.level-expart {
    background: linear-gradient(
        135deg,
        #2e004f,
        #4b0082,
        #2a003a
    );

    color: #f8f5ef;

    border: 2px solid #bfa760; /* 少し落ち着いた金 */

    box-shadow:
        0 4px 10px rgba(0, 0, 0, 0.5),
        0 0 12px rgba(191, 167, 96, 0.35),
        inset 0 0 8px rgba(255, 255, 255, 0.08);

    text-shadow:
        0 1px 2px rgba(0, 0, 0, 0.8);

    letter-spacing: 0.18em;
}