.lesson-shell {
    width: min(1280px, calc(100% - 2rem));
    margin: 0 auto;
    padding: 1.4rem 0 4rem;
}

.back-link {
    display: inline-flex;
    margin-bottom: 1rem;
    text-decoration: none;
}

.lesson-layout {
    display: grid;
    grid-template-columns: minmax(0, 0.9fr) minmax(420px, 1.1fr);
    gap: 1rem;
    align-items: start;
}

.lesson-content,
.editor-card,
.boss-banner {
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--white);
    box-shadow: var(--shadow);
}

.lesson-content {
    padding: 1.25rem;
}

.lesson-content h1,
.boss-banner h1 {
    margin: 0.8rem 0 0.6rem;
    font-size: 2.25rem;
    line-height: 1.12;
}

.lesson-description,
.lesson-text p,
.mission-box p {
    color: var(--muted);
}

.lesson-text {
    display: grid;
    gap: 1rem;
    margin-top: 1.2rem;
}

.lesson-text h2 {
    margin: 0;
    font-size: 1.3rem;
}

.lesson-text p,
.lesson-text ul,
.lesson-text ol {
    margin: 0;
}

.lesson-text ul,
.lesson-text ol {
    padding-left: 1.2rem;
}

.example-box,
.mission-box {
    padding: 1rem;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #f8fafc;
}

.example-box strong {
    color: var(--purple-dark);
}

.example-box code,
.lesson-text code {
    display: inline-flex;
    max-width: 100%;
    padding: 0.1rem 0.35rem;
    overflow-wrap: anywhere;
    border-radius: 6px;
    background: var(--lilac);
    color: var(--purple-dark);
    font-family: Consolas, Monaco, monospace;
}

.mission-box {
    margin-top: 1rem;
    border-color: #bfdbfe;
    background: #eff6ff;
}

.mission-box h2 {
    margin: 0 0 0.35rem;
}

.editor-card {
    position: sticky;
    top: 92px;
    padding: 1rem;
}

.boss-banner {
    margin-bottom: 1rem;
    padding: 1.3rem;
    border-color: #fde68a;
    background: #fffbeb;
}

.boss-banner p {
    max-width: 760px;
    color: #854d0e;
}

.boss-banner strong {
    display: inline-flex;
    min-height: 34px;
    align-items: center;
    padding: 0.25rem 0.65rem;
    border-radius: 8px;
    color: #713f12;
    background: #fef3c7;
}

.boss-mission {
    border-color: #fde68a;
    background: #fffbeb;
}

.feedback {
    display: grid;
    gap: 0.35rem;
    margin-top: 1rem;
    padding: 0.9rem;
    border-radius: 8px;
    border: 1px solid var(--line);
}

.feedback strong,
.feedback p {
    margin: 0;
}

.feedback.success {
    border-color: #bbf7d0;
    color: #166534;
    background: #f0fdf4;
}

.feedback.error {
    border-color: #fecaca;
    color: #991b1b;
    background: #fef2f2;
}

.achievement-unlocks {
    margin: 0;
    padding-left: 1.1rem;
}

@media (max-width: 980px) {
    .lesson-layout {
        grid-template-columns: 1fr;
    }

    .editor-card {
        position: static;
    }
}

@media (max-width: 620px) {
    .lesson-content h1,
    .boss-banner h1 {
        font-size: 1.85rem;
    }
}