/* ============================================================
 * Quản lý khóa học (QLKH) - design tokens
 * Chủ đạo: #251098 (tím), nền nhạt: #F5F7FF, nhấn: #FF5C00, trắng đen.
 * ============================================================ */

:root {
    --qlkh-primary:        #251098;
    --qlkh-primary-light:  #4a35c4;
    --qlkh-primary-dark:   #1a0a73;
    --qlkh-accent:         #FF5C00;
    --qlkh-accent-dark:    #cc4900;
    --qlkh-danger:         #b50000;
    --qlkh-text:           #000000;
    --qlkh-muted:          #5f5f5f;
    --qlkh-bg-card:        #ffffff;
    --qlkh-bg-accent:      #F5F7FF;
    --qlkh-bg-hover:       #ebeefc;
    --qlkh-border:         #e0e0e0;
    --qlkh-border-soft:    #ececec;
    --qlkh-radius:         12px;
    --qlkh-radius-sm:      6px;
    --qlkh-shadow:         0 2px 8px rgba(0,0,0,0.04);
    --qlkh-shadow-hover:   0 4px 12px rgba(37,16,152,0.10);
    --qlkh-fs-h:           20px;
    --qlkh-fs-body:        16px;
    --qlkh-fs-note:        12px;
}

.qlkh-wrap {
    font-family: 'Roboto', Arial, 'Segoe UI', 'Helvetica Neue', sans-serif;
    color: var(--qlkh-text);
    font-size: var(--qlkh-fs-body);
    line-height: 1.5;
    max-width: 1100px;
    margin: 0 auto;
}

/* ===== Hero ===== */
.qlkh-hero {
    background: var(--qlkh-bg-accent);
    border-left: 4px solid var(--qlkh-primary);
    border-radius: var(--qlkh-radius);
    padding: 20px 24px;
    margin-bottom: 24px;
    box-shadow: var(--qlkh-shadow);
}
.qlkh-hero__name {
    margin: 0 0 6px;
    font-size: 24px;
    color: var(--qlkh-primary);
    font-weight: 600;
}
.qlkh-hero__meta {
    margin: 0;
    color: var(--qlkh-muted);
    font-size: var(--qlkh-fs-body);
}

/* ===== Section title ===== */
.qlkh-section-title {
    margin: 24px 0 14px;
    font-size: var(--qlkh-fs-h);
    color: var(--qlkh-primary);
    display: flex;
    align-items: center;
    gap: 8px;
    line-height: 1;
}
.qlkh-section-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    color: var(--qlkh-primary);
}

/* ===== Card ===== */
.qlkh-card {
    background: var(--qlkh-bg-card);
    border: 1px solid var(--qlkh-border-soft);
    border-radius: var(--qlkh-radius);
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: var(--qlkh-shadow);
}
.qlkh-card h2, .qlkh-card h3 { margin-top: 0; color: var(--qlkh-primary); }

.qlkh-empty {
    text-align: center;
    color: var(--qlkh-muted);
    font-style: italic;
    padding: 24px;
}

/* ===== Link ===== */
.qlkh-link {
    color: var(--qlkh-primary);
    text-decoration: none;
    font-weight: 600;
}
.qlkh-link:hover { color: var(--qlkh-primary-dark); text-decoration: underline; }

/* ===== Course grid ===== */
.qlkh-course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
}
.qlkh-course-card {
    display: block;
    background: var(--qlkh-bg-card);
    border: 1px solid var(--qlkh-border-soft);
    border-radius: var(--qlkh-radius);
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: box-shadow 0.15s, transform 0.15s;
    box-shadow: var(--qlkh-shadow);
}
.qlkh-course-card:hover {
    box-shadow: var(--qlkh-shadow-hover);
    transform: translateY(-2px);
}
.qlkh-course-card__cover {
    height: 140px;
    background-size: cover;
    background-position: center;
    background-color: var(--qlkh-bg-accent);
}
.qlkh-course-card__cover--default {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--qlkh-primary);
}
.qlkh-course-card__cover--default svg {
    width: 64px;
    height: 64px;
}
.qlkh-course-card__body { padding: 14px 16px; }
.qlkh-course-card__title {
    margin: 0 0 6px;
    font-size: 16px;
    color: var(--qlkh-text);
    font-weight: 600;
    line-height: 1.3;
}
.qlkh-course-card__meta {
    margin: 0 0 10px;
    color: var(--qlkh-muted);
    font-size: 14px;
}

/* ===== Progress bar ===== */
.qlkh-progress {
    width: 100%;
    height: 6px;
    background: var(--qlkh-bg-accent);
    border-radius: 3px;
    overflow: hidden;
}
.qlkh-progress__bar {
    height: 100%;
    background: var(--qlkh-accent);
    transition: width 0.3s;
}
.qlkh-progress__label {
    margin: 4px 0 0;
    font-size: 12px;
    color: var(--qlkh-muted);
}

/* ===== Course detail header ===== */
.qlkh-course-header {
    background: var(--qlkh-bg-card);
    border: 1px solid var(--qlkh-border-soft);
    border-radius: var(--qlkh-radius);
    overflow: hidden;
    margin-bottom: 24px;
    box-shadow: var(--qlkh-shadow);
}
.qlkh-course-header__cover {
    height: 200px;
    background-size: cover;
    background-position: center;
    background-color: var(--qlkh-bg-accent);
}
.qlkh-course-header__body { padding: 20px 24px; }
.qlkh-course-header__title {
    margin: 0 0 10px;
    font-size: 26px;
    color: var(--qlkh-primary);
    font-weight: 600;
}
.qlkh-course-header__desc {
    color: var(--qlkh-text);
    font-size: 16px;
    line-height: 1.6;
}

/* ===== Lecture list ===== */
.qlkh-lecture-list {
    list-style: none;
    padding: 0;
    margin: 0;
    border: 1px solid var(--qlkh-border-soft);
    border-radius: var(--qlkh-radius);
    overflow: hidden;
    background: var(--qlkh-bg-card);
    box-shadow: var(--qlkh-shadow);
}
.qlkh-lecture-item {
    border-bottom: 1px solid var(--qlkh-border-soft);
}
.qlkh-lecture-item:last-child { border-bottom: none; }
.qlkh-lecture-link {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 18px;
    text-decoration: none;
    color: var(--qlkh-text);
    transition: background 0.12s;
}
.qlkh-lecture-link:hover {
    background: var(--qlkh-bg-accent);
}
.qlkh-lecture-item__num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--qlkh-bg-accent);
    color: var(--qlkh-primary);
    border-radius: 50%;
    font-weight: 700;
    font-size: 14px;
    flex-shrink: 0;
}
.qlkh-lecture-item__title {
    flex: 1;
    font-size: 16px;
    font-weight: 500;
}
.qlkh-lecture-item--viewed .qlkh-lecture-item__num {
    background: var(--qlkh-primary);
    color: #fff;
}

/* ===== Lecture player page ===== */
.qlkh-lecture-title {
    margin: 0 0 16px;
    font-size: 24px;
    color: var(--qlkh-primary);
    font-weight: 600;
}
.qlkh-video-wrap {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    background: #000;
    border-radius: var(--qlkh-radius);
    overflow: hidden;
    margin-bottom: 16px;
    box-shadow: var(--qlkh-shadow);
}
.qlkh-video-wrap iframe,
.qlkh-video-wrap video {
    position: absolute;
    top: 0; left: 0;
    width: 100%;
    height: 100%;
    border: none;
}
.qlkh-video-empty {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    text-align: center;
    color: #fff;
    font-size: 16px;
    padding: 20px;
}
.qlkh-lecture-desc {
    margin-top: 16px;
    line-height: 1.6;
}
.qlkh-lecture-nav {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-top: 20px;
    flex-wrap: wrap;
}

/* ===== Buttons ===== */
.qlkh-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 18px;
    border: 1px solid var(--qlkh-primary);
    border-radius: var(--qlkh-radius-sm);
    background: var(--qlkh-bg-card);
    color: var(--qlkh-primary);
    font-weight: 600;
    text-decoration: none;
    font-size: 16px;
    line-height: 1.4;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    box-sizing: border-box;
}
.qlkh-btn:hover {
    background: var(--qlkh-bg-accent);
    color: var(--qlkh-primary-dark);
}
.qlkh-btn-primary {
    background: var(--qlkh-primary);
    color: #fff;
}
.qlkh-btn-primary:hover {
    background: var(--qlkh-primary-dark);
    color: #fff;
}
.qlkh-btn-accent {
    background: var(--qlkh-accent);
    border-color: var(--qlkh-accent);
    color: #fff;
}
.qlkh-btn-accent:hover {
    background: var(--qlkh-accent-dark);
    border-color: var(--qlkh-accent-dark);
    color: #fff;
}

/* ===== Badges ===== */
.qlkh-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    line-height: 1.4;
    white-space: nowrap;
    vertical-align: middle;
}
.qlkh-badge-ok   { background: #dcedc8; color: #1b5e20; }
.qlkh-badge-mute { background: #f1f3f4; color: #5f5f5f; }

/* ===== Messages (admin flash) ===== */
.qlkh-msg {
    padding: 10px 14px;
    border-radius: 6px;
    margin: 12px 0;
    font-size: 14px;
}
.qlkh-msg-ok  { background: var(--qlkh-bg-accent); color: var(--qlkh-primary); border-left: 4px solid var(--qlkh-primary); }
.qlkh-msg-err { background: #fce4e4; color: var(--qlkh-danger); border-left: 4px solid var(--qlkh-danger); }

/* ===== Mobile ===== */
@media (max-width: 600px) {
    .qlkh-hero {
        padding: 16px;
    }
    .qlkh-hero__name { font-size: 20px; }
    .qlkh-course-header__cover { height: 140px; }
    .qlkh-course-header__title { font-size: 22px; }
    .qlkh-course-header__body { padding: 16px; }
    .qlkh-lecture-link { padding: 12px 14px; gap: 10px; }
    .qlkh-lecture-item__num { width: 28px; height: 28px; font-size: 13px; }
    .qlkh-lecture-item__title { font-size: 14px; }
    .qlkh-lecture-nav { flex-direction: column; }
    .qlkh-lecture-nav .qlkh-btn { width: 100%; }
}