/* ============================================================
   Components — Druid Learning Hub
   Course cards, stat cards, feature cards, chips, tabs, grids.
   ============================================================ */

/* ---- Course Card ---- */
.course-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: box-shadow var(--transition-base), transform var(--transition-base);
    display: flex;
    flex-direction: column;
}
.course-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.course-card__thumb {
    width: 100%;
    height: 160px;
    background: linear-gradient(135deg, var(--color-primary-100), var(--color-primary-200));
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.course-card__thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.course-card__thumb .material-symbols-outlined {
    font-size: 48px;
    color: var(--color-primary);
    opacity: 0.5;
}
.course-card__body {
    padding: var(--space-4);
    flex: 1;
    display: flex;
    flex-direction: column;
}
.course-card__category {
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-2);
}
.course-card__title {
    font-family: var(--font-heading);
    font-size: var(--text-base);
    font-weight: var(--font-semibold);
    color: var(--color-text);
    margin-bottom: var(--space-2);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.course-card__desc {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-3);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex: 1;
}
.course-card__meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
}
.course-card__meta-item {
    display: flex;
    align-items: center;
    gap: 4px;
}
.course-card__meta-item .material-symbols-outlined { font-size: 16px; }
.course-card__footer {
    padding: var(--space-3) var(--space-4);
    border-top: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: var(--text-xs);
}
.course-card__instructor {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--color-text-secondary);
}
.course-card__difficulty {
    font-weight: var(--font-semibold);
}

/* ---- Stat Card ---- */
.stat-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    display: flex;
    align-items: flex-start;
    gap: var(--space-4);
}
.stat-card__icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.stat-card__icon--primary { background: var(--color-primary-light); color: var(--color-primary); }
.stat-card__icon--success { background: var(--color-success-light); color: var(--color-success); }
.stat-card__icon--warning { background: var(--color-warning-light); color: var(--color-warning); }
.stat-card__icon--error { background: var(--color-error-light); color: var(--color-error); }
.stat-card__value {
    font-family: var(--font-heading);
    font-size: var(--text-2xl);
    font-weight: var(--font-bold);
    line-height: 1;
}
.stat-card__label {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-top: var(--space-1);
}

/* ---- Feature Cards ---- */
.feature-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    text-align: center;
    transition: box-shadow var(--transition-base), transform var(--transition-base);
}
.feature-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.feature-card__icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-lg);
    background: var(--color-primary-light);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-4);
}
.feature-card__icon .material-symbols-outlined { font-size: 28px; }
.feature-card__title {
    font-family: var(--font-heading);
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    margin-bottom: var(--space-2);
}
.feature-card__desc {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

/* ---- Challenge Card ---- */
.challenge-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    transition: box-shadow var(--transition-base);
}
.challenge-card:hover { box-shadow: var(--shadow-md); }
.challenge-card__header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}
.challenge-card__icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.challenge-card__icon .material-symbols-outlined { font-size: 22px; }
.challenge-card__title {
    font-weight: var(--font-semibold);
    font-size: var(--text-sm);
}
.challenge-card__desc {
    font-size: var(--text-xs);
    color: var(--color-text-secondary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.challenge-card__footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    margin-top: auto;
}

/* ---- Filter Chips ---- */
.chip-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}
.chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 6px 14px;
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}
.chip:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text);
}
.chip--active {
    background: var(--color-primary);
    color: #FFF;
    border-color: var(--color-primary);
}
.chip--active:hover {
    background: var(--color-primary-hover);
    color: #FFF;
}

/* ---- Tabs ---- */
.tabs {
    display: flex;
    gap: var(--space-1);
    border-bottom: 1px solid var(--color-border);
    overflow-x: auto;
}
.tab {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    border-bottom: 2px solid transparent;
    cursor: pointer;
    transition: color var(--transition-fast), border-color var(--transition-fast);
    white-space: nowrap;
}
.tab:hover { color: var(--color-text); }
.tab--active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

/* ---- Empty State ---- */
.empty-state {
    text-align: center;
    padding: var(--space-12) var(--space-4);
    color: var(--color-text-secondary);
}
.empty-state .material-symbols-outlined {
    font-size: 48px;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-4);
}
.empty-state__title {
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    color: var(--color-text);
    margin-bottom: var(--space-2);
}
.empty-state__desc {
    font-size: var(--text-sm);
    max-width: 400px;
    margin: 0 auto;
}

/* ---- Grid Layouts ---- */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-6); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-6); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-6); }

@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 768px) {
    .grid-2 { grid-template-columns: 1fr; }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
    .grid-3 { grid-template-columns: 1fr; }
    .grid-4 { grid-template-columns: 1fr; }
}

/* ---- Module Accordion ---- */
.module-accordion {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: var(--space-3);
}
.module-accordion__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4);
    cursor: pointer;
    background: var(--color-bg-secondary);
    transition: background var(--transition-fast);
}
.module-accordion__header:hover { background: var(--color-bg-tertiary); }
.module-accordion__title {
    font-weight: var(--font-semibold);
    font-size: var(--text-sm);
}
.module-accordion__count {
    font-size: var(--text-xs);
    color: var(--color-text-secondary);
}
.module-accordion__body {
    border-top: 1px solid var(--color-border);
}
.module-accordion__lesson {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    color: var(--color-text);
    transition: background var(--transition-fast);
    border-bottom: 1px solid var(--color-border);
}
.module-accordion__lesson:last-child { border-bottom: none; }
.module-accordion__lesson:hover { background: var(--color-bg-secondary); }
.module-accordion__lesson .material-symbols-outlined { font-size: 18px; color: var(--color-text-secondary); }
.module-accordion__lesson--completed .material-symbols-outlined { color: var(--color-success); }