:root{
    --bg:#07111f;--bg2:#101d33;--card:#16243a;--card2:#1e304b;--line:#2e4669;--text:#edf5ff;--muted:#9eb2ce;--brand:#38bdf8;--brand2:#60a5fa;--success:#22c55e;--warning:#f59e0b;--danger:#ef4444;--shadow:0 22px 60px rgba(0,0,0,.32)
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:Inter,Segoe UI,Arial,sans-serif;background:radial-gradient(circle at top left,#123e61,transparent 32%),linear-gradient(135deg,#06111f,#111827 55%,#08111f);color:var(--text);min-height:100vh;line-height:1.6;padding:28px 16px}
.page-shell{max-width:1100px;margin:auto}.hero-card{display:grid;grid-template-columns:1fr 260px;gap:22px;align-items:center;padding:34px;border:1px solid rgba(96,165,250,.26);border-radius:24px;background:linear-gradient(135deg,rgba(30,48,75,.92),rgba(17,31,54,.85));box-shadow:var(--shadow);margin-bottom:22px;overflow:hidden;position:relative}.hero-card:before{content:"";position:absolute;width:260px;height:260px;border-radius:50%;background:rgba(56,189,248,.12);filter:blur(8px);right:-90px;top:-110px}.hero-card>*{position:relative}.badge{display:inline-flex;align-items:center;gap:6px;border:1px solid rgba(56,189,248,.35);background:rgba(56,189,248,.12);color:#c7efff;padding:7px 12px;border-radius:999px;font-size:13px;font-weight:700;margin-bottom:12px}.badge.success{background:rgba(34,197,94,.16);border-color:rgba(34,197,94,.4);color:#caffd9}.hero-card h1{font-size:38px;line-height:1.1;margin-bottom:10px}.hero-card p,.panel-title p{color:var(--muted)}.mini-card{background:rgba(8,17,31,.72);border:1px solid rgba(158,178,206,.18);border-radius:18px;padding:20px;display:grid;gap:6px}.mini-card small,.mini-card span{color:var(--muted)}.mini-card strong{font-family:Consolas,monospace;font-size:24px;color:#86efac}.panel,.result-card{background:rgba(22,36,58,.92);border:1px solid rgba(158,178,206,.18);border-radius:22px;padding:24px;box-shadow:var(--shadow);margin-bottom:22px}.panel-title{margin-bottom:18px}.panel-title h2,.result-head h2,.solution h2{font-size:24px}.alert-error{background:rgba(239,68,68,.13);border:1px solid rgba(239,68,68,.42);color:#fecaca;padding:14px;border-radius:14px;margin-bottom:16px;font-weight:700}.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-bottom:18px}.mode-option{display:flex;align-items:center;gap:10px;padding:14px;border-radius:16px;background:var(--bg2);border:1px solid var(--line);cursor:pointer;font-weight:800}.mode-option.active,.mode-option:has(input:checked){border-color:var(--brand);box-shadow:0 0 0 4px rgba(56,189,248,.10);background:rgba(56,189,248,.12)}.mode-option input{accent-color:var(--brand)}.input-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.field-group label{display:block;font-weight:800;margin-bottom:8px}.field-group input{width:100%;padding:14px 16px;border-radius:14px;border:1px solid var(--line);background:#0d1728;color:var(--text);outline:none;font-family:Consolas,monospace;font-size:18px;letter-spacing:3px;font-weight:800}.field-group input:focus{border-color:var(--brand);box-shadow:0 0 0 4px rgba(56,189,248,.12)}.field-group small{color:var(--muted);font-size:13px}.live-preview{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:18px}.live-preview>div{background:var(--bg2);border:1px solid var(--line);border-radius:16px;padding:14px}.live-preview span{color:var(--muted);font-size:13px}.bits,.bit-output{display:flex;flex-wrap:wrap;gap:7px;margin-top:8px}.bits span,.bit-output span{width:34px;height:34px;border-radius:10px;display:inline-flex;align-items:center;justify-content:center;background:#203350;border:1px solid #395579;color:#dbeafe;font-family:Consolas,monospace;font-weight:900}.bits.small span{width:28px;height:28px;border-radius:8px;font-size:13px}.button-row{display:flex;gap:14px;margin-top:22px}.btn{border:0;border-radius:14px;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;padding:14px 20px;font-weight:900;cursor:pointer;transition:.2s;width:100%}.btn-primary{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#06111f}.btn-reset{background:#263752;color:#dbeafe}.btn:hover{transform:translateY(-1px);filter:brightness(1.05)}.result-card{border-left:5px solid var(--success)}.result-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-bottom:18px}.output-code{font-size:34px;font-family:Consolas,monospace;font-weight:900;color:#86efac;background:rgba(34,197,94,.12);padding:12px 18px;border-radius:16px;border:1px solid rgba(34,197,94,.35)}.summary-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.summary-item{background:#101d33;border:1px solid var(--line);border-radius:16px;padding:14px}.summary-item span{display:block;color:var(--muted);font-size:13px}.summary-item strong{font-family:Consolas,monospace;font-size:17px}.summary-item.highlight{background:rgba(34,197,94,.12);border-color:rgba(34,197,94,.35)}.bit-output{padding-top:16px}.bit-output span{background:linear-gradient(135deg,#16a34a,#22c55e);border-color:#22c55e;color:white}.solution-toggle{width:100%;padding:15px 18px;border:1px solid rgba(56,189,248,.35);background:rgba(56,189,248,.12);color:#dff7ff;border-radius:16px;font-weight:900;cursor:pointer}.solution{margin-top:20px}.step-section{background:#101d33;border:1px solid var(--line);border-radius:18px;margin-top:14px;overflow:hidden}.step-section summary{cursor:pointer;padding:16px 18px;font-weight:900;color:#e0f2fe;background:rgba(96,165,250,.08)}.table-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;padding:16px}.table-card,.calc-box{background:#0d1728;border:1px solid var(--line);border-radius:14px;padding:14px}.table-card h4{color:var(--brand);margin-bottom:6px}.table-card p,.calc-box p{font-family:Consolas,monospace;color:#dcecff}.sbox-wrap{display:grid;grid-template-columns:1fr 1fr;gap:12px;padding:0 16px 16px}.sbox-card{background:#0d1728;border:1px solid var(--line);border-radius:14px;padding:14px}.sbox-card h4{margin-bottom:8px;color:var(--brand)}.sbox-card table{width:100%;border-collapse:collapse}.sbox-card td{border:1px solid var(--line);text-align:center;padding:8px;font-family:Consolas,monospace}.step-list{display:grid;gap:12px;padding:16px}.step{display:grid;grid-template-columns:38px 1fr;gap:12px;background:#17263d;border:1px solid var(--line);border-radius:16px;padding:14px}.step>b{width:34px;height:34px;border-radius:50%;background:rgba(56,189,248,.14);border:1px solid rgba(56,189,248,.38);display:inline-flex;align-items:center;justify-content:center;color:#bae6fd}.step h3{font-size:16px;margin-bottom:5px}.step p{color:#c9d7ea;font-family:Consolas,monospace}.step.important{border-color:rgba(245,158,11,.5);background:rgba(245,158,11,.08)}.note{color:#fcd34d!important}.success-box{border-color:rgba(34,197,94,.45);background:rgba(34,197,94,.08)}footer{text-align:center;color:var(--muted);padding:18px}@media(max-width:780px){body{padding:12px}.hero-card,.input-grid,.live-preview,.summary-grid{grid-template-columns:1fr}.hero-card{padding:24px}.hero-card h1{font-size:30px}.mode-grid{grid-template-columns:1fr}.result-head{align-items:flex-start;flex-direction:column}.output-code{font-size:26px}.sbox-wrap,.table-grid{grid-template-columns:1fr}.button-row{flex-direction:column}.panel,.result-card{padding:18px}.bits span,.bit-output span{width:30px;height:30px}}

/* Reference-style calculation tables */
.reference-table-card{padding:16px;margin:16px;border-radius:16px;background:#0d1728;border:1px solid var(--line)}
.reference-table-card h4{color:#e0f2fe;margin-bottom:10px;font-size:16px}.table-scroll{overflow-x:auto}.bit-table{width:100%;border-collapse:collapse;min-width:620px;font-family:Consolas,monospace}.bit-table th,.bit-table td{border:1px solid #314968;text-align:center;padding:9px 10px;color:#dbeafe}.bit-table thead th{background:#13233a;color:#7dd3fc;font-weight:900}.bit-table .row-label{text-align:left;background:#15263e;color:#f8fafc;font-weight:900;min-width:170px}.bit-table tbody tr:nth-child(even) td:not(.row-label){background:#101d33}.bit-table tbody tr:hover td{background:rgba(56,189,248,.08)}.empty-cell{color:#53657d!important}.table-note{margin-top:10px;color:#9eb2ce;font-size:13px}.formula-card{display:flex;gap:10px;align-items:center;margin:16px;padding:14px;border-radius:14px;background:rgba(56,189,248,.08);border:1px solid rgba(56,189,248,.24);color:#dff7ff}.formula-card span{font-family:Consolas,monospace}.sbox-explain-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:0 16px 16px}.calc-box h4{color:#7dd3fc;margin-bottom:6px}.sbox-card th{border:1px solid var(--line);padding:8px;background:#13233a;color:#7dd3fc;font-family:Consolas,monospace}
@media(max-width:780px){.reference-table-card,.formula-card{margin:12px}.sbox-explain-grid{grid-template-columns:1fr;margin:0 12px 12px}.bit-table{min-width:560px}.bit-table th,.bit-table td{padding:8px}.bit-table .row-label{min-width:140px}}