/* =====================================================
   COURSE DETAIL PAGE - aicode.ptit.edu.vn Edition
   ===================================================== */

/* ── Layout ─────────────────────────────────────────── */
.detail-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 360px;
    gap: 36px;
    padding: 36px 0 80px;
    align-items: start;
    width: 100%;
    box-sizing: border-box;
}

.detail-main {
    min-width: 0;
    width: 100%;
    box-sizing: border-box;
}

/* ── Hero Banner ─────────────────────────────────────── */
.detail-hero {
    background: linear-gradient(135deg, #181810 0%, #be123c 50%, #f97316 100%);
    border: 2.5px solid var(--border-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-solid-lg);
    padding: 48px;
    color: #fff;
    position: relative;
    overflow: hidden;
    margin-bottom: 32px;
}

.detail-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.06) 1px, transparent 1px);
    background-size: 32px 32px;
    pointer-events: none;
}

.detail-hero-title {
    font-family: var(--font-brand);
    font-size: 32px;
    font-weight: 900;
    margin-bottom: 14px;
    line-height: 1.25;
    letter-spacing: -0.4px;
    position: relative;
    z-index: 1;
}

.detail-hero-meta {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 18px;
    position: relative;
    z-index: 1;
}

.detail-hero-meta span {
    font-size: 13px;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 5px;
    background: rgba(24, 24, 16, 0.6);
    padding: 5px 14px;
    border-radius: var(--radius-full);
    border: 1.5px solid rgba(255, 255, 255, 0.4);
    box-shadow: 2px 2px 0px #000;
}

.detail-hero-desc {
    font-size: 15.5px;
    opacity: 0.95;
    line-height: 1.7;
    max-width: 620px;
    position: relative;
    z-index: 1;
}

/* ── Tabs ─────────────────────────────────────────────── */
.detail-tabs {
    display: flex;
    gap: 8px;
    background: var(--surface-primary);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-solid-sm);
    padding: 6px;
    margin-bottom: 28px;
}

.detail-tab-btn {
    flex: 1;
    padding: 10px 18px;
    border: 2px solid transparent;
    border-radius: var(--radius-sm);
    background: transparent;
    font-family: var(--font);
    font-size: 14px;
    font-weight: 700;
    color: var(--text-label-2);
    cursor: pointer;
    transition: all var(--transition);
    text-align: center;
}

.detail-tab-btn:hover {
    color: var(--brand-primary);
    background: var(--surface-secondary);
}

.detail-tab-btn.active {
    background: var(--brand-primary);
    color: #ffffff;
    border-color: var(--border-primary);
    box-shadow: 2px 2px 0px var(--border-primary);
}

/* ── Sidebar Sticky Card ─────────────────────────────── */
.detail-sidebar-card {
    background: var(--surface-primary);
    border: 2.5px solid var(--border-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-solid);
    padding: 24px;
    position: sticky;
    top: calc(var(--header-h) + 20px);
}

.detail-sidebar-card .btn-enroll {
    width: 100%;
    padding: 12px;
    font-size: 15px;
    font-weight: 800;
    margin-top: 16px;
}

/* ── Chapter / Curriculum Accordion ───────────────────── */
.chapter-accordion-item {
    background: var(--surface-primary);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-solid);
    margin-bottom: 16px;
    overflow: hidden;
    transition: all var(--transition);
}

.chapter-accordion-header {
    padding: 18px 22px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    background: var(--surface-primary);
    transition: background var(--transition);
}

.chapter-accordion-header:hover {
    background: var(--surface-secondary);
}

.chapter-title {
    font-family: var(--font-brand);
    font-size: 16px;
    font-weight: 800;
    color: var(--text-label-1);
}

.chapter-content-box {
    padding: 20px 24px;
    border-top: 2px solid var(--border-primary);
    background: var(--surface-secondary);
}

/* ── Sidebar Session Cards ───────────────────────────── */
.session-card {
    background: #ffffff;
    border: 2px solid var(--border-primary);
    box-shadow: 2.5px 2.5px 0px var(--border-primary);
    border-radius: 8px;
    padding: 12px 14px;
    margin-bottom: 10px;
    cursor: pointer;
    text-decoration: none;
    display: block;
    transition: all 0.15s ease;
}

.session-card:hover {
    transform: translate(-1px, -1px);
    box-shadow: 3.5px 3.5px 0px var(--border-primary);
    background: #f8fafc;
}

.session-chapter-tag {
    font-size: 10.5px;
    font-weight: 900;
    letter-spacing: 0.5px;
    color: #ea580c;
    text-transform: uppercase;
}

.session-status-badge {
    font-size: 11px;
    font-weight: 800;
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid var(--border-primary);
    display: inline-block;
    line-height: 1.2;
}

.session-status-badge.completed {
    background: #dcfce7;
    color: #15803d;
    border-color: #86efac;
}

.session-status-badge.in-progress {
    background: #fff7ed;
    color: #c2410c;
    border-color: #fed7aa;
}

.session-title {
    font-family: var(--font);
    font-size: 13.5px;
    font-weight: 800;
    color: #181810;
    line-height: 1.4;
}