.decorated-heading {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: #fff;
    line-height: 1.3;
    display: inline-block;
    position: relative;
    padding: 1.5rem 3rem;
    border-left: 2px solid var(--primary);
    border-right: 2px solid var(--primary);
    background: transparent;
}

.decorated-heading::before,
.decorated-heading::after {
    content: '';
    position: absolute;
    left: -10px;
    right: -10px;
    height: 2px;
    background: var(--primary);
}

.decorated-heading::before {
    top: 0;
}

.decorated-heading::after {
    bottom: 0;
}