:root {
    --ink: #172b3a;
    --muted: #52616f;
    --blue: #1a4d86;
    --blue-soft: #eaf3ff;
    --red: #b23a48;
    --red-dark: #8b2a35;
    --gold: #f3c15f;
    --line: #d9e4ee;
    --surface: #ffffff;
    --surface-soft: #f7fafc;
    --max: 1120px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    color: var(--ink);
    background: var(--surface);
    line-height: 1.65;
}

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

a:hover {
    color: var(--red);
}

.site-header {
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.96);
    position: sticky;
    top: 0;
    z-index: 10;
}

.nav-shell {
    width: min(100% - 32px, var(--max));
    margin: 0 auto;
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--ink);
    text-decoration: none;
    font-weight: 800;
}

.brand img {
    width: 42px;
    height: auto;
}

.site-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 6px;
}

.site-nav a {
    text-decoration: none;
    color: var(--ink);
    padding: 8px 10px;
    border-radius: 8px;
    font-weight: 650;
    font-size: 0.95rem;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
    background: var(--blue-soft);
    color: var(--blue);
}

.hero {
    background: linear-gradient(180deg, #ffffff 0%, #f4f8fb 100%);
    border-bottom: 1px solid var(--line);
}

.compact-hero .hero-inner {
    padding-top: 42px;
    padding-bottom: 38px;
}

.hero-inner,
.page-shell {
    width: min(100% - 32px, var(--max));
    margin: 0 auto;
}

.hero-inner {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 42px;
    align-items: center;
    padding: 56px 0 46px;
}

.eyebrow {
    margin: 0 0 10px;
    color: var(--red);
    font-weight: 800;
    letter-spacing: 0;
    text-transform: uppercase;
    font-size: 0.82rem;
}

h1,
h2,
h3 {
    line-height: 1.15;
    letter-spacing: 0;
    color: var(--ink);
}

h1 {
    font-size: 4.2rem;
    margin: 0 0 18px;
    max-width: 900px;
}

h2 {
    font-size: 2.05rem;
    margin: 42px 0 14px;
}

h3 {
    font-size: 1.18rem;
    margin: 26px 0 10px;
}

.lede {
    font-size: 1.18rem;
    color: var(--muted);
    max-width: 760px;
    margin: 0 0 22px;
}

.hero-cover {
    width: 100%;
    max-width: 260px;
    justify-self: end;
    filter: drop-shadow(0 18px 26px rgba(23, 43, 58, 0.18));
}

.button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    margin-top: 24px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 11px 16px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 800;
    line-height: 1.2;
}

.button.primary {
    color: #ffffff;
    background: var(--red);
}

.button.primary:hover {
    color: #ffffff;
    background: var(--red-dark);
}

.button.secondary {
    color: var(--blue);
    background: var(--blue-soft);
}

.button.secondary:hover {
    color: var(--red);
}

.page-shell {
    padding: 42px 0 60px;
}

.article-layout {
    display: grid;
    grid-template-columns: minmax(0, 740px) 300px;
    gap: 46px;
    align-items: start;
}

.article-body {
    font-size: 1.06rem;
}

.article-body p {
    margin: 0 0 18px;
}

.article-body ul,
.article-body ol {
    padding-left: 1.4rem;
    margin: 0 0 20px;
}

.article-body li {
    margin-bottom: 10px;
}

.article-meta {
    color: var(--muted);
    font-size: 0.95rem;
    margin-bottom: 24px;
}

.sidebar {
    position: sticky;
    top: 92px;
    display: grid;
    gap: 18px;
}

.panel,
.article-card,
.lesson-box,
.toc {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
}

.panel,
.lesson-box,
.toc {
    padding: 18px;
}

.panel img {
    display: block;
    width: 120px;
    margin: 0 auto 14px;
}

.panel p,
.toc p {
    margin: 0 0 12px;
    color: var(--muted);
}

.toc ol {
    margin: 0;
    padding-left: 1.2rem;
}

.toc a {
    text-decoration: none;
}

.lesson-box {
    background: var(--surface-soft);
    margin: 24px 0;
}

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

.example-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin: 18px 0 24px;
}

.mini-card {
    border: 1px solid var(--line);
    border-left: 4px solid var(--gold);
    border-radius: 8px;
    padding: 14px;
    background: #ffffff;
}

.mini-card strong {
    display: block;
    color: var(--ink);
}

.cluster-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 0 0 34px;
}

.cluster-nav a {
    padding: 9px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--blue);
    background: var(--surface-soft);
    text-decoration: none;
    font-weight: 750;
    line-height: 1.2;
}

.cluster-nav a:hover {
    border-color: var(--blue);
    color: var(--red);
    background: var(--surface);
}

.article-section {
    scroll-margin-top: 96px;
}

.article-section + .article-section {
    margin-top: 46px;
    padding-top: 38px;
    border-top: 1px solid var(--line);
}

.section-heading {
    max-width: 760px;
}

.section-heading h2 {
    margin-top: 0;
}

.section-heading p:not(.eyebrow) {
    margin: 0;
    color: var(--muted);
}

.hub-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
    margin: 24px 0 0;
}

.article-card {
    padding: 22px;
    text-decoration: none;
    color: var(--ink);
    display: grid;
    gap: 12px;
    min-height: 230px;
}

.article-card:hover {
    border-color: var(--blue);
    color: var(--ink);
    transform: translateY(-1px);
}

.article-card span {
    color: var(--red);
    font-weight: 800;
    font-size: 0.84rem;
}

.article-card h2,
.article-card h3 {
    font-size: 1.35rem;
    margin: 0;
}

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

.audio-list-page {
    display: grid;
    gap: 38px;
}

.audio-section h2 {
    margin-top: 0;
}

.audio-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
}

.audio-card {
    display: grid;
    gap: 7px;
    min-height: 132px;
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    text-decoration: none;
    background: var(--surface);
}

.audio-card:hover {
    border-color: var(--blue);
    color: var(--ink);
    transform: translateY(-1px);
}

.audio-card span {
    color: var(--red);
    font-size: 0.78rem;
    font-weight: 800;
    text-transform: uppercase;
}

.audio-card strong {
    line-height: 1.25;
}

.audio-card small {
    align-self: end;
    color: var(--muted);
}

.audio-player-box {
    margin: 0 0 24px;
    padding: 18px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface-soft);
}

.audio-player-box audio {
    display: block;
    width: 100%;
}

.practice-panel {
    display: grid;
    gap: 18px;
    margin: 28px 0 26px;
    padding: 22px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
}

.practice-block + .practice-block {
    padding-top: 16px;
    border-top: 1px solid var(--line);
}

.practice-block h2 {
    font-size: 1.22rem;
    margin: 0 0 8px;
}

.practice-block p,
.practice-block ol {
    margin-bottom: 0;
}

.transcript-line {
    padding: 14px 16px;
    border-radius: 8px;
    color: var(--ink);
    background: var(--blue-soft);
    font-weight: 800;
    line-height: 1.35;
}

.related {
    border-top: 1px solid var(--line);
    margin-top: 44px;
    padding-top: 26px;
}

.related ul {
    display: grid;
    gap: 8px;
    padding-left: 1.1rem;
}

.site-footer {
    background: var(--ink);
    color: #ffffff;
    padding: 24px 0;
}

.footer-shell {
    width: min(100% - 32px, var(--max));
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    gap: 18px;
    flex-wrap: wrap;
}

.site-footer a {
    color: #ffffff;
}

@media (max-width: 840px) {
    .nav-shell {
        align-items: flex-start;
        flex-direction: column;
        padding: 12px 0;
    }

    .site-nav {
        justify-content: flex-start;
    }

    .hero-inner,
    .article-layout,
    .hub-grid,
    .audio-grid {
        grid-template-columns: 1fr;
    }

    .hero-inner {
        padding: 38px 0 34px;
    }

    h1 {
        font-size: 2.8rem;
    }

    h2 {
        font-size: 1.7rem;
    }

    .hero-cover {
        justify-self: start;
        max-width: 190px;
    }

    .sidebar {
        position: static;
    }

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

@media (max-width: 520px) {
    .hero-inner,
    .page-shell,
    .nav-shell,
    .footer-shell {
        width: min(100% - 24px, var(--max));
    }

    .site-nav a {
        padding: 7px 8px;
        font-size: 0.9rem;
    }

    .button-row {
        align-items: stretch;
        flex-direction: column;
    }

    .button {
        width: 100%;
    }

    h1 {
        font-size: 2.1rem;
    }

    h2 {
        font-size: 1.45rem;
    }
}