.top {
    position: relative;
    min-height: 60vh;
    display: flex;
    align-items: flex-start;
    justify-content: flex-start;
    padding: 14rem 2% 4rem;
    box-sizing: border-box;

    background-image: url("../img/aboutUsPage.jpg");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.top::before {
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.2);
    z-index: 0;
}

.top .title-section {
    z-index: 1;
    padding-top: 5rem;
    color: var(--navy-blue);
    font-size: 3rem;
}

.bottom {
    position: relative;
    z-index: 2;
    margin-top: -11.5rem;
    padding: 4rem 8% 6rem;
    background-color: var(--federal-blue);
    box-shadow: 0 -5px 10px rgba(0, 0, 0, 0.3);
}

.bottom .section-headline {
    font-size: 4rem;
    color: var(--gold-color);
    margin-bottom: 2.5rem;
}

.bottom .content-section {
    margin-bottom: 3rem;
}

.mission-section {
    display: flex;
    align-items: flex-start;
    gap: 3rem;
    border-bottom: 2px solid rgba(226, 232, 240, 0.3);
    padding-bottom: 3rem;
}

.mission-text {
    flex: 2;
    color: var(--off-white);
    font-size: 1.05rem;
    line-height: 1.8;
    padding-left: 1.25rem;
    border-left: 3px solid var(--gold-color);
}

.mission-image {
    flex: 1;
    max-width: 620px;
    width: 100%;
    object-fit: cover;
    display: block;
    border-radius: 8px;
    box-shadow: 0 8px 18px rgba(0, 0, 0, 0.45);
}

.expertise-title {
    font-size: 4rem;
    color: var(--gold-color);
    margin: 2rem 0 1.5rem;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    text-align: center;
}

.expertise-section {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 2rem;
}

.expertise-block {
    background: var(--navy-blue);
    border-radius: 10px;
    padding: 1.75rem 1.5rem 1.5rem;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.35);
    border: 1px solid rgba(148, 163, 184, 0.4);
}

.expertise-block h5 {
    font-size: 1.25rem;
    color: var(--off-white);
    margin-bottom: 0.75rem;
}

.expertise-block ul {
    margin: 0;
    padding-left: 1.2rem;
}

.expertise-block li {
    color: #E2E8F0;
    font-size: 0.98rem;
    line-height: 1.7;
    margin-bottom: 0.5rem;
    position: relative;
}

.expertise-block li::before {
    content: "";
    position: absolute;
    left: -0.8rem;
    top: 0.6rem;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--gold-color);
}

.bottom .section-subline {
    text-align: center;
    font-size: 4rem;
    color: var(--gold-color);
    margin-bottom: 2.5rem;
}

.operate-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3rem;
    border-bottom: 2px solid rgba(226, 232, 240, 0.3);
    padding-bottom: 3rem;
}


.operate-text {
    color: var(--off-white);
    max-width: 1800px;
    width: 100%;
    text-align: center;
    font-size: 1.05rem;
    line-height: 1.8;
    padding-bottom: 1.25rem;
    border-bottom: 3px solid var(--gold-color);
}

/* Responsive Design */

/* ≤ 2560px: ultra-wide */
@media (max-width: 2560px) {
    .bottom {
        max-width: 100%;
    }

    .operate-text {
        max-width: 1400px;
    }
}

/* ≤ 1920px: standard desktops */
@media (max-width: 1920px) {
    .bottom {
        padding: 4rem 8% 5rem;
    }

    .bottom .section-headline,
    .expertise-title,
    .bottom .section-subline {
        letter-spacing: 0.02em;
    }
}

/* ≤ 1200px: laptops */
@media (max-width: 1200px) {
    .top {
        padding: 12rem 4% 3rem;
        min-height: 50vh;
    }

    .bottom {
        margin-top: -9rem;
        padding: 3.5rem 6% 4.5rem;
    }

    .mission-image {
        flex: 1;
        max-width: 400px;
        width: 100%;
    }


    .bottom .section-headline,
    .expertise-title,
    .bottom .section-subline {
        font-size: 3.2rem;
    }

    .mission-section {
        gap: 2.25rem;
    }

    .mission-text,
    .operate-text {
        font-size: 1rem;
    }

    .operate-text {
        max-width: 1000px;
    }
}

/* ≤ 992px: large tablets / small laptops */
@media (max-width: 992px) {
    .top {
        padding: 10rem 4% 3rem;
        min-height: 45vh;
        background-position: center;
    }

    .bottom {
        margin-top: -7rem;
        padding: 3rem 5% 4rem;
    }

    .mission-section {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .mission-text {
        padding-left: 0;
        border-left: none;
        border-top: 3px solid var(--gold-color);
        padding-top: 1.25rem;
    }

    .mission-image {
        max-width: 100%;
        width: 100%;
    }

    .expertise-section {
        grid-template-columns: 1fr;
        gap: 1.75rem;
    }

    .operate-section {
        gap: 2rem;
    }

    .operate-text {
        max-width: 800px;
        padding-bottom: 1rem;
    }
}

/* ≤ 768px: tablets */
@media (max-width: 768px) {
    .top {
        padding: 8rem 2rem 2.5rem;
        min-height: 40vh;
    }

    .bottom {
        margin-top: -5rem;
        padding: 2.75rem 2rem 3.5rem;
    }

    .bottom .section-headline,
    .expertise-title,
    .bottom .section-subline {
        font-size: 2.4rem;
        text-align: center;
    }

    .bottom .content-section {
        margin-bottom: 2.25rem;
    }

    .mission-text,
    .operate-text {
        font-size: 0.98rem;
        line-height: 1.7;
    }

    .expertise-block {
        padding: 1.5rem 1.25rem 1.25rem;
    }
}

/* ≤ 480px: small mobile */
@media (max-width: 480px) {
    .top {
        padding: 6.5rem 1.25rem 2rem;
        min-height: 32vh;
    }

    .bottom {
        margin-top: 0;
        padding: 2.5rem 1.25rem 3rem;
        box-shadow: 0 -3px 8px rgba(0, 0, 0, 0.35);
    }

    .bottom .section-headline,
    .expertise-title,
    .bottom .section-subline {
        font-size: 2rem;
        margin-bottom: 1.75rem;
    }

    .mission-section {
        gap: 1.75rem;
        padding-bottom: 2.25rem;
    }

    .mission-text {
        font-size: 0.95rem;
        padding-top: 1rem;
    }

    .mission-image {
        border-radius: 6px;
        box-shadow: 0 6px 14px rgba(0, 0, 0, 0.4);
    }

    .expertise-block h5 {
        font-size: 1.1rem;
    }

    .expertise-block li {
        font-size: 0.9rem;
    }

    .operate-text {
        font-size: 0.95rem;
        padding-bottom: 0.9rem;
        border-bottom-width: 2px;
    }
}