.course-shell {
    padding-bottom: var(--space-20);
}

.course-hero {
    padding: var(--space-16) 0 var(--space-12);
    background:
        radial-gradient(circle at top left, rgba(224, 122, 95, 0.16), transparent 28%),
        radial-gradient(circle at right 20%, rgba(61, 90, 128, 0.12), transparent 24%),
        linear-gradient(135deg, #fff8f2 0%, var(--color-bg) 52%, #f7f5f0 100%);
}

.course-hero-grid {
    display: grid;
    gap: var(--space-8);
    grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.9fr);
    align-items: start;
}

.course-kicker {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: 0.45rem 0.85rem;
    border-radius: var(--radius-full);
    background: rgba(224, 122, 95, 0.12);
    color: var(--color-primary-dark);
    font-size: var(--text-sm);
    font-family: var(--font-heading);
    margin-bottom: var(--space-4);
}

.course-hero-title {
    font-size: clamp(2.25rem, 4.5vw, 4rem);
    line-height: 1.05;
    margin-bottom: var(--space-4);
}

.course-hero-desc {
    max-width: 60ch;
    font-size: var(--text-lg);
    line-height: var(--leading-relaxed);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-6);
}

.course-meta-row,
.course-stat-grid,
.course-action-row,
.course-chip-row {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
}

.course-chip,
.course-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: 0.55rem 0.9rem;
    border: 1px solid rgba(61, 90, 128, 0.12);
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.8);
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
}

.course-hero-card,
.course-panel,
.course-outline,
.course-exercise-card,
.course-empty,
.course-section-card,
.course-nav-card,
.course-progress-card,
.course-next-card {
    border: 1px solid rgba(61, 90, 128, 0.12);
    border-radius: var(--radius-2xl);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(247, 245, 240, 0.96));
    box-shadow: var(--shadow-md);
}

.course-hero-card {
    padding: var(--space-6);
}

.course-stat-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-4);
}

.course-stat {
    padding: var(--space-4);
    border-radius: var(--radius-xl);
    background: rgba(255, 255, 255, 0.75);
}

.course-stat-value {
    display: block;
    font-family: var(--font-heading);
    font-size: var(--text-2xl);
    font-weight: var(--font-semibold);
    color: var(--color-text);
}

.course-stat-label {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
}

.course-content-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.75fr);
    gap: var(--space-8);
    align-items: start;
}

.course-stack {
    display: grid;
    gap: var(--space-6);
}

.course-panel,
.course-outline,
.course-nav-card,
.course-section-card,
.course-progress-card,
.course-next-card {
    padding: var(--space-6);
}

.course-section-heading {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    margin-bottom: var(--space-5);
}

.course-section-heading h2,
.course-section-heading h3 {
    margin: 0;
    font-size: var(--text-2xl);
}

.course-outline-list {
    display: grid;
    gap: var(--space-4);
}

.course-outline-item {
    border: 1px solid rgba(61, 90, 128, 0.1);
    border-radius: var(--radius-xl);
    background: rgba(255, 255, 255, 0.72);
    overflow: hidden;
}

.course-outline-link,
.course-outline-section {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    width: 100%;
    padding: var(--space-4) var(--space-5);
    text-decoration: none;
    color: inherit;
}

.course-outline-link:hover,
.course-outline-section:hover {
    background: rgba(224, 122, 95, 0.08);
}

.course-outline-link.active,
.course-outline-section.active {
    background: rgba(224, 122, 95, 0.1);
}

.course-outline-title {
    font-family: var(--font-heading);
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
}

.course-outline-meta {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.course-outline-sections {
    display: grid;
    gap: 1px;
    padding: 0 var(--space-4) var(--space-4);
}

.course-outline-section {
    border-radius: var(--radius-lg);
    padding: var(--space-3) var(--space-4);
    background: rgba(253, 251, 247, 0.9);
}

.course-richtext {
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

.course-richtext > :first-child {
    margin-top: 0;
}

.course-richtext h2,
.course-richtext h3,
.course-richtext h4 {
    color: var(--color-text);
    font-family: var(--font-heading);
    margin-top: var(--space-8);
    margin-bottom: var(--space-3);
}

.course-richtext pre,
.course-richtext code {
    font-family: var(--font-mono);
}

.course-richtext pre {
    overflow-x: auto;
    padding: var(--space-4);
    border-radius: var(--radius-xl);
    background: #1f2430;
    color: #f7f7f7;
}

.course-richtext blockquote {
    margin: var(--space-6) 0;
    padding: var(--space-4) var(--space-5);
    border-left: 4px solid var(--color-primary);
    background: rgba(224, 122, 95, 0.08);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

.course-note {
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius-xl);
    background: rgba(61, 90, 128, 0.08);
    color: var(--color-text-secondary);
}

.course-empty {
    padding: var(--space-8);
    text-align: center;
}

.course-empty h3 {
    margin-bottom: var(--space-3);
}

.course-empty p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-5);
}

.course-progress {
    display: grid;
    gap: var(--space-3);
}

.course-progress-bar {
    height: 10px;
    border-radius: var(--radius-full);
    background: rgba(61, 90, 128, 0.12);
    overflow: hidden;
}

.course-progress-fill {
    height: 100%;
    border-radius: inherit;
    background: linear-gradient(90deg, var(--color-primary), #f2a88d);
}

.course-progress-meter {
    display: block;
    width: 100%;
    height: 10px;
    appearance: none;
    -webkit-appearance: none;
    border: 0;
    border-radius: var(--radius-full);
    background: rgba(61, 90, 128, 0.12);
}

.course-progress-meter::-webkit-progress-bar {
    border-radius: var(--radius-full);
    background: rgba(61, 90, 128, 0.12);
}

.course-progress-meter::-webkit-progress-value {
    border-radius: var(--radius-full);
    background: linear-gradient(90deg, var(--color-primary), #f2a88d);
}

.course-progress-meter::-moz-progress-bar {
    border-radius: var(--radius-full);
    background: linear-gradient(90deg, var(--color-primary), #f2a88d);
}

.course-next-card {
    display: grid;
    gap: var(--space-3);
}

.course-next-card h3,
.course-next-card p {
    margin: 0;
}

.course-next-card p {
    color: var(--color-text-secondary);
}

.course-kicker-compact {
    margin-bottom: 0;
    width: fit-content;
}

.course-action-row-spaced {
    margin-top: var(--space-6);
}

.course-chip-row-spaced {
    margin-top: var(--space-5);
}

.course-card-title {
    margin-top: var(--space-4);
}

.course-card-description,
.course-answer-prompt {
    margin-top: var(--space-3);
}

.course-nav-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: var(--space-3);
}

.course-nav-card a {
    color: var(--color-text-secondary);
    text-decoration: none;
}

.course-nav-card a:hover {
    color: var(--color-primary);
}

.course-list-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-6);
}

.course-card {
    height: 100%;
    display: flex;
    flex-direction: column;
    padding: var(--space-6);
    border: 1px solid rgba(61, 90, 128, 0.12);
    border-radius: var(--radius-2xl);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(247, 245, 240, 0.96));
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.course-card p {
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

.course-card-footer {
    margin-top: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    padding-top: var(--space-6);
}

.course-exercise-list {
    display: grid;
    gap: var(--space-5);
}

.course-exercise-card {
    padding: var(--space-5);
}

.course-exercise-options {
    display: grid;
    gap: var(--space-3);
    margin-top: var(--space-4);
}

.course-option {
    position: relative;
}

.course-option input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.course-option label {
    display: block;
    padding: var(--space-4);
    border: 1px solid rgba(61, 90, 128, 0.12);
    border-radius: var(--radius-xl);
    background: rgba(255, 255, 255, 0.85);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.course-option label:hover {
    border-color: rgba(224, 122, 95, 0.45);
    background: rgba(224, 122, 95, 0.06);
}

.course-option input:checked + label {
    border-color: var(--color-primary);
    background: rgba(224, 122, 95, 0.1);
}

.course-feedback {
    display: none;
    margin-top: var(--space-4);
    padding: var(--space-4);
    border-radius: var(--radius-xl);
    font-size: var(--text-sm);
}

.course-feedback.success {
    background: var(--color-success-light);
    color: #24523f;
}

.course-feedback.error {
    background: var(--color-error-light);
    color: #8c3f2e;
}

.course-feedback.open {
    display: block;
}

.course-search {
    max-width: 560px;
    margin: 0 auto;
}

.course-search input {
    width: 100%;
    padding: var(--space-4) var(--space-5);
    border: 1px solid rgba(61, 90, 128, 0.14);
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.88);
    font-size: var(--text-base);
}

.course-search input:focus {
    outline: 2px solid rgba(224, 122, 95, 0.2);
    border-color: rgba(224, 122, 95, 0.4);
}

.course-nav-actions {
    display: flex;
    justify-content: space-between;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.course-nav-actions .btn {
    min-width: 148px;
}

@media (max-width: 1024px) {
    .course-hero-grid,
    .course-content-grid,
    .course-list-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 720px) {
    .course-hero {
        padding: var(--space-12) 0 var(--space-8);
    }

    .course-hero-title {
        font-size: clamp(2rem, 10vw, 3rem);
    }

    .course-stat-grid {
        grid-template-columns: 1fr 1fr;
    }

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

    .course-nav-actions .btn {
        width: 100%;
    }
}