:root {
    --primary-color: #1e3a8a; /* Deep Blue */
    --accent-color: #9c6f44; /* Academic Gold/Brown */
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    --font-sans: 'Inter', sans-serif;
    --font-serif: 'Playfair Display', serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

h1, h2, h3, h4 {
    font-family: var(--font-serif);
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* Layout */
.layout {
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    gap: 3rem;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    flex: 0 0 300px;
    position: sticky;
    top: 2rem;
    height: fit-content;
}

.profile-container {
    background-color: var(--surface-color);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.profile-img {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--surface-color);
    box-shadow: var(--shadow-md);
    margin-bottom: 1.5rem;
}

.name {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.headline {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.location {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 1.5rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.social-links a {
    color: var(--text-secondary);
    transition: color 0.2s, transform 0.2s;
}

.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

.action-buttons {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.2s;
    cursor: pointer;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: 1px solid var(--primary-color);
}

.btn-primary:hover {
    background-color: #152c69;
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.btn-outline:hover {
    background-color: #f0f4f8;
}

/* Main Content */
.content {
    flex: 1;
    min-width: 0;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.tab-btn {
    background: none;
    border: none;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem 1rem;
    position: relative;
    transition: color 0.2s;
    white-space: nowrap;
}

.tab-btn:hover {
    color: var(--primary-color);
}

.tab-btn.active {
    color: var(--primary-color);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--accent-color);
    border-radius: 3px 3px 0 0;
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.fade-in {
    animation: fadeIn 0.4s ease-in-out;
}

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

section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.section-desc {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Cards General */
.card {
    background-color: var(--surface-color);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: 1.5rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.about-card p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 1.05rem;
}
.about-card p:last-child {
    margin-bottom: 0;
}

/* Timeline (Experience & Education) */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 7px;
    width: 2px;
    height: 100%;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}

.timeline-dot {
    position: absolute;
    left: -2rem;
    top: 1.5rem;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: var(--surface-color);
    border: 3px solid var(--accent-color);
}

.experience-card h3, .education-card h3 {
    margin-bottom: 0.2rem;
    font-family: var(--font-sans);
    font-weight: 600;
}

.company, .degree {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.3rem;
}

.date, .location, .grade {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.8rem;
}

.experience-card p, .education-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.skills {
    margin-top: 1rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--primary-color);
}

/* Grid Layout (Publications & Projects) */
.grid-layout {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.pub-card, .project-card {
    display: flex;
    flex-direction: column;
}

.pub-card h3, .project-card h3 {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.meta {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.pub-card p, .project-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    flex-grow: 1;
    margin-bottom: 1.5rem;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tech-stack span {
    background-color: #f1f5f9;
    color: var(--primary-color);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

.links-row {
    display: flex;
    gap: 1rem;
}

.link-btn {
    text-decoration: none;
    color: var(--accent-color);
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.link-btn:hover {
    color: #7b5531;
    text-decoration: underline;
}

/* Awards */
.award-category {
    margin-bottom: 3rem;
}

.category-title {
    font-family: var(--font-sans);
    font-size: 1.2rem;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

.award-card {
    padding: 1.5rem;
}

.award-header {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.award-icon {
    font-size: 2rem;
    line-height: 1;
}

.award-info h4 {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    margin-bottom: 0.2rem;
}

.media-container {
    margin-top: 1.5rem;
    display: flex;
    gap: 15px;
    overflow-x: auto;
    padding-bottom: 5px;
}

.media-placeholder {
    width: 100%;
    height: 120px;
    background-color: #f1f5f9;
    border: 2px dashed #cbd5e1;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: background-color 0.2s, color 0.2s;
}

.media-placeholder:hover {
    background-color: #e2e8f0;
    color: var(--primary-color);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    padding-top: 50px;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.8);
    backdrop-filter: blur(5px);
}

.modal-content {
    margin: auto;
    display: block;
    max-width: 90%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 8px;
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    transition: 0.3s;
    cursor: pointer;
}

.close-modal:hover,
.close-modal:focus {
    color: #bbb;
    text-decoration: none;
    cursor: pointer;
}

/* Responsive */
@media (max-width: 900px) {
    .layout {
        flex-direction: column;
        padding: 1rem;
    }
    
    .sidebar {
        position: static;
        flex: auto;
    }
    
    .profile-container {
        padding: 1.5rem;
    }
}

/* Filtering & Placeholders */
.filter-container {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
.filter-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    background: transparent;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all 0.2s ease;
}
.filter-btn:hover {
    background: var(--bg-color);
}
.filter-btn.active {
    background: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
}

.placeholder-notice {
    background: #f8f9fa;
    border: 1px dashed #ced4da;
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    color: #6c757d;
    margin-top: 20px;
}

/* Toast Notification */
.toast {
    visibility: hidden;
    min-width: 250px;
    background-color: #333;
    color: #fff;
    text-align: center;
    border-radius: 8px;
    padding: 16px;
    position: fixed;
    z-index: 10000;
    left: 50%;
    top: 30px;
    transform: translateX(-50%);
    font-size: 15px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    opacity: 0;
    transition: opacity 0.3s, top 0.3s;
}

.toast.show {
    visibility: visible;
    opacity: 1;
    top: 50px;
}

/* Diploma Thumbnails */
.diploma-thumb {
    height: 200px;
    width: auto;
    border-radius: 8px;
    object-fit: contain;
    cursor: pointer;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s, box-shadow 0.2s;
    background-color: #fff;
    padding: 5px;
    flex-shrink: 0;
}
.diploma-thumb:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}