/* 既存LPの共通カード・見出しを基調に、このページの余白と数式を調整。 */
.explanation-lp {
    max-width: 900px;
}
.explanation-lp .explanation-hero {
    padding: 12px 0 4px;
    margin-bottom: 28px;
    text-align: center;
}
.explanation-badge {
    display: inline-block;
    margin-bottom: 18px;
    padding: 5px 14px;
    background: #f4f8fc;
    border: 1px solid #cce0ff;
    color: #062852;
    font-size: 13px;
    font-weight: 700;
}
.explanation-lp .hero-title {
    margin-bottom: 0;
    padding-left: 0;
    border-left: 0;
    font-size: 27px;
    line-height: 1.65;
}
.explanation-hero .sp-only {
    display: none;
}
.explanation-lp .explanation-lead,
.explanation-lp .explanation-body {
    padding: 30px 34px;
    font-size: 15px;
    line-height: 1.95;
    color: #333;
}
.explanation-lead p,
.explanation-body p {
    margin: 0 0 18px;
}
.explanation-lead p:last-child,
.explanation-body p:last-child {
    margin-bottom: 0;
}
.explanation-lead p:last-child {
    color: #062852;
    font-weight: 700;
}
.explanation-lp .explanation-section {
    margin-top: 44px;
    margin-bottom: 0;
}
.explanation-lp .section-title {
    margin-bottom: 20px;
    line-height: 1.65;
}
.explanation-body strong {
    color: #062852;
}
.explanation-body .explanation-key {
    margin: 24px 0;
    padding: 18px 22px;
    background: #f4f8fc;
    border-left: 3px solid #8dbcf0;
    color: #062852;
    font-weight: 700;
    line-height: 1.9;
}
.explanation-math-note {
    margin: 24px 0;
    padding: 0 18px;
    border: 1px solid #d2dfed;
    border-radius: 8px;
    background: #f8fbff;
}
.explanation-equation {
    max-width: 100%;
    margin: 0 0 18px;
    overflow-x: auto;
    overflow-y: hidden;
    padding: 2px 0;
}
.explanation-lp mjx-container {
    max-width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    vertical-align: middle;
}
.explanation-math-note .feature-accordion-body {
    padding: 4px 0 20px;
    line-height: 1.9;
}
.explanation-cta {
    margin: 26px 0 22px;
}
.explanation-cta .btn-internal-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: min(390px, 100%);
    padding: 16px 20px;
    background: #f4f8fc;
    color: #062852;
    border: 1px solid #8dbcf0;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 700;
    line-height: 1.65;
    text-decoration: none;
}
.explanation-cta .btn-internal-link:hover {
    background: #e5effa;
}
.explanation-cta a:focus-visible,
.explanation-course-links a:focus-visible {
    outline: 3px solid #8dbcf0;
    outline-offset: 4px;
}
.explanation-course-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px 28px;
    font-size: 14px;
}
.explanation-course-links a {
    color: #062852;
    text-underline-offset: 4px;
}
@media (max-width: 600px) {
    .explanation-lp {
        padding: 0 16px;
    }
    .explanation-lp .hero-title {
        font-size: 23px;
        letter-spacing: .01em;
    }
    .explanation-hero .sp-only {
        display: initial;
    }
    .explanation-lp .explanation-lead,
    .explanation-lp .explanation-body {
        padding: 23px 20px;
        font-size: 14.5px;
        line-height: 1.9;
    }
    .explanation-lp .section-title {
        font-size: 18px;
    }
    .explanation-lp .explanation-section {
        margin-top: 36px;
    }
    .explanation-body .explanation-key {
        padding: 15px 16px;
    }
    .explanation-math-note {
        padding: 0 12px;
    }
    .explanation-course-links {
        flex-direction: column;
        align-items: center;
    }
}