/* ============================================
   Kỹ năng mềm Page Styles
   ============================================ */

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0 5rem;
    position: relative;
    overflow: hidden;
}

.hero-pattern {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    opacity: 0.5;
}

.hero-section .display-4 {
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-section .btn-light {
    background-color: rgba(255, 255, 255, 0.95);
    border: none;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.hero-section .btn-light:hover {
    background-color: white;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* Sticky Sidebar */
.sticky-sidebar {
    position: sticky;
    top: 100px;
    max-height: calc(100vh - 120px);
    overflow-y: auto;
    padding: 1.5rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.sticky-sidebar::-webkit-scrollbar {
    width: 6px;
}

.sticky-sidebar::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

.sticky-sidebar::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 10px;
}

.sticky-sidebar::-webkit-scrollbar-thumb:hover {
    background: #555;
}

/* Navigation Pills */
.nav-pills .nav-link {
    color: #495057;
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.95rem;
}

.nav-pills .nav-link:hover {
    background-color: #f8f9fa;
    color: #667eea;
    transform: translateX(5px);
}

.nav-pills .nav-link.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

/* Group Header */
.group-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 3px solid #f0f0f0;
}

.topic-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    flex-shrink: 0;
}

.group-header h2 {
    margin: 0;
    font-weight: 700;
}

/* Topic Cards */
.topic-card {
    background: white;
    border: 1px solid #e9ecef;
    border-radius: 12px;
    transition: all 0.3s ease;
    height: 100%;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.topic-card:hover {
    border-color: #667eea;
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.15);
    transform: translateY(-5px);
}

.topic-card h3 {
    font-size: 1.1rem;
}

.topic-card a {
    transition: color 0.3s ease;
}

.topic-card:hover a {
    color: #667eea !important;
}

/* Metric Badge */
.metric-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.35rem 0.75rem;
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    color: #495057;
}

.metric-badge.text-success {
    background: #d4edda;
    border-color: #c3e6cb;
    color: #155724;
}

/* Scroll Margin for Anchor Links */
.scroll-margin-top {
    scroll-margin-top: 100px;
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Card Styling */
.card {
    border-radius: 12px;
}

/* Accordion Styling */
.accordion-item {
    border: 1px solid #e9ecef;
    margin-bottom: 1rem;
    border-radius: 8px !important;
    overflow: hidden;
}

.accordion-button {
    font-weight: 600;
    background-color: #f8f9fa;
}

.accordion-button:not(.collapsed) {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.accordion-button:focus {
    box-shadow: none;
    border-color: #667eea;
}

/* Responsive Adjustments */
@media (max-width: 991.98px) {
    .hero-section {
        padding: 3rem 0;
    }

    .hero-section .display-4 {
        font-size: 2rem;
    }

    .group-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .topic-icon {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }
}

@media (max-width: 767.98px) {
    .hero-section .display-4 {
        font-size: 1.75rem;
    }

    .hero-section .lead {
        font-size: 1rem;
    }

    .metric-badge {
        font-size: 0.7rem;
        padding: 0.25rem 0.5rem;
    }
}

/* Animation for cards on scroll */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.topic-card {
    animation: fadeInUp 0.6s ease-out;
}

/* Breadcrumb styling */
.breadcrumb {
    background-color: transparent;
    padding: 0;
    margin-bottom: 1.5rem;
}

.breadcrumb-item + .breadcrumb-item::before {
    content: "›";
    font-size: 1.2rem;
}

.breadcrumb-item a {
    color: #667eea;
    text-decoration: none;
}

.breadcrumb-item a:hover {
    text-decoration: underline;
}

/* Z-index utilities */
.z-1 {
    z-index: 1;
}

/* Print Styles */
@media print {
    .hero-section,
    .sticky-sidebar,
    .breadcrumb {
        display: none;
    }
    
    .topic-card {
        break-inside: avoid;
        page-break-inside: avoid;
    }
}