/*======================================================================
    Matt Henes Mathematics Website
    styles.css — Clean consolidated version
    July 2026

    Used by:
    - Homepage
    - Math 005B
    - Future course pages
======================================================================*/

:root {
    --primary-blue: #2C5D97;
    --primary-blue-dark: #234B7A;
    --primary-blue-light: #5F88B8;

    --background: #F7F8FA;
    --card: #FFFFFF;
    --border: #D8DEE6;

    --text: #222222;
    --text-light: #666666;
    --heading: #1E3555;

    --shadow: 0 2px 10px rgba(0, 0, 0, .08);
    --shadow-hover: 0 8px 24px rgba(0, 0, 0, .14);

    --content-width: 1200px;
    --card-radius: 16px;
    --transition: .18s ease;

    --font-stack:
        "Segoe UI",
        "Aptos",
        "Helvetica Neue",
        Arial,
        sans-serif;
}


/*======================================================================
    RESET AND BASE STYLES
======================================================================*/

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--background);
    color: var(--text);
    font-family: var(--font-stack);
    line-height: 1.5;
}

img {
    display: block;
    max-width: 100%;
}

h1,
h2,
h3 {
    color: var(--heading);
}

h1 {
    margin: 0 0 .4rem;
    font-size: 2.3rem;
    font-weight: 700;
}

h2 {
    font-size: 1.8rem;
}

h3 {
    font-size: 1.3rem;
}

p {
    margin-top: 0;
    color: var(--text-light);
}

a {
    color: var(--primary-blue);
    text-decoration: none;
    transition: var(--transition);
}

a:hover,
a:focus-visible {
    color: var(--primary-blue-dark);
}


/*======================================================================
    PAGE LAYOUT
======================================================================*/

.wrapper,
.page-shell {
    width: min(100%, var(--content-width));
    margin: 0 auto;
    padding: 2rem;
}

.page-shell {
    max-width: 1060px;
}


/*======================================================================
    HEADER AND NAVIGATION
======================================================================*/

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: white;
    border-bottom: 1px solid var(--border);
}

.header-inner {
    width: min(100%, var(--content-width));
    min-height: 66px;
    margin: 0 auto;
    padding: .9rem 2rem;
    display: flex;
    align-items: center;
    gap: 2rem;
}

.site-title,
.site-name {
    margin-right: auto;
    color: var(--heading);
    font-size: 1.45rem;
    font-weight: 700;
    text-decoration: none;
}

.site-title:hover,
.site-title:focus-visible,
.site-name:hover,
.site-name:focus-visible {
    color: var(--primary-blue);
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 1.75rem;
}

.main-nav a {
    color: var(--heading);
    font-weight: 600;
}

.main-nav a:hover,
.main-nav a:focus-visible {
    color: var(--primary-blue);
}

.menu-button {
    display: none;
    border: 0;
    background: transparent;
    color: var(--heading);
    font-size: 1.5rem;
    cursor: pointer;
}


/*======================================================================
    HOMEPAGE HERO
======================================================================*/

.hero {
    padding: 2.5rem 0 1.5rem;
    text-align: center;
}

.hero h1 {
    margin: 0 0 .4rem;
    font-size: clamp(2rem, 4vw, 2.7rem);
}

.hero p {
    margin: 0;
    font-size: 1.1rem;
}


/*======================================================================
    HOMEPAGE COURSE CARDS
======================================================================*/

.course-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 2rem;
}

.course-grid.bottom {
    grid-template-columns: repeat(2, 320px);
    justify-content: center;
}

a.course-card,
a.course-card-link {
    display: block;
    padding: 1.6rem;
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--card-radius);
    box-shadow: var(--shadow);
    color: var(--text);
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
}

a.course-card:hover,
a.course-card:focus-visible,
a.course-card-link:hover,
a.course-card-link:focus-visible {
    color: var(--text);
    text-decoration: none;
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

a.course-card:active,
a.course-card-link:active {
    transform: translateY(1px);
    box-shadow: none;
}

a.course-card:focus-visible,
a.course-card-link:focus-visible {
    outline: 3px solid var(--primary-blue-light);
    outline-offset: 4px;
}

a.course-card *,
a.course-card-link * {
    text-decoration: none !important;
}

.course-card .course-icon,
.course-card-link .course-icon {
    width: 108px;
    height: 82px;
    margin: 0 auto .75rem;
    object-fit: contain;
}

.course-card h2 {
    margin: .5rem 0 .2rem;
    text-align: center;
}

.course-card p {
    margin: 0;
    color: var(--text);
    font-weight: 600;
    text-align: center;
}


/*======================================================================
    COURSE PAGE BANNER
======================================================================*/

.course-banner {
    padding: .4rem 0 1.15rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.course-banner-icon {
    width: 72px;
    height: 72px;
    flex: 0 0 72px;
    object-fit: contain;
}

.course-banner h1 {
    margin: 0;
    font-size: clamp(1.75rem, 4vw, 2.4rem);
    line-height: 1.1;
}

.course-banner p {
    margin: .3rem 0 0;
}


/*======================================================================
    CURRENT SECTION PANEL
======================================================================*/

.current-section,
.semester-card {
    margin-bottom: 2rem;
    overflow: hidden;
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--card-radius);
    box-shadow: var(--shadow);
}

.current-semester {
    margin-bottom: 3rem;
}

.semester-card {
    padding: 2rem;
}

.semester-card h2 {
    margin-top: 0;
}

.section-bar {
    padding: .55rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    border-bottom: 1px solid var(--border);
}

.section-bar h2,
.learning-resources > h2 {
    margin: 0;
}

.section-bar h2 {
    font-size: 1.3rem;
}

.section-selector {
    display: inline-flex;
    padding: 2px;
    border: 1px solid var(--primary-blue);
    border-radius: 999px;
    background: #F2F5F8;
    overflow: hidden;
}

.semester-card .section-selector {
    margin: 1.5rem 0 2rem;
}

.section-button {
    padding: .28rem .7rem;
    border: 0;
    border-radius: 999px;
    background: transparent;
    color: var(--primary-blue);
    font: inherit;
    font-size: .82rem;
    font-weight: 700;
    line-height: 1.15;
    cursor: pointer;
    transition: var(--transition);
}

.section-button:hover {
    background: var(--primary-blue-light);
    color: white;
}

.section-button.active,
.section-button.is-active {
    background: var(--primary-blue);
    color: white;
}


/*======================================================================
    ADMINISTRATIVE LINKS
======================================================================*/

.admin-links {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.semester-card .admin-links {
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 1rem;
}

.admin-link {
    min-height: 64px;
    padding: .35rem .7rem;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: .55rem;
    color: var(--primary-blue);
    font-size: .84rem;
    font-weight: 600;
    line-height: 1.15;
    text-align: center;
    text-decoration: none;
    border-right: 1px solid var(--border);
}

.admin-link:last-child {
    border-right: 0;
}

.admin-link:hover,
.admin-link:focus-visible {
    background: #F7FAFF;
    color: var(--primary-blue);
}

.admin-link img {
    width: 56px;
    height: 56px;
    flex: 0 0 56px;
    object-fit: contain;
}

.semester-card .admin-link {
    min-height: auto;
    justify-content: flex-start;
    background: #FAFAFA;
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--heading);
}


/*======================================================================
    LEARNING RESOURCES AND CHAPTERS
======================================================================*/

.learning-resources {
    margin-top: 2.4rem;
}

.learning-resources > h2 {
    margin-bottom: .9rem;
}

.chapter {
    margin-bottom: 1rem;
    overflow: hidden;
    background: white;
    border: 1px solid var(--border);
    border-radius: 14px;
    box-shadow: var(--shadow);
}

.chapter > summary {
    padding: .55rem .9rem;
    list-style: none;
    color: var(--heading);
    font-size: 1.08rem;
    font-weight: 700;
    cursor: pointer;
    user-select: none;
}

.chapter > summary::-webkit-details-marker {
    display: none;
}

.chapter > summary::before {
    content: "▸";
    margin-right: .65rem;
    color: var(--primary-blue);
}

.chapter[open] > summary::before {
    content: "▾";
}

.chapter[open] > summary {
    border-bottom: 1px solid var(--border);
}

.chapter-lessons {
    padding: .45rem;
    display: grid;
    gap: .4rem;
}


/*======================================================================
    LESSON CARDS
======================================================================*/

.lesson {
    overflow: hidden;
    background: white;
    border: 1px solid var(--border);
    border-radius: 11px;
}

.lesson-heading {
    width: 100%;
    min-height: 38px;
    padding: .32rem .6rem;
    display: grid;
    grid-template-columns: max-content 1fr max-content;
    align-items: center;
    gap: .6rem;
    border: 0;
    background: white;
    color: var(--text);
    font: inherit;
    line-height: 1.2;
    text-align: left;
    cursor: pointer;
    transition: var(--transition);
}

.lesson-heading:hover,
.lesson-heading:focus-visible {
    background: #F9FBFD;
}

.section-number,
.section-title {
    font-weight: 700;
}

.section-number {
    color: var(--heading);
}

.lesson-toggle {
    color: var(--primary-blue);
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1;
}

.lesson-content {
    background: white;
    border-top: 1px solid var(--border);
}

.lesson-content[hidden] {
    display: none;
}


/*======================================================================
    RESOURCE LINKS
======================================================================*/

.lesson-content > .resource-link {
    min-height: 42px;
    padding: .25rem .55rem;
    display: grid;
    grid-template-columns: 34px 1fr;
    align-items: center;
    gap: .5rem;
    color: var(--text);
    text-decoration: none;
    border-bottom: 1px solid var(--border);
}

.lesson-content > .resource-link:last-child {
    border-bottom: 0;
}

.lesson-content > .resource-link:hover,
.lesson-content > .resource-link:focus-visible {
    background: #F9FBFD;
    color: var(--primary-blue);
}

.resource-link img {
    width: 28px;
    height: 28px;
    justify-self: center;
    object-fit: contain;
}

.resource-link strong {
    display: block;
    margin: 0;
    color: var(--primary-blue);
    font-size: .88rem;
    line-height: 1.15;
}

.resource-link small {
    display: block;
    margin-top: .08rem;
    color: var(--text);
    font-size: .72rem;
    font-weight: 400;
    line-height: 1.2;
}


/*======================================================================
    BUTTONS, CARDS, UTILITIES, FOOTER
======================================================================*/

.button {
    display: inline-block;
    padding: .7rem 1.2rem;
    background: var(--primary-blue);
    color: white;
    border-radius: 8px;
}

.button:hover,
.button:focus-visible {
    background: var(--primary-blue-dark);
    color: white;
}

.card {
    padding: 2rem;
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--card-radius);
    box-shadow: var(--shadow);
}

.center {
    text-align: center;
}

.hidden {
    display: none;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

footer,
.site-footer {
    margin-top: 4rem;
    padding: 1.5rem;
    background: white;
    border-top: 1px solid var(--border);
    color: var(--text-light);
    font-size: .95rem;
    text-align: center;
}


/*======================================================================
    RESPONSIVE LAYOUT
======================================================================*/

@media (max-width: 900px) {
    .course-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .course-grid.bottom {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 760px) {
    .wrapper,
    .page-shell {
        padding: 1.1rem;
    }

    .header-inner {
        padding: .8rem 1.1rem;
    }

    .menu-button {
        display: block;
    }

    .main-nav {
        display: none;
        position: absolute;
        top: 66px;
        right: 1rem;
        z-index: 10;
        width: min(250px, calc(100% - 2rem));
        padding: .8rem;
        flex-direction: column;
        align-items: stretch;
        gap: .2rem;
        background: white;
        border: 1px solid var(--border);
        border-radius: 12px;
        box-shadow: var(--shadow);
    }

    .main-nav.is-open,
    .main-nav.mobile-open {
        display: flex;
    }

    .main-nav a {
        padding: .45rem;
    }

    .hero {
        padding: 1.5rem 0 1rem;
    }

    .course-grid,
    .course-grid.bottom {
        grid-template-columns: 1fr;
        gap: .65rem;
        margin-top: .65rem;
    }

    a.course-card,
    a.course-card-link {
        min-height: 76px;
        padding: .65rem .9rem;
        display: grid;
        grid-template-columns: 96px 1fr;
        grid-template-rows: auto auto;
        align-items: center;
        column-gap: .8rem;
    }

    .course-card .course-icon,
    .course-card-link .course-icon {
        width: 86px;
        height: 60px;
        margin: 0;
        grid-column: 1;
        grid-row: 1 / span 2;
    }

    .course-card h2 {
        margin: 0;
        align-self: center;
        text-align: left;
        font-size: 1.18rem;
        line-height: 1.15;
    }

    .course-card p {
        display: none;
    }

    .course-banner {
        padding-top: 0;
    }

    .section-bar {
        padding: .5rem .8rem;
        align-items: center;
        flex-direction: row;
    }

    .section-bar h2 {
        font-size: 1.05rem;
    }

    .section-selector {
        width: auto;
        flex: 0 0 auto;
    }

    .section-button {
        flex: 0 0 auto;
        padding: .24rem .5rem;
        font-size: .76rem;
    }

    .admin-links {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .admin-link {
        min-height: 58px;
        padding: .3rem .1rem;
        flex-direction: column;
        gap: .12rem;
        font-size: .62rem;
        line-height: 1.05;
        border-right: 1px solid var(--border);
        border-bottom: 0;
    }

    .admin-link img {
        width: 30px;
        height: 30px;
        flex-basis: 30px;
    }

    .lesson-heading {
        min-height: 36px;
        padding: .3rem .5rem;
    }

    .lesson-content > .resource-link {
        min-height: 40px;
        padding: .22rem .45rem;
        grid-template-columns: 30px 1fr;
        gap: .4rem;
    }

    .lesson-content > .resource-link img {
        width: 25px;
        height: 25px;
    }

    .resource-link strong {
        font-size: .84rem;
    }

    .resource-link small {
        font-size: .68rem;
    }
}

@media (max-width: 600px) {
    .course-grid,
    .course-grid.bottom {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 460px) {
    .site-title,
    .site-name {
        font-size: 1.12rem;
    }

    .course-banner-icon {
        width: 58px;
        height: 58px;
        flex-basis: 58px;
    }

    .course-banner p {
        display: none;
    }

    .section-bar {
        gap: .55rem;
    }

    .section-bar h2 {
        font-size: 1rem;
    }

    .section-button {
        padding: .22rem .42rem;
        font-size: .72rem;
    }
}


/*======================================================================
    UNIFORM NAVIGATION WITH CLASSES DROPDOWN
======================================================================*/

.main-nav {
    gap: 1.45rem;
}

.nav-dropdown {
    position: relative;
}

.nav-dropdown-button {
    display: inline-flex;
    align-items: center;
    gap: .3rem;
    padding: 0;
    border: 0;
    background: transparent;
    color: var(--heading);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
}

.nav-dropdown-button:hover,
.nav-dropdown-button:focus-visible,
.nav-dropdown.is-open > .nav-dropdown-button {
    color: var(--primary-blue);
}

.dropdown-arrow {
    font-size: .75em;
    transition: transform var(--transition);
}

.nav-dropdown.is-open .dropdown-arrow {
    transform: rotate(180deg);
}

.nav-dropdown-menu {
    display: none;
    position: absolute;
    top: calc(100% + .7rem);
    left: 50%;
    z-index: 1100;
    width: 230px;
    padding: .45rem;
    transform: translateX(-50%);
    background: white;
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: var(--shadow-hover);
}

.nav-dropdown.is-open .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu {
    display: grid;
}

.nav-dropdown-menu a {
    padding: .55rem .7rem;
    border-radius: 8px;
    font-size: .93rem;
}

.nav-dropdown-menu a:hover,
.nav-dropdown-menu a:focus-visible {
    background: #F3F6FA;
}

/* Vertical bars were intentionally omitted: the spacing and dropdown provide
   clearer grouping and a more contemporary, less cluttered header. */


@media (max-width: 760px) {
    .nav-dropdown {
        width: 100%;
    }

    .nav-dropdown-button {
        width: 100%;
        justify-content: space-between;
        padding: .45rem;
    }

    .nav-dropdown-menu {
        position: static;
        width: 100%;
        padding: .15rem 0 .25rem .75rem;
        transform: none;
        border: 0;
        border-left: 2px solid var(--border);
        border-radius: 0;
        box-shadow: none;
    }

    .nav-dropdown:focus-within .nav-dropdown-menu {
        display: none;
    }

    .nav-dropdown.is-open .nav-dropdown-menu {
        display: grid;
    }

    .nav-dropdown-menu a {
        padding: .45rem;
    }
}

/*======================================================================
    ABOUT AND RESOURCES PAGES
    Consolidated from the former content-pages.css file.
======================================================================*/

/* Additional styles for Resources and About pages */

.content-page {
    padding-top: 2.4rem;
    padding-bottom: 3rem;
}

.page-intro {
    max-width: 760px;
    margin-bottom: 2rem;
}

.page-intro h1 {
    margin: .1rem 0 .35rem;
    font-size: clamp(2rem, 5vw, 2.7rem);
}

.page-intro p {
    font-size: 1.08rem;
}

.eyebrow {
    display: block;
    color: var(--primary-blue);
    font-size: .8rem;
    font-weight: 800;
    letter-spacing: .08em;
    text-transform: uppercase;
}

.resource-section,
.education-section {
    margin-top: 2.4rem;
}

.resource-section > h2,
.education-section > h2 {
    margin-bottom: 1rem;
}

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

.information-card,
.detail-card,
.education-list,
.about-photo-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--card-radius);
    box-shadow: var(--shadow);
}

.information-card {
    display: block;
    padding: 1.25rem;
    color: var(--text);
    text-decoration: none;
}

.information-card:hover,
.information-card:focus-visible {
    color: var(--text);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.information-card h3 {
    margin: 0 0 .35rem;
}

.information-card p {
    margin: 0 0 .7rem;
}

.card-action {
    color: var(--primary-blue);
    font-size: .9rem;
    font-weight: 700;
}

.about-layout {
    display: grid;
    grid-template-columns: minmax(190px, 270px) minmax(0, 1fr);
    align-items: start;
    gap: 2rem;
}

.about-photo-card {
    overflow: hidden;
}

.about-photo-card img {
    width: 100%;
    height: auto;
}

.about-copy {
    font-size: 1.04rem;
}

.about-copy p {
    color: var(--text);
}

.about-details-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.detail-card {
    padding: 1.35rem;
}

.detail-card h2 {
    margin: 0 0 .8rem;
    font-size: 1.35rem;
}

.detail-card p:last-child {
    margin-bottom: 0;
}

.education-list {
    overflow: hidden;
}

.education-list article {
    display: grid;
    grid-template-columns: 72px minmax(0, 1fr);
    gap: 1rem;
    padding: 1rem 1.2rem;
    border-bottom: 1px solid var(--border);
}

.education-list article:last-child {
    border-bottom: 0;
}

.degree-year {
    color: var(--primary-blue);
    font-weight: 800;
}

.main-nav a[aria-current="page"] {
    color: var(--primary-blue);
}

@media (max-width: 760px) {
    .resource-card-grid,
    .about-details-grid {
        grid-template-columns: 1fr;
    }

    .about-layout {
        grid-template-columns: 1fr;
    }

    .about-photo-card {
        width: min(240px, 72vw);
        margin: 0 auto;
    }
}


/*======================================================================
    ABOUT PAGE LAYOUT CORRECTION
======================================================================*/

.office-hours-banner {
    margin-bottom: 1.7rem;
    padding: 1.15rem 1.3rem;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--card-radius);
    box-shadow: var(--shadow);
}

.office-hours-banner h2 {
    margin: 0 0 .75rem;
    font-size: 1.3rem;
}

.office-hours-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.4rem;
}

.office-hours-grid p {
    margin: 0;
}

.about-layout {
    display: grid;
    grid-template-columns: 150px minmax(0, 1fr);
    align-items: start;
    gap: 1.6rem;
}

.about-photo-card {
    width: 150px;
    max-width: 100%;
    overflow: hidden;
}

.about-photo-card img {
    display: block;
    width: 100%;
    height: auto;
}

.compact-education {
    border: 0;
    border-radius: 0;
    box-shadow: none;
}

.compact-education article {
    display: block;
    padding: .75rem 0;
}

@media (max-width: 620px) {
    .about-details-grid,
    .resource-card-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 520px) {
    .office-hours-grid,
    .about-layout {
        grid-template-columns: 1fr;
    }

    .about-photo-card {
        width: 150px;
        margin: 0 auto;
    }
}


/* Keeps the pointer path between Classes and its dropdown continuous. */
@media (min-width: 761px) {
    .nav-dropdown.is-open::after {
        content: "";
        position: absolute;
        top: 100%;
        left: -1rem;
        width: calc(100% + 2rem);
        height: .9rem;
    }
}