/* =========================================
   Archive: Lesson
   ========================================= */
.lesson-archive-container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 40px 20px;
    display: flex;
    gap: 40px;
}

.archive-filter-sidebar {
    width: 280px;
    flex-shrink: 0;
    position: sticky;
    top: 20px;
    align-self: flex-start;
    overflow: visible;
}

.sidebar-card {
    background: white;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    padding: 20px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    padding-bottom: 16px;
    display: flex;
    flex-direction: column;
    max-height: calc(100vh - 40px);
}

.sidebar-scroll {
    overflow: auto;
    min-height: 0;
    padding-right: 4px;
}

.sidebar-action-bar {
    position: sticky;
    bottom: 18px;
    z-index: 4;
    margin-top: 18px;
    padding-top: 14px;
    background: linear-gradient(to top, rgba(255, 255, 255, 1) 72%, rgba(255, 255, 255, 0));
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 12px;
    border-bottom: 1px solid #f1f5f9;
    margin-bottom: 20px;
}

.sidebar-header h2 {
    font-size: 1.1rem;
    font-weight: bold;
    margin: 0;
    display: flex;
    align-items: center;
    gap: 8px;
    color: #1e293b;
}

.sidebar-header i {
    color: var(--primary);
    font-size: 1.1rem;
}

.reset-filters-btn {
    font-size: 0.75rem;
    color: var(--primary);
    font-weight: 600;
    cursor: pointer;
    border: none;
    background: none;
    padding: 0;
    transition: all 0.2s;
}

.reset-filters-btn:hover {
    text-decoration: underline;
}

.filter-group {
    margin-bottom: 24px;
}

.filter-divider {
    height: 1px;
    background: #f1f5f9;
    margin: 24px 0;
}

.filter-group h3 {
    font-size: 0.875rem;
    font-weight: bold;
    color: #334155;
    margin-bottom: 12px;
}

.filter-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 6px 0;
    cursor: pointer;
    transition: all 0.2s;
}

.filter-option:hover .filter-label {
    color: var(--primary);
}

.filter-option input[type="checkbox"],
.filter-option input[type="radio"] {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    border: 1px solid #cbd5e1;
    cursor: pointer;
    flex-shrink: 0;
}

.filter-option input[type="checkbox"]:checked,
.filter-option input[type="radio"]:checked {
    accent-color: var(--primary);
}

.filter-option input[type="checkbox"]:hover,
.filter-option input[type="radio"]:hover {
    border-color: var(--primary);
}

.filter-label {
    font-size: 0.875rem;
    color: #64748b;
    transition: color 0.2s;
    font-weight: 500;
}

.lesson-archive-container .search-btn {
    width: 100%;
    padding: 12px 16px;
    background: #334155;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s;
    margin-top: 0;
    z-index: 3;
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.lesson-archive-container .search-btn:hover {
    background: #475569;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.lesson-archive-container .search-btn i {
    font-size: 0.875rem;
}

.sidebar-banner {
    background: linear-gradient(135deg, rgba(151, 204, 232, 0.1) 0%, rgba(151, 204, 232, 0.05) 100%);
    border: 1px solid rgba(151, 204, 232, 0.2);
    border-radius: 8px;
    padding: 20px;
    text-align: center;
    margin-top: 24px;
}

.banner-label {
    display: inline-block;
    color: var(--primary);
    font-size: 0.75rem;
    font-weight: bold;
    margin-bottom: 8px;
}

.sidebar-banner h4 {
    font-size: 1rem;
    font-weight: bold;
    color: #1e293b;
    margin-bottom: 8px;
}

.sidebar-banner p {
    font-size: 0.75rem;
    color: #64748b;
    margin-bottom: 12px;
}

.banner-btn {
    font-size: 0.75rem;
    background: white;
    border: 1px solid #e2e8f0;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}

.banner-btn:hover {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    border-color: var(--primary);
    color: var(--primary);
}

.lesson-main-content {
    flex: 1;
    width: 100%;
}

.content-header {
    margin-bottom: 32px;
}

.content-header-top {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 24px;
}

.content-title {
    flex: 1;
    min-width: 0;
}

.content-controls {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.content-title h1,
.lesson-archive-title {
    font-size: 2rem;
    font-weight: bold;
    color: #1e293b;
    margin: 0 0 8px;
}

.lesson-archive-subtitle {
    color: #666;
    font-size: 0.9rem;
    margin: 0;
}

@media (max-width: 768px) {
    .content-title h1,
    .lesson-archive-title {
        font-size: 1.5rem;
    }
    .lesson-archive-subtitle {
        font-size: 0.85rem;
    }
}

.content-subtitle {
    font-size: 0.875rem;
    color: #64748b;
}

.content-subtitle strong {
    color: #1e293b;
    font-weight: bold;
}

.lesson-archive-container .search-box {
    position: relative;
    width: 220px;
    flex-shrink: 1;
}

.lesson-archive-container .search-box input {
    padding: 10px 16px 10px 40px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    font-size: 0.875rem;
    width: 100%;
    box-sizing: border-box;
}

.lesson-archive-container .search-box input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 1px var(--primary);
}

.lesson-archive-container .search-box i {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: #94a3b8;
}

.sort-select {
    padding: 10px 16px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    font-size: 0.875rem;
    cursor: pointer;
    background: white;
    transition: border-color 0.2s;
    color: #1e293b;
}

.sort-select:hover {
    border-color: var(--primary);
}

.content-title__major {
    display: inline-block;
    margin-left: 12px;
    font-size: 0.7em;
    font-weight: 700;
    color: var(--primary);
}

.active-filters {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-top: 12px;
}

.active-filter-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(63, 142, 237, 0.1);
    color: var(--primary);
    border: 1px solid rgba(63, 142, 237, 0.3);
    border-radius: 999px;
    padding: 4px 12px;
    font-size: 0.8rem;
    font-weight: 600;
    transition: background 0.2s;
}

.active-filter-chip:hover {
    background: rgba(63, 142, 237, 0.2);
    color: var(--primary);
}

.active-filter-chip i {
    font-size: 0.7rem;
    opacity: 0.7;
}

.active-filters__clear {
    font-size: 0.78rem;
    color: #94a3b8;
    text-decoration: underline;
    margin-left: 4px;
}

.active-filters__clear:hover {
    color: #64748b;
}

.lesson-card-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 40px;
}

.lesson-archive-card {
    position: relative;
    background: #fff;
    border-radius: 16px;
    border: 1px solid #e6ebf2;
    padding: 18px;
    display: flex;
    flex-direction: row;
    align-items: stretch;
    gap: 18px;
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.lesson-archive-card__overlay {
    position: absolute;
    inset: 0;
    z-index: 1;
    border-radius: 16px;
}

.lesson-archive-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.12);
}

.lesson-archive-card__thumb {
    flex: 0 0 240px;
    max-width: 240px;
}

.lesson-archive-thumb {
    position: relative;
    width: 100%;
    padding-top: 75%;
    background: #f2f5f9;
    border-radius: 12px;
    overflow: hidden;
}

.lesson-archive-thumb img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.lesson-archive-card__content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 16px;
    min-width: 0;
    pointer-events: none;
}

.lesson-archive-card__tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 6px;
}

.lesson-archive-code {
    background: #1e293b;
    color: #fff;
    font-size: 0.68rem;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 4px;
    letter-spacing: 0.05em;
    font-variant-numeric: tabular-nums;
}

.lesson-archive-tag {
    background: rgba(63, 142, 237, 0.12);
    color: var(--primary);
    border: 1px solid rgba(63, 142, 237, 0.25);
    font-size: 0.7rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 999px;
    letter-spacing: 0.02em;
}

.lesson-archive-tag--major {
    background: #fff;
    color: var(--primary);
    border-color: var(--primary);
}

.lesson-archive-card__title {
    font-size: 1.22rem;
    margin: 2% 0 3%;
    font-weight: 700;
    line-height: 1.5;
}

.lesson-archive-card:hover .lesson-archive-card__title {
    color: var(--primary);
}

.lesson-archive-card__desc {
    font-size: 0.9rem;
    color: #5b677a;
    line-height: 1.6;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.lesson-archive-meta {
    background: #f7f9fc;
    border: 1px solid #edf1f7;
    border-radius: 12px;
    padding: 12px;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 16px;
    font-size: 0.82rem;
}

.lesson-archive-meta__label {
    color: #8a94a6;
    font-size: 0.7rem;
    display: block;
    margin-bottom: 2px;
    letter-spacing: 0.02em;
}

.lesson-archive-meta__value {
    color: #2b3445;
    font-weight: 700;
}

.lesson-archive-card__actions {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    gap: 15px;
    border-left: 1px solid #edf1f7;
    padding-left: 16px;
    min-width: 170px;
    justify-content: flex-start;
}

.lesson-archive-apply {
    background: var(--primary);
    color: #fff;
    font-weight: 700;
    text-align: center;
    padding: 10px 14px;
    border-radius: 12px;
    box-shadow: 0 6px 14px rgba(63, 142, 237, 0.2);
}

.lesson-archive-apply:hover {
    background: #2d74c9;
}

.lesson-archive-detail {
    background: #fff;
    color: #4b5563;
    border: 1px solid #d5dbe5;
    padding: 8px 12px;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 700;
    text-align: center;
}

.lesson-archive-detail:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.lesson-archive-card__code {
    display: block;
    font-size: 14px;
    color: #939eac;
    text-align: center;
    letter-spacing: 0.04em;
}

@media (max-width: 767px) {
    .lesson-archive-card {
        flex-direction: column;
    }

    .lesson-archive-card__thumb {
        flex: 1 1 auto;
        max-width: none;
    }

    .lesson-archive-card__actions {
        border-left: none;
        border-top: 1px solid #edf1f7;
        padding-left: 0;
        padding-top: 16px;
        min-width: 0;
    }
}

@media (min-width: 768px) {
    .lesson-archive-meta {
        grid-template-columns: minmax(0, 2.5fr) minmax(120px, 1fr) minmax(72px, 0.65fr);
    }
}

.load-more-container {
    text-align: center;
    margin-top: 40px;
}

.load-more-btn {
    padding: 14px 40px;
    background: white;
    border: 2px solid #e2e8f0;
    color: #1e293b;
    font-weight: bold;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.load-more-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.no-lessons {
    grid-column: 1 / -1;
    background: white;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    color: #64748b;
}

/* スマホ用フィルターボタン（PC非表示） */
.mobile-filter-toggle {
    display: none;
}
.mobile-filter-close {
    display: none;
}
.mobile-filter-overlay {
    display: none;
}

@media (max-width: 1023px) {
    .lesson-archive-container {
        display: block;
        padding: 24px 16px 32px;
    }

    .archive-filter-sidebar {
        display: none;
        flex-direction: column;
        position: fixed;
        top: 0;
        left: 0;
        width: 85vw;
        max-width: 360px;
        height: 100vh;
        z-index: 1000;
        background: #fff;
        overflow-y: auto;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        padding: 0;
        box-shadow: 2px 0 16px rgba(0,0,0,0.15);
    }

    .sidebar-action-bar {
        position: sticky;
        bottom: 0;
        margin-top: 16px;
        padding-top: 12px;
        padding-bottom: max(12px, env(safe-area-inset-bottom));
        background: #fff;
    }

    .sidebar-card {
        max-height: none;
        flex: 1 1 auto;
        min-height: 100%;
        box-sizing: border-box;
    }

    .sidebar-scroll {
        overflow: visible;
        min-height: auto;
        padding-right: 0;
    }
    .archive-filter-sidebar.is-open {
        display: flex;
        transform: translateX(0);
    }

    .mobile-filter-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        background: var(--primary, #3f8eed);
        color: #fff;
        border: none;
        padding: 14px 20px;
        border-radius: 10px;
        font-size: 1rem;
        font-weight: bold;
        cursor: pointer;
        margin-bottom: 12px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.15);
        width: 100%;
        max-width: none;
    }

    .mobile-filter-close {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        background: none;
        border: none;
        font-size: 1.3rem;
        color: #666;
        cursor: pointer;
        padding: 4px;
        margin-left: auto;
    }

    .mobile-filter-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0,0,0,0.4);
        z-index: 999;
    }
    .mobile-filter-overlay.is-open {
        display: block;
    }

    .sidebar-header {
        display: flex;
        align-items: center;
    }

    .lesson-main-content {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .content-header-top {
        flex-direction: column;
        align-items: flex-start;
    }

    .content-controls {
        flex-direction: row;
        align-items: stretch;
        flex-wrap: nowrap;
        gap: 8px;
        width: 100%;
    }

    .lesson-archive-container .search-box {
        flex: 1 1 auto;
        min-width: 0;
    }

    .lesson-archive-container .search-box input {
        max-width: 100%;
        min-width: 0;
    }

    .lesson-archive-container .sort-select {
        flex: 0 0 auto;
    }

    /* SPボトムナビ(60px)と被らないようドロワー高さを縮める */
    .archive-filter-sidebar {
        height: calc(100vh - 60px);
    }
}