/* static/css/styles.css
   Course list & course detail pages.
   Built on top of common.css design tokens (--primary blue / --purple).
------------------------------------------------------------------ */

.cs-course-page {
    width: 95%;
    margin: 0 auto;
    padding: var(--gap-smm) var(--gap-smmm);
    display: flex;
    flex-direction: column;
    gap: var(--gap);
}

/* Keyboard focus visibility (accessibility floor) */
.cs-course-page a:focus-visible,
.cs-course-page button:focus-visible,
.cs-course-detail-page a:focus-visible,
.cs-course-detail-page button:focus-visible,
.cs-select-wrap select:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    border-radius: 6px;
}

/* ============================================================
   BREADCRUMB (shared between list & detail)
============================================================ */

.cs-breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: var(--text-2xl);
    color: #fff;
    position: absolute;
    top: 30px;
    right: 40px;
}

.cs-breadcrumb a {
    color: #fff;
    text-decoration: none;
    transition: color var(--transition);
}

.cs-breadcrumb a:hover {
    color: #fff;
}

.cs-breadcrumb .current {
    color: #fff;
    font-weight: 600;
}

.cs-breadcrumb-detail {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: var(--text-2xl);
    color: var(--ink-600);
}

.cs-breadcrumb-detail a {
    color: var(--ink-600);
    text-decoration: none;
    transition: color var(--transition);
}

.cs-breadcrumb-detail a:hover {
    color: var(--primary);
}

.cs-breadcrumb-detail .current {
    color: var(--ink-900);
    font-weight: 600;
}

/* ============================================================
   HERO
============================================================ */
.cs-hero-course {
    position: relative;
    overflow: hidden;
    padding: var(--gap-2xl) var(--gap-3xl);
    margin-bottom: var(--gap-lg);




    width: 100%;
    height: 400px;


    background-image: url("/static/images/myimageupscaler_quick_d19a8f50f70944b0c4b2fdf4553d2462.png");

    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.cs-hero-glow {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: .35;
    pointer-events: none;
}

.cs-hero-glow-1 {
    width: 320px;
    height: 320px;
    background: var(--purple);
    top: -120px;
    inset-inline-end: -80px;
}

.cs-hero-glow-2 {
    width: 260px;
    height: 260px;
    background: var(--accent);
    bottom: -140px;
    inset-inline-start: -60px;
}

.cs-hero-content {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    gap: var(--gap-smmm);
}

.cs-hero-content-img {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
}

.cs-hero-eyebrow {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 4px 14px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
    color: #fff;
    font-size: var(--text-lg);
    font-weight: 500;
    letter-spacing: .2px;
    backdrop-filter: blur(4px);
}

.cs-hero-content h1 {
    color: #fff;
    font-size: var(--text-7xl);
    font-weight: 800;
    line-height: 1.35;
}

.cs-hero-content h1 span {
    color: #fff;
}

.cs-hero-content p {
    color: rgba(255, 255, 255, 0.88);
    font-size: var(--text-2xl);
    font-weight: 700;
    line-height: 1.9;
    margin-bottom: var(--gap-sm);
}

.cs-search-wrap {
    display: flex;
    align-items: center;
    gap: var(--gap-xs);
    background: var(--card);
    border-radius: 999px;
    padding: 4px 10px 4px 5px;
    box-shadow: var(--shadow-elevated);
    margin-top: var(--gap-xs);
    width: 80%;
    margin: 0 auto;
}



.cs-search-icon {
    color: var(--ink-400);
    flex-shrink: 0;
}

.cs-search-wrap input[type="text"] {
    flex: 1;
    border: none;
    outline: none;
    background: transparent;
    font-size: var(--text-xl);
    color: var(--ink-900);
    padding: 8px 4px;
}

.cs-search-wrap input[type="text"]::placeholder {
    color: var(--ink-400);
}

.cs-search-wrap button {
    border: none;
    cursor: pointer;
    padding: 9px 22px;
    border-radius: 999px;
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    font-size: var(--text-lg);
    transition: filter var(--transition), transform var(--transition);
}

.cs-search-wrap button:hover {
    filter: brightness(1.06);
    transform: translateY(-1px);
}

/* ============================================================
   PAGE BODY
============================================================ */
.cs-page-body {
    display: grid;
    grid-template-columns: 1fr 280px;
    gap: var(--gap-lg);
    align-items: start;
}

.cs-page-body-full {
    display: block;
}

.cs-main-full {
    width: 100%;
}

/* ============================================================
   TOOLBAR (search/filters/sort at top)
============================================================ */
.cs-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--gap-md);
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: var(--gap-smmm) var(--gap-sm);
    margin-bottom: var(--gap-sm);
    box-shadow: var(--shadow-sm);
    flex-wrap: wrap;
}

.cs-toolbar-sticky {
    position: sticky;
    top: 8px;
    z-index: 20;
}

.cs-toolbar-cats-wrap {
    position: relative;
    flex: 1;
    min-width: 0;
    overflow: hidden;
}

.cs-toolbar-cats {
    display: flex;
    align-items: center;
    gap: var(--gap-xs);
    overflow-x: auto;
    scrollbar-width: none;
    padding-inline-end: 24px;
}

.cs-toolbar-cats::-webkit-scrollbar {
    display: none;
}

/* subtle fade hints that the chip list keeps scrolling, so users don't miss categories */
.cs-toolbar-fade {
    position: absolute;
    top: 0;
    bottom: 0;
    inset-inline-end: 0;
    width: 32px;
    background: linear-gradient(to right, var(--card), transparent);
    pointer-events: none;
}

/* ---- active filters summary ---- */
.cs-active-filters {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    background: var(--primary-softer);
    border: 1px solid var(--primary-soft);
    border-radius: var(--radius-sm);
    padding: 8px 14px;
    margin: var(--gap-xs) 0;
    font-size: var(--text-base);
}

.cs-active-filters-label {
    color: var(--ink-600);
    font-weight: 600;
}

.cs-filter-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--card);
    color: var(--ink-900);
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 3px 10px;
    font-weight: 500;
}

.cs-filter-pill a {
    color: var(--ink-400);
    text-decoration: none;
    font-weight: 700;
    transition: color var(--transition);
}

.cs-filter-pill a:hover {
    color: var(--red);
}

.cs-clear-all {
    margin-inline-start: auto;
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.cs-clear-all:hover {
    text-decoration: underline;
}

.cs-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
    padding: 7px 16px;
    border-radius: 999px;
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--ink-600);
    background: var(--card-soft);
    border: 1px solid transparent;
    text-decoration: none;
    transition: all var(--transition);
}

.cs-chip:hover {
    color: var(--primary);
    background: var(--primary-softer);
}

.cs-chip.active {
    color: #fff;
    background: var(--primary);
    box-shadow: var(--shadow-btn);
}

.cs-chip-badge {
    border-radius: 999px;
    padding: 0 7px;
    font-size: var(--text-base);
}

.cs-chip:not(.active) .cs-chip-badge {
    color: var(--ink-600);
}

.cs-toolbar-sort {
    display: flex;
    align-items: center;
    gap: var(--gap-xs);
    flex-shrink: 0;
}

.cs-toolbar-sort label {
    font-size: var(--text-lg);
    color: var(--ink-600);
    font-weight: 500;
    white-space: nowrap;
}

.cs-select-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.cs-select-wrap select {
    appearance: none;
    border: 1px solid var(--border);
    background: var(--card-soft);
    color: var(--ink-900);
    font-weight: 500;
    font-size: var(--text-lg);
    border-radius: var(--radius-sm);
    padding: 8px 32px 8px 14px;
    cursor: pointer;
    transition: border-color var(--transition);
}

.cs-select-wrap select:hover,
.cs-select-wrap select:focus {
    border-color: var(--primary);
    outline: none;
}

.cs-select-wrap svg {
    position: absolute;
    inset-inline-start: 10px;
    color: var(--ink-400);
    pointer-events: none;
}

/* ============================================================
   CONTENT HEAD
============================================================ */
.cs-content-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: var(--gap-md) 0 var(--gap-sm);
    flex-wrap: wrap;
    gap: var(--gap-xs);
}

.cs-content-head h2 {
    font-size: var(--text-3xl);
    font-weight: 700;
    color: var(--ink-900);
    display: flex;
    align-items: center;
    gap: var(--gap-xs);
}

.cs-query-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: var(--text-base);
    font-weight: 500;
    color: var(--primary);
    background: var(--primary-softer);
    border-radius: 999px;
    padding: 3px 12px;
}

.cs-query-tag a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 700;
}

.cs-result-count {
    font-size: var(--text-lg);
    color: var(--ink-600);
    background: var(--card-soft);
    padding: 4px 12px;
    border-radius: 999px;
}

/* ============================================================
   SIDEBAR (kept for detail page category nav reuse if needed)
============================================================ */
.cs-sidebar-course {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: var(--gap-sm);
    position: sticky;
    top: var(--gap-sm);
}

.cs-sidebar-course-title {
    font-weight: 700;
    color: var(--ink-900);
    margin-bottom: var(--gap-xs);
    font-size: var(--text-xl);
}

.cs-cat-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.cs-cat-list a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 10px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--ink-700);
    font-size: var(--text-lg);
    transition: background var(--transition), color var(--transition);
}

.cs-cat-list a:hover {
    background: var(--primary-softer);
    color: var(--primary);
}

.cs-cat-list a.active {
    background: var(--primary);
    color: #fff;
}

.cs-badge {
    background: var(--ink-100);
    color: var(--ink-600);
    border-radius: 999px;
    padding: 1px 8px;
    font-size: var(--text-sm);
}

.cs-cat-list a.active .cs-badge {
    background: rgba(255, 255, 255, 0.3);
    color: #fff;
}

.cs-all-link {
    display: block;
    text-align: center;
    margin-top: var(--gap-xs);
    color: var(--primary);
    font-size: var(--text-base);
    font-weight: 600;
    text-decoration: none;
}

/* ============================================================
   COURSE GRID / CARD
============================================================ */
.cs-course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: var(--gap-sm);
}

.cs-card-course {
    background: var(--card);
    border-radius: var(--radius-lg);
    padding: var(--gap-smmm);
    box-shadow: var(--shadow-sm);
    min-width: 0;
    transition: box-shadow .15s ease, transform .15s ease;
}

.cs-card-course:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-soft);
}

.cs-card-course-a {
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.cs-card-thumb {
    position: relative;
    aspect-ratio: 16 / 10;
    background: var(--primary-softer);
    overflow: hidden;
    border-radius: var(--radius-md);
}

.cs-card-thumb img {
    width: 100%;
    height: 100%;
    border-radius: var(--radius-md);
    object-fit: cover;
    transition: transform .4s var(--ease);
}


.cs-card-thumb-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.6rem;
    background: linear-gradient(135deg, var(--primary-softer), var(--purple-soft));
}

.cs-discount-badge {
    position: absolute;
    top: 10px;
    inset-inline-start: 10px;
    background: linear-gradient(120deg, var(--red), var(--gold));
    color: #fff;
    font-size: var(--text-sm);
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 999px;
    box-shadow: 0 2px 8px rgba(224, 85, 63, .35);
}

.cs-cat-badge {
    position: absolute;
    top: 10px;
    inset-inline-end: 10px;
    background: rgba(17, 17, 17, 0.55);
    backdrop-filter: blur(4px);
    color: #fff;
    font-size: var(--text-sm);
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 999px;
}

.cs-card-body-course {
    padding: var(--gap-smmm) var(--gap-smmm) 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
}

.cs-card-title-course {
    font-weight: 700;
    font-size: var(--text-2xl);
    color: var(--ink-900);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.cs-card-desc {
    font-size: var(--text-lg);
    color: var(--ink-600);
    line-height: 1.8;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.cs-card-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 2px;
    padding-bottom: var(--gap-xs);
}

.cs-meta-item {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: var(--text-lg);
    color: var(--ink-600);
}

.cs-meta-item svg {
    color: var(--primary);
    flex-shrink: 0;
}

.cs-stars {
    color: var(--gold);
    font-size: var(--text-xl);
    letter-spacing: 1px;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.cs-stars b {
    color: var(--ink-700);
    font-size: var(--text-base);
    font-weight: 600;
}

.cs-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--gap-xs);
    padding: var(--gap-smmm) var(--gap-smmm);
    border-top: 1px solid var(--rule);
    margin-top: var(--gap-smmm);
}

.cs-price-block {
    display: flex;
    flex-direction: column;
    line-height: 1.4;
}

.cs-price-main {
    font-size: var(--text-base);
    color: var(--ink-400);
    text-decoration: line-through;
}

.cs-price-discount {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--ink-900);
}

.cs-price-free {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--green);
}

.cs-btn-enroll {
    text-decoration: none;
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    font-size: var(--text-lg);
    padding: 8px 18px;
    border-radius: var(--radius-sm);
    transition: filter var(--transition), transform var(--transition);
    flex-shrink: 0;
}

.cs-btn-enroll:hover {
    filter: brightness(1.07);
    transform: translateY(-1px);
}

/* ============================================================
   EMPTY STATE
============================================================ */
.cs-empty {
    text-align: center;
    padding: var(--gap-2xl) var(--gap-lg);
    background: var(--card);
    border: 1px dashed var(--border);
    border-radius: var(--radius-md);
}

.cs-empty-icon {
    font-size: 2.6rem;
    margin-bottom: var(--gap-xs);
}

.cs-empty h3 {
    color: var(--ink-900);
    font-size: var(--text-2xl);
    margin-bottom: 6px;
}

.cs-empty p {
    color: var(--ink-600);
    font-size: var(--text-lg);
}

/* ============================================================
   PAGINATION
============================================================ */
.cs-pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    margin-top: var(--gap-lg);
    flex-wrap: wrap;
}

.cs-page-numbers {
    display: flex;
    align-items: center;
    gap: 6px;
}

.cs-page-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    min-width: 38px;
    height: 38px;
    padding: 0 12px;
    justify-content: center;
    border-radius: var(--radius-sm);
    background: var(--card);
    border: 1px solid var(--border);
    color: var(--ink-700);
    font-weight: 600;
    font-size: var(--text-lg);
    text-decoration: none;
    transition: all var(--transition);
}

.cs-page-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.cs-page-btn.active {
    background: var(--primary);
    color: #fff;
    border-color: transparent;
    box-shadow: var(--shadow-btn);
}

.cs-page-btn.disabled {
    opacity: .4;
    pointer-events: none;
}

.cs-page-dots {
    color: var(--ink-400);
    padding: 0 4px;
}

/* ============================================================
   BACK TO TOP
============================================================ */
.cs-back-to-top {
    position: fixed;
    bottom: 24px;
    inset-inline-end: 24px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: #fff;
    box-shadow: var(--shadow-elevated);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity var(--transition), transform var(--transition), visibility var(--transition);
    z-index: 30;
}

.cs-back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.cs-back-to-top:hover {
    filter: brightness(1.08);
}

/* ============================================================
   COURSE DETAIL PAGE
============================================================ */
.cs-course-detail-page {
    width: 95%;
    margin: 0 auto;
    padding: var(--gap-smm) var(--gap-smmm);
    display: flex;
    flex-direction: column;
    gap: var(--gap);
}

.cs-detail-topnav {
    display: flex;
    align-items: center;
    gap: var(--gap-sm);
}

.cs-detail-topnav .cs-breadcrumb {
    margin-bottom: 0;
}

/* ---- in-page section nav: always tells the user which section they're in ---- */
.cs-section-nav {
    position: sticky;
    top: 8px;
    z-index: 15;
    display: flex;
    gap: var(--gap-sm);
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 6px;
    width: fit-content;
    box-shadow: var(--shadow-sm);
}

.cs-section-link {
    text-decoration: none;
    color: var(--ink-600);
    font-weight: 600;
    font-size: var(--text-base);
    padding: 8px 18px;
    border-radius: 999px;
    transition: all var(--transition);
}

.cs-section-link:hover {
    color: var(--primary);
}

.cs-section-link.active {
    background: var(--primary);
    color: #fff;
}

/* ---- mobile sticky purchase bar ---- */
.cs-mobile-buy-bar {
    display: none;
}

.cs-course-detail-hero {
    display: grid;
    grid-template-columns: 1fr 1.1fr;
    gap: var(--gap-lg);
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--gap-lg);
    box-shadow: var(--shadow-card);
}

.cs-course-detail-media {
    position: relative;
    border-radius: var(--radius-md);
    overflow: hidden;
    aspect-ratio: 4 / 3;
    background: linear-gradient(135deg, var(--primary-softer), var(--purple-soft));
}

.cs-course-detail-media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.cs-detail-placeholder {
    font-size: 4rem;
}

.cs-detail-discount {
    top: 14px;
    inset-inline-start: 14px;
    font-size: var(--text-base);
    padding: 6px 14px;
}

.cs-course-detail-info {
    display: flex;
    flex-direction: column;
    gap: var(--gap-smmm);
}

.cs-course-category {
    display: inline-flex;
    width: fit-content;
    padding: 4px 14px;
    border-radius: 999px;
    background: var(--primary-softer);
    color: var(--primary);
    font-size: var(--text-lg);
    font-weight: 600;
}

.cs-course-detail-info h1 {
    font-size: var(--text-6xl);
    font-weight: 800;
    color: var(--ink-900);
    line-height: 1.4;
}

.cs-detail-short {
    color: var(--ink-600);
    font-size: var(--text-xl);
    line-height: 1.9;
}

.cs-course-detail-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--gap-sm);
    padding: var(--gap-smm) 0;
    border-top: 1px solid var(--rule);
    border-bottom: 1px solid var(--rule);
}

.cs-course-detail-meta .cs-meta-item {
    font-size: var(--text-lg);
    color: var(--ink-700);
}

.cs-course-detail-meta .cs-stars {
    font-size: var(--text-xl);
}

.cs-view-count {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: var(--text-lg);
    color: var(--ink-600);
}

.cs-view-count svg {
    color: var(--purple);
}

.cs-detail-purchase-card {
    margin-top: auto;
    background: var(--card-soft);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: var(--gap-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--gap-sm);
}

.cs-course-detail-price {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.cs-course-detail-price .cs-price-main {
    font-size: var(--text-2xl);
}

.cs-course-detail-price .cs-price-discount {
    font-size: var(--text-4xl);
    gap: 7px;
    display: flex;
}

.cs-course-detail-price .cs-price-free {
    font-size: var(--text-4xl);
}

.cs-buy-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    background: var(--primary);
    color: #fff;
    font-weight: 700;
    font-size: var(--text-xl);
    padding: 12px 26px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-btn);
    transition: filter var(--transition), transform var(--transition);
}

.cs-buy-btn:hover {
    filter: brightness(1.06);
    transform: translateY(-1px);
}

.cs-guarantee {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: var(--text-lg);
    color: var(--ink-600);
}

.cs-guarantee svg {
    color: var(--green);
    flex-shrink: 0;
}

#cs-desc,
#cs-related {
    scroll-margin-top: 90px;
}

.cs-course-detail-body {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--gap-lg);
    box-shadow: var(--shadow-card);
}

.cs-course-detail-body h2,
.cs-course-related h2 {
    font-size: var(--text-3xl);
    font-weight: 700;
    color: var(--ink-900);
    margin-bottom: var(--gap-sm);
    padding-inline-start: 14px;
}

.cs-course-detail-body p {
    color: var(--ink-700);
    font-size: var(--text-xl);
    line-height: 2.1;
}

.cs-course-related {
    display: flex;
    flex-direction: column;
    gap: var(--gap-sm);
}

/* ============================================================
   RESPONSIVE
============================================================ */
@media (max-width: 980px) {
    .cs-page-body {
        grid-template-columns: 1fr;
    }

    .cs-course-detail-hero {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .cs-hero-course {
        padding: var(--gap-lg) var(--gap-sm);
    }

    .cs-hero-content h1 {
        font-size: var(--text-5xl);
    }

    .cs-toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    .cs-toolbar-sort {
        justify-content: space-between;
    }

    .cs-detail-purchase-card {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }

    .cs-buy-btn {
        justify-content: center;
    }

    .cs-section-nav {
        width: 100%;
        overflow-x: auto;
    }

    .cs-mobile-buy-bar {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: var(--gap-sm);
        position: fixed;
        bottom: 0;
        inset-inline-start: 0;
        inset-inline-end: 0;
        background: var(--card);
        border-top: 1px solid var(--border);
        padding: 10px 16px calc(10px + env(safe-area-inset-bottom));
        box-shadow: 0 -6px 20px rgba(20, 26, 46, .08);
        z-index: 40;
    }

    .cs-mobile-buy-price {
        display: flex;
        flex-direction: column;
        line-height: 1.3;
    }

    .cs-mobile-buy-bar .cs-buy-btn {
        padding: 10px 20px;
        font-size: var(--text-lg);
    }

    .cs-back-to-top {
        bottom: 84px;
        /* stay above the mobile buy bar */
    }
}