:root {
    --ink: #1e2527;
    --muted: #607074;
    --paper: #f8f7f1;
    --surface: #ffffff;
    --line: #d9ddd6;
    --accent: #2d6f73;
    --accent-soft: #dcebea;
    --warm: #d99a3e;
}

body {
    margin: 0;
    color: var(--ink);
    background: var(--paper);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a {
    color: var(--accent);
    text-decoration-thickness: 0.08em;
    text-underline-offset: 0.2em;
}

.course-nav {
    background: rgba(248, 247, 241, 0.96);
    border-bottom: 1px solid var(--line);
}

.navbar-brand {
    font-weight: 750;
    letter-spacing: 0;
}

.course-hero {
    background: linear-gradient(135deg, #f8f7f1 0%, #e7f1ed 55%, #f5e8d4 100%);
    border-bottom: 1px solid var(--line);
    padding: clamp(2rem, 5vw, 5rem) 0;
}

.course-hero__grid {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.8fr);
    gap: 2rem;
    align-items: end;
}

.course-hero h1,
.section-heading h1,
.lesson-detail h1 {
    font-weight: 800;
    letter-spacing: 0;
}

.course-hero h1 {
    max-width: 780px;
    font-size: clamp(2.2rem, 5vw, 4.6rem);
    line-height: 1;
}

.section-kicker {
    color: var(--accent);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
}

.course-search {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 1rem;
}

.course-section {
    padding: clamp(2rem, 4vw, 4rem) 0;
}

.lesson-tabs {
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.lesson-tabs .nav-link {
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--ink);
}

.lesson-tabs .nav-link.active {
    background: var(--accent);
}

.lesson-tab-content {
    margin-bottom: 2rem;
}

.featured-lesson {
    display: grid;
    grid-template-columns: minmax(220px, 0.7fr) minmax(0, 1fr);
    gap: 1.5rem;
    align-items: center;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 1rem;
}

.featured-lesson img {
    width: 100%;
    aspect-ratio: 4 / 3;
    border-radius: 6px;
    object-fit: cover;
}

.lesson-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1rem;
}

.lesson-card {
    overflow: hidden;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
}

.lesson-card img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

.lesson-card__body {
    display: grid;
    gap: 0.7rem;
    padding: 1rem;
}

.lesson-card__body span,
.lesson-card__meta {
    color: var(--muted);
    font-size: 0.86rem;
}

.lesson-card h2 {
    font-size: 1.25rem;
    margin: 0;
}

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

.lesson-card__meta {
    display: flex;
    gap: 0.75rem;
}

.empty-state,
.delete-panel,
.login-box {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 1.5rem;
}

.lesson-detail {
    padding: clamp(2rem, 4vw, 4rem) 0;
}

.lesson-detail__header {
    max-width: 900px;
    margin-bottom: 1.5rem;
}

.lesson-cover {
    width: 100%;
    max-height: 520px;
    border-radius: 8px;
    object-fit: cover;
}

.lesson-body {
    max-width: 900px;
    margin: 2rem 0;
    font-size: 1.08rem;
    line-height: 1.75;
}

.lesson-body h2,
.lesson-body h3 {
    margin-top: 2rem;
}

.attachments {
    margin-top: 2rem;
}

.attachments h2 {
    font-size: 1.35rem;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
}

.image-grid figure {
    margin: 0;
}

.image-grid img,
.image-strip img {
    width: 100%;
    border-radius: 8px;
    object-fit: cover;
}

.image-grid img {
    aspect-ratio: 4 / 3;
}

.image-grid figcaption {
    color: var(--muted);
    font-size: 0.9rem;
    margin-top: 0.35rem;
}

.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: end;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.dashboard-table {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 0.5rem;
}

.status-pill {
    display: inline-flex;
    border-radius: 999px;
    padding: 0.25rem 0.55rem;
    font-size: 0.8rem;
    font-weight: 700;
}

.status-pill--published {
    background: var(--accent-soft);
    color: #16484a;
}

.status-pill--draft {
    background: #f4e4c8;
    color: #6b4216;
}

.narrow-container {
    max-width: 980px;
}

.editor-form {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 1.25rem;
}

.form-actions {
    display: flex;
    gap: 0.75rem;
    margin-top: 1.25rem;
}

.existing-files {
    border-top: 1px solid var(--line);
    margin-top: 1.5rem;
    padding-top: 1rem;
}

.existing-files h2 {
    font-size: 1rem;
    margin-top: 0.5rem;
}

.image-strip {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 0.75rem;
}

.image-strip img {
    aspect-ratio: 1;
}

.login-container {
    max-width: 460px;
}

.login-box input {
    display: block;
    width: 100%;
    min-height: 42px;
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 0.5rem 0.75rem;
}

.course-footer {
    color: var(--muted);
    border-top: 1px solid var(--line);
    padding: 1.25rem 0;
}

@media (max-width: 768px) {
    .course-hero__grid,
    .featured-lesson {
        grid-template-columns: 1fr;
    }

    .section-heading {
        align-items: stretch;
        flex-direction: column;
    }
}