/* ==========================================================
   LITTLE EXPLORERS LEARNING HUB
   TEACHER RESOURCE LIBRARY

   File:
   styles/teacher-resources-library.css

   Page:
   library/teacher-resources/index.html

   Theme:
   Teacher Support • Planning • Professional Practice
   ========================================================== */


/* ==========================================================
   1. COLOR SYSTEM
   ========================================================== */

:root {
    --teacher-navy: #31546b;
    --teacher-navy-dark: #243f52;

    --teacher-blue: #4f86a8;
    --teacher-blue-light: #e7f1f7;

    --teacher-green: #6f9678;
    --teacher-green-light: #e8f1e9;

    --teacher-orange: #d9914d;
    --teacher-orange-light: #fdf0df;

    --teacher-purple: #8277a3;
    --teacher-purple-light: #eeeaf5;

    --teacher-coral: #d57963;
    --teacher-coral-light: #f8e7e2;

    --teacher-aqua: #55a1a0;
    --teacher-aqua-light: #e3f3f2;

    --teacher-cream: #faf7ef;
    --teacher-paper: #fffdf9;
    --teacher-white: #ffffff;

    --teacher-text: #35434d;
    --teacher-muted: #69757d;

    --teacher-border: #dce5e5;
    --teacher-border-dark: #c7d4d5;

    --teacher-shadow:
        0 10px 30px rgba(49, 84, 107, 0.09);

    --teacher-shadow-hover:
        0 18px 42px rgba(49, 84, 107, 0.16);

    --teacher-radius: 20px;
    --teacher-transition: 0.28s ease;

    --teacher-width: 1240px;
}


/* ==========================================================
   2. RESET
   ========================================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-width: 320px;

    font-family: "Inter", sans-serif;

    font-size: 16px;
    line-height: 1.65;

    color: var(--teacher-text);

    background:
        linear-gradient(
            180deg,
            var(--teacher-paper) 0%,
            #ffffff 55%,
            var(--teacher-cream) 100%
        );

    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

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

a {
    color: inherit;
    text-decoration: none;
}

button,
input {
    font: inherit;
}

h1,
h2,
h3,
h4 {
    font-family: "Nunito", sans-serif;
}

.container {
    width: min(92%, var(--teacher-width));
    margin-inline: auto;
}


/* ==========================================================
   3. HEADER
   ========================================================== */

body > header {
    position: sticky;
    top: 0;
    z-index: 1000;

    background:
        rgba(255, 253, 249, 0.97);

    border-bottom:
        1px solid var(--teacher-border);

    box-shadow:
        0 3px 16px rgba(49, 84, 107, 0.08);

    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.nav-container {
    min-height: 86px;

    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 2rem;
}


/* ==========================================================
   4. HEADER BRAND
   ========================================================== */

.logo {
    display: inline-flex;
    align-items: center;

    gap: 12px;
    flex-shrink: 0;

    color: var(--teacher-navy);
}

.logo img {
    width: 58px;
    height: 58px;

    object-fit: contain;
}

.logo > div {
    display: flex;
    flex-direction: column;
}

.logo h1 {
    margin: 0;

    color: var(--teacher-navy);

    font-size: 1.4rem;
    font-weight: 800;
    line-height: 1.05;
}

.logo span {
    margin-top: 4px;

    color: var(--teacher-coral);

    font-size: 0.75rem;
    font-weight: 800;

    letter-spacing: 0.08em;
    text-transform: uppercase;
}


/* ==========================================================
   5. NAVIGATION
   ========================================================== */

nav {
    margin-left: auto;
}

nav ul {
    display: flex;
    align-items: center;

    gap: 1.35rem;

    margin: 0;
    padding: 0;

    list-style: none;
}

nav a {
    position: relative;

    display: inline-flex;

    padding: 0.5rem 0;

    color: var(--teacher-navy);

    font-size: 0.94rem;
    font-weight: 700;

    transition:
        color var(--teacher-transition),
        transform var(--teacher-transition);
}

nav a::after {
    content: "";

    position: absolute;

    left: 0;
    bottom: 0;

    width: 0;
    height: 3px;

    border-radius: 999px;

    background: var(--teacher-coral);

    transition: width var(--teacher-transition);
}

nav a:hover {
    color: var(--teacher-coral);
    transform: translateY(-1px);
}

nav a:hover::after,
nav a.active::after {
    width: 100%;
}

nav a.active {
    color: var(--teacher-coral);
}


/* ==========================================================
   6. MOBILE MENU
   ========================================================== */

.mobile-menu {
    display: none;

    width: 46px;
    height: 46px;

    align-items: center;
    justify-content: center;

    border: 0;
    border-radius: 12px;

    background: var(--teacher-navy);
    color: #ffffff;

    font-size: 1.35rem;

    cursor: pointer;

    transition:
        background var(--teacher-transition),
        transform var(--teacher-transition);
}

.mobile-menu:hover {
    background: var(--teacher-navy-dark);
    transform: translateY(-2px);
}


/* ==========================================================
   7. HERO
   ========================================================== */

.study-hero {
    position: relative;
    overflow: hidden;

    padding: 6rem 0 5.8rem;

    background:
        radial-gradient(
            circle at 8% 20%,
            rgba(79, 134, 168, 0.18),
            transparent 25%
        ),

        radial-gradient(
            circle at 90% 18%,
            rgba(217, 145, 77, 0.18),
            transparent 25%
        ),

        radial-gradient(
            circle at 76% 110%,
            rgba(111, 150, 120, 0.16),
            transparent 30%
        ),

        linear-gradient(
            135deg,
            #edf5f8 0%,
            #faf7ef 52%,
            #f8e9e3 100%
        );

    border-bottom:
        1px solid var(--teacher-border);
}

.study-hero::before {
    content: "📝";

    position: absolute;

    left: 4%;
    top: 17%;

    font-size:
        clamp(3rem, 6vw, 5.5rem);

    opacity: 0.10;

    transform: rotate(-8deg);

    pointer-events: none;
}

.study-hero::after {
    content: "📚";

    position: absolute;

    right: 5%;
    bottom: 10%;

    font-size:
        clamp(3rem, 6vw, 5.5rem);

    opacity: 0.10;

    transform: rotate(8deg);

    pointer-events: none;
}

.study-hero .container {
    position: relative;
    z-index: 2;
}


/* ==========================================================
   8. BREADCRUMB
   ========================================================== */

.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;

    gap: 0.45rem;

    margin-bottom: 1.75rem;

    color: var(--teacher-muted);

    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--teacher-navy);
    font-weight: 700;

    transition: color var(--teacher-transition);
}

.breadcrumb a:hover {
    color: var(--teacher-coral);
}


/* ==========================================================
   9. HERO TYPOGRAPHY
   ========================================================== */

.study-hero h1 {
    max-width: 950px;

    margin: 0 0 1.2rem;

    color: var(--teacher-navy);

    font-size:
        clamp(2.7rem, 6vw, 4.8rem);

    font-weight: 800;

    line-height: 1.04;

    letter-spacing: -0.045em;
}

.study-hero > .container > p {
    max-width: 900px;

    margin: 0 0 2.3rem;

    color: var(--teacher-text);

    font-size:
        clamp(1.05rem, 1.8vw, 1.22rem);

    line-height: 1.75;
}


/* ==========================================================
   10. BUTTONS
   ========================================================== */

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.9rem;
}

.hero-buttons .btn {
    display: inline-flex;

    align-items: center;
    justify-content: center;

    min-height: 50px;

    padding: 0.78rem 1.45rem;

    border-radius: 999px;

    font-size: 0.95rem;
    font-weight: 800;

    transition:
        background var(--teacher-transition),
        color var(--teacher-transition),
        border-color var(--teacher-transition),
        transform var(--teacher-transition),
        box-shadow var(--teacher-transition);
}

.hero-buttons .btn:hover {
    transform: translateY(-3px);
}

.btn-primary {
    background: var(--teacher-navy);
    color: #ffffff;

    box-shadow:
        0 8px 20px rgba(49, 84, 107, 0.22);
}

.btn-primary:hover {
    background: var(--teacher-navy-dark);

    box-shadow:
        0 12px 28px rgba(49, 84, 107, 0.28);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.9);

    color: var(--teacher-navy);

    border:
        1px solid var(--teacher-border-dark);
}

.btn-secondary:hover {
    color: var(--teacher-coral);
    border-color: var(--teacher-coral);
}


/* ==========================================================
   11. SECTION HEADERS
   ========================================================== */

.section-header {
    max-width: 850px;

    margin: 0 auto 3.2rem;

    text-align: center;
}

.section-label {
    display: inline-block;

    margin-bottom: 0.8rem;

    color: var(--teacher-coral);

    font-size: 0.76rem;
    font-weight: 800;

    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.section-header h2 {
    margin: 0 0 1rem;

    color: var(--teacher-navy);

    font-size:
        clamp(2rem, 4vw, 3rem);

    font-weight: 800;

    line-height: 1.1;
}

.section-header p {
    margin: 0;

    color: var(--teacher-muted);

    font-size: 1.04rem;

    line-height: 1.75;
}


/* ==========================================================
   12. FEATURED INTRODUCTION
   ========================================================== */

.featured-study {
    padding: 5.6rem 0;

    background: var(--teacher-paper);
}

.featured-study-card {
    display: grid;

    grid-template-columns:
        minmax(0, 0.95fr)
        minmax(0, 1.05fr);

    overflow: hidden;

    background: var(--teacher-white);

    border:
        1px solid var(--teacher-border);

    border-radius: 24px;

    box-shadow: var(--teacher-shadow);
}

.featured-image {
    min-width: 0;

    display: flex;
    align-items: center;
    justify-content: center;

    padding: 1rem;

    background:
        linear-gradient(
            145deg,
            var(--teacher-blue-light),
            var(--teacher-green-light)
        );
}

.featured-image img {
    width: 100%;

    aspect-ratio: 1 / 1;

    object-fit: contain;
    object-position: center;

    border-radius: 16px;
}

.featured-text {
    display: flex;
    flex-direction: column;
    justify-content: center;

    padding:
        clamp(2rem, 5vw, 4rem);
}

.featured-label {
    display: inline-block;

    width: fit-content;

    margin-bottom: 0.9rem;

    color: var(--teacher-coral);

    font-size: 0.76rem;
    font-weight: 800;

    letter-spacing: 0.11em;
    text-transform: uppercase;
}

.featured-text h2 {
    margin: 0 0 1rem;

    color: var(--teacher-navy);

    font-size:
        clamp(2rem, 4vw, 3rem);

    line-height: 1.12;
}

.featured-text > p {
    margin: 0 0 1.7rem;

    color: var(--teacher-muted);

    line-height: 1.75;
}


/* ==========================================================
   13. FEATURED HIGHLIGHTS
   ========================================================== */

.featured-highlights {
    display: grid;

    grid-template-columns:
        repeat(3, minmax(0, 1fr));

    gap: 0.65rem;
}

.featured-highlights div {
    padding: 0.72rem 0.8rem;

    background: var(--teacher-cream);

    border:
        1px solid var(--teacher-border);

    border-radius: 10px;

    color: var(--teacher-navy);

    font-size: 0.86rem;
    font-weight: 700;

    text-align: center;
}


/* ==========================================================
   14. GENERAL SECTIONS
   ========================================================== */

.study-section {
    padding: 5.8rem 0;

    background: #ffffff;
}

.study-section.alternate {
    background:
        linear-gradient(
            180deg,
            var(--teacher-cream),
            #ffffff
        );
}


/* ==========================================================
   15. RESOURCE CATEGORY GRID
   ========================================================== */

.interest-grid {
    display: grid;

    grid-template-columns:
        repeat(3, minmax(0, 1fr));

    gap: 1.5rem;

    align-items: stretch;
}

.interest-card {
    position: relative;

    display: flex;
    flex-direction: column;

    min-width: 0;

    padding: 1.8rem;

    background: var(--teacher-white);

    border:
        1px solid var(--teacher-border);

    border-top-width: 5px;

    border-radius: var(--teacher-radius);

    box-shadow:
        0 7px 22px rgba(49, 84, 107, 0.06);

    transition:
        transform var(--teacher-transition),
        box-shadow var(--teacher-transition),
        border-color var(--teacher-transition);
}

.interest-card:hover {
    transform: translateY(-6px);

    box-shadow:
        var(--teacher-shadow-hover);
}


/* ==========================================================
   16. CATEGORY COLORS
   ========================================================== */

.interest-card.blue {
    border-top-color: var(--teacher-blue);
}

.interest-card.green {
    border-top-color: var(--teacher-green);
}

.interest-card.orange {
    border-top-color: var(--teacher-orange);
}

.interest-card.purple {
    border-top-color: var(--teacher-purple);
}

.interest-card.coral {
    border-top-color: var(--teacher-coral);
}

.interest-card.aqua {
    border-top-color: var(--teacher-aqua);
}


/* ==========================================================
   17. CATEGORY ICONS
   ========================================================== */

.interest-icon {
    width: 54px;
    height: 54px;

    display: flex;
    align-items: center;
    justify-content: center;

    margin-bottom: 1rem;

    border-radius: 15px;

    background: var(--teacher-blue-light);

    font-size: 1.55rem;
}

.interest-card.green .interest-icon {
    background: var(--teacher-green-light);
}

.interest-card.orange .interest-icon {
    background: var(--teacher-orange-light);
}

.interest-card.purple .interest-icon {
    background: var(--teacher-purple-light);
}

.interest-card.coral .interest-icon {
    background: var(--teacher-coral-light);
}

.interest-card.aqua .interest-icon {
    background: var(--teacher-aqua-light);
}

.interest-card h3 {
    margin: 0 0 0.7rem;

    color: var(--teacher-navy);

    font-size: 1.2rem;

    line-height: 1.3;
}

.interest-card p {
    flex: 1;

    margin: 0 0 1.1rem;

    color: var(--teacher-muted);

    font-size: 0.94rem;

    line-height: 1.7;
}

.interest-card a {
    display: inline-flex;

    align-items: center;

    margin-top: auto;

    color: var(--teacher-navy);

    font-size: 0.9rem;
    font-weight: 800;

    transition:
        color var(--teacher-transition),
        transform var(--teacher-transition);
}

.interest-card a:hover {
    color: var(--teacher-coral);

    transform: translateX(4px);
}


/* ==========================================================
   18. NEWSLETTER
   ========================================================== */

.newsletter {
    padding: 5.8rem 0;

    background:
        linear-gradient(
            135deg,
            #edf5f8 0%,
            #faf7ef 50%,
            #eef5ed 100%
        );
}

.newsletter-box {
    display: grid;

    grid-template-columns:
        minmax(0, 1.25fr)
        minmax(320px, 0.75fr);

    gap: 3rem;

    align-items: center;

    padding:
        clamp(2rem, 5vw, 4rem);

    background: rgba(255, 255, 255, 0.9);

    border:
        1px solid var(--teacher-border);

    border-radius: 26px;

    box-shadow: var(--teacher-shadow);
}

.newsletter-tag {
    display: inline-block;

    margin-bottom: 0.8rem;

    color: var(--teacher-coral);

    font-size: 0.76rem;
    font-weight: 800;

    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.newsletter-content h2 {
    max-width: 650px;

    margin: 0 0 1rem;

    color: var(--teacher-navy);

    font-size:
        clamp(2rem, 4vw, 3rem);

    line-height: 1.1;
}

.newsletter-content > p {
    max-width: 700px;

    margin: 0 0 1.5rem;

    color: var(--teacher-muted);

    line-height: 1.75;
}

.newsletter-benefits {
    display: grid;

    grid-template-columns:
        repeat(2, minmax(0, 1fr));

    gap: 0.65rem;
}

.newsletter-benefits div {
    padding: 0.7rem 0.85rem;

    background: var(--teacher-paper);

    border:
        1px solid var(--teacher-border);

    border-radius: 10px;

    color: var(--teacher-navy);

    font-size: 0.86rem;
    font-weight: 700;
}


/* ==========================================================
   19. NEWSLETTER CARD
   ========================================================== */

.newsletter-card {
    padding: 2rem;

    background:
        linear-gradient(
            145deg,
            var(--teacher-navy),
            #416a80
        );

    border-radius: 20px;

    color: #ffffff;

    box-shadow:
        0 14px 34px rgba(49, 84, 107, 0.2);
}

.newsletter-card h3 {
    margin: 0 0 0.4rem;

    color: #ffffff;

    font-size: 1.5rem;
}

.newsletter-card > p {
    margin: 0 0 1.35rem;

    color: rgba(255, 255, 255, 0.8);

    font-size: 0.9rem;
}

.newsletter-form {
    display: flex;
    flex-direction: column;

    gap: 0.8rem;
}

.input-group {
    display: flex;
    align-items: center;

    min-height: 52px;

    padding: 0 0.9rem;

    background: #ffffff;

    border-radius: 12px;
}

.input-icon {
    flex-shrink: 0;

    margin-right: 0.6rem;

    font-size: 1rem;
}

.input-group input {
    width: 100%;

    min-width: 0;

    border: 0;
    outline: 0;

    background: transparent;

    color: var(--teacher-text);

    font-size: 0.94rem;
}

.input-group input::placeholder {
    color: #8a949a;
}

.newsletter-form button {
    min-height: 52px;

    border: 0;
    border-radius: 12px;

    background: var(--teacher-orange);

    color: #ffffff;

    font-weight: 800;

    cursor: pointer;

    transition:
        background var(--teacher-transition),
        transform var(--teacher-transition);
}

.newsletter-form button:hover {
    background: #c67c3e;

    transform: translateY(-2px);
}


/* ==========================================================
   20. FOOTER
   ========================================================== */

footer {
    background:
        linear-gradient(
            135deg,
            #243f52 0%,
            #31546b 52%,
            #416a80 100%
        );

    color: #ffffff;
}

.footer-grid {
    display: grid;

    grid-template-columns:
        1.35fr repeat(3, 1fr);

    gap: 2.8rem;

    padding-top: 4rem;
    padding-bottom: 3.5rem;
}


/* ==========================================================
   21. FOOTER BRAND
   NO LOGO
   ========================================================== */

.footer-site-name {
    display: inline-block;

    margin-bottom: 1rem;

    color: #ffffff;

    font-family: "Nunito", sans-serif;

    font-size: 1.35rem;
    font-weight: 800;

    line-height: 1.2;

    transition:
        color var(--teacher-transition),
        transform var(--teacher-transition);
}

.footer-site-name:hover {
    color: var(--teacher-orange);

    transform: translateY(-2px);
}

.footer-brand p {
    max-width: 340px;

    margin: 0;

    color: rgba(255, 255, 255, 0.82);

    line-height: 1.7;
}


/* ==========================================================
   22. FOOTER COLUMNS
   ========================================================== */

.footer-column {
    display: flex;
    flex-direction: column;

    gap: 0.45rem;
}

.footer-column h4 {
    margin: 0 0 0.7rem;

    color: #ffffff;

    font-size: 1.05rem;
    font-weight: 800;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.82);

    font-size: 0.92rem;

    transition:
        color var(--teacher-transition),
        transform var(--teacher-transition);
}

.footer-column a:hover {
    color: var(--teacher-orange);

    transform: translateX(3px);
}


/* ==========================================================
   23. FOOTER BOTTOM
   ========================================================== */

.footer-bottom {
    padding: 1.2rem 0;

    border-top:
        1px solid rgba(255, 255, 255, 0.18);

    text-align: center;
}

.footer-bottom p {
    margin: 0.15rem 0;

    color: rgba(255, 255, 255, 0.68);

    font-size: 0.85rem;
}


/* ==========================================================
   24. ACCESSIBILITY
   ========================================================== */

a:focus-visible,
button:focus-visible,
input:focus-visible {
    outline: 3px solid var(--teacher-orange);

    outline-offset: 4px;
}


/* ==========================================================
   25. TABLET
   ========================================================== */

@media (max-width: 1100px) {

    nav ul {
        gap: 0.8rem;
    }

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

    .newsletter-box {
        grid-template-columns: 1fr;
    }

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


/* ==========================================================
   26. MOBILE
   ========================================================== */

@media (max-width: 768px) {

    .nav-container {
        min-height: 76px;
    }

    nav {
        display: none;
    }

    .mobile-menu {
        display: flex;
    }

    nav.mobile-nav-open {
        display: block;

        position: absolute;

        top: 76px;
        left: 0;
        right: 0;

        padding: 1rem;

        background: var(--teacher-paper);

        border-bottom:
            1px solid var(--teacher-border);

        box-shadow:
            0 12px 28px rgba(49, 84, 107, 0.12);
    }

    nav.mobile-nav-open ul {
        flex-direction: column;
        align-items: stretch;

        gap: 0.25rem;
    }

    nav.mobile-nav-open a {
        display: block;

        padding: 0.85rem 1rem;

        border-radius: 10px;
    }

    nav.mobile-nav-open a:hover {
        background: var(--teacher-blue-light);
    }

    nav.mobile-nav-open a::after {
        display: none;
    }


    /* HERO */

    .study-hero {
        padding: 4.8rem 0 5rem;
    }

    .study-hero h1 {
        font-size:
            clamp(2.3rem, 10vw, 3.5rem);
    }

    .study-hero > .container > p {
        font-size: 1rem;
    }


    /* BUTTONS */

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .hero-buttons .btn {
        width: 100%;
    }


    /* FEATURED */

    .featured-study {
        padding: 4.5rem 0;
    }

    .featured-study-card {
        grid-template-columns: 1fr;
    }

    .featured-image {
        padding: 0.75rem;
    }

    .featured-text {
        padding: 2rem 1.5rem 2.3rem;
    }

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


    /* SECTIONS */

    .study-section,
    .newsletter {
        padding: 4.5rem 0;
    }


    /* RESOURCE CARDS */

    .interest-grid {
        grid-template-columns: 1fr;

        gap: 1.15rem;
    }

    .interest-card {
        padding: 1.5rem;
    }


    /* NEWSLETTER */

    .newsletter-box {
        padding: 1.5rem;
    }

    .newsletter-benefits {
        grid-template-columns: 1fr;
    }

    .newsletter-card {
        padding: 1.5rem;
    }


    /* FOOTER */

    .footer-grid {
        grid-template-columns: 1fr;

        gap: 2rem;

        padding-top: 3.3rem;
        padding-bottom: 3rem;
    }
}


/* ==========================================================
   27. SMALL PHONES
   ========================================================== */

@media (max-width: 480px) {

    .container {
        width: min(91%, var(--teacher-width));
    }

    .logo > div {
        display: none;
    }

    .featured-highlights {
        grid-template-columns: 1fr;
    }

    .featured-text {
        padding: 1.7rem 1.25rem 2rem;
    }

    .interest-card {
        padding: 1.35rem;
    }

    .interest-icon {
        width: 48px;
        height: 48px;

        font-size: 1.35rem;
    }

    .newsletter-box {
        padding: 1.15rem;
    }

    .newsletter-card {
        padding: 1.25rem;
    }
}


/* ==========================================================
   28. REDUCED MOTION
   ========================================================== */

@media (prefers-reduced-motion: reduce) {

    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}