:root {
    --catalog-bg: #f5f7fb;
    --catalog-surface: #ffffff;
    --catalog-text: #1e293b;
    --catalog-muted: #64748b;
    --catalog-border: #e2e8f0;
    --catalog-shadow: 0 20px 45px rgba(15, 23, 42, 0.08);
    --catalog-orange: #f28a2e;
    --catalog-orange-soft: #fff0df;
    --catalog-blue: #1f4ea3;
    --catalog-blue-dark: #0f2c63;
    --catalog-green: #1ea97c;
}

.catalog-body {
    margin: 0;
    min-height: 100vh;
    background: var(--catalog-bg);
    color: var(--catalog-text);
    font-family: 'Inter', 'Segoe UI', Tahoma, sans-serif;
}

.catalog-container {
    width: min(1200px, calc(100% - 32px));
    margin: 0 auto;
}

.catalog-site-header {
    background: var(--catalog-surface);
    border-bottom: 1px solid rgba(148, 163, 184, 0.2);
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(8px);
}

.catalog-site-header-inner {
    min-height: 76px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.catalog-logo {
    text-decoration: none;
    color: var(--catalog-blue-dark);
    font-weight: 800;
    font-size: 1.15rem;
    letter-spacing: 0.02em;
}

.catalog-logo span {
    color: var(--catalog-orange);
}

.catalog-nav {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
}

.catalog-nav a {
    text-decoration: none;
    color: var(--catalog-text);
    font-weight: 600;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

.catalog-nav a:hover,
.catalog-nav a.is-active {
    color: var(--catalog-blue);
}

.catalog-auth-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.catalog-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    border: 1px solid transparent;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 10px 16px;
    text-decoration: none;
    transition: all 0.2s ease;
}

.catalog-btn-outline {
    border-color: var(--catalog-border);
    color: var(--catalog-text);
    background: var(--catalog-surface);
}

.catalog-btn-outline:hover {
    border-color: var(--catalog-orange);
    color: var(--catalog-orange);
}

.catalog-btn-dark {
    background: #0f172a;
    color: #ffffff;
}

.catalog-btn-dark:hover {
    transform: translateY(-1px);
    box-shadow: 0 10px 18px rgba(15, 23, 42, 0.2);
}

.catalog-page-hero {
    background: radial-gradient(circle at 8% 10%, rgba(31, 78, 163, 0.18) 0, transparent 40%),
        radial-gradient(circle at 90% 10%, rgba(242, 138, 46, 0.18) 0, transparent 45%),
        #ffffff;
    border-bottom: 1px solid var(--catalog-border);
    padding: 56px 0;
}

.catalog-page-hero h1 {
    margin: 0;
    font-size: clamp(1.8rem, 2.3vw, 2.4rem);
    color: #0f172a;
}

.catalog-page-hero p {
    margin: 12px 0 0;
    color: var(--catalog-muted);
    max-width: 680px;
}

.catalog-list-controls {
    padding: 28px 0 8px;
}

.catalog-list-controls-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    flex-wrap: wrap;
}

.catalog-search {
    position: relative;
    width: min(500px, 100%);
    flex: 1;
}

.catalog-search input {
    width: 100%;
    height: 50px;
    border-radius: 14px;
    border: 1px solid var(--catalog-border);
    background: #fff;
    padding: 0 16px 0 46px;
    font-size: 0.97rem;
    color: var(--catalog-text);
    font-family: inherit;
}

.catalog-search input:focus {
    outline: none;
    border-color: rgba(31, 78, 163, 0.48);
    box-shadow: 0 0 0 4px rgba(31, 78, 163, 0.12);
}

.catalog-search i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--catalog-muted);
}

.catalog-featured-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--catalog-text);
    user-select: none;
}

.catalog-featured-toggle input {
    width: 18px;
    height: 18px;
    accent-color: var(--catalog-orange);
}

.catalog-result-count {
    margin: 0;
    color: var(--catalog-muted);
    font-size: 0.88rem;
}

.catalog-courses-section {
    padding: 14px 0 60px;
}

.catalog-courses-grid {
    display: grid;
    grid-template-columns: repeat(1, minmax(0, 1fr));
    gap: 22px;
}

.catalog-course-card {
    background: var(--catalog-surface);
    border-radius: 24px;
    border: 1px solid var(--catalog-border);
    overflow: hidden;
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.08);
    display: flex;
    flex-direction: column;
    min-height: 100%;
}

.catalog-course-image-wrap {
    aspect-ratio: 16 / 10;
    background: #e2e8f0;
    overflow: hidden;
}

.catalog-course-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.catalog-course-card:hover .catalog-course-image {
    transform: scale(1.04);
}

.catalog-course-body {
    padding: 18px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    flex: 1;
}

.catalog-course-title {
    margin: 0;
    font-size: 1.05rem;
    line-height: 1.35;
    color: #0f172a;
}

.catalog-course-intro {
    margin: 0;
    color: var(--catalog-muted);
    line-height: 1.5;
    font-size: 0.92rem;
    flex: 1;
}

.catalog-course-link {
    margin-top: auto;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    border: 2px solid var(--catalog-orange);
    color: var(--catalog-orange);
    border-radius: 999px;
    padding: 9px 14px;
    font-weight: 700;
    font-size: 0.78rem;
    letter-spacing: 0.02em;
    align-self: flex-start;
    transition: all 0.2s ease;
}

.catalog-course-link:hover {
    background: var(--catalog-orange);
    color: #ffffff;
}

.catalog-empty-state {
    grid-column: 1 / -1;
    text-align: center;
    border: 1px dashed var(--catalog-border);
    border-radius: 24px;
    padding: 50px 20px;
    color: var(--catalog-muted);
    background: #ffffff;
}

.catalog-empty-state h3 {
    margin: 0 0 10px;
    color: #0f172a;
}

.catalog-footer {
    border-top: 1px solid var(--catalog-border);
    background: #ffffff;
    padding: 24px 0;
    text-align: center;
    color: #64748b;
    font-size: 0.9rem;
}

.catalog-featured {
    position: relative;
    overflow: hidden;
    padding: 62px 0 66px;
    background:
        radial-gradient(circle at 8% 10%, rgba(31, 78, 163, 0.14) 0, transparent 40%),
        radial-gradient(circle at 92% 16%, rgba(242, 138, 46, 0.15) 0, transparent 44%),
        linear-gradient(180deg, #f8fbff 0%, #ffffff 80%);
}

.catalog-featured::before {
    content: '';
    position: absolute;
    width: clamp(160px, 28vw, 320px);
    height: clamp(160px, 28vw, 320px);
    right: -100px;
    top: -88px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(242, 138, 46, 0.2) 0, rgba(242, 138, 46, 0) 70%);
    pointer-events: none;
}

.catalog-featured-title {
    position: relative;
    overflow: hidden;
    text-align: center;
    margin: 0 auto 32px;
    max-width: min(920px, 100%);
    padding: clamp(20px, 3vw, 34px) clamp(18px, 4vw, 42px);
    border-radius: 24px;
    border: 1px solid rgba(148, 163, 184, 0.28);
    background:
        linear-gradient(128deg, rgba(255, 255, 255, 0.96) 0%, rgba(255, 255, 255, 0.95) 58%, rgba(255, 241, 227, 0.9) 100%);
    box-shadow: 0 22px 46px rgba(15, 23, 42, 0.12);
    backdrop-filter: blur(4px);
}

.catalog-featured-title::after {
    content: '';
    position: absolute;
    inset: auto auto -56px -50px;
    width: 220px;
    height: 220px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(31, 78, 163, 0.18) 0, rgba(31, 78, 163, 0) 70%);
    pointer-events: none;
}

.catalog-featured-kicker {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin: 0;
    color: var(--catalog-blue-dark);
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.16em;
}

.catalog-featured-kicker::before,
.catalog-featured-kicker::after {
    content: '';
    width: 28px;
    height: 2px;
    border-radius: 999px;
}

.catalog-featured-kicker::before {
    background: linear-gradient(90deg, rgba(242, 138, 46, 0.2) 0%, rgba(242, 138, 46, 1) 100%);
}

.catalog-featured-kicker::after {
    background: linear-gradient(90deg, rgba(31, 78, 163, 1) 0%, rgba(31, 78, 163, 0.18) 100%);
}

.catalog-featured-title h2 {
    margin: 14px 0 0;
    color: #0f172a;
    font-size: clamp(1.85rem, 2.8vw, 2.7rem);
    line-height: 1.15;
    letter-spacing: -0.02em;
}

.catalog-featured-title p {
    margin: 14px auto 0;
    max-width: 620px;
    color: #55657a;
    font-size: 1rem;
    line-height: 1.7;
}

.catalog-carousel-shell {
    display: grid;
    grid-template-columns: 52px 1fr 52px;
    align-items: center;
    gap: 16px;
}

.catalog-carousel-window {
    overflow: hidden;
    padding: 4px;
}

.catalog-featured-track {
    display: flex;
    gap: 24px;
    transition: transform 0.35s ease;
    will-change: transform;
}

.catalog-featured-track .catalog-course-card {
    flex: 0 0 100%;
}

.catalog-carousel-control {
    width: 52px;
    height: 52px;
    border-radius: 999px;
    border: 1px solid var(--catalog-border);
    background: #ffffff;
    color: var(--catalog-blue-dark);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.1);
    transition: all 0.2s ease;
}

.catalog-carousel-control:hover:not(:disabled) {
    background: var(--catalog-blue-dark);
    color: #ffffff;
}

.catalog-carousel-control:disabled {
    opacity: 0.35;
    cursor: not-allowed;
    box-shadow: none;
}

.catalog-featured-footer {
    text-align: center;
    margin-top: 28px;
}

.catalog-show-all-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: 999px;
    text-decoration: none;
    border: 2px solid #0f172a;
    color: #0f172a;
    font-weight: 700;
    letter-spacing: 0.02em;
    transition: all 0.2s ease;
}

.catalog-show-all-btn:hover {
    background: #0f172a;
    color: #ffffff;
}

.catalog-course-hero {
    background: linear-gradient(120deg, #1f4ea3 0%, #2766d6 48%, #4c8cf7 100%);
    color: #ffffff;
    padding: clamp(56px, 9vw, 110px) 0;
    position: relative;
    overflow: hidden;
}

.catalog-course-hero::after {
    content: '';
    position: absolute;
    inset: auto -15% -80px;
    height: 180px;
    background: radial-gradient(circle at center, rgba(255, 255, 255, 0.26) 0, rgba(255, 255, 255, 0) 70%);
}

.catalog-course-hero h1 {
    margin: 0;
    max-width: 760px;
    font-size: clamp(2rem, 4vw, 3rem);
    line-height: 1.2;
    position: relative;
    z-index: 1;
}

.catalog-meta-row {
    background: #ffffff;
    border-bottom: 1px solid var(--catalog-border);
}

.catalog-meta-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
    padding: 24px 0;
}

.catalog-meta-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px;
    border-radius: 14px;
    background: #f8fafc;
    border: 1px solid #eef2f7;
}

.catalog-meta-icon {
    width: 36px;
    height: 36px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: #e8eefb;
    color: var(--catalog-blue-dark);
    flex-shrink: 0;
}

.catalog-meta-text {
    margin: 0;
    font-size: 0.88rem;
    color: #334155;
    line-height: 1.45;
}

.catalog-course-main {
    padding: 34px 0;
}

.catalog-course-main-grid {
    display: grid;
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 26px;
    align-items: start;
}

.catalog-course-actions {
    background: #ffffff;
    border-radius: 20px;
    border: 1px solid var(--catalog-border);
    padding: 16px;
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.07);
    position: sticky;
    top: 100px;
    display: grid;
    gap: 10px;
}

.catalog-action-btn {
    width: 100%;
    min-height: 50px;
    border-radius: 14px;
    border: 2px solid #d4dae3;
    background: #ffffff;
    color: #1e293b;
    font-weight: 700;
    font-family: inherit;
    letter-spacing: 0.01em;
    cursor: pointer;
    transition: all 0.2s ease;
}

.catalog-action-btn:hover,
.catalog-action-btn.is-active {
    transform: translateY(-1px);
}

.catalog-action-btn.is-buy {
    border-color: #ef4444;
    color: #b91c1c;
}

.catalog-action-btn[data-action='description'] {
    border-color: var(--catalog-orange);
    color: #c05613;
}

.catalog-action-btn[data-action='syllabus'] {
    border-color: #94a3b8;
    color: #334155;
}

.catalog-action-btn.is-active[data-action='description'] {
    background: var(--catalog-orange-soft);
}

.catalog-action-btn.is-active[data-action='syllabus'] {
    background: #f1f5f9;
}

.catalog-course-content {
    background: #ffffff;
    border: 1px solid var(--catalog-border);
    border-radius: 24px;
    padding: clamp(22px, 3vw, 34px);
    box-shadow: var(--catalog-shadow);
}

.catalog-detail-cover {
    margin-bottom: 22px;
    border-radius: 18px;
    overflow: hidden;
    border: 1px solid #e2e8f0;
    background: #f8fafc;
}

.catalog-detail-cover-image {
    width: 100%;
    max-height: 360px;
    object-fit: cover;
    display: block;
}

.catalog-description-header {
    margin-bottom: 20px;
}

.catalog-description-title {
    margin: 0;
    color: var(--catalog-orange);
    font-size: clamp(1.55rem, 2.5vw, 2.05rem);
}

.catalog-description-kicker {
    margin: 10px 0 0;
    color: #334155;
    letter-spacing: 0.09em;
    font-size: 0.79rem;
    font-weight: 700;
}

.catalog-description-block + .catalog-description-block {
    margin-top: 26px;
}

.catalog-description-subtitle {
    margin: 0 0 12px;
    color: #0f172a;
    font-size: 1rem;
    font-weight: 800;
    letter-spacing: 0.03em;
}

.catalog-description-paragraph {
    margin: 0;
    color: #334155;
    line-height: 1.7;
}

.catalog-description-paragraph + .catalog-description-paragraph {
    margin-top: 12px;
}

.catalog-syllabus-section,
.catalog-materials-section,
.catalog-audience-section {
    padding: 14px 0 34px;
}

.catalog-section-heading {
    margin: 0;
    color: #0f172a;
    font-size: clamp(1.45rem, 2.4vw, 1.95rem);
}

.catalog-section-subheading {
    margin: 10px 0 0;
    color: #334155;
    font-size: 0.8rem;
    letter-spacing: 0.09em;
    font-weight: 700;
}

.catalog-syllabus-grid {
    margin-top: 20px;
    display: grid;
    gap: 14px;
}

.catalog-syllabus-card {
    border-radius: 20px;
    background: #ffffff;
    border: 1px solid var(--catalog-border);
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.06);
    padding: 18px;
}

.catalog-syllabus-title {
    margin: 0;
    color: #1e3a8a;
    font-size: 1rem;
}

.catalog-syllabus-bullets {
    margin: 10px 0 0;
    padding-left: 18px;
    color: #334155;
}

.catalog-syllabus-bullets li + li {
    margin-top: 6px;
}

.catalog-materials-list {
    margin-top: 20px;
    display: grid;
    gap: 10px;
}

.catalog-materials-locked {
    border: 1px solid #fecaca;
    background: #fff7ed;
    border-radius: 16px;
    padding: 18px;
}

.catalog-materials-locked h3 {
    margin: 0;
    color: #9a3412;
    font-size: 1rem;
}

.catalog-materials-locked p {
    margin: 10px 0 14px;
    color: #7c2d12;
    line-height: 1.5;
}

.catalog-material-item {
    display: grid;
    grid-template-columns: 40px 1fr auto;
    gap: 12px;
    align-items: center;
    text-decoration: none;
    border: 1px solid var(--catalog-border);
    background: #ffffff;
    border-radius: 14px;
    padding: 12px;
    transition: all 0.2s ease;
}

.catalog-material-item:hover {
    border-color: #93c5fd;
    background: #f8fbff;
    transform: translateY(-1px);
}

.catalog-material-index {
    width: 30px;
    height: 30px;
    border-radius: 999px;
    background: #e2ecff;
    color: #1e3a8a;
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
}

.catalog-material-title {
    color: #0f172a;
    font-weight: 600;
    line-height: 1.35;
}

.catalog-material-open {
    color: #2563eb;
    font-size: 0.84rem;
    font-weight: 700;
}

.catalog-audience-grid {
    margin-top: 22px;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px 20px;
}

.catalog-audience-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    background: #ffffff;
    border: 1px solid var(--catalog-border);
    border-radius: 14px;
    padding: 12px;
}

.catalog-audience-check {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: rgba(30, 169, 124, 0.16);
    color: var(--catalog-green);
    display: grid;
    place-items: center;
    flex-shrink: 0;
    margin-top: 1px;
}

.catalog-audience-text {
    color: #334155;
    line-height: 1.45;
    font-size: 0.92rem;
}

.catalog-toast {
    position: fixed;
    right: 20px;
    bottom: 24px;
    z-index: 60;
    background: #0f172a;
    color: #ffffff;
    border-radius: 12px;
    padding: 12px 14px;
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.3);
    opacity: 0;
    transform: translateY(12px);
    pointer-events: none;
    transition: all 0.25s ease;
}

.catalog-toast.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.catalog-not-found {
    padding: 80px 0;
}

.catalog-not-found h1 {
    margin: 0 0 10px;
    color: #0f172a;
}

.catalog-not-found p {
    margin: 0 0 18px;
    color: var(--catalog-muted);
}

@media (min-width: 700px) {
    .catalog-courses-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .catalog-featured-track .catalog-course-card {
        flex: 0 0 calc((100% - 24px) / 2);
    }
}

@media (min-width: 1024px) {
    .catalog-courses-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .catalog-featured-track .catalog-course-card {
        flex: 0 0 calc((100% - 48px) / 3);
    }
}

@media (max-width: 960px) {
    .catalog-site-header-inner {
        min-height: 68px;
        flex-wrap: wrap;
        justify-content: center;
        padding: 10px 0;
    }

    .catalog-nav {
        justify-content: center;
    }

    .catalog-auth-actions {
        width: 100%;
        justify-content: center;
    }

    .catalog-course-main-grid {
        grid-template-columns: 1fr;
    }

    .catalog-course-actions {
        position: static;
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .catalog-action-btn {
        min-height: 46px;
        font-size: 0.82rem;
    }

    .catalog-meta-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 767px) {
    .catalog-featured {
        padding: 52px 0 58px;
    }

    .catalog-featured-title {
        margin-bottom: 24px;
        padding: 18px 14px 20px;
        border-radius: 18px;
    }

    .catalog-featured-kicker {
        font-size: 0.69rem;
        letter-spacing: 0.14em;
    }

    .catalog-featured-kicker::before,
    .catalog-featured-kicker::after {
        width: 20px;
    }

    .catalog-featured-title h2 {
        font-size: clamp(1.55rem, 7vw, 2rem);
    }

    .catalog-featured-title p {
        font-size: 0.92rem;
        line-height: 1.6;
    }

    .catalog-carousel-shell {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .catalog-carousel-control {
        display: none;
    }

    .catalog-featured-track {
        gap: 16px;
    }

    .catalog-featured-track .catalog-course-card {
        flex: 0 0 100%;
    }

    .catalog-course-actions {
        grid-template-columns: 1fr;
    }

    .catalog-meta-grid,
    .catalog-audience-grid {
        grid-template-columns: 1fr;
    }

    .catalog-material-item {
        grid-template-columns: 34px 1fr;
    }

    .catalog-material-open {
        grid-column: 2;
    }
}