/* ============================================
   KnowledgeBase - Bootstrap 5 Custom Stylesheet
   ============================================ */

/* --- Root Variables --- */
:root {
    --color-primary: #4A90D9;
    --color-primary-dark: #3A7BC8;
    --color-accent: #7B68EE;
    --color-accent-light: #9B88EE;
    --color-secondary: #26C6DA;
    --color-bg: #f4f6f9;
    --color-surface: #ffffff;
    --color-text: #2c3e50;
    --color-text-light: #6b7c93;
    --color-text-muted: #a0aec0;
    --color-border: #e2e8f0;
    --color-shadow: rgba(0, 0, 0, 0.08);
    --color-tag-bg: #edf2f7;
    --color-tag-text: #4a5568;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --shadow-card: 0 2px 12px var(--color-shadow);
    --shadow-hover: 0 6px 24px rgba(0, 0, 0, 0.12);
    --transition: 0.3s ease;
    --max-width: 1200px;
}

/* --- General Styling --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', 'Kanit', sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.site-main {
    flex: 1;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--color-primary-dark);
}

/* --- Navbar --- */
.navbar {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.navbar-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text) !important;
    letter-spacing: -0.5px;
}

.navbar-brand:hover {
    color: var(--color-primary) !important;
}

.nav-link {
    color: var(--color-text) !important;
    font-weight: 500;
    margin: 0 8px;
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary) !important;
}

/* --- Hero Section --- */
.hero-section {
    position: relative;
    text-align: center;
    color: white;
    overflow: hidden;
}

.hero-section-fluid {
    position: relative;
    text-align: center;
    color: white;
    overflow: hidden;
    width: 100vw;
    margin-left: calc(-50vw + 50%);
}

.hero-section::before,
.hero-section-fluid::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0; 
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    animation: fadeInDown 0.8s ease-out;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-section h1 {
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 1rem;
}

.hero-section .lead {
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
}

.search-box-hero {
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.search-box-hero .input-group {
    border-radius: 8px;
}

.search-box-hero .form-control {
    padding: 12px 16px;
    font-size: 1rem;
    border-radius: 8px 0 0 8px;
}

.search-box-hero .btn {
    padding: 12px 24px;
    font-weight: 600;
    border-radius: 0 8px 8px 0;
}

/* --- Section Header --- */
.section-header {
    margin-bottom: 3rem;
}

.section-header h2 {
    color: var(--color-text);
    font-weight: 700;
    letter-spacing: -0.5px;
}

.section-header .badge {
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
}

/* --- Article Cards --- */
.article-card {
    height: 100%;
    border: none;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    display: flex;
    flex-direction: column;
}

.card-img-top-wrapper {
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.card-body {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-title {
    line-height: 1.4;
    min-height: auto;
}

.card-title a {
    color: var(--color-text);
    text-decoration: none;
}

.card-title a:hover {
    color: var(--color-primary);
}

.card-text {
    flex-grow: 1;
    font-size: 0.95rem;
    line-height: 1.6;
}

.card-footer {
    background-color: #f9f9f9;
    padding: 1.25rem;
    border-top: 1px solid var(--color-border);
}

.card-footer .btn {
    font-weight: 600;
    padding: 0.5rem 1rem;
    transition: var(--transition);
}

.card-footer .btn:hover {
    transform: translateX(4px);
}

/* --- Badge Styling --- */
.badge {
    border-radius: 20px;
    padding: 0.4rem 0.8rem;
    font-weight: 600;
    font-size: 0.75rem;
}

.badge.bg-primary {
    background-color: var(--color-primary) !important;
}

.badge.bg-success {
    background-color: var(--color-secondary) !important;
}

/* --- Hover Links --- */
.hover-link {
    transition: var(--transition);
}

.hover-link:hover {
    color: var(--color-primary) !important;
    text-decoration: underline;
}

/* --- Article Page --- */
.article-detail {
    background: white;
    padding: 0 2rem 2rem 2rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
}

.article-detail h1 {
    color: var(--color-text);
    font-weight: 800;
    letter-spacing: -1px;
    line-height: 1.2;
}

.article-body-content {
    color: var(--color-text-light);
    line-height: 1.8;
}

.article-body-content p {
    margin-bottom: 1.5rem;
}

.article-body-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--color-text);
}

.article-body-content h3 {
    font-size: 1.35rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--color-text);
}

.article-body-content ul,
.article-body-content ol {
    margin: 1.5rem 0;
    padding-left: 2rem;
}

.article-body-content li {
    margin-bottom: 0.75rem;
}

.article-body-content code {
    background-color: var(--color-tag-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
    color: #e83e8c;
}

.article-body-content pre {
    background-color: var(--color-tag-bg);
    padding: 1rem;
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin: 1.5rem 0;
}

.article-body-content blockquote {
    border-left: 4px solid var(--color-primary);
    padding-left: 1.5rem;
    margin: 1.5rem 0;
    font-style: italic;
    color: var(--color-text-light);
}

.article-body-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin: 1.5rem 0;
}

/* --- Breadcrumb --- */
.breadcrumb {
    background-color: transparent;
    padding: 0;
}

.breadcrumb-item {
    display: inline-block;
}

.breadcrumb-item a {
    color: var(--color-primary);
    text-decoration: none;
}

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

.breadcrumb-item.active {
    color: var(--color-text-muted);
}

.breadcrumb-item + .breadcrumb-item::before {
    content: '/';
    display: inline-block;
    margin: 0 0.75rem;
    color: var(--color-border);
}

/* --- Alerts --- */
.alert {
    border: none;
    border-radius: var(--radius-md);
}

.alert-info {
    background-color: #e7f3ff;
    border-left: 4px solid var(--color-primary);
    color: #004085;
}

.alert-info a {
    color: var(--color-primary);
    font-weight: 600;
}

/* --- Footer --- */
.site-footer {
    background-color: #1a1a1a;
    color: #ffffff;
    margin-top: auto;
    padding: 3rem 0 1rem;
}

.site-footer a {
    color: #999;
    text-decoration: none;
}

.site-footer a:hover {
    color: white;
}

.site-footer h6 {
    font-weight: 700;
    color: white;
}

.site-footer .text-muted {
    color: #888 !important;
}

.site-footer hr {
    border-color: #333;
}

/* --- Buttons --- */
.btn-primary {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    font-weight: 600;
    transition: var(--transition);
}

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    box-shadow: 0 0 0 0.2rem rgba(74, 144, 217, 0.25);
}

.btn-primary:active {
    background-color: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
}

.btn-outline-primary {
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.btn-outline-primary:hover,
.btn-outline-primary:focus {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
}

.btn-light {
    background-color: white;
    border-color: white;
    color: var(--color-primary);
    font-weight: 600;
    transition: var(--transition);
}

.btn-light:hover {
    background-color: #f9f9f9;
    border-color: #f9f9f9;
    color: var(--color-primary-dark);
}

/* --- Form Control --- */
.form-control {
    border-color: var(--color-border);
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    transition: var(--transition);
}

.form-control:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 0.2rem rgba(74, 144, 217, 0.25);
}

.input-group-lg .form-control {
    padding: 0.75rem 1rem;
    font-size: 1rem;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .hero-section {
        min-height: 400px;
    }

    .hero-section h1 {
        font-size: 2rem;
    }

    .article-detail {
        padding: 1rem;
    }

    .card {
        margin-bottom: 1rem;
    }

    .container {
        padding-left: 1rem;
        padding-right: 1rem;
    }

    .navbar-brand {
        font-size: 1rem;
    }

    .section-header .row {
        flex-direction: column;
    }

    .section-header .text-md-end {
        text-align: left !important;
        margin-top: 1rem;
    }
}

@media (max-width: 480px) {
    .hero-section h1 {
        font-size: 1.5rem;
    }

    .hero-section .lead {
        font-size: 0.95rem;
    }

    .display-5 {
        font-size: 1.75rem;
    }

    .article-body-content h2 {
        font-size: 1.5rem;
    }

    .article-body-content h3 {
        font-size: 1.15rem;
    }
}

/* --- Print Styles --- */
@media print {
    .navbar,
    .site-footer,
    .breadcrumb {
        display: none;
    }

    .article-detail {
        box-shadow: none;
        padding: 0;
    }
}

/* --- Main Content --- */
.site-main {
    flex: 1; 
    width: 100%;
    margin: 0 auto;
    padding: 0;
}

/* --- Hero / Search Section --- */
.hero-section {
    text-align: center;
    padding: 80px 0 60px;
    background:
        linear-gradient(135deg, rgba(30, 45, 75, 0.88) 0%, rgba(45, 35, 90, 0.85) 50%, rgba(25, 40, 70, 0.9) 100%),
        url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    background-size: cover, 60px 60px;
    background-position: center, center;
    border-radius: var(--radius-lg);
    margin: 24px 0 0;
    position: relative;
}

.hero-logo {
    margin-bottom: 32px;
}

.hero-logo .logo-icon {
    width: 72px;
    height: 72px;
}

.hero-logo .logo-text {
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-tagline {
    color: rgba(255, 255, 255, 0.75);
    font-size: 1.1rem;
    margin-top: 8px;
}

.search-container {
    max-width: 640px;
    margin: 0 auto;
}

.search-form {
    display: flex;
    align-items: center;
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: 50px;
    padding: 6px 6px 6px 24px;
    transition: border-color var(--transition), box-shadow var(--transition);
    box-shadow: var(--shadow-card);
}

.search-form:focus-within {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px rgba(74, 144, 217, 0.15);
}

.search-input {
    flex: 1;
    border: none;
    outline: none;
    font-size: 1rem;
    color: var(--color-text);
    background: transparent;
    padding: 10px 0;
}

.search-input::placeholder {
    color: var(--color-text-muted);
}

.search-btn {
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: #fff;
    border: none;
    border-radius: 50px;
    padding: 12px 28px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity var(--transition), transform var(--transition);
    white-space: nowrap;
}

.search-btn:hover {
    opacity: 0.9;
    transform: scale(1.02);
}

/* --- Articles Section --- */
.articles-section {
    padding: 20px 0 60px;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.section-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--color-text);
}

.result-count {
    font-size: 0.9rem;
    color: var(--color-text-light);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 20px;
}

/* --- Article Card --- */
.article-card {
    background: var(--color-surface);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    display: flex;
    flex-direction: column;
}

.card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: linear-gradient(135deg, #e8edf5, #dce3ed);
}

.card-image-placeholder {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #e8edf5, #dce3ed);
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-image-placeholder svg {
    width: 48px;
    height: 48px;
    opacity: 0.4;
}

.card-body {
    padding: 20px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 8px;
    line-height: 1.4;
    display: -webkit-box; 
    -webkit-box-orient: vertical; 
    min-height: 2.5rem; 
    display: -webkit-box; 
    -webkit-line-clamp: 3;  
    overflow: hidden;
}



.card-title a {
    color: inherit;
    transition: color var(--transition);
}

.card-title a:hover {
    color: var(--color-primary);
}

.card-description {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: 16px;
    flex: 1;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--color-text-muted);
    padding-top: 12px;
    border-top: 1px solid var(--color-border);
}

.card-date {
    display: flex;
    align-items: center;
    gap: 4px;
}

.card-read-more {
    font-weight: 600;
    color: var(--color-primary);
    font-size: 0.85rem;
    transition: color var(--transition);
}

.card-read-more:hover {
    color: var(--color-primary-dark);
}

/* --- Empty State --- */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--color-text-light);
}

.empty-state svg {
    width: 80px;
    height: 80px;
    opacity: 0.3;
    margin-bottom: 16px;
}

.empty-state h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--color-text);
}

.empty-state p {
    font-size: 0.95rem;
}

/* --- Single Article Page --- */
.article-page {
    padding: 40px 0 60px;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 24px;
}

.breadcrumb a {
    color: var(--color-primary);
    transition: color var(--transition);
}

.breadcrumb a:hover {
    color: var(--color-primary-dark);
}

.breadcrumb .separator {
    color: var(--color-text-muted);
}

.article-detail {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    overflow: hidden;
}

.article-detail-image {
    width: 100%;
    max-height: 450px;
    object-fit: cover;
}

.article-detail-body {
    padding: 32px;
}

.article-detail-title {
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-text);
    margin-bottom: 16px;
    line-height: 1.3;
}

.article-detail-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--color-border);
    flex-wrap: wrap;
}

.article-detail-meta .meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.article-detail-content {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--color-text);
}

.article-detail-content p {
    margin-bottom: 16px;
}

.article-detail-content h2,
.article-detail-content h3 {
    margin-top: 28px;
    margin-bottom: 12px;
    font-weight: 700;
}

.article-detail-content img {
    border-radius: var(--radius-sm);
    margin: 20px 0;
}

.article-detail-content blockquote {
    border-left: 4px solid var(--color-primary);
    padding-left: 20px;
    margin: 20px 0;
    color: var(--color-text-light);
    font-style: italic;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 24px;
    color: var(--color-primary);
    font-weight: 600;
    font-size: 0.95rem;
    transition: color var(--transition);
}

.back-link:hover {
    color: var(--color-primary-dark);
}

/* --- Footer --- */
.site-footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: 20px 0;
    text-align: center;
    margin-top: auto;
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .hero-section {
        padding: 48px 0 36px;
        border-radius: var(--radius-sm);
        margin: 16px 0 0;
    }

    .hero-logo .logo-text {
        font-size: 1.6rem;
    }

    .hero-logo .logo-icon {
        width: 56px;
        height: 56px;
    }

    .search-form {
        padding: 4px 4px 4px 18px;
    }

    .search-btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }

    .articles-grid {
        grid-template-columns: 1fr;
    }

    .article-detail-body {
        padding: 20px;
    }

    .article-detail-title {
        font-size: 1.5rem;
    }
}