/* ═══════════════════════════════════════════════════════════
   Components - Buttons, Cards, Forms, Badges, etc.
   ═══════════════════════════════════════════════════════════ */

/* ─── Buttons ──────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: var(--text-sm);
    cursor: pointer;
    transition: var(--transition-normal);
    border: 2px solid transparent;
    text-decoration: none;
    line-height: 1.4;
}
.btn:active { transform: scale(0.98); }
.btn svg { width: 16px; height: 16px; }

.btn-primary {
    background: var(--brand-secondary);
    color: white;
    box-shadow: 0 2px 4px rgba(0, 194, 168, 0.3);
}
.btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 194, 168, 0.4);
    color: white;
}

.btn-secondary {
    background: var(--bg-primary);
    color: var(--gray-700);
    border-color: var(--gray-300);
}
.btn-secondary:hover {
    border-color: var(--gray-400);
    background: var(--gray-50);
}

.btn-danger {
    background: var(--danger);
    color: white;
}
.btn-danger:hover {
    background: var(--danger-dark);
    color: white;
}

.btn-ghost {
    background: transparent;
    color: var(--gray-600);
}
.btn-ghost:hover {
    background: var(--gray-100);
    color: var(--gray-800);
}

.btn-outline {
    background: transparent;
    color: var(--gray-700);
    border: 2px solid var(--gray-300);
}
.btn-outline:hover {
    border-color: var(--gray-400);
    background: var(--gray-50);
}

.btn-sm { padding: 6px 12px; font-size: var(--text-xs); }
.btn-lg { padding: 14px 28px; font-size: var(--text-base); }
.btn-icon { padding: 8px; }
.btn-block { width: 100%; }

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* ─── Cards ────────────────────────────────────────────── */
.card {
    background: var(--bg-primary);
    border-radius: var(--card-radius, var(--radius-lg));
    box-shadow: var(--shadow-sm);
    padding: var(--space-6);
    border: 1px solid var(--gray-200);
    transition: var(--transition-normal);
}
.card:hover {
    box-shadow: var(--shadow-md);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-4);
}
.card-title {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--gray-800);
}
.card-body {
    color: var(--gray-600);
    font-size: var(--text-sm);
}
.card-footer {
    margin-top: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid var(--gray-200);
}

/* ─── Forms ────────────────────────────────────────────── */
.form-group {
    margin-bottom: var(--space-4);
}

.form-label {
    display: block;
    font-weight: 500;
    font-size: var(--text-sm);
    color: var(--gray-700);
    margin-bottom: var(--space-1);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    font-size: var(--text-sm);
    font-family: var(--font-primary);
    transition: var(--transition-fast);
    background: var(--bg-primary);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--brand-secondary);
    box-shadow: 0 0 0 3px rgba(0, 194, 168, 0.1);
}

.form-input.error,
.form-select.error {
    border-color: var(--danger);
}

.form-hint {
    font-size: var(--text-xs);
    color: var(--gray-500);
    margin-top: var(--space-1);
}

.form-error {
    font-size: var(--text-xs);
    color: var(--danger);
    margin-top: var(--space-1);
}

.form-checkbox {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    cursor: pointer;
}
.form-checkbox input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--brand-secondary);
}

/* ─── Badges ───────────────────────────────────────────── */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.025em;
}
.badge-success { background: var(--success-light); color: var(--success-dark); }
.badge-warning { background: var(--warning-light); color: var(--warning-dark); }
.badge-danger { background: var(--danger-light); color: var(--danger-dark); }
.badge-info { background: var(--info-light); color: var(--info-dark); }
.badge-neutral { background: var(--gray-100); color: var(--gray-600); }
.badge-primary { background: rgba(0,194,168,0.1); color: var(--brand-secondary); }

.notification-badge {
    position: absolute;
    top: -4px;
    right: -4px;
    min-width: 18px;
    height: 18px;
    padding: 0 5px;
    border-radius: 9px;
    background: var(--danger);
    color: white;
    font-size: 11px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

/* ─── Tags ─────────────────────────────────────────────── */
.tag {
    display: inline-flex;
    align-items: center;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: var(--text-xs);
    font-weight: 500;
    background: var(--gray-100);
    color: var(--gray-700);
    border: 1px solid var(--gray-200);
}

.filter-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 500;
    background: var(--gray-100);
    color: var(--gray-600);
    border: 1px solid var(--gray-200);
    cursor: pointer;
    transition: var(--transition-fast);
    text-decoration: none;
}
.filter-tag:hover {
    border-color: var(--brand-secondary);
    color: var(--brand-secondary);
}
.filter-tag.active {
    background: rgba(0,194,168,0.1);
    border-color: var(--brand-secondary);
    color: var(--brand-secondary);
}

/* ─── Progress Bar ─────────────────────────────────────── */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}
.progress-fill {
    height: 100%;
    border-radius: var(--radius-full);
    background: var(--brand-gradient);
    transition: width 0.5s ease;
}
.progress-fill.success { background: var(--success); }
.progress-fill.warning { background: var(--warning); }
.progress-fill.danger { background: var(--danger); }
.progress-bar.lg { height: 12px; }
.progress-bar.sm { height: 4px; }

/* ─── Alerts ───────────────────────────────────────────── */
.alert {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
    padding: var(--space-4);
    border-radius: var(--radius-lg);
    border-left: 4px solid;
    margin-bottom: var(--space-4);
}
.alert-success { background: var(--success-light); border-color: var(--success); color: var(--success-dark); }
.alert-warning { background: var(--warning-light); border-color: var(--warning); color: var(--warning-dark); }
.alert-danger { background: var(--danger-light); border-color: var(--danger); color: var(--danger-dark); }
.alert-info { background: var(--info-light); border-color: var(--info); color: var(--info-dark); }
.alert-icon { font-size: var(--text-xl); flex-shrink: 0; }
.alert-content { flex: 1; }
.alert-title { font-weight: 600; margin-bottom: 4px; }
.alert-message { font-size: var(--text-sm); }
.alert-close {
    background: none; border: none; cursor: pointer;
    font-size: var(--text-lg); opacity: 0.5; padding: 0;
}
.alert-close:hover { opacity: 1; }

/* ─── Tables ───────────────────────────────────────────── */
.table-wrapper {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-200);
}
.table {
    width: 100%;
    border-collapse: collapse;
}
.table th {
    text-align: left;
    padding: var(--space-3) var(--space-4);
    font-weight: 600;
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-500);
    background: var(--gray-50);
    border-bottom: 2px solid var(--gray-200);
}
.table td {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    color: var(--gray-700);
    border-bottom: 1px solid var(--gray-100);
}
.table tbody tr:hover { background: var(--gray-50); }

/* ─── Avatar ───────────────────────────────────────────── */
.avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    object-fit: cover;
    background: var(--gray-200);
}
.avatar-sm { width: 32px; height: 32px; }
.avatar-lg { width: 56px; height: 56px; }
.avatar-xl { width: 80px; height: 80px; }

/* ─── Modal ────────────────────────────────────────────── */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
}
.modal-overlay.active { opacity: 1; visibility: visible; }
.modal {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.95);
    transition: var(--transition-normal);
}
.modal-overlay.active .modal { transform: scale(1); }
.modal-content {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.95);
    transition: var(--transition-normal);
}
.modal-overlay.active .modal-content { transform: scale(1); }
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-4) var(--space-6);
    border-bottom: 1px solid var(--gray-200);
}
.modal-title { font-size: var(--text-lg); font-weight: 600; }
.modal-close { cursor: pointer; color: var(--gray-400); }
.modal-close:hover { color: var(--gray-700); }
.modal-body { padding: var(--space-6); }
.modal-footer {
    display: flex; justify-content: flex-end; gap: var(--space-3);
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid var(--gray-200);
}

/* ─── Toast ────────────────────────────────────────────── */
.toast-container {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}
.toast {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid;
    min-width: 300px;
    animation: slideUp 0.3s ease;
}
.toast-success { border-color: var(--success); }
.toast-error { border-color: var(--danger); }
.toast-warning { border-color: var(--warning); }
.toast-info { border-color: var(--info); }

/* ─── Pagination ───────────────────────────────────────── */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    margin-top: var(--space-6);
}
.page-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--gray-600);
    background: var(--bg-primary);
    border: 1px solid var(--gray-200);
    transition: var(--transition-fast);
    text-decoration: none;
}
.page-btn:hover { border-color: var(--brand-secondary); color: var(--brand-secondary); }
.page-btn.active {
    background: var(--brand-secondary);
    color: white;
    border-color: var(--brand-secondary);
}

/* ─── Dropdown ─────────────────────────────────────────── */
.dropdown {
    position: relative;
    display: inline-block;
}
.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    min-width: 200px;
    background: var(--bg-primary);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    padding: var(--space-2);
    display: none;
}
.dropdown-menu.show { display: block; }
.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-sm);
    font-size: var(--text-sm);
    color: var(--gray-700);
    text-decoration: none;
    transition: var(--transition-fast);
}
.dropdown-item:hover {
    background: var(--gray-100);
    color: var(--gray-900);
}

/* ─── Empty State ──────────────────────────────────────── */
.empty-state {
    text-align: center;
    padding: var(--space-16) var(--space-8);
}
.empty-state-icon { font-size: 64px; margin-bottom: var(--space-4); }
.empty-state-title { font-size: var(--text-xl); font-weight: 600; color: var(--gray-700); margin-bottom: var(--space-2); }
.empty-state-message { color: var(--gray-500); margin-bottom: var(--space-6); }

/* ─── Breadcrumb ───────────────────────────────────────── */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-sm);
    color: var(--gray-500);
    margin-bottom: var(--space-6);
}
.breadcrumb a { color: var(--gray-500); }
.breadcrumb a:hover { color: var(--brand-secondary); }
.breadcrumb .current { color: var(--gray-700); font-weight: 500; }
.breadcrumb .separator { color: var(--gray-300); }

/* ─── Loading ──────────────────────────────────────────── */
.spinner,
.loading-spinner {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 3px solid var(--gray-200);
    border-top-color: var(--brand-secondary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.loading-spinner.sm,
.spinner.sm { width: 16px; height: 16px; border-width: 2px; }
.loading-spinner.lg,
.spinner.lg { width: 40px; height: 40px; border-width: 4px; }
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ─── Keyframe Animations ──────────────────────────────── */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes scaleIn { from { opacity: 0; transform: scale(0.95); } to { opacity: 1; transform: scale(1); } }
@keyframes pulse { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.05); } }
@keyframes shake { 0%, 100% { transform: translateX(0); } 25%, 75% { transform: translateX(-5px); } 50% { transform: translateX(5px); } }

/* ─── UTILITY CLASSES ─────────────────────────────────── */
.skip-link {
    position: absolute;
    top: -100%;
    left: 16px;
    padding: 8px 16px;
    background: var(--brand-secondary);
    color: white;
    border-radius: var(--radius-md);
    font-weight: 600;
    z-index: 10000;
    transition: top 0.2s;
}
.skip-link:focus {
    top: 16px;
}

.mt-sm { margin-top: 8px; }
.mt-md { margin-top: 16px; }
.mt-lg { margin-top: 24px; }
.mb-sm { margin-bottom: 8px; }
.mb-md { margin-bottom: 16px; }
.mb-lg { margin-bottom: 24px; }
.text-center { text-align: center; }
.text-sm { font-size: var(--text-sm); }
.text-xs { font-size: var(--text-xs); }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }
.w-full { width: 100%; }
.gap-sm { gap: 8px; }
.gap-md { gap: 16px; }
.gap-lg { gap: 24px; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-col { flex-direction: column; }
.flex-1 { flex: 1; }
.flex-wrap { flex-wrap: wrap; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }
.p-sm { padding: 8px; }
.p-md { padding: 16px; }
.p-lg { padding: 24px; }
.p-xl { padding: 32px; }
.gap-4 { gap: 4px; }
.gap-20 { gap: 20px; }
.no-underline { text-decoration: none; }
.rounded-full { border-radius: 50%; }
.font-semibold { font-weight: 600; }

.grid-courses {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.project-thumb {
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
}

.grid-tracks {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 24px;
}

.track-pill {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--color-primary);
    color: white;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
}

.track-hero {
    padding: 32px;
    background: linear-gradient(135deg, var(--color-deep-navy) 0%, var(--color-deep-navy-dark) 100%);
    color: white;
    text-align: center;
}

.track-hero-icon {
    font-size: 48px;
    margin-bottom: 12px;
}

.track-hero-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 4px;
}

.track-hero-meta {
    font-size: 13px;
    opacity: 0.7;
}

.badge-primary {
    display: inline-block;
    padding: 6px 12px;
    background: rgba(0, 194, 168, 0.1);
    border-radius: 6px;
    font-size: 13px;
    color: var(--color-primary);
    font-weight: 600;
}

.detail-hero-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 48px;
    align-items: start;
}

.detail-sidebar {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 24px;
    color: var(--text-primary);
}

.project-tech-badge {
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
}

.chapter-number {
    width: 40px;
    height: 40px;
    background: var(--color-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.track-enrolled-banner {
    padding: 16px 20px;
    background: rgba(0, 194, 168, 0.05);
    border: 1px solid var(--color-primary);
    border-radius: var(--radius-md);
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.track-course-row {
    display: flex;
    overflow: hidden;
}

.track-course-thumb {
    width: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    flex-shrink: 0;
}