width:440px;position:relative}.converter-card{background:var(--card-bg);border:1px solid var(--card-border);-webkit-backdrop-filter:blur(28px);border-radius:var(--radius-2xl);box-shadow:0 28px 56px #000000bf, 0 0 40px var(--card-glow);padding:24px;transition:box-shadow .6s,border-color .6s}.brand-row{justify-content:space-between;align-items:center;margin-bottom:14px;display:flex}.badge-zero-drift{font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.8px;color:var(--accent-emerald);background:#34d39924;border:1px solid #34d39959;border-radius:50px;padding:4px 10px;font-size:10px;font-weight:700}.category-theme-label{color:var(--accent-cyan);font-size:11px;font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.5px;font-weight:700}.category-select-wrapper label{text-transform:uppercase;letter-spacing:1px;color:var(--text-secondary);margin-bottom:6px;font-size:11px;font-weight:600;display:block}select{appearance:none;background-color:var(--dropdown-bg);border:1px solid var(--dropdown-border);color:var(--text-primary);cursor:pointer;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' 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14px;font-size:15px;font-weight:600}.preferences-row{border-top:1px solid #ffffff1a;justify-content:space-between;align-items:center;gap:8px;margin:16px 0;padding-top:14px;display:flex}.system-toggle{border:1px solid var(--card-border);background:#00000073;border-radius:50px;padding:3px;display:flex}.toggle-btn{color:var(--text-secondary);cursor:pointer;background:0 0;border:none;border-radius:50px;padding:5px 10px;font-size:11px;font-weight:600;transition:all .2s}.toggle-btn.active{color:var(--accent-cyan);background:#38bdf840;border:1px solid #38bdf880}.precision-box{color:var(--text-secondary);align-items:center;gap:6px;font-size:11px;display:flex}.precision-select{border-radius:var(--radius-sm);background-size:11px;padding:5px 26px 5px 8px;font-size:11px}.converter-grid{flex-direction:column;gap:12px;margin-bottom:16px;display:flex}.unit-box{border:1px solid var(--card-border);border-radius:var(--radius-lg);background:#0000006b;padding:14px;transition:border-color .2s}.unit-box:focus-within{border-color:#38bdf880}.unit-box label{text-transform:uppercase;letter-spacing:.8px;color:var(--text-secondary);margin-bottom:6px;font-size:10px;display:block}.num-row{align-items:center;gap:8px;margin-bottom:10px;display:flex}.big-input{width:100%;color:var(--text-primary);font-size:28px;font-weight:700;font-family:var(--font-mono);background:0 0;border:none;outline:none}.big-result{color:var(--accent-cyan)}.unit-symbol{font-family:var(--font-mono);color:var(--accent-cyan);opacity:.95;font-size:17px;font-weight:700}.unit-select{border-radius:var(--radius-sm);width:100%;padding:10px 34px 10px 12px;font-size:13px;font-weight:500}.converter-swap-btn{color:var(--accent-cyan);cursor:pointer;z-index:10;background:#38bdf82e;border:1px solid #38bdf873;border-radius:50%;justify-content:center;align-self:center;align-items:center;width:44px;height:44px;margin:-4px 0;transition:all .2s cubic-bezier(.4,0,.2,1);display:flex;box-shadow:0 4px 14px #00000080}.converter-swap-btn:hover{border-color:var(--accent-cyan);background:#38bdf859;transform:rotate(180deg)scale(1.12);box-shadow:0 0 20px #38bdf866}.scale-anchor-card{border-radius:var(--radius-lg);background:#fbbf241f;border:1px solid #fbbf2459;align-items:center;gap:10px;margin-bottom:16px;padding:10px 14px;animation:.3s fadeIn;display:flex}.scale-anchor-card.hidden{display:none}.scale-anchor-text{color:var(--accent-amber);font-size:12px;font-weight:600}.copy-wrapper{margin-top:4px}.copy-btn{border:1px solid var(--card-border);width:100%;color:var(--text-primary);border-radius:var(--radius-lg);cursor:pointer;background:#ffffff14;justify-content:center;align-items:center;gap:8px;padding:13px;font-size:13px;font-weight:600;transition:all .2s;display:flex}.copy-btn:hover{background:#ffffff29;border-color:#ffffff4d}.copy-btn.copied{border-color:var(--accent-emerald);color:var(--accent-emerald);background:#34d39947}@keyframes fadeIn{0%{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:translateY(0)}}