.article4 {
    background-color: #f5f5f5;
}

.a4-title {
    text-align: center;
    margin-bottom: 6rem;
}

.a4-title p {
    color: #888;
    font-size: 28px;
    margin-bottom: 1.5rem;
}

.a4-title h1 {
    color: #222;
    font-size: 45px;
    font-weight: 800;
}

.a4-box-wrapper {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.a4-box {
    padding: 60px 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    gap: 3rem;
    border-radius: 7px;
    background-color: #fff;
    box-shadow: 0 4px 16px rgb(0 0 0 / 3%);
    overflow: hidden;
}

.a4-box:nth-child(1),
.a4-box:nth-child(2) {
    position: relative;
    border: 1px solid var(--sub-color);
}

.a4-box:nth-child(1)::before,
.a4-box:nth-child(2)::before {
    content: 'HOT';
    position: absolute;
    top: 4px; right: -33px;
    transform: rotate(45deg);
    width: 100px;
    height: 23px;
    color: #fff;
    font-size: 13px;
    font-weight: 400;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--sub-color);
    letter-spacing: 0;
}

.a4-box:nth-child(1)::after,
.a4-box:nth-child(2)::after {
    content: '';
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 7px;
    background-color: var(--sub-color);
}

.a4-box-title p {
    color: #333;
    font-size: 18px;
    font-weight: 500;
    margin-bottom: .7rem;
}

.a4-box-title h1 {
    color: #222;
    font-size: 28px;
}

.a4-box-qual {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.a4-box-qual li {
    color: #444;
    font-size: 15px;
}

.a4-box-image img {
    height: 100px;
    -webkit-filter: invert(76%) sepia(62%) saturate(4390%) hue-rotate(338deg) brightness(102%) contrast(103%);
    filter: invert(76%) sepia(62%) saturate(4390%) hue-rotate(338deg) brightness(102%) contrast(103%);
    user-select: none;
}



/*==================================================*/
@media (max-width: 1250px) {
    .a4-title {
        margin-bottom: 5rem;
    }
    
    .a4-box-wrapper {
        gap: 1rem;
    }
}


@media (max-width: 1050px) {
    .a4-box {
        padding: 45px 10px;
        gap: 2rem;
    }

    .a4-box:nth-child(1)::before,
    .a4-box:nth-child(2)::before {
        top: 7px;
        height: 18px;
        font-size: 11px;
    }

    .a4-box-title p {
        font-size: 16px;
        margin-bottom: .5rem;
    }

    .a4-box-title h1 {
        font-size: 24px;
    }

    .a4-box-qual li {
        font-size: 13px;
    }
    
    .a4-box-image img {
        height: 80px;
    }
}


@media (max-width: 850px) {
    .a4-box-wrapper {
        grid-template-columns: repeat(2, 1fr);
    }
}


@media (max-width: 650px) {
    .a4-title {
        margin-bottom: 3rem;
    }
    
    .a4-title p {
        font-size: 20px;
        margin-bottom: 1rem;
    }

    .a4-title h1 {
        font-size: 35px;
    }
}


@media (max-width: 450px) {
    .a4-title p {
        font-size: 16px;
        margin-bottom: .5rem;
    }

    .a4-title h1 {
        font-size: 26px;
    }

    .a4-box {
        padding: 35px 10px;
        gap: 1.5rem;
    }

    .a4-box:nth-child(1)::before,
    .a4-box:nth-child(2)::before {
        top: 6px; right: -35px;
        height: 16px;
        font-size: 10px;
        border-radius: 7px 7px 0 0;
    }

    .a4-box:nth-child(1)::after,
    .a4-box:nth-child(2)::after {
        bottom: -1px;
    }

    .a4-box-title p {
        font-size: 13px;
        margin-bottom: .3rem;
    }

    .a4-box-title h1 {
        font-size: 18px;
    }

    .a4-box-qual li {
        font-size: 11px;
    }

    .a4-box-image img {
        height: 60px;
    }
}