/* ========== ROOT COLORS ========== */
    :root {
      --bg: #0f1724;
      --card: #121827;
      --muted: #9fb0d2;
      --accent: #f2a900;
      --good: #22c55e;
    }

    /* ========== GLOBAL RESET ========== */
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      margin: 0;
      background: linear-gradient(180deg, var(--bg), #071327);
      color: #eef6ff;
      font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

    /* ========== HEADER NAV ========== */
    header {
      background: #121827;
      padding: 12px 20px;
      position: sticky;
      top: 0;
      z-index: 1000;
    }
    .header-nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .header-nav .logo {
      font-size: 1.5rem;
      font-weight: bold;
      color: #fff;
    }
    .header-nav .logo span {
      color: #082f5cdc;
    }
    .header-nav ul {
      display: flex;
      gap: 18px;
      list-style: none;
    }
    .header-nav ul li a {
      color: var(--muted);
      font-weight: 500;
      transition: color 0.2s ease;
      text-decoration: none;
    }
    .header-nav ul li a:hover {
      color: var(--accent);
    }
    /* Hamburger */
    .hamburger {
      display: none;
      font-size: 1.6rem;
      cursor: pointer;
      color: var(--accent);
    }
    @media (max-width: 768px) {
      .hamburger { display: block; }
      #nav-menu {
        position: absolute;
        top: 60px;
        right: 20px;
        background: #121827;
        flex-direction: column;
        width: 200px;
        padding: 15px;
        display: none;
        border-radius: 8px;
      }
      #nav-menu.active { display: flex; }
      #nav-menu li { margin-bottom: 12px; }
    }

    /* ========== HERO SECTION ========== */
    .hero {
      flex: 1;
      padding: 40px 20px;
      display: flex;
      justify-content: center;
      align-items: flex-start;
    }
    .wrap {
      width: 100%;
      max-width: 800px;
    }
    .title {
      font-size: 1.5rem;
      color: var(--accent);
      font-weight: 700;
    }
    .meta {
      color: var(--muted);
      font-size: 0.9rem;
    }
    .header-meta {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 16px;
      flex-wrap: wrap;
      gap: 10px;
    }

    /* ========== CARD (main box) ========== */
    .card {
      background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
      border-radius: 12px;
      padding: 18px;
      box-shadow: 0 10px 30px rgba(2,8,23,0.6);
      border: 1px solid rgba(255,255,255,0.03);
    }

    /* ========== PRICE LIST ========== */
    .list { display: flex; flex-direction: column; gap: 12px; }
    .row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 12px;
      border-radius: 8px;
      background: rgba(255,255,255,0.03);
    }
    .coin {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 600;
    }
    .price {
      font-weight: 700;
      color: var(--good);
      font-size: 1rem;
    }

    /* ========== CALCULATOR ========== */
    .calculator {
      margin-top: 20px;
      background: rgba(255,255,255,0.02);
      padding: 15px;
      border-radius: 8px;
    }
    .calculator h3 {
      margin-bottom: 10px;
      font-size: 1rem;
      color: var(--accent);
    }
    label {
      display: block;
      font-size: 0.85rem;
      color: var(--muted);
      margin-top: 10px;
    }
    input, select, button {
      width: 100%;
      padding: 10px;
      border-radius: 6px;
      border: none;
      margin-top: 6px;
      font-size: 1rem;
    }
    button {
      background: var(--accent);
      color: #071327;
      font-weight: 700;
      cursor: pointer;
      transition: background 0.2s ease;
    }
    button:hover { background: #e0a000; }
    #calc-output {
      margin-top: 12px;
      font-weight: 700;
      color: var(--good);
    }

    /* ========== FOOTER ========== */
    footer {
      background: #121827;
      color: var(--muted);
      padding: 20px;
      text-align: center;
      margin-top: auto;
    }
    footer a {
      color: var(--accent);
      text-decoration: none;
      margin: 0 8px;
    }
    footer a:hover { text-decoration: underline; }

    /* Responsive tweaks */
    @media (max-width: 480px) {
      .title { font-size: 1.2rem; }
      .price { font-size: 0.9rem; }
    }