/* Header and Frame-based navigation for IEKTopics 2026. */
#legacy-site-nav {
    display: none !important;
}

#header,
.index__main {
    margin-top: 0;
}

#header {
    position: fixed;
    top: 0;
    height: auto;
    min-height: 80px;
    background: #fff;
    box-shadow: none;
    z-index: 100;
}

#header > .headerContent {
    max-width: 1920px;
    height: auto;
    min-height: 80px;
    padding: 0 24px;
}

#header .logo > a {
    display: flex;
    align-items: center;
    width: 288px;
    height: 35px;
    overflow: hidden;
}

/* Keep the brand title compact at every viewport size. */
#header .logo {
    transform: scale(.7);
    transform-origin: left center;
}

#header .logoArtwork {
    display: block;
    flex: 0 0 202px;
    width: 202px;
    height: 35px;
    overflow: hidden;
}

#header .logoArtwork img {
    display: block;
    width: 288px;
    max-width: none;
    height: 35px;
}

#header .logoYear {
    display: block;
    flex: 0 0 auto;
    color: #000;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 32px;
    font-weight: 700;
    line-height: 35px;
    letter-spacing: .4px;
    white-space: nowrap;
}

#header #menuBtn {
    margin: 0;
    padding: 0;
    border: 0;
    background: transparent;
    cursor: pointer;
}

#header .mainMenu {
    height: auto;
    min-height: 80px;
}

#header .mainMenu > li {
    flex: 0 0 auto;
}

#header .mainMenu > li + li::before {
    top: 10px;
    height: 60px;
    background: #bababa;
}

#header .mainTitle,
#header .navGroup {
    color: #231815;
}

#header .mainTitle {
    display: flex;
    align-items: center;
    height: auto;
    min-height: 80px;
    padding: 0 28px;
    white-space: nowrap;
}

#header .navGroup {
    position: relative;
    height: auto;
    min-height: 80px;
    cursor: pointer;
}

#header .navTitle {
    display: flex;
    align-items: center;
    width: 100%;
    height: auto;
    min-height: 80px;
    padding: 0 28px;
    white-space: normal;
}

#header .navTitle .chapter {
    flex: 0 0 auto;
    font-size: 16px;
    font-weight: 700;
    white-space: nowrap;
}

#header .navTitle .text {
    min-width: 0;
    flex: 1 1 auto;
    max-width: 180px;
    margin-left: 20px;
    color: var(--section-color);
    font-size: 16px;
    font-weight: 500;
    line-height: 1.25;
    white-space: normal;
    overflow-wrap: anywhere;
}

/* Override the legacy 2025 nth-child palette with the 2026 section data. */
#header .mainMenu li.navSection .navTitle .text {
    color: var(--section-color);
}

#header .navSection--chapter-2 .navTitle .text,
#header .navSection--chapter-3 .navTitle .text,
#header .navSection--conclusion .navTitle .text {
    max-width: 190px;
}

#header .subMenu {
    position: absolute;
    top: var(--nav-height);
    left: 0;
    display: none;
    width: 380px;
    max-width: calc(100vw - 24px);
    padding: 5px 12px 0;
    color: #231815;
    background: rgba(255, 255, 255, .9);
    box-shadow: none;
    z-index: 110;
}

#header .subMenu::before {
    background: var(--section-color);
}

#header .navGroup:hover .subMenu,
#header .navGroup:focus-within .subMenu,
#header .navGroup.is-open .subMenu {
    display: block;
}

#header .subMenu .list {
    display: block;
    padding: 12px 10px;
    border-top: 1px solid #bababa;
    font-size: 16px;
    line-height: 1.5;
}

#header .subMenu .list:first-child {
    border-top: 0;
}

#header .subMenu .list a {
    display: block;
    color: #231815;
    font-size: 16px;
    line-height: 1.5;
}

#header .menuCategory + .menuCategory {
    margin-top: 0;
}

#header .menuCategoryTitle {
    padding: 8px 10px 7px;
    border-top: 1px solid #bababa;
    color: var(--section-color);
    font-size: 20px;
    font-weight: 700;
    line-height: 1.3;
}

/* Frame 6 uses the chapter-two dropdown accent for its top rule and categories. */
#header .mainMenu li.navSection--chapter-2 .subMenu::before {
    background: #26b7bc;
}

#header .navSection--chapter-2 .menuCategoryTitle {
    color: #26b7bc;
}

#header .menuCategory:first-child .menuCategoryTitle {
    border-top: 0;
}

#header .menuCategoryTitle + .list {
    border-top: 0;
}

#header .menuCategory .list {
    padding-top: 13px;
    padding-bottom: 13px;
}

#header .menuCategoryTitle {
    padding-top: 11px;
    padding-bottom: 10px;
}

#header #menuBtn:focus-visible,
#header .mainTitle:focus-visible,
#header .navGroup:focus-visible,
#header .subMenu a:focus-visible {
    outline: 3px solid #f5b335;
    outline-offset: 3px;
}

@media (min-width: 901px) {
    /* Keep the desktop dropdown translucent over the key visual. */
    #header .mainMenu li.navSection .subMenu {
        background: rgba(255, 255, 255, .9);
    }

    #header #menuBtn {
        display: none;
    }

    #header #site-nav {
        position: static;
        top: auto;
        left: auto;
        display: block;
        width: auto;
        height: auto;
        min-height: 80px;
        max-width: calc(100% - 312px);
        max-height: none;
        margin-left: auto;
        overflow: visible;
        background: transparent;
        min-width: 0;
        flex: 0 1 auto;
    }

    #header .mainMenu {
        display: flex;
        flex-direction: row;
        align-items: stretch;
        width: auto;
        height: auto;
        min-height: 80px;
        min-width: 0;
    }

    #header .mainMenu > li {
        flex: 1 1 auto;
        min-width: 0;
    }

    #header .mainMenu > li + li::before {
        top: 10px;
        left: 0;
        width: 1px;
        height: calc(100% - 20px);
        transform: none;
    }

    #header .navHome .mainTitle,
    #header .navHistory .mainTitle {
        padding-right: 28px;
        padding-left: 28px;
    }
}

/* Match the 1920px desktop composition in Frames 5 and 6. */
@media (min-width: 1840px) {
    #header #site-nav {
        width: 1478px;
        max-width: calc(100% - 312px);
        flex-basis: 1478px;
    }

    #header .mainMenu > li {
        flex: 1 1 auto;
    }

    #header .navHome {
        width: 86px;
    }

    #header .navSection--preface {
        width: 91px;
    }

    #header .navSection--chapter-1 {
        width: 286px;
    }

    #header .navSection--chapter-2 {
        width: 289px;
    }

    #header .navSection--chapter-3 {
        width: 292px;
    }

    #header .navSection--conclusion {
        width: 313px;
    }

    #header .navHistory {
        width: 121px;
    }

    #header .mainTitle,
    #header .navTitle {
        width: 100%;
    }

    #header .navTitle .chapter,
    #header .navTitle .text,
    #header .mainTitle .title {
        font-size: 18px;
    }
}

/* Compact desktop navigation between the mobile and wide-desktop layouts. */
@media (min-width: 901px) and (max-width: 1680px) {
    #header > .headerContent {
        padding: 0 5px;
    }

    #header #site-nav {
        max-width: calc(100% - 220px);
    }

    #header .mainMenu {
        height: auto;
        min-height: 80px;
    }

    #header .mainTitle,
    #header .navTitle {
        padding-right: 14px;
        padding-left: 14px;
    }

    #header .navTitle .text {
        max-width: 145px;
        margin-left: 10px;
        font-size: 14px;
    }

    #header .navTitle .chapter,
    #header .mainTitle .title {
        font-size: 14px;
    }

    #header .subMenu {
        top: var(--nav-height);
    }
}

@media (min-width: 901px) and (max-width: 1199px) {
    #header > .headerContent {
        padding: 0 10px;
    }

    #header #site-nav {
        max-width: calc(100% - 185px);
    }

    #header .mainTitle,
    #header .navTitle {
        padding-right: 8px;
        padding-left: 8px;
    }

    #header .navTitle .text {
        min-width: 0;
        max-width: 145px;
        overflow-wrap: anywhere;
        white-space: normal;
    }

    #header .navTitle .chapter,
    #header .mainTitle .title {
        font-size: 13px;
    }
}

@media (max-width: 900px) {
    :root {
        --nav-height: 60px;
    }

    #header {
        height: 60px;
        min-height: 60px;
    }

    #header > .headerContent {
        height: 100%;
        min-height: 0;
        padding: 0 15px;
    }

    #header .logo > a {
        width: 168px;
        height: 21px;
    }

    #header .logoArtwork {
        flex-basis: 118px;
        width: 118px;
        height: 21px;
    }

    #header .logoArtwork img {
        width: 168px;
        height: auto;
    }

    #header .logoYear {
        font-size: 19px;
        line-height: 21px;
        letter-spacing: .2px;
    }

    #header #menuBtn {
        position: relative;
        display: block !important;
        flex: 0 0 30px;
        width: 30px;
        height: 30px;
        margin-left: auto;
        z-index: 101;
    }

    #header #site-nav {
        position: fixed;
        top: 60px;
        left: 0;
        display: flex;
        flex: none;
        justify-content: flex-start;
        width: 100%;
        min-width: 0;
        max-width: none;
        height: auto;
        max-height: calc(100% - 60px);
        margin-left: 0;
        overflow-x: hidden;
        overflow-y: auto;
        background: #fff;
        opacity: 0;
        visibility: hidden;
        pointer-events: none;
        transition: opacity .4s ease, visibility 0s linear .4s;
    }

    #header #menuBtn > span,
    #header #menuBtn > span::before,
    #header #menuBtn > span::after {
        position: absolute;
        left: 0;
        display: block;
        width: 30px;
        height: 3px;
        background: #004ea2;
    }

    #header #menuBtn > span {
        top: 50%;
        transform: translateY(-50%);
    }

    #header #menuBtn > span::before,
    #header #menuBtn > span::after {
        content: '';
        transition: transform .3s ease;
    }

    #header #menuBtn > span::before {
        top: -10px;
    }

    #header #menuBtn > span::after {
        top: 10px;
    }

    #header #menuBtn.active > span {
        background: transparent;
    }

    #header #menuBtn.active > span::before {
        transform: translateY(10px) rotate(45deg);
    }

    #header #menuBtn.active > span::after {
        transform: translateY(-10px) rotate(-45deg);
    }

    #header #site-nav.is-open {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
        transition-delay: 0s;
    }

    #header .mainMenu {
        display: flex;
        flex: none;
        flex-direction: column;
        align-items: stretch;
        width: 100%;
        height: auto;
        min-width: 0;
    }

    #header .mainMenu > li {
        flex: none;
        width: 100%;
        min-width: 0;
        min-height: 44px;
    }

    #header .mainMenu > li + li::before {
        top: 0;
        left: 15px;
        width: calc(100% - 30px);
        height: 1px;
        transform: none;
    }

    #header .mainMenu > li > .mainTitle,
    #header .mainMenu > li > .navGroup {
        width: 100%;
    }

    #header .navGroup {
        height: auto;
    }

    #header .mainTitle,
    #header .navTitle {
        min-height: 44px;
        height: auto;
        padding: 10px 15px;
    }

    #header .navTitle {
        justify-content: space-between;
        padding-right: 45px;
    }

    #header .navTitle .text {
        min-width: 0;
        max-width: none;
        margin-left: auto;
        padding-left: 20px;
        text-align: right;
    }

    #header .navGroup::after {
        content: '';
        position: absolute;
        top: 21px;
        right: 18px;
        width: 8px;
        height: 8px;
        border-right: 2px solid currentColor;
        border-bottom: 2px solid currentColor;
        transform: rotate(45deg);
        transition: transform .2s ease;
    }

    #header .navGroup.is-open::after {
        transform: rotate(225deg);
    }

    #header .subMenu {
        position: static;
        display: block;
        width: 100%;
        max-width: none;
        max-height: 0;
        padding: 0 15px;
        box-shadow: none;
        opacity: 0;
        overflow: hidden;
        transition: max-height .4s ease, opacity .4s ease;
    }

    #header .navGroup:hover .subMenu,
    #header .navGroup:focus-within .subMenu {
        display: none;
    }

    #header .navGroup.is-open .subMenu {
        display: block;
        max-height: 2000px;
        opacity: 1;
    }

    #header .subMenu .list {
        padding: 8px 0;
        color: #fff;
    }

    #header .subMenu .list a {
        color: #fff;
    }

    #header .menuCategoryTitle {
        padding: 8px 0 7px;
    }

    #header .menuCategory .list {
        padding-top: 8px;
        padding-bottom: 8px;
    }

    #header .navSection--chapter-2 .menuCategoryTitle {
        color: #ef5b16;
    }
}

@media (prefers-reduced-motion: reduce) {
    #header #site-nav,
    #header .subMenu {
        transition: none;
    }

    #header .navGroup::after {
        transition: none;
    }
}