:root {
    --primary-color: #1e3a8a; /* Navy blue */
    --primary-light: #3b82f6; /* Blue */
    --secondary-color: #d97706; /* Amber/Gold */
    --bg-color: #f8fafc; /* Very light slate */
    --text-main: #1e293b;
    --text-light: #64748b;
    --white: #ffffff;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Sarabun', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

.hidden {
    display: none !important;
}

/* --- Top Navigation Bar --- */
.top-nav {
    position: absolute;
    top: 0;
    right: 0;
    width: 100%;
    display: flex;
    justify-content: flex-end;
    padding: 1.5rem 3rem;
    z-index: 100;
    pointer-events: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
    pointer-events: auto;
}

.top-nav .nav-link {
    color: var(--white);
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    transition: var(--transition);
    text-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

.top-nav .nav-link:hover {
    color: var(--secondary-color);
}

.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown::after {
    content: '';
    position: absolute;
    bottom: -1rem;
    left: 0;
    width: 100%;
    height: 1rem;
}

.dropdown-content {
    display: none;
    position: absolute;
    right: 0;
    background-color: var(--white);
    min-width: 200px;
    box-shadow: var(--shadow-lg);
    border-radius: 0.5rem;
    overflow: hidden;
    z-index: 100;
    margin-top: 0.5rem;
}

.dropdown:hover .dropdown-content {
    display: block;
    animation: fadeIn 0.3s ease;
}

.dropdown-content a {
    color: var(--text-main) !important;
    padding: 0.75rem 1rem;
    text-decoration: none;
    display: block;
    transition: var(--transition);
    text-shadow: none !important;
    font-size: 1rem !important;
}

.dropdown-content a:hover {
    background-color: var(--bg-color);
    color: var(--primary-color) !important;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- Hero Section --- */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    color: var(--white);
    padding: 6rem 2rem 2rem;
    transition: var(--transition);
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 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="0.05"%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');
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    max-width: 1000px;
    width: 100%;
}

.profile-image-container {
    width: 200px;
    height: 200px;
    margin: 0 auto 2rem;
    border-radius: 50%;
    padding: 8px;
    background: linear-gradient(45deg, var(--secondary-color), #fcd34d);
    box-shadow: 0 0 30px rgba(217, 119, 6, 0.4);
}

.profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    border: 4px solid var(--white);
}

.profile-info {
    margin-bottom: 4rem;
    animation: fadeInDown 1s ease-out;
}

.profile-info .title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--white);
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.profile-info .subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    color: #cbd5e1;
    margin-bottom: 1.5rem;
}

.teacher-name {
    font-size: 1.8rem;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.teacher-position {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 0.5rem;
}

.teacher-details {
    font-size: 1.1rem;
    color: #cbd5e1;
    opacity: 0.85;
}

.evaluation-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    animation: fadeInUp 1s ease-out 0.3s backwards;
}

.eval-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 1rem;
    padding: 2rem 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.eval-card:hover {
    transform: translateY(-10px);
    background: rgba(255, 255, 255, 0.2);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
    border-color: var(--secondary-color);
}

.eval-icon {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.eval-card h4 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.eval-card p {
    font-size: 1rem;
    color: #cbd5e1;
}

/* --- Main Layout --- */
.main-container {
    display: flex;
    min-height: 100vh;
    background-color: var(--bg-color);
}

.sidebar {
    width: 320px;
    background: var(--white);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-sm);
    z-index: 20;
    position: sticky;
    top: 0;
    height: 100vh;
}

.sidebar-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    background: var(--primary-color);
    color: var(--white);
}

.back-btn {
    background: transparent;
    border: none;
    color: #cbd5e1;
    font-size: 1rem;
    cursor: pointer;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.back-btn:hover {
    color: var(--white);
}

.sidebar-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
}

.nav-menu {
    overflow-y: auto;
    flex: 1;
    padding: 1rem 0;
}

.nav-section {
    margin-bottom: 1.5rem;
}

.nav-section-title {
    padding: 0.5rem 1.5rem;
    font-size: 0.9rem;
    text-transform: uppercase;
    color: var(--text-light);
    font-weight: 700;
    letter-spacing: 0.05em;
    background: var(--bg-color);
}

.nav-item {
    display: block;
    padding: 0.75rem 1.5rem;
    color: var(--text-main);
    text-decoration: none;
    border-left: 4px solid transparent;
    transition: var(--transition);
    cursor: pointer;
    font-size: 1rem;
}

.nav-item:hover {
    background: var(--bg-color);
    color: var(--primary-color);
}

.nav-item.active {
    background: #eff6ff;
    border-left-color: var(--primary-color);
    color: var(--primary-color);
    font-weight: 600;
}

.content-area {
    flex: 1;
    padding: 3rem;
    overflow-y: auto;
}

.content-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.category-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary-light);
    color: var(--white);
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

#contentTitle {
    font-size: 2rem;
    color: var(--primary-color);
}

.description-box {
    background: var(--white);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 2rem;
    font-size: 1.1rem;
    line-height: 1.8;
}

.evidence-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.docs-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
}

.doc-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.5rem;
    background: var(--white);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.doc-btn i {
    color: #ef4444; /* PDF Red */
    font-size: 1.25rem;
}

.doc-btn:hover {
    border-color: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.gallery-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
}

.gallery-item {
    position: relative;
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    background: var(--white);
    transition: var(--transition);
}

.gallery-item:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-md);
}

.gallery-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
    transition: var(--transition);
}

.gallery-item:hover img {
    filter: brightness(0.9);
}

.gallery-caption {
    padding: 0.75rem;
    font-size: 0.9rem;
    color: var(--text-main);
    text-align: center;
    background: var(--white);
    border-top: 1px solid var(--border-color);
}

/* Lightbox */
.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.lightbox-content {
    max-width: 90%;
    max-height: 80vh;
    border-radius: 4px;
    box-shadow: 0 0 20px rgba(0,0,0,0.5);
    animation: zoomIn 0.3s ease;
}

.close-lightbox {
    position: absolute;
    top: 20px;
    right: 40px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
}

#lightboxCaption {
    margin-top: 1rem;
    color: var(--white);
    font-size: 1.2rem;
    text-align: center;
}

/* Animations */
@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes zoomIn {
    from { transform: scale(0.9); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

/* Responsive */
@media (max-width: 992px) {
    .main-container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        max-height: 50vh;
        position: relative;
    }
    
    .content-area {
        padding: 1.5rem;
    }
}

@media (max-width: 768px) {
    .profile-info .title { font-size: 2rem; }
    .profile-info .subtitle { font-size: 1.2rem; }
    
    .evaluation-cards {
        grid-template-columns: 1fr;
    }
}