:root {
      --ink: #07142c;
      --gold: #e7bf69;
      --gold-2: #f7dfa0;
      --paper: #050d1e;
      --muted: #8b9bb8;
      --radius: 24px;
    }
    * { box-sizing: border-box; }
    body {
      margin: 0; color: #f1f5f9; background: var(--paper);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.7;
    }
    a { color: inherit; text-decoration: none; }
    .topbar { position: sticky; top: 0; z-index: 20; background: rgba(7,20,44,.92); border-bottom: 1px solid rgba(255,255,255,.1); backdrop-filter: blur(16px); }
    .nav { max-width: 1100px; margin: 0 auto; padding: 14px 22px; display: flex; align-items: center; justify-content: space-between; }
    .brand { display: flex; align-items: center; gap: 10px; font-weight: 800; }
    .brand-mark { width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center; color: #111c33; font-weight: 900; background: linear-gradient(135deg, var(--gold-2), var(--gold)); }
    .container { max-width: 1040px; margin: 0 auto; padding: 40px 22px 90px; }
    .calc-header { text-align: center; margin-bottom: 34px; }
    .kicker { color: var(--gold); font-weight: 800; font-size: 13px; letter-spacing: .1em; text-transform: uppercase; }
    h1 { font-size: clamp(28px, 4.5vw, 42px); margin: 10px 0 12px; }
    .lead { color: #9bb0d1; font-size: 16px; max-width: 680px; margin: 0 auto; }
    
    .calc-card { background: rgba(12, 29, 61, 0.88); border: 1px solid rgba(255,255,255,.14); border-radius: var(--radius); padding: 36px; box-shadow: 0 30px 80px rgba(0,0,0,.45); backdrop-filter: blur(20px); margin-bottom: 36px; }
    .card-heading { display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid rgba(255,255,255,.1); padding-bottom: 14px; margin-bottom: 24px; }
    .card-heading h2 { font-size: 22px; color: #fff; margin: 0; display: flex; align-items: center; gap: 10px; }
    .badge { background: rgba(231,191,105,.12); color: var(--gold-2); border: 1px solid rgba(231,191,105,.3); padding: 4px 10px; border-radius: 999px; font-size: 12px; font-weight: 700; }

    .input-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-bottom: 26px; }
    .input-group { background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.1); border-radius: 16px; padding: 18px; transition: border-color .2s; }
    .input-group:focus-within { border-color: var(--gold); background: rgba(255,255,255,.07); }
    .input-label { display: block; font-size: 13px; color: var(--gold-2); margin-bottom: 8px; font-weight: 700; }
    .input-field { width: 100%; background: transparent; border: 0; outline: 0; color: #fff; font-size: 24px; font-weight: 900; font-family: inherit; }
    .input-field::placeholder { color: rgba(255,255,255,.2); font-size: 16px; }
    .hint { font-size: 11px; color: var(--muted); margin-top: 6px; }

    .divider { height: 1px; background: rgba(255,255,255,.1); margin: 6px 0 24px; }

    .section-title { font-size: 15px; color: #fff; font-weight: 800; margin-bottom: 14px; display: flex; align-items: center; gap: 8px; }
    .section-title::before { content: ""; width: 4px; height: 15px; background: var(--gold); border-radius: 2px; display: inline-block; }
    
    .result-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
    .result-box { background: rgba(231,191,105,.05); border: 1px solid rgba(231,191,105,.22); border-radius: 16px; padding: 18px 12px; text-align: center; }
    .result-title { font-size: 12px; color: var(--gold-2); margin-bottom: 6px; font-weight: 700; }
    .result-val { font-size: 20px; font-weight: 900; color: #fff; word-break: break-all; }

    .preset-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; align-items: center; }
    .preset-btn { border: 1px solid rgba(255,255,255,.18); background: rgba(255,255,255,.06); color: #fff; padding: 7px 12px; border-radius: 10px; font-size: 12px; cursor: pointer; transition: background .2s, border-color .2s; }
    .preset-btn:hover { border-color: var(--gold); background: rgba(231,191,105,.12); color: var(--gold-2); }
    
    .footer { text-align: center; margin-top: 40px; font-size: 13px; color: var(--muted); }
    .footer a { color: var(--gold-2); }

    @media (max-width: 860px) {
      .input-grid { grid-template-columns: 1fr; }
      .result-grid { grid-template-columns: repeat(2, 1fr); }
      .calc-card { padding: 22px; }
    }