/* Страница курса — premium (.course-detail-page) */

.course-detail-page {
    --course-brand-1: #1e3a8a;
    --course-brand-2: #667eea;
    --course-brand-3: #764ba2;
    --course-brand-4: #c471ed;
    --course-muted: #5c6370;
    --course-radius: 18px;
    --course-shadow: 0 14px 36px rgba(30, 27, 75, 0.1);
    --tab-violet: #667eea;
    --tab-purple: #764ba2;
    --tab-rose: #c471ed;
    --tab-glow: rgba(102, 126, 234, 0.45);
}

.course-detail-page .course-title {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--course-brand-2) 0%, var(--course-brand-3) 50%, #f093fb 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 2rem;
    position: relative;
    padding-bottom: 1rem;
    animation: courseTitleGlow 3s ease-in-out infinite;
}

.course-detail-page .course-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 4px;
    background: linear-gradient(90deg, var(--course-brand-2), var(--course-brand-3), var(--course-brand-4));
    border-radius: 2px;
    animation: courseLineExpand 1.5s ease-out;
}

@keyframes courseTitleGlow {
    0%, 100% { filter: drop-shadow(0 0 5px rgba(102, 126, 234, 0.3)); }
    50% { filter: drop-shadow(0 0 15px rgba(118, 75, 162, 0.5)); }
}

@keyframes courseLineExpand {
    from { width: 0; }
    to { width: 100px; }
}

.course-detail-page #skills .list-group-item {
    padding: 8px 0;
    border-left: 3px solid transparent;
    transition: all 0.2s ease;
    margin-bottom: 0;
}

.course-detail-page #skills .list-group-item:hover {
    border-left-color: var(--course-brand-2);
    padding-left: 10px;
    background-color: rgba(102, 126, 234, 0.04);
}

.course-detail-page #skills .skill-item {
    font-size: 1.05em;
    line-height: 1.4;
    color: #333;
    margin: 0;
    padding: 0;
}

.course-detail-page #skills .list-group-item:not(:last-child) {
    border-bottom: 1px solid #e9ecef;
    padding-bottom: 8px;
    margin-bottom: 0;
}

.course-detail-page .course-tabs-label {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: #8b8fa8;
    margin-bottom: 0.65rem;
    padding-left: 0.25rem;
}

.course-detail-page .course-tabs-shell {
    background: linear-gradient(155deg, #ffffff 0%, #f8f6ff 48%, #f3f0ff 100%);
    border: 1px solid rgba(102, 126, 234, 0.14);
    border-radius: var(--course-radius);
    padding: 0.5rem;
    box-shadow:
        0 4px 6px rgba(30, 27, 75, 0.02),
        0 16px 40px rgba(102, 126, 234, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.95);
}

.course-detail-page .course-info-tabs {
    gap: 0.4rem;
    margin-bottom: 0 !important;
}

.course-detail-page .course-info-tabs .nav-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border-radius: 14px;
    padding: 0.85rem 1.1rem;
    font-weight: 600;
    font-size: 0.92rem;
    line-height: 1.25;
    color: #4a4f68;
    background: rgba(255, 255, 255, 0.65);
    border: 1px solid transparent;
    box-shadow: 0 1px 2px rgba(30, 27, 75, 0.04);
    transition:
        transform 0.25s cubic-bezier(0.34, 1.2, 0.64, 1),
        background 0.25s ease,
        color 0.25s ease,
        border-color 0.25s ease,
        box-shadow 0.25s ease;
    white-space: normal;
    text-align: left;
    position: relative;
    overflow: hidden;
}

.course-detail-page .course-info-tabs .nav-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--tab-violet), var(--tab-purple) 55%, var(--tab-rose));
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 0;
}

.course-detail-page .course-info-tabs .nav-link > * {
    position: relative;
    z-index: 1;
}

.course-detail-page .course-tab-icon-wrap {
    flex-shrink: 0;
    width: 2.35rem;
    height: 2.35rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(145deg, rgba(102, 126, 234, 0.12), rgba(118, 75, 162, 0.08));
    color: var(--tab-purple);
    font-size: 0.95rem;
    transition: background 0.25s ease, color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.course-detail-page .course-info-tabs .nav-link:hover {
    color: var(--tab-purple);
    border-color: rgba(102, 126, 234, 0.2);
    background: #fff;
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.12);
    transform: translateY(-1px);
}

.course-detail-page .course-info-tabs .nav-link.active {
    color: #fff;
    border-color: transparent;
    box-shadow:
        0 8px 24px var(--tab-glow),
        0 2px 8px rgba(118, 75, 162, 0.25),
        inset 0 1px 0 rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.course-detail-page .course-info-tabs .nav-link.active::before {
    opacity: 1;
}

.course-detail-page .course-info-tabs .nav-link.active .course-tab-icon-wrap {
    background: rgba(255, 255, 255, 0.22);
    color: #fff;
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.35);
}

.course-detail-page .course-info-tabs .nav-link:focus-visible {
    outline: 2px solid var(--tab-violet);
    outline-offset: 2px;
}

.course-detail-page .course-tab-panel {
    position: relative;
    margin-top: 1.25rem;
    background: #fff;
    border-radius: 20px;
    padding: 1.75rem 1.85rem;
    border: 1px solid rgba(102, 126, 234, 0.1);
    box-shadow:
        0 2px 4px rgba(30, 27, 75, 0.02),
        0 20px 48px rgba(102, 126, 234, 0.08);
    overflow: hidden;
}

.course-detail-page .course-tab-panel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--tab-violet), var(--tab-purple), var(--tab-rose));
}

.course-detail-page .course-tab-panel::after {
    content: '';
    position: absolute;
    top: -80px;
    right: -80px;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(196, 113, 237, 0.06) 0%, transparent 70%);
    pointer-events: none;
}

.course-detail-page .course-sidebar-card {
    border-radius: var(--course-radius);
    overflow: hidden;
    border: 1px solid rgba(30, 27, 75, 0.06) !important;
    box-shadow: var(--course-shadow);
}

.course-detail-page .course-sidebar-card .card-img-top {
    object-fit: cover;
    object-position: center bottom;
}

.course-detail-page .course-sidebar-card .badge {
    border-radius: 999px;
    padding: 0.35rem 0.65rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--course-brand-2), var(--course-brand-3)) !important;
}

.course-detail-page .course-sidebar-card .btn-primary {
    border-radius: 999px;
    font-weight: 700;
    padding: 0.65rem 1rem;
    border: none;
    background: linear-gradient(135deg, var(--course-brand-2), var(--course-brand-3));
    box-shadow: 0 6px 18px rgba(102, 126, 234, 0.28);
}

.course-detail-page .course-back-btn {
    border-radius: 999px;
    font-weight: 600;
    padding: 0.55rem 1.15rem;
}

.course-detail-page .course-mobile-cta {
    display: none;
}

@media (min-width: 768px) {
    .course-detail-page .course-tabs-shell {
        padding: 0.55rem;
    }

    .course-detail-page .course-info-tabs {
        flex-wrap: nowrap !important;
        gap: 0.35rem !important;
    }

    .course-detail-page .course-info-tabs .nav-item {
        flex: 1 1 0;
        min-width: 0;
    }

    .course-detail-page .course-info-tabs .nav-link {
        justify-content: center;
        text-align: center;
        flex-direction: column;
        gap: 0.45rem;
        padding: 0.95rem 0.65rem;
        font-size: 0.82rem;
        white-space: normal;
        min-height: 5.5rem;
    }

    .course-detail-page .course-tab-icon-wrap {
        width: 2.5rem;
        height: 2.5rem;
        font-size: 1rem;
    }

    .course-detail-page .course-tab-panel {
        padding: 2rem 2.25rem;
    }
}

@media (min-width: 992px) {
    .course-detail-page .course-info-tabs .nav-link {
        font-size: 0.88rem;
        padding: 1rem 0.85rem;
    }
}

@media (max-width: 767.98px) {
    .course-detail-page {
        padding-bottom: 5.5rem;
    }

    .course-detail-page > .container {
        padding-top: 1rem !important;
        padding-bottom: 1.5rem !important;
    }

    .course-detail-page .course-title {
        font-size: clamp(1.25rem, 5.5vw, 1.45rem);
        letter-spacing: 0.04em;
        line-height: 1.25;
        margin-bottom: 1.15rem;
        padding-bottom: 0.65rem;
        animation: none;
        text-transform: none;
    }

    .course-detail-page .course-title::after {
        width: 56px;
        height: 3px;
        animation: none;
    }

    .course-detail-page .course-sidebar-card {
        border-radius: 20px;
        margin-bottom: 1rem !important;
    }

    .course-detail-page .course-sidebar-card .card-img-top,
    .course-detail-page .course-sidebar-card .bg-light {
        max-height: 254px;
        object-fit: cover;
    }

    .course-detail-page .course-sidebar-card .card-body {
        padding: 1rem 1.05rem;
    }

    .course-detail-page .course-sidebar-card .course-sidebar-enroll {
        display: none;
    }

    .course-detail-page .course-tabs-shell {
        padding: 0.35rem;
        border-radius: 16px;
        background: #fff;
        box-shadow: 0 8px 28px rgba(30, 27, 75, 0.08);
    }

    .course-detail-page .course-info-tabs {
        flex-direction: row !important;
        flex-wrap: nowrap !important;
        overflow-x: auto;
        gap: 0.35rem !important;
        padding-bottom: 0.15rem;
        -webkit-overflow-scrolling: touch;
        scroll-snap-type: x proximity;
        scrollbar-width: none;
    }

    .course-detail-page .course-info-tabs::-webkit-scrollbar {
        display: none;
    }

    .course-detail-page .course-info-tabs .nav-item {
        width: auto;
        flex-shrink: 0;
    }

    .course-detail-page .course-info-tabs .nav-link {
        width: auto;
        min-width: 7.5rem;
        max-width: 9.5rem;
        min-height: auto;
        flex-direction: column;
        justify-content: center;
        text-align: center;
        gap: 0.35rem;
        padding: 0.65rem 0.55rem;
        font-size: 0.72rem;
        scroll-snap-align: start;
    }

    .course-detail-page .course-tab-icon-wrap {
        width: 2rem;
        height: 2rem;
        font-size: 0.82rem;
    }

    .course-detail-page .course-tab-panel {
        margin-top: 0.85rem;
        padding: 1.1rem 1rem;
        border-radius: 18px;
        font-size: 0.92rem;
        line-height: 1.6;
    }

    .course-detail-page .course-tab-panel h2,
    .course-detail-page .course-tab-panel h3,
    .course-detail-page .course-tab-panel h4 {
        font-size: 1.05rem;
        font-weight: 700;
        color: var(--course-brand-1);
    }

    .course-detail-page #skills .skill-item {
        font-size: 0.92rem;
    }

    .course-detail-page .course-video-card {
        border-radius: 18px !important;
        overflow: hidden;
        box-shadow: 0 8px 24px rgba(30, 27, 75, 0.08) !important;
    }

    .course-detail-page .course-video-card .card-title {
        font-size: 1rem;
        font-weight: 700;
    }

    .course-detail-page .course-back-wrap {
        margin-top: 1.5rem !important;
    }

    .course-detail-page .course-mobile-cta {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 0.75rem;
        position: fixed;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: 1030;
        padding: 0.75rem 1rem calc(0.75rem + env(safe-area-inset-bottom, 0px));
        background: rgba(255, 255, 255, 0.94);
        -webkit-backdrop-filter: blur(12px);
        backdrop-filter: blur(12px);
        border-top: 1px solid rgba(30, 27, 75, 0.08);
        box-shadow: 0 -8px 32px rgba(30, 27, 75, 0.1);
    }

    .course-detail-page .course-mobile-cta__info {
        display: flex;
        flex-direction: column;
        min-width: 0;
    }

    .course-detail-page .course-mobile-cta__price {
        font-size: 1.05rem;
        font-weight: 800;
        color: var(--course-brand-1);
        line-height: 1.2;
    }

    .course-detail-page .course-mobile-cta__meta {
        font-size: 0.72rem;
        color: var(--course-muted);
    }

    .course-detail-page .course-mobile-cta__btn {
        flex-shrink: 0;
        border-radius: 999px;
        font-weight: 700;
        padding: 0.6rem 1.15rem;
        border: none;
        background: linear-gradient(135deg, var(--course-brand-2), var(--course-brand-3));
        box-shadow: 0 6px 18px rgba(102, 126, 234, 0.3);
    }
}

/* ������������� �� ����� */
.course-detail-page .course-teachers {
    margin-top: 0.25rem;
}

.course-detail-page .course-teachers__head {
    margin-bottom: 1rem;
}

.course-detail-page .course-teachers__title {
    margin: 0.35rem 0 0;
    font-size: clamp(1.25rem, 2.4vw, 1.55rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--course-brand-1);
}

.course-detail-page .course-teacher-card {
    display: flex;
    gap: 0.9rem;
    align-items: flex-start;
    padding: 1rem 1.1rem;
    border-radius: var(--course-radius);
    border: 1px solid rgba(30, 27, 75, 0.08);
    background:
        linear-gradient(160deg, rgba(255, 255, 255, 0.95), rgba(248, 249, 255, 0.92)),
        linear-gradient(135deg, rgba(102, 126, 234, 0.08), rgba(118, 75, 162, 0.06));
    box-shadow: 0 10px 28px rgba(30, 27, 75, 0.06);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.course-detail-page .course-teacher-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 32px rgba(30, 27, 75, 0.1);
}

.course-detail-page .course-teacher-card__photo {
    width: 72px;
    height: 72px;
    border-radius: 16px;
    object-fit: cover;
    object-position: center top;
    flex-shrink: 0;
    box-shadow: 0 4px 14px rgba(30, 27, 75, 0.12);
}

.course-detail-page .course-teacher-card__photo--placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15), rgba(118, 75, 162, 0.12));
    color: var(--course-brand-2);
    font-size: 1.35rem;
}

.course-detail-page .course-teacher-card__name {
    margin: 0 0 0.35rem;
    font-size: 1rem;
    font-weight: 700;
    line-height: 1.25;
    color: #1a1d26;
}

.course-detail-page .course-teacher-card__edu {
    margin: 0;
    font-size: 0.82rem;
    line-height: 1.45;
    color: var(--course-muted);
}

.course-detail-page .course-teachers__more {
    margin-top: 0.9rem;
    font-size: 0.88rem;
}

.course-detail-page .course-teachers__more a {
    color: var(--course-brand-2);
    font-weight: 600;
    text-decoration: none;
}

.course-detail-page .course-teachers__more a:hover {
    text-decoration: underline;
}

@media (max-width: 575.98px) {
    .course-detail-page .course-teacher-card__photo {
        width: 64px;
        height: 64px;
        border-radius: 14px;
    }
}