/* =================================================================
   COURSES — Education Phase 2
   Namespace: .crs-*
   Three sub-views: list, detail, lesson
   ================================================================= */

.crs-wrapper {
    margin-left: 20px;
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    color: #fff;
    font-family: 'Inter', sans-serif;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

.crs-glass {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(24px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

/* HEADER */
.crs-header { display: flex; justify-content: space-between; align-items: center; padding: 24px 32px; flex-wrap: wrap; gap: 16px; }
.crs-title { margin: 0; font-size: 28px; font-weight: 800; letter-spacing: 1px; background: linear-gradient(135deg, #fff, #c084fc); -webkit-background-clip: text; -webkit-text-fill-color: transparent; text-transform: uppercase; }
.crs-subtitle { margin: 4px 0 0; color: #a1a1aa; font-size: 14px; }
.crs-stat-chip { display: flex; align-items: center; gap: 8px; background: rgba(0, 0, 0, 0.3); padding: 8px 16px; border-radius: 12px; font-size: 13px; font-weight: 600; border: 1px solid rgba(255, 255, 255, 0.05); }
.crs-stat-chip i { color: #06b6d4; }

/* CONTROLS */
.crs-controls { display: flex; flex-wrap: wrap; gap: 16px; padding: 16px 24px; align-items: center; justify-content: space-between; }
.crs-filters { display: flex; gap: 12px; flex-wrap: wrap; }
.crs-select { background: rgba(0, 0, 0, 0.4); border: 1px solid rgba(255, 255, 255, 0.1); color: #e4e4e7; padding: 10px 16px; border-radius: 12px; outline: none; font-family: 'Inter'; font-size: 13px; cursor: pointer; }
.crs-select:focus { border-color: #c084fc; }

/* COURSES GRID (LIST VIEW) */
.crs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.crs-card {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.04), rgba(0, 0, 0, 0.3));
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 16px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
}

.crs-card:hover {
    transform: translateY(-4px);
    border-color: #c084fc;
    box-shadow: 0 20px 40px rgba(168, 85, 247, 0.2);
}

.crs-card-cover {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    display: block;
    background: rgba(0, 0, 0, 0.4);
}

.crs-card-body { padding: 16px 20px 20px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.crs-card-tier { display: flex; gap: 8px; align-items: center; font-size: 11px; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; color: #a1a1aa; }
.crs-card-tier .crs-badge-free { color: #4ade80; }
.crs-card-tier .crs-badge-prem { color: #facc15; }
.crs-card-title { margin: 4px 0 0; font-size: 18px; font-weight: 800; color: #fff; line-height: 1.3; }
.crs-card-sub { margin: 0; font-size: 13px; color: #a1a1aa; line-height: 1.5; flex: 1; }
.crs-card-meta { display: flex; justify-content: space-between; align-items: center; margin-top: 12px; padding-top: 12px; border-top: 1px solid rgba(255, 255, 255, 0.05); font-size: 12px; color: #a1a1aa; }
.crs-card-rating { color: #facc15; font-weight: 700; }
.crs-card-rating i { margin-right: 4px; }

/* DETAIL VIEW */
.crs-back-btn {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: #a1a1aa;
    padding: 8px 16px;
    border-radius: 12px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s;
    align-self: flex-start;
}
.crs-back-btn:hover { background: rgba(255, 255, 255, 0.05); color: #fff; border-color: #c084fc; }

.crs-detail-hero { padding: 32px; display: grid; grid-template-columns: minmax(0, 280px) 1fr; gap: 32px; align-items: center; }
.crs-detail-cover { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; border-radius: 12px; }
.crs-detail-info h2 { margin: 0; font-size: 32px; font-weight: 900; color: #fff; line-height: 1.1; letter-spacing: -0.5px; }
.crs-detail-info h2 span { background: linear-gradient(to right, #ffffff, #c084fc); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.crs-detail-info p { color: #a1a1aa; line-height: 1.6; margin-top: 12px; }
.crs-detail-stats { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 16px; }
.crs-detail-stats .crs-stat-chip { font-size: 12px; }

@media (max-width: 768px) {
    .crs-detail-hero { grid-template-columns: 1fr; }
}

/* LESSON LIST */
.crs-lesson-list { padding: 16px 32px 32px; display: flex; flex-direction: column; gap: 8px; }
.crs-lesson-row {
    display: grid;
    grid-template-columns: 36px 1fr auto auto;
    gap: 16px;
    align-items: center;
    padding: 16px 20px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.04);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
}
.crs-lesson-row:hover { background: rgba(192, 132, 252, 0.05); border-color: #c084fc; }
.crs-lesson-row.crs-locked { opacity: 0.55; cursor: not-allowed; }
.crs-lesson-row.crs-completed { border-color: rgba(74, 222, 128, 0.4); }

.crs-lesson-num { width: 36px; height: 36px; border-radius: 50%; background: rgba(192, 132, 252, 0.15); color: #c084fc; display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 14px; }
.crs-lesson-row.crs-completed .crs-lesson-num { background: rgba(74, 222, 128, 0.15); color: #4ade80; }
.crs-lesson-info h4 { margin: 0; color: #fff; font-size: 15px; font-weight: 700; }
.crs-lesson-info p { margin: 4px 0 0; color: #a1a1aa; font-size: 12px; line-height: 1.5; }
.crs-lesson-meta { font-size: 11px; color: #71717a; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; white-space: nowrap; }
.crs-lesson-status i { font-size: 18px; color: #71717a; }
.crs-lesson-row.crs-completed .crs-lesson-status i { color: #4ade80; }

/* LESSON VIEW (Player) */
.crs-lesson-shell { display: grid; grid-template-columns: minmax(0, 1fr) minmax(280px, 360px); gap: 24px; }
@media (max-width: 1024px) { .crs-lesson-shell { grid-template-columns: 1fr; } }

.crs-player-wrap { background: #000; border-radius: 16px; overflow: hidden; aspect-ratio: 16 / 9; position: relative; }
.crs-player-wrap iframe { width: 100%; height: 100%; border: 0; }
.crs-player-empty { display: flex; align-items: center; justify-content: center; width: 100%; height: 100%; color: #71717a; font-size: 14px; gap: 8px; }

.crs-lesson-content { padding: 24px 28px; }
.crs-lesson-content h1 { margin: 0; font-size: 26px; font-weight: 900; color: #fff; }
.crs-lesson-content h2 { font-size: 20px; color: #c084fc; margin-top: 24px; margin-bottom: 12px; }
.crs-lesson-content h3 { font-size: 16px; color: #c084fc; margin-top: 20px; margin-bottom: 8px; }
.crs-lesson-content p { line-height: 1.7; color: #d4d4d8; margin: 12px 0; }
.crs-lesson-content ul, .crs-lesson-content ol { line-height: 1.7; color: #d4d4d8; padding-left: 22px; }
.crs-lesson-content code { background: rgba(0, 0, 0, 0.4); padding: 2px 6px; border-radius: 4px; color: #6ee7b7; font-family: 'JetBrains Mono', monospace; font-size: 13px; }
.crs-lesson-content pre { background: rgba(0, 0, 0, 0.4); padding: 16px; border-radius: 12px; overflow-x: auto; border: 1px solid rgba(255, 255, 255, 0.05); }
.crs-lesson-content pre code { background: transparent; padding: 0; }
.crs-lesson-content strong { color: #fff; }

/* LESSON SIDE: Quiz panel */
.crs-side-panel { padding: 20px 24px; display: flex; flex-direction: column; gap: 16px; }
.crs-side-panel h3 { margin: 0; font-size: 14px; font-weight: 700; color: #fff; text-transform: uppercase; letter-spacing: 1.2px; }
.crs-progress-bar { background: rgba(0, 0, 0, 0.3); height: 8px; border-radius: 4px; overflow: hidden; }
.crs-progress-fill { height: 100%; background: linear-gradient(90deg, #06b6d4, #c084fc); transition: width 0.4s; }
.crs-quiz-question { padding: 14px; background: rgba(0, 0, 0, 0.25); border-radius: 12px; border: 1px solid rgba(255, 255, 255, 0.04); }
.crs-quiz-question h4 { margin: 0 0 12px; font-size: 14px; color: #fff; line-height: 1.5; }
.crs-quiz-choices { display: flex; flex-direction: column; gap: 8px; }
.crs-quiz-choice { display: flex; gap: 10px; padding: 10px 12px; background: rgba(255, 255, 255, 0.02); border: 1px solid rgba(255, 255, 255, 0.06); border-radius: 8px; cursor: pointer; transition: all 0.2s; font-size: 13px; color: #e4e4e7; }
.crs-quiz-choice:hover { background: rgba(192, 132, 252, 0.08); border-color: #c084fc; }
.crs-quiz-choice.crs-selected { background: rgba(192, 132, 252, 0.18); border-color: #c084fc; }
.crs-quiz-choice.crs-correct { background: rgba(74, 222, 128, 0.15); border-color: #4ade80; color: #d1fae5; }
.crs-quiz-choice.crs-wrong { background: rgba(239, 83, 80, 0.15); border-color: #ef5350; color: #fecaca; }
.crs-quiz-choice input { accent-color: #c084fc; }
.crs-quiz-explain { font-size: 12px; color: #a1a1aa; padding: 8px 10px; margin-top: 8px; border-left: 2px solid #c084fc; line-height: 1.5; }

.crs-btn { padding: 12px 18px; border-radius: 12px; cursor: pointer; font-size: 13px; font-weight: 700; letter-spacing: 0.5px; border: 1px solid rgba(255, 255, 255, 0.1); display: inline-flex; align-items: center; gap: 8px; transition: all 0.2s; }
.crs-btn-primary { background: linear-gradient(135deg, #7e22ce, #a855f7); color: #fff; border-color: rgba(255, 255, 255, 0.15); }
.crs-btn-primary:hover { background: linear-gradient(135deg, #9333ea, #c084fc); transform: translateY(-1px); }
.crs-btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }
.crs-btn-ghost { background: transparent; color: #d4d4d8; }
.crs-btn-ghost:hover { background: rgba(255, 255, 255, 0.04); }

.crs-quiz-result { padding: 14px 16px; border-radius: 12px; font-size: 13px; font-weight: 700; line-height: 1.5; }
.crs-quiz-result.crs-passed { background: rgba(74, 222, 128, 0.12); color: #d1fae5; border: 1px solid rgba(74, 222, 128, 0.3); }
.crs-quiz-result.crs-failed { background: rgba(239, 83, 80, 0.12); color: #fecaca; border: 1px solid rgba(239, 83, 80, 0.3); }

/* EMPTY / LOADING STATES */
.crs-empty {
    padding: 60px 32px;
    text-align: center;
    color: #71717a;
    font-size: 14px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 16px;
    border: 1px dashed rgba(255, 255, 255, 0.08);
}
.crs-empty i { font-size: 36px; margin-bottom: 12px; display: block; opacity: 0.4; }
.crs-empty h3 { margin: 8px 0; color: #d4d4d8; font-size: 16px; }

/* Hide views by default — JS toggles which one is shown */
.crs-view { display: none; }
.crs-view.crs-active { display: block; }

/* Lock badge */
.crs-lock-badge { background: rgba(250, 204, 21, 0.15); color: #facc15; padding: 2px 8px; border-radius: 4px; font-size: 10px; letter-spacing: 1px; font-weight: 800; }