:root{--bg:#07131c;--panel:#0d202c;--line:#244451;--text:#edf8f7;--muted:#9db8ba;--volt:#c8ff3d;--cyan:#4de3d2}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at 80% -10%,#164551 0,transparent 34%),var(--bg);color:var(--text);font:16px/1.55 Inter,system-ui,sans-serif}.wrap{width:min(900px,calc(100% - 32px));margin:auto}header{border-bottom:1px solid var(--line);padding:18px 0}.nav{display:flex;justify-content:space-between;align-items:center}.brand{color:var(--text);text-decoration:none;font-size:1.3rem;font-weight:850}.brand i{color:var(--volt);font-style:normal}.back{color:var(--cyan);text-decoration:none;font-weight:700}.hero{padding:52px 0 24px}.eyebrow{color:var(--cyan);font-size:.8rem;font-weight:800;letter-spacing:.14em;text-transform:uppercase}h1{font-size:clamp(2.25rem,6vw,4.5rem);line-height:1;letter-spacing:-.045em;margin:10px 0 15px}.lead{color:var(--muted);font-size:1.08rem;max-width:720px}.calculator{background:linear-gradient(160deg,#102936,var(--panel));border:1px solid var(--line);border-radius:22px;padding:26px;margin:20px 0 35px}.fields{display:grid;grid-template-columns:1fr 1fr;gap:17px}.field label{display:block;margin-bottom:6px;color:#c9dbdc;font-weight:700}.inputrow{display:flex;align-items:center;background:#071a23;border:1px solid #2b4b57;border-radius:12px;overflow:hidden}.inputrow:focus-within{border-color:var(--cyan)}input,select{width:100%;border:0;outline:0;background:#071a23;color:var(--text);padding:12px 13px;font:inherit}.unit{padding-right:13px;color:var(--muted)}.result{margin-top:20px;padding:20px;border-radius:15px;background:#071a23}.result small{display:block;color:var(--muted)}output{display:block;color:var(--volt);font-size:2.25rem;font-weight:850}.copy{padding:5px 0 40px}.copy h2{margin:25px 0 7px}.copy p{color:var(--muted)}.links{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:15px 0 42px}.links a{border:1px solid var(--line);border-radius:12px;padding:14px;color:var(--text);text-decoration:none;font-weight:700}.links a:hover{border-color:var(--cyan)}footer{border-top:1px solid var(--line);padding:24px 0 38px;color:var(--muted);font-size:.85rem}@media(max-width:620px){.fields,.links{grid-template-columns:1fr}.wrap{width:calc(100% - 22px)}.hero{padding-top:38px}.calculator{padding:20px 16px}}