:root {
      --gielis-bg: #f7f7f7;
      --gielis-card: #ffffff;
      --gielis-border: #e8e8e8;
      --gielis-muted: #666666;
      --gielis-ink: #111111;
      --gielis-accent: #b30059;
    }

    body {
      margin: 0;
      background: var(--gielis-bg);
      color: var(--gielis-ink);
      font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
    }

    .gielis-wrap {
      max-width: 1100px;
      margin: 0 auto;
      padding: 24px;
    }

    .gielis-header {
      margin-bottom: 18px;
    }

    .gielis-kicker {
      margin: 0 0 0.35rem 0;
      color: var(--gielis-accent);
      font-size: 0.82rem;
      font-weight: 700;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    .gielis-header h1 {
      margin: 0 0 8px;
      font-size: clamp(1.9rem, 4vw, 3rem);
      line-height: 1.1;
      letter-spacing: -0.03em;
      color: #111111;
    }

    .gielis-lead {
      max-width: 820px;
      margin: 0;
      color: var(--gielis-muted);
      font-size: 0.98rem;
      line-height: 1.65;
    }

    .gielis-section {
      margin-top: 28px;
    }

    .gielis-section h2,
    .gielis-section h3 {
      color: #111111;
    }

    .gielis-section p,
    .gielis-section li {
      line-height: 1.65;
      color: #333333;
    }

    .gielis-section ul {
      padding-left: 1.25rem;
    }

    .gielis-card {
      margin-top: 22px;
      background: var(--gielis-card);
      border: 1px solid var(--gielis-border);
      border-radius: 16px;
      padding: 18px;
      box-shadow: 0 1px 8px rgba(0, 0, 0, 0.04);
    }

    .gielis-formula {
      overflow-x: auto;
      padding: 8px 0;
      margin: 12px 0;
    }

    .gielis-note {
      background: #ffffff;
      border-left: 4px solid var(--gielis-accent);
      border-radius: 12px;
      padding: 14px 16px;
      margin-top: 16px;
    }

    #gielis-app {
      margin-top: 18px;
    }

    .gielis-back-wrap {
      display: flex;
      justify-content: center;
      width: 100%;
      margin: 24px 0 28px;
    }

    mjx-container {
      overflow-x: auto;
      overflow-y: hidden;
      max-width: 100%;
    }

    @media (max-width: 640px) {
      .gielis-wrap {
        padding: 18px;
      }

      .gielis-card {
        padding: 16px;
      }
    }