.t6-hero {
    color: #fff;
    background: var(--navy-900);
    border-bottom: 5px solid var(--gold-500);
}

.t6-hero-inner,
.t6-layout {
    width: min(1180px, calc(100% - 40px));
    margin-inline: auto;
}

.t6-hero-inner {
    padding-block: 52px 58px;
}

.t6-hero h1 {
    margin: 0;
    font-size: clamp(2.5rem, 6vw, 4.7rem);
    line-height: 1;
    letter-spacing: -.045em;
}

.t6-hero-inner > p:last-child {
    max-width: 780px;
    margin: 18px 0 0;
    color: #d5e0eb;
    font-size: .85rem;
    line-height: 1.7;
}

.t6-layout {
    display: grid;
    grid-template-columns: 245px minmax(0, 1fr);
    align-items: start;
    padding-block: 46px 78px;
    gap: 24px;
}

.t6-sidebar {
    position: sticky;
    top: 15px;
    overflow: hidden;
    background: #fff;
    border: 1px solid var(--line);
}

.t6-sidebar > strong {
    display: block;
    padding: 14px 16px;
    color: #fff;
    background: var(--navy-900);
    font-size: .72rem;
}

.t6-sidebar nav {
    display: grid;
}

.t6-sidebar a {
    padding: 10px 15px;
    color: var(--blue-600);
    border-bottom: 1px solid #e6ebf1;
    font-size: .61rem;
    text-decoration: none;
}

.t6-sidebar a:hover,
.t6-sidebar a:focus-visible {
    color: var(--navy-900);
    background: #f3f6f9;
}

.t6-content {
    display: grid;
    min-width: 0;
    gap: 10px;
}

.t6-notice {
    padding: 17px 19px;
    background: #fff8d5;
    border-left: 5px solid var(--gold-500);
}

.t6-notice strong {
    color: var(--navy-900);
    font-size: .71rem;
}

.t6-notice p {
    margin: 5px 0 0;
    color: #5d5b4e;
    font-size: .63rem;
    line-height: 1.6;
}

.t6-topic {
    scroll-margin-top: 18px;
    background: #fff;
    border: 1px solid var(--line);
}

.t6-topic summary {
    display: flex;
    align-items: center;
    min-height: 58px;
    padding: 13px 17px;
    color: var(--navy-900);
    cursor: pointer;
    background: #f5f7fa;
    font-size: .78rem;
    font-weight: 700;
    list-style: none;
    gap: 13px;
}

.t6-topic summary::-webkit-details-marker {
    display: none;
}

.t6-topic summary::after {
    margin-left: auto;
    color: var(--blue-600);
    content: "+";
    font-size: 1.15rem;
}

.t6-topic[open] summary {
    color: #fff;
    background: var(--navy-900);
}

.t6-topic[open] summary::after {
    color: var(--gold-500);
    content: "−";
}

.t6-topic summary span {
    display: grid;
    width: 30px;
    height: 30px;
    color: var(--navy-900);
    background: var(--gold-500);
    border-radius: 2px;
    font-size: .6rem;
    place-items: center;
}

.t6-topic-body {
    padding: 24px;
    color: #47566d;
}

.t6-topic-body p,
.t6-topic-body li {
    font-size: .7rem;
    line-height: 1.8;
}

.t6-topic-body p {
    margin: 0 0 13px;
}

.t6-topic-body ul,
.t6-topic-body ol {
    margin: 0 0 18px;
    padding-left: 20px;
}

.t6-topic-body h3 {
    margin: 20px 0 8px;
    color: var(--navy-900);
    font-size: .85rem;
}

.t6-topic-body h3:first-child {
    margin-top: 0;
}

.t6-topic-body > a {
    display: inline-flex;
    margin-top: 7px;
    color: var(--blue-600);
    font-size: .63rem;
    font-weight: 700;
}

.t6-highlight {
    display: flex;
    align-items: center;
    margin-bottom: 16px;
    padding: 18px;
    color: #fff;
    background: var(--navy-800);
    gap: 18px;
}

.t6-highlight strong {
    flex: 0 0 auto;
    color: var(--gold-500);
    font-size: 1.25rem;
}

.t6-highlight span {
    font-size: .68rem;
    line-height: 1.6;
}

.t6-tags {
    display: flex;
    flex-wrap: wrap;
    margin: 14px 0;
    gap: 7px;
}

.t6-tags span {
    padding: 7px 10px;
    color: var(--navy-900);
    background: #eaf0f7;
    border-left: 3px solid var(--blue-600);
    font-size: .6rem;
    font-weight: 700;
}

.semester-grid,
.mode-grid,
.assessment-grid {
    display: grid;
    margin: 16px 0;
    gap: 10px;
}

.semester-grid,
.mode-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.assessment-grid {
    grid-template-columns: 1fr 1fr;
}

.semester-grid article,
.mode-grid article,
.assessment-grid article {
    padding: 16px;
    background: #f5f7fa;
    border-top: 4px solid var(--blue-600);
}

.semester-grid strong,
.semester-grid span,
.mode-grid strong,
.assessment-grid strong,
.assessment-grid span {
    display: block;
}

.semester-grid strong,
.mode-grid strong,
.assessment-grid strong {
    color: var(--navy-900);
    font-size: .7rem;
}

.semester-grid span,
.assessment-grid span {
    margin-top: 4px;
    color: var(--blue-600);
    font-size: .59rem;
    font-weight: 700;
}

.semester-grid p,
.mode-grid p {
    margin: 10px 0 0;
    font-size: .61rem;
}

.t6-caution {
    padding: 12px 14px;
    color: #7b3a25;
    background: #fff0e9;
    border-left: 4px solid var(--red-500);
}

.t6-formula {
    margin: 15px 0;
    padding: 13px 15px;
    color: var(--navy-900);
    background: #fff6c7;
    border: 1px solid #f1d765;
    font-size: .66rem;
    font-weight: 700;
    text-align: center;
}

@media (max-width: 820px) {
    .t6-layout {
        grid-template-columns: 1fr;
    }

    .t6-sidebar {
        position: static;
    }

    .t6-sidebar nav {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 580px) {
    .t6-hero-inner,
    .t6-layout {
        width: min(100% - 28px, 1180px);
    }

    .t6-hero-inner {
        padding-block: 40px 45px;
    }

    .t6-hero h1 {
        font-size: 2.7rem;
    }

    .t6-layout {
        padding-block: 28px 58px;
    }

    .t6-sidebar nav {
        grid-template-columns: 1fr;
    }

    .t6-topic-body {
        padding: 19px;
    }

    .semester-grid,
    .mode-grid,
    .assessment-grid {
        grid-template-columns: 1fr;
    }

    .t6-highlight {
        align-items: flex-start;
        flex-direction: column;
    }
}