.course-details-overlay {
    position: fixed;
    inset: 0;
    z-index: 1100;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: rgba(3, 7, 18, 0.82);
    backdrop-filter: blur(3px);
}

.course-details-overlay[hidden] {
    display: none;
}

.course-details-dialog {
    width: min(860px, 100%);
    max-height: min(90vh, 900px);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    color: var(--text-main, #f9fafb);
    background: var(--bg-card, #1f2937);
    border: 1px solid var(--border-main, #4b5563);
    border-radius: 1rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.course-details-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    padding: 1.1rem 1.25rem;
    border-bottom: 1px solid var(--border-main, #4b5563);
}

.course-details-source {
    margin: 0 0 0.25rem;
    color: var(--text-muted, #9ca3af);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.course-details-title {
    margin: 0;
    color: var(--accent-color, #60a5fa);
    font-family: 'Roboto Slab', serif;
    font-size: clamp(1.05rem, 2.5vw, 1.45rem);
    line-height: 1.3;
}

.course-details-close,
.course-details-close-button {
    border: 0;
    color: inherit;
    background: transparent;
    cursor: pointer;
}

.course-details-close {
    padding: 0 0.25rem;
    color: var(--text-muted, #9ca3af);
    font-size: 1.75rem;
    line-height: 1;
}

.course-details-close:hover,
.course-details-close:focus-visible {
    color: var(--text-main, #fff);
}

.course-details-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 0.65rem;
    padding: 1rem 1.25rem;
    background: rgba(17, 24, 39, 0.35);
    border-bottom: 1px solid var(--border-main, #4b5563);
}

.course-details-meta-item {
    min-width: 0;
}

.course-details-meta-item dt {
    margin-bottom: 0.15rem;
    color: var(--text-muted, #9ca3af);
    font-size: 0.68rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.course-details-meta-item dd {
    margin: 0;
    color: var(--text-main, #f3f4f6);
    font-size: 0.84rem;
    line-height: 1.4;
    overflow-wrap: anywhere;
}

.course-details-content {
    overflow-y: auto;
    padding: 1.1rem 1.25rem;
}

.course-details-section + .course-details-section {
    margin-top: 1.1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-main, #4b5563);
}

.course-details-section-title {
    margin: 0 0 0.45rem;
    color: var(--accent-color, #93c5fd);
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.course-details-text,
.course-details-syllabus-item p {
    margin: 0;
    color: var(--text-main, #e5e7eb);
    font-size: 0.88rem;
    line-height: 1.65;
    white-space: pre-wrap;
}

.course-details-list {
    margin: 0;
    padding-left: 1.2rem;
    color: var(--text-main, #e5e7eb);
    font-size: 0.88rem;
    line-height: 1.55;
}

.course-details-syllabus {
    display: grid;
    gap: 0.65rem;
}

.course-details-syllabus-item {
    padding: 0.7rem 0.8rem;
    background: rgba(17, 24, 39, 0.38);
    border: 1px solid var(--border-main, #374151);
    border-radius: 0.65rem;
}

.course-details-syllabus-item h5 {
    margin: 0 0 0.25rem;
    color: var(--text-main, #f9fafb);
    font-size: 0.86rem;
    font-weight: 700;
}

.course-details-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.8rem 1.25rem;
    color: var(--text-muted, #9ca3af);
    font-size: 0.72rem;
    border-top: 1px solid var(--border-main, #4b5563);
}

.course-details-close-button {
    flex: 0 0 auto;
    padding: 0.45rem 0.8rem;
    color: #fff;
    background: #374151;
    border-radius: 0.5rem;
    font-size: 0.78rem;
    font-weight: 700;
}

.course-details-close-button:hover,
.course-details-close-button:focus-visible {
    background: #4b5563;
}

.course-more-info {
    display: block;
    width: 100%;
    margin-top: 0.6rem;
    padding: 0.42rem 0.55rem;
    color: #e0f2fe;
    background: rgba(8, 145, 178, 0.2);
    border: 1px solid rgba(34, 211, 238, 0.45);
    border-radius: 0.45rem;
    cursor: pointer;
    font: inherit;
    font-size: 0.72rem;
    font-weight: 700;
    line-height: 1.2;
}

.course-more-info:hover,
.course-more-info:focus-visible {
    color: #fff;
    background: rgba(8, 145, 178, 0.45);
    outline: 2px solid rgba(103, 232, 249, 0.7);
    outline-offset: 1px;
}

body.course-details-open {
    overflow: hidden;
}

@media (max-width: 640px) {
    .course-details-overlay {
        align-items: flex-end;
        padding: 0;
    }

    .course-details-dialog {
        max-height: 94vh;
        border-radius: 1rem 1rem 0 0;
    }

    .course-details-header,
    .course-details-meta,
    .course-details-content,
    .course-details-footer {
        padding-left: 1rem;
        padding-right: 1rem;
    }

    .course-details-footer {
        align-items: flex-end;
    }
}