/* ==========================================================================
   1. 강의 목록 카드 스타일 (Lecture List Card)
   - [적용]: archive-sf_lto_lecture.php
   ========================================================================== */
.sf-lt-one-lecture-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    padding: 0;
    margin: 0;
}
.sf-lt-one-lecture-card {
    border: 1px solid #e0e0e0; border-radius: 4px; overflow: hidden;
    transition: box-shadow 0.2s ease-in-out; list-style-type: none;
}
.sf-lt-one-lecture-card:hover {
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}
.sf-lt-one-lecture-card__link {
    display: block; color: inherit;
}
.sf-lt-one-lecture-card__link:hover {
    text-decoration: none;
}
.sf-lt-one-lecture-card__thumbnail img {
    display: block; width: 100%; height: auto; border-bottom: 1px solid #e0e0e0;
}
.sf-lt-one-lecture-card__content {
    padding: 1rem;
}
.sf-lt-one-lecture-card__title {
    font-size: 1.2rem; margin: 0 0 0.5rem;
}
.sf-lt-one-lecture-card__excerpt {
    font-size: 0.9rem; color: #666;
}

/* ==========================================================================
   2. 2단 강의 레이아웃 (Two-Column Lecture Layout)
   - [적용]: single-sf_lto_chapter.php
   ========================================================================== */
.sf-lt-one-lecture-container {
    display: flex; flex-direction: column; max-width: 1200px;
    margin: 2rem auto; gap: 2rem;
}
.sf-lt-one-lecture-sidebar {
    flex-basis: 100%; background-color: #f7f7f7;
    border: 1px solid #e5e5e5; border-radius: 4px;
}
.sf-lt-one-sidebar-inner {
    padding: 1.5rem;
}
.sf-lt-one-sidebar-title {
    font-size: 1.3rem; margin-top: 0; margin-bottom: 1.5rem;
    border-bottom: 1px solid #ddd; padding-bottom: 1rem;
}
.sf-lt-one-sidebar-title a {
    color: inherit; text-decoration: none;
}
.sf-lt-one-sidebar-nav ol {
    list-style: none; padding: 0; margin: 0;
}
.sf-lt-one-sidebar-nav__item a {
    display: block; padding: 0.6rem 1rem; border-radius: 4px; color: #444;
}
.sf-lt-one-sidebar-nav__item a:hover {
    background-color: #e9e9e9; text-decoration: none;
}
.sf-lt-one-sidebar-nav__item.is-current a {
    background-color: #0073aa; color: #fff; font-weight: bold;
}
.sf-lt-one-content-area-wide {
    flex: 1; min-width: 0; padding: 2rem;
    background-color: #fff; border: 1px solid #e5e5e5; border-radius: 4px;
}
.sf-lt-one-parent-lecture-link {
    font-size: 0.9rem; color: #777; margin: 0 0 0.5rem;
}
.sf-lt-one-chapter-navigation {
    margin-top: 3rem; border-top: 1px solid #eee; padding-top: 1.5rem;
}
.sf-lt-one-nav-links {
    display: flex; justify-content: space-between; gap: 1rem;
}
.sf-lt-one-nav-previous, .sf-lt-one-nav-next {
    flex: 1;
}
.sf-lt-one-nav-next {
    text-align: right;
}
.sf-lt-one-nav-links a {
    display: block; padding: 1rem; border: 1px solid #e0e0e0;
    border-radius: 4px; font-size: 0.9rem;
}
.sf-lt-one-nav-links a:hover {
    background-color: #f5f5f5; text-decoration: none;
}
.sf-lt-one-post-title {
    display: block; font-weight: bold; color: #333;
}
/* ==========================================================================
   3. 강의 레이아웃 반응형
   ========================================================================== */
@media screen and (max-width: 991px) {
    .sf-lt-one-lecture-container {
        margin: 1rem;
    }
    .sf-lt-one-nav-links {
        flex-direction: column;
    }
    .sf-lt-one-nav-next {
        text-align: left;
    }
}
@media screen and (min-width: 992px) {
    .sf-lt-one-lecture-container {
        flex-direction: row;
    }
    .sf-lt-one-lecture-sidebar {
        flex: 0 0 300px;
    }
    .sf-lt-one-nav-links {
        flex-direction: row;
    }
    .sf-lt-one-nav-next {
        text-align: right;
    }
}