@import url('./fonts.css?v=20261009b');

:root {
    --ink: #172033;
    --muted: #667085;
    --blue: #3154ad;
    --blue2: #243f8e;
    --paper: #fff;
    --soft: #f5f7fb;
    --line: #e6e9f0;
    --max: 1180px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--ink);
    font-family: 'Nunito Sans', 'Noto Sans KR', sans-serif;
    background: #fff;
}

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

.wrap {
    width: min(var(--max), calc(100% - 44px));
    margin: auto;
}

.site-header {
    height: 82px;
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, .96);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 10;
}

.nav-wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 19px;
    font-weight: 700;
}

.brand img {
    width: 74px;
    height: 46px;
    object-fit: cover;
    object-position: center;
}

.brand strong {
    color: var(--blue);
}

nav {
    display: flex;
    align-items: center;
    gap: 30px;
    font-size: 14px;
    font-weight: 700;
}

nav a:hover {
    color: var(--blue);
}

.youtube-link {
    padding: 11px 16px;
    border: 1px solid var(--line);
    border-radius: 10px;
}

.breadcrumbs {
    display: flex;
    gap: 9px;
    align-items: center;
    color: #8991a1;
    font-size: 13px;
    padding-top: 34px;
}

.breadcrumbs a:hover {
    color: var(--blue);
}

.lesson-hero {
    background: linear-gradient(120deg, #fff 62%, #f4f6fb 62%);
    border-bottom: 1px solid var(--line);
}

.lesson-heading {
    min-height: 410px;
    display: grid;
    grid-template-columns: 1fr 330px;
    gap: 85px;
    align-items: center;
}

.eyebrow {
    margin: 0 0 14px;
    color: var(--blue);
    font-size: 12px;
    font-weight: 900;
    letter-spacing: .15em;
}

.lesson-heading h1 {
    max-width: 760px;
    margin: 0;
    font-size: 54px;
    line-height: 1.05;
    letter-spacing: -.04em;
}

.lesson-korean {
    margin: 12px 0 18px;
    color: var(--blue);
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 54px;
    line-height: 1;
    font-weight: 800;
}

.lead {
    max-width: 720px;
    margin: 0;
    color: var(--muted);
    font-size: 18px;
    line-height: 1.7;
}

.lesson-summary {
    padding: 28px 30px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: rgba(255, 255, 255, .88);
    box-shadow: 0 14px 35px rgba(33, 49, 89, .06);
}

.lesson-summary > span,
.side-label {
    color: var(--blue);
    font-size: 11px;
    font-weight: 900;
    letter-spacing: .12em;
}

.lesson-summary ul {
    margin: 18px 0 0;
    padding: 0;
    list-style: none;
}

.lesson-summary li {
    position: relative;
    margin: 12px 0;
    padding-left: 22px;
    color: var(--muted);
    font-size: 14px;
}

.lesson-summary li:before {
    content: '\2713';
    position: absolute;
    left: 0;
    color: var(--blue);
    font-weight: 900;
}

.video-section {
    padding: 70px 0 45px;
}

.lesson-wrap {
    max-width: 980px;
}

.video-frame {
    position: relative;
    width: 100%;
    padding-top: 56.25%;
    overflow: hidden;
    border-radius: 22px;
    background: #10131d;
    box-shadow: 0 20px 55px rgba(24, 34, 56, .15);
}

.video-frame iframe {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
}

.video-note {
    margin: 18px 0 0;
    color: var(--muted);
    text-align: center;
    font-size: 13px;
}

.lesson-content {
    padding: 55px 0 90px;
}

.lesson-layout {
    display: grid;
    grid-template-columns: minmax(0, 780px) 270px;
    gap: 80px;
    justify-content: center;
    align-items: start;
}

.article section {
    margin-bottom: 75px;
    scroll-margin-top: 110px;
}

.article h2 {
    margin: 0 0 20px;
    font-size: 36px;
    line-height: 1.15;
    letter-spacing: -.025em;
}

.article p {
    margin: 0 0 20px;
    color: #4f596c;
    font-size: 17px;
    line-height: 1.8;
}

.callout {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 28px;
    align-items: center;
    margin-top: 32px;
    padding: 28px;
    border: 1px solid #dfe4f0;
    border-radius: 18px;
    background: var(--soft);
}

.callout-ko {
    color: var(--blue);
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 46px;
    font-weight: 800;
    text-align: center;
}

.callout strong {
    display: block;
    margin-bottom: 5px;
    font-size: 18px;
}

.callout p {
    margin: 0;
    font-size: 15px;
}

.letter-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-top: 28px;
}

.letter {
    min-height: 125px;
    border: 1px solid var(--line);
    border-radius: 15px;
    background: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.letter strong {
    color: var(--blue);
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 38px;
}

.letter span {
    margin-top: 5px;
    color: var(--muted);
    font-size: 13px;
    font-weight: 700;
}

.small-note {
    margin-top: 20px !important;
    color: #7d8696 !important;
    font-size: 13px !important;
}

.syllable-examples {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
    margin-top: 30px;
}

.syllable-examples > div {
    padding: 25px 20px;
    border-radius: 16px;
    background: var(--soft);
    text-align: center;
}

.syllable-examples span,
.syllable-examples small {
    display: block;
    color: var(--muted);
}

.syllable-examples strong {
    display: block;
    margin: 10px 0 5px;
    color: var(--blue);
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 48px;
}

.practice {
    padding: 34px;
    border-radius: 20px;
    background: #f2f4fb;
}

.practice h2 {
    font-size: 30px;
}

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

.lesson-nav {
    position: relative;
}

.sticky-card {
    position: sticky;
    top: 115px;
    padding: 25px;
    border: 1px solid var(--line);
    border-radius: 17px;
    background: #fff;
}

.sticky-card > strong {
    display: block;
    margin: 5px 0 20px;
    font-size: 24px;
}

.sticky-card > a:not(.next-mini) {
    display: block;
    padding: 10px 0;
    color: var(--muted);
    font-size: 14px;
    font-weight: 700;
}

.sticky-card > a:hover {
    color: var(--blue);
}

.side-divider {
    height: 1px;
    margin: 18px 0;
    background: var(--line);
}

.next-mini {
    display: block;
    margin-top: 9px;
    color: var(--blue);
    font-size: 14px;
    line-height: 1.5;
}

.next-mini b {
    display: block;
    color: var(--ink);
}

.next-lesson {
    padding: 0 0 90px;
}

.next-card {
    display: grid;
    grid-template-columns: 150px 1fr 160px;
    align-items: center;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: 19px;
    background: #fff;
    transition: .2s;
}

.next-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 16px 40px rgba(20, 24, 50, .08);
}

.next-card > div:first-child {
    align-self: stretch;
    padding: 28px;
    background: var(--blue);
    color: #fff;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.next-card > div:first-child span {
    font-size: 10px;
    font-weight: 900;
    letter-spacing: .12em;
}

.next-card > div:first-child strong {
    margin-top: 5px;
    font-size: 48px;
}

.next-card > div:nth-child(2) {
    padding: 28px 35px;
}

.next-card small {
    color: var(--muted);
    font-weight: 900;
    letter-spacing: .08em;
}

.next-card h2 {
    margin: 5px 0;
    font-size: 26px;
}

.next-card p {
    margin: 0;
    color: var(--muted);
}

.next-card > b {
    padding: 25px;
    color: var(--blue);
    text-align: right;
}

.youtube-cta {
    padding: 0 0 90px;
}

.youtube-box {
    display: grid;
    grid-template-columns: 1fr 220px;
    align-items: center;
    overflow: hidden;
    padding: 55px 65px;
    border-radius: 25px;
    background: var(--blue);
    color: #fff;
}

.eyebrow.light {
    color: #c8d4f4;
}

.youtube-box h2 {
    margin: 0;
    font-size: 40px;
}

.youtube-box p:not(.eyebrow) {
    max-width: 650px;
    color: #dbe2f5;
    line-height: 1.65;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 15px 21px;
    border-radius: 11px;
    font-size: 15px;
    font-weight: 800;
}

.btn.white {
    margin-top: 10px;
    background: #fff;
    color: var(--blue);
}

.yt-mark {
    width: 180px;
    height: 130px;
    border: 3px solid rgba(255, 255, 255, .25);
    border-radius: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 70px;
    transform: rotate(-5deg);
}

footer {
    padding: 45px 0 22px;
    background: #182238;
    color: #d7dce7;
}

.footer-grid {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 13px;
}

.footer-brand img {
    width: 65px;
    height: 40px;
    object-fit: cover;
    border-radius: 6px;
}

.footer-grid > div:last-child {
    display: flex;
    gap: 22px;
    font-size: 13px;
}

.copyright {
    margin-top: 35px;
    padding-top: 20px;
    border-top: 1px solid #344058;
    color: #929bad;
    font-size: 12px;
}

@media (max-width: 900px) {
    .site-header {
        height: auto;
        padding: 12px 0;
    }

    .brand span {
        display: none;
    }

    nav a:not(.youtube-link) {
        display: none;
    }

    .lesson-heading {
        grid-template-columns: 1fr;
        gap: 25px;
        padding: 60px 0;
    }

    .lesson-heading h1 {
        font-size: 43px;
    }

    .lesson-summary {
        max-width: 520px;
    }

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

    .lesson-nav {
        display: none;
    }

    .youtube-box {
        grid-template-columns: 1fr;
        padding: 42px 30px;
    }

    .yt-mark {
        display: none;
    }

    .next-card {
        grid-template-columns: 105px 1fr;
    }

    .next-card > b {
        grid-column: 1 / -1;
        padding: 16px 20px;
        border-top: 1px solid var(--line);
        text-align: left;
    }
}

@media (max-width: 560px) {
    .wrap {
        width: min(100% - 28px, var(--max));
    }

    .breadcrumbs {
        overflow: hidden;
        white-space: nowrap;
    }

    .lesson-heading h1 {
        font-size: 37px;
    }

    .lesson-korean {
        font-size: 45px;
    }

    .lead {
        font-size: 16px;
    }

    .video-section {
        padding-top: 35px;
    }

    .video-frame {
        border-radius: 12px;
    }

    .article h2 {
        font-size: 30px;
    }

    .article p {
        font-size: 16px;
    }

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

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

    .syllable-examples {
        grid-template-columns: 1fr;
    }

    .next-card {
        grid-template-columns: 85px 1fr;
    }

    .next-card > div:first-child {
        padding: 20px;
    }

    .next-card > div:first-child strong {
        font-size: 38px;
    }

    .next-card > div:nth-child(2) {
        padding: 22px 18px;
    }

    .next-card h2 {
        font-size: 21px;
    }

    .footer-grid {
        align-items: flex-start;
        gap: 30px;
        flex-direction: column;
    }

    .footer-grid > div:last-child {
        flex-wrap: wrap;
    }
}


/* ============================================================
   DYNAMIC LESSON.PHP COMPATIBILITY
   The rules below adapt the original lesson design to the
   database-driven lesson.php markup.
============================================================ */

/* Breadcrumb generated by lesson.php */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 18px 0 0;
    color: #8991a1;
    font-size: 13px;
    font-weight: 700;
}

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

/* Dynamic hero */
.lesson-page .lesson-hero {
    padding: 18px 0 34px;
    background: linear-gradient(120deg, #fff 62%, #f4f6fb 62%);
    border-bottom: 1px solid var(--line);
}

.lesson-page .lesson-hero .wrap {
    min-height: 170px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.lesson-page .lesson-hero h1 {
    max-width: 800px;
    margin: 4px 0 0;
    font-size: 44px;
    line-height: 1.08;
    letter-spacing: -.035em;
}

.lesson-page .lesson-korean {
    margin: 15px 0 14px;
    color: var(--blue);
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 50px;
    line-height: 1;
    font-weight: 800;
}

.lesson-page .lesson-intro {
    max-width: 850px;
    margin: 0;
    color: var(--muted);
    font-size: 17px;
    line-height: 1.65;
}

/* Video generated by lesson.php */
.lesson-video {
    padding: 48px 0 22px;
}

.lesson-video .wrap {
    max-width: 980px;
}

/* Main dynamic article */
.lesson-page .lesson-content {
    padding: 45px 0 75px;
}

.lesson-page .lesson-layout {
    grid-template-columns: minmax(0, 760px) 250px;
    gap: 65px;
    max-width: 1120px;
}

.lesson-article {
    min-width: 0;
}

.lesson-section {
    margin-bottom: 58px;
    scroll-margin-top: 110px;
}

.lesson-section .eyebrow {
    margin-bottom: 13px;
}

.lesson-section h2 {
    margin: 0 0 18px;
    font-size: 32px;
    line-height: 1.18;
    letter-spacing: -.025em;
}

.lesson-section p {
    margin: 0 0 18px;
    color: #4f596c;
    font-size: 16px;
    line-height: 1.75;
}

.lesson-section ul {
    margin: 0;
    padding-left: 22px;
    color: #4f596c;
    font-size: 16px;
    line-height: 1.7;
}

.lesson-section li {
    margin: 7px 0;
}

/* Korean letter grids stored in content_html */
.hangul-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 10px;
    margin: 26px 0;
}

.hangul-grid span {
    min-height: 82px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: var(--soft);
    color: var(--blue);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 34px;
    font-weight: 700;
}

/* Syllable examples from DB */
.lesson-section .syllable-examples {
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin: 26px 0;
}

.lesson-section .syllable-examples > div {
    min-height: 145px;
    padding: 22px 14px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.lesson-section .syllable-examples strong {
    margin: 0;
    font-size: 30px;
    line-height: 1.35;
    white-space: nowrap;
}

/* Pronunciation/practice section */
.lesson-section-practice {
    padding: 30px;
    border-radius: 20px;
    background: #f2f4fb;
}

.lesson-section-practice h2 {
    font-size: 28px;
}

.lesson-section-practice p:last-child {
    margin-bottom: 0;
}

/* Summary */
.lesson-section-summary {
    padding: 30px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
}

/* TOC: override the global nav flex rules */
.lesson-toc {
    position: sticky;
    top: 105px;
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: 17px;
    background: #fff;
    box-shadow: 0 12px 35px rgba(33, 49, 89, .05);
}

.lesson-toc > strong {
    display: block;
    margin-bottom: 14px;
    font-size: 18px;
}

.lesson-toc nav {
    display: block;
    font-size: 14px;
    font-weight: 700;
}

.lesson-toc nav a {
    display: block;
    padding: 9px 0;
    border-bottom: 1px solid #f0f2f6;
    color: var(--muted);
    line-height: 1.35;
}

.lesson-toc nav a:last-child {
    border-bottom: 0;
}

.lesson-toc nav a:hover {
    color: var(--blue);
}

/* Discreet private-lesson contact */
.lesson-help {
    margin: 10px 0 55px;
    padding: 30px 32px;
    border: 1px solid #dfe4f0;
    border-radius: 18px;
    background: var(--soft);
}

.lesson-help h2 {
    margin: 0 0 10px;
    font-size: 24px;
}

.lesson-help p {
    max-width: 620px;
    margin: 0 0 15px;
    color: var(--muted);
    font-size: 15px;
    line-height: 1.65;
}

.lesson-help a {
    color: var(--blue);
    font-size: 14px;
    font-weight: 800;
}

/* Previous / next navigation */
.lesson-navigation {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin: 0 0 15px;
    font-size: 14px;
}

.lesson-navigation a {
    min-height: 100px;
    padding: 20px;
    border: 1px solid var(--line);
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.lesson-navigation a:hover {
    border-color: #cfd6e6;
    box-shadow: 0 10px 30px rgba(20, 24, 50, .06);
}

.lesson-navigation span {
    color: var(--muted);
    font-size: 12px;
}

.lesson-navigation strong {
    margin-top: 5px;
    font-size: 16px;
}

.lesson-next {
    text-align: right;
}

/* Bottom YouTube CTA generated by lesson.php */
.lesson-youtube {
    padding: 0 0 80px;
}

.lesson-youtube .wrap {
    padding: 48px 55px;
    border-radius: 24px;
    background: var(--blue);
    color: #fff;
}

.lesson-youtube .eyebrow {
    color: #c8d4f4;
}

.lesson-youtube h2 {
    margin: 0 0 10px;
    font-size: 34px;
}

.lesson-youtube p:not(.eyebrow) {
    max-width: 650px;
    margin: 0 0 22px;
    color: #dbe2f5;
    line-height: 1.65;
}

.lesson-youtube .btn {
    background: #fff;
    color: var(--blue);
}

/* Mobile navigation compatibility with homepage */
.mobile-nav {
    display: none;
}

@media (max-width: 900px) {
    .desktop-nav {
        display: none;
    }

    .mobile-nav {
        display: flex;
        align-items: center;
        gap: 10px;
    }

    .mobile-nav details {
        position: relative;
    }

    .mobile-nav summary {
        width: 46px;
        height: 46px;
        border: 1px solid var(--line);
        border-radius: 10px;
        background: #fff;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 24px;
        font-weight: 700;
        cursor: pointer;
        list-style: none;
    }

    .mobile-nav summary::-webkit-details-marker {
        display: none;
    }

    .mobile-menu {
        position: absolute;
        top: 56px;
        right: 0;
        width: 210px;
        padding: 8px;
        border: 1px solid var(--line);
        border-radius: 12px;
        background: #fff;
        box-shadow: 0 18px 45px rgba(20, 28, 47, .14);
        z-index: 20;
    }

    .mobile-menu a {
        display: block !important;
        padding: 12px 14px;
        border-radius: 8px;
        font-size: 14px;
        font-weight: 700;
    }

    .lesson-page .lesson-layout {
        grid-template-columns: 1fr;
        gap: 0;
    }

    .lesson-toc {
        display: none;
    }

    .lesson-page .lesson-hero h1 {
        font-size: 39px;
    }

    .hangul-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .lesson-section .syllable-examples {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 560px) {
    .lesson-page .lesson-hero {
        padding-bottom: 28px;
    }

    .lesson-page .lesson-hero .wrap {
        min-height: 0;
    }

    .lesson-page .lesson-hero h1 {
        font-size: 34px;
    }

    .lesson-page .lesson-korean {
        font-size: 43px;
    }

    .lesson-page .lesson-intro {
        font-size: 16px;
    }

    .lesson-video {
        padding-top: 30px;
    }

    .lesson-section {
        margin-bottom: 45px;
    }

    .lesson-section h2 {
        font-size: 27px;
    }

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

    .lesson-section .syllable-examples {
        grid-template-columns: 1fr;
    }

    .lesson-section-practice,
    .lesson-section-summary,
    .lesson-help {
        padding: 24px 20px;
    }

    .lesson-navigation {
        grid-template-columns: 1fr;
    }

    .lesson-youtube {
        padding-bottom: 55px;
    }

    .lesson-youtube .wrap {
        width: calc(100% - 28px);
        padding: 35px 24px;
        border-radius: 18px;
    }

    .lesson-youtube h2 {
        font-size: 28px;
    }
}

/* Links to other lessons inside lesson content */
.lesson-reference {
    color: #4338ca;
    font-weight: 600;
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
    transition: color 0.15s ease;
}

.lesson-reference:hover {
    color: #312e81;
    text-decoration-thickness: 2px;
}

.lesson-reference:focus {
    outline: 2px solid #4338ca;
    outline-offset: 2px;
    border-radius: 2px;
}