/*
|--------------------------------------------------------------------------
| Project2 Learning UI v1.0
|--------------------------------------------------------------------------
| Shared lesson/content presentation for public, admin preview and future EPs.
*/

.knowledge-content,
.lesson-content {
    --lesson-text: #172033;
    --lesson-muted: #667085;
    --lesson-border: #e6eaf0;
    --lesson-surface: #ffffff;
    --lesson-soft: #f7f9fc;
    --lesson-primary-soft: #eef6ff;
    --lesson-success-soft: #ecfdf3;
    --lesson-warning-soft: #fff8e6;
    --lesson-danger-soft: #fff1f0;

    color: var(--lesson-text);
    font-size: 1rem;
    line-height: 1.8;
    overflow-wrap: anywhere;
}

.knowledge-content *,
.lesson-content * {
    box-sizing: border-box;
}

.lesson-section {
    display: grid;
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 16px;
    margin: 0 0 28px;
    padding: 22px;
    border: 1px solid var(--lesson-border);
    border-radius: 18px;
    background: var(--lesson-surface);
    box-shadow: 0 8px 24px rgba(16, 24, 40, 0.045);
}

.lesson-section-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 14px;
    background: var(--lesson-soft);
    font-size: 1.35rem;
    line-height: 1;
}

.lesson-section-body {
    min-width: 0;
}

.lesson-section-body > :first-child {
    margin-top: 0;
}

.lesson-section-body > :last-child {
    margin-bottom: 0;
}

.lesson-section h2 {
    margin: 0 0 14px;
    font-size: clamp(1.25rem, 2.4vw, 1.55rem);
    line-height: 1.35;
}

.lesson-section p {
    margin: 0 0 14px;
}

.lesson-section ul,
.lesson-section ol {
    margin: 0 0 14px;
    padding-left: 1.35rem;
}

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

.lesson-key-message {
    margin-top: 16px;
    padding: 16px 18px;
    border-left: 4px solid #3b82f6;
    border-radius: 12px;
    background: var(--lesson-primary-soft);
    line-height: 1.75;
}

.lesson-example-card,
.lesson-practice-item,
.lesson-mistake {
    margin-top: 16px;
    padding: 18px;
    border: 1px solid var(--lesson-border);
    border-radius: 14px;
    background: var(--lesson-soft);
}

.lesson-example-title {
    margin-bottom: 10px;
    font-weight: 700;
}

.lesson-practice-item {
    background: var(--lesson-surface);
}

.lesson-mistake {
    border-color: #ffd7d2;
    background: var(--lesson-danger-soft);
}

.lesson-check-list {
    list-style: none;
    padding-left: 0 !important;
}

.lesson-check-list li {
    position: relative;
    padding-left: 30px;
}

.lesson-check-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    top: 0;
    font-weight: 700;
    color: #159455;
}

.lesson-answer {
    margin-top: 12px;
    border: 1px solid var(--lesson-border);
    border-radius: 12px;
    background: var(--lesson-success-soft);
    overflow: hidden;
}

.lesson-answer summary {
    cursor: pointer;
    padding: 12px 14px;
    font-weight: 700;
    user-select: none;
}

.lesson-answer-content {
    padding: 0 14px 14px;
}

.lesson-formula {
    display: block;
    width: 100%;
    max-width: 100%;
    margin: 16px 0;
    padding: 12px 14px;
    border-radius: 12px;
    background: #fbfcfe;
    text-align: center;
    overflow-x: auto;
    overflow-y: hidden;
    line-height: normal !important;
    -webkit-overflow-scrolling: touch;
}

/*
|--------------------------------------------------------------------------
| KaTeX protection
|--------------------------------------------------------------------------
| Prevent broad project CSS such as span { display:block }, vertical-align,
| line-height or positioning rules from breaking superscripts/subscripts.
*/

.knowledge-content .katex,
.lesson-content .katex {
    display: inline-block !important;
    position: static;
    max-width: 100%;
    font-size: 1.08em;
    line-height: 1.2 !important;
    white-space: nowrap;
    text-indent: 0;
}

.knowledge-content .katex *,
.lesson-content .katex * {
    box-sizing: content-box;
}

.knowledge-content .katex-display,
.lesson-content .katex-display {
    display: block !important;
    width: max-content;
    min-width: 100%;
    margin: 0 !important;
    padding: 2px 0;
    text-align: center;
    overflow: visible;
}

.knowledge-content .katex-display > .katex,
.lesson-content .katex-display > .katex {
    display: inline-block !important;
    text-align: initial;
}

.knowledge-content .katex .base,
.knowledge-content .katex .strut,
.knowledge-content .katex .mord,
.knowledge-content .katex .mbin,
.knowledge-content .katex .mrel,
.knowledge-content .katex .mspace,
.knowledge-content .katex .msupsub,
.knowledge-content .katex .vlist-t,
.knowledge-content .katex .vlist-r,
.knowledge-content .katex .vlist,
.lesson-content .katex .base,
.lesson-content .katex .strut,
.lesson-content .katex .mord,
.lesson-content .katex .mbin,
.lesson-content .katex .mrel,
.lesson-content .katex .mspace,
.lesson-content .katex .msupsub,
.lesson-content .katex .vlist-t,
.lesson-content .katex .vlist-r,
.lesson-content .katex .vlist {
    line-height: inherit !important;
}

.knowledge-content .katex .msupsub,
.lesson-content .katex .msupsub {
    display: inline-block !important;
    vertical-align: baseline !important;
}

.knowledge-content .katex .vlist-t,
.knowledge-content .katex .vlist-r,
.knowledge-content .katex .vlist,
.lesson-content .katex .vlist-t,
.lesson-content .katex .vlist-r,
.lesson-content .katex .vlist {
    position: relative !important;
}

.lesson-key-message .lesson-formula {
    margin: 8px 0 14px;
    background: rgba(255, 255, 255, 0.72);
}

.lesson-key-message .katex {
    font-size: 1.1em;
}

@media (max-width: 767.98px) {
    .lesson-section {
        grid-template-columns: 1fr;
        gap: 12px;
        padding: 17px;
        border-radius: 15px;
    }

    .lesson-section-icon {
        width: 40px;
        height: 40px;
    }

    .lesson-formula {
        padding: 10px;
    }
}

@media print {
    .lesson-section {
        break-inside: avoid;
        box-shadow: none;
        border-color: #cfd4dc;
    }

    .lesson-answer {
        break-inside: avoid;
    }

    .lesson-answer[open] summary {
        display: none;
    }
}