/* Premium CSS Style System for Prof. Paschal U. Chinedu Website */

:root {
    --bg-dark: #0a0e17;
    --bg-card: rgba(20, 28, 45, 0.65);
    --border-color: rgba(255, 255, 255, 0.07);
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --primary-accent: #00f2fe;
    --secondary-accent: #4facfe;
    --glow-color: rgba(0, 242, 254, 0.15);
    --gold-accent: #f5a623;
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    --transition-speed: 0.4s;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-body);
    overflow-x: hidden;
    line-height: 1.6;
    min-height: 100vh;
}

/* Ambient Glow Backgrounds */
.ambient-glow {
    position: fixed;
    border-radius: 50%;
    filter: blur(140px);
    z-index: -1;
    pointer-events: none;
    opacity: 0.45;
    mix-blend-mode: screen;
}

.glow-1 {
    width: 500px;
    height: 500px;
    top: -150px;
    left: -100px;
    background: radial-gradient(circle, rgba(79, 172, 254, 0.6) 0%, rgba(0, 242, 254, 0) 70%);
}

.glow-2 {
    width: 600px;
    height: 600px;
    bottom: -200px;
    right: -100px;
    background: radial-gradient(circle, rgba(157, 80, 187, 0.5) 0%, rgba(0, 0, 0, 0) 70%);
}

.glow-3 {
    width: 350px;
    height: 350px;
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: radial-gradient(circle, rgba(0, 242, 254, 0.3) 0%, rgba(0, 0, 0, 0) 70%);
}

/* Navigation Header */
#main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(10, 14, 23, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.25rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.logo-accent {
    color: var(--primary-accent);
}

.nav-menu {
    display: flex;
    gap: 1rem;
}

.nav-link {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    font-weight: 500;
    padding: 0.5rem 1rem;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover, .nav-link.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 20%;
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-accent), var(--secondary-accent));
    border-radius: 2px;
}

.badge-live {
    background: #ef4444;
    color: white;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 1px 6px;
    border-radius: 4px;
    margin-left: 4px;
    vertical-align: middle;
    animation: pulse 1.8s infinite;
}

@keyframes pulse {
    0% { opacity: 0.7; }
    50% { opacity: 1; }
    100% { opacity: 0.7; }
}

.mobile-toggle {
    display: none;
    font-size: 1.4rem;
    cursor: pointer;
    color: var(--text-primary);
}

/* Content Wrapper & Section Navigation */
.content-wrapper {
    max-width: 1200px;
    margin: 80px auto 40px auto;
    padding: 2rem;
    min-height: calc(100vh - 180px);
}

.main-section {
    display: none;
    animation: fadeIn var(--transition-speed) ease forwards;
}

.main-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Home Section Styles */
.hero-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 4rem;
    align-items: center;
    padding: 3rem 0;
}

.badge-computing {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 242, 254, 0.08);
    border: 1px solid rgba(0, 242, 254, 0.2);
    color: var(--primary-accent);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    line-height: 1.15;
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 0.5rem;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary-accent) 0%, var(--secondary-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--gold-accent);
    margin-bottom: 1.5rem;
}

.hero-desc {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
    max-width: 580px;
}

.hero-ctas {
    display: flex;
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 0.85rem 1.8rem;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-body);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-accent) 0%, var(--secondary-accent) 100%);
    color: #050505;
    border: none;
    box-shadow: 0 4px 15px var(--glow-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 242, 254, 0.35);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-links a {
    color: var(--text-secondary);
    font-size: 1.4rem;
    transition: color 0.3s ease;
}

.social-links a:hover {
    color: var(--primary-accent);
}

/* Avatar Frame & Fallback */
.hero-visual {
    display: flex;
    justify-content: center;
    position: relative;
}

.avatar-frame {
    position: relative;
    width: 320px;
    height: 380px;
    border-radius: 20px;
    overflow: hidden;
}

.avatar-img-container {
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, #1a2436 0%, #0e1624 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 20px;
}

.avatar-fallback {
    font-size: 8rem;
    color: rgba(255, 255, 255, 0.1);
}

.frame-border {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 2px solid rgba(0, 242, 254, 0.3);
    border-radius: 20px;
    pointer-events: none;
    box-shadow: inset 0 0 20px rgba(0, 242, 254, 0.1);
}

/* Stats Ribbon */
.stats-ribbon {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 20px;
    margin: 3rem 0;
}

.stat-card {
    text-align: center;
}

.stat-num {
    font-family: var(--font-heading);
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--primary-accent);
    margin-bottom: 0.25rem;
}

.stat-lbl {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Expertise Grid */
.section-heading-centered {
    text-align: center;
    font-family: var(--font-heading);
    font-size: 2.2rem;
    margin-bottom: 2rem;
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.expertise-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2rem;
    border-radius: 15px;
    transition: all 0.3s ease;
}

.expertise-card:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 242, 254, 0.25);
    box-shadow: 0 8px 30px rgba(0, 242, 254, 0.08);
}

.card-icon {
    font-size: 2rem;
    color: var(--primary-accent);
    margin-bottom: 1.25rem;
}

.expertise-card h3 {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    margin-bottom: 0.75rem;
}

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

/* Section Common Headers */
.section-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.section-desc {
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-size: 1.1rem;
}

/* About / CV Page Layout */
.about-grid {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 3rem;
}

.profile-details-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2.5rem;
    border-radius: 20px;
}

.profile-details-card h3, .timeline-card h3 {
    font-family: var(--font-heading);
    font-size: 1.6rem;
    margin-bottom: 1.5rem;
}

.profile-details-card p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.info-table {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.info-row {
    display: flex;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding-bottom: 0.75rem;
}

.info-key {
    width: 140px;
    font-weight: 600;
    color: var(--primary-accent);
}

.info-val {
    flex: 1;
    color: var(--text-primary);
}

.timeline {
    position: relative;
    border-left: 2px solid rgba(255, 255, 255, 0.08);
    padding-left: 2rem;
}

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

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.35rem;
    top: 0.3rem;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--primary-accent);
    box-shadow: 0 0 8px var(--primary-accent);
}

.timeline-date {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--gold-accent);
    margin-bottom: 0.25rem;
}

.timeline-title {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.timeline-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* Research & Publications Section Styles */
.publications-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.pub-tab-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.6rem 1.25rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.pub-tab-btn.active, .pub-tab-btn:hover {
    background: var(--primary-accent);
    color: #050505;
    border-color: var(--primary-accent);
    font-weight: 600;
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.pub-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 1.8rem;
    border-radius: 12px;
    transition: all 0.3s ease;
}

.pub-card:hover {
    border-color: rgba(255, 255, 255, 0.15);
    background: rgba(255, 255, 255, 0.03);
}

.pub-type {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 2px 8px;
    border-radius: 4px;
    margin-bottom: 0.75rem;
}

.pub-type.journal { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.pub-type.book { background: rgba(16, 185, 129, 0.15); color: #34d399; }
.pub-type.conference { background: rgba(245, 158, 11, 0.15); color: #fbbf24; }

.pub-card h3 {
    font-family: var(--font-heading);
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.pub-authors {
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.pub-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Live Stream Section Styles */
.stream-layout {
    display: grid;
    grid-template-columns: 1.4fr 0.6fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.video-player-container {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    background: #000;
    border: 1px solid var(--border-color);
}

.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, rgba(0,0,0,0.5) 0%, rgba(0,0,0,0.1) 40%, rgba(0,0,0,0.8) 100%);
    z-index: 5;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 1.5rem;
    pointer-events: none;
}

.live-indicator-flashing {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    align-self: flex-start;
    background: #ef4444;
    color: white;
    font-weight: 700;
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 4px;
}

.live-indicator-flashing .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: white;
    animation: flash 1s infinite alternate;
}

@keyframes flash {
    from { opacity: 0.3; }
    to { opacity: 1; }
}

.overlay-details h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.overlay-details p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.stream-details {
    margin-top: 1.5rem;
}

.stream-details h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
}

.stream-details p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.course-code-badges {
    display: flex;
    gap: 0.5rem;
}

.code-badge {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* Chat Sidebar Styles */
.stream-chat {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 15px;
    display: flex;
    flex-direction: column;
    height: 480px;
}

.chat-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chat-header h4 {
    font-family: var(--font-heading);
    font-weight: 600;
}

.chat-viewer-count {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.msg-item {
    font-size: 0.9rem;
    line-height: 1.4;
}

.msg-author {
    font-weight: 700;
    color: var(--primary-accent);
}

.system-msg {
    color: var(--gold-accent);
    font-style: italic;
}

.chat-input-form {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 0.5rem;
}

.chat-input-form input {
    flex: 1;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.6rem 1rem;
    color: white;
    font-family: var(--font-body);
}

.chat-input-form input:focus {
    outline: none;
    border-color: var(--primary-accent);
}

.btn-chat-send {
    background: var(--primary-accent);
    color: #050505;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s ease;
}

.btn-chat-send:active {
    transform: scale(0.95);
}

/* Upcoming schedule grid */
.upcoming-sessions {
    margin-top: 4rem;
}

.upcoming-sessions h3 {
    font-family: var(--font-heading);
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.schedule-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.schedule-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 12px;
}

.sch-date {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--gold-accent);
    margin-bottom: 0.5rem;
}

.schedule-card h4 {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
}

.sch-level {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* News & Events CSS */
.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.news-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 15px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.news-card:hover {
    transform: translateY(-5px);
    border-color: rgba(255, 255, 255, 0.15);
}

.news-img-placeholder {
    height: 180px;
    background: linear-gradient(135deg, #16222f 0%, #0b111a 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: rgba(0, 242, 254, 0.15);
}

.news-body {
    padding: 1.5rem;
}

.news-date {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--gold-accent);
    margin-bottom: 0.5rem;
    display: block;
}

.news-body h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.news-body p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Contact Page Layout */
.contact-grid {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 3rem;
}

.contact-info {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2.5rem;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-info h3 {
    font-family: var(--font-heading);
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
}

.contact-detail-row {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.contact-detail-row i {
    font-size: 1.25rem;
    color: var(--primary-accent);
    margin-top: 0.25rem;
}

.skype-badge {
    align-self: flex-start;
    background: rgba(0, 242, 254, 0.05);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
}

.contact-form-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2.5rem;
    border-radius: 20px;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.9rem;
    font-weight: 600;
}

.form-group input, .form-group textarea {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    color: white;
    font-family: var(--font-body);
}

.form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--primary-accent);
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* Footer Section */
footer {
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
    text-align: center;
    background: rgba(10, 14, 23, 0.9);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-sdu {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Photo Gallery Styles */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.gallery-card {
    position: relative;
    height: 250px;
    border-radius: 15px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    background: #000;
}

.gallery-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.gallery-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 1.5rem;
    background: linear-gradient(0deg, rgba(10, 14, 23, 0.95) 0%, rgba(10, 14, 23, 0.4) 70%, rgba(10, 14, 23, 0) 100%);
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.4s ease;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
}

.gallery-card:hover .gallery-img {
    transform: scale(1.08);
}

.gallery-card:hover .gallery-overlay {
    opacity: 1;
    transform: translateY(0);
}

.gallery-overlay h4 {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    color: var(--primary-accent);
    margin-bottom: 0.25rem;
}

.gallery-overlay p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Responsive Styling */
@media (max-width: 968px) {
    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    .hero-desc {
        margin-left: auto;
        margin-right: auto;
    }
    .hero-ctas, .social-links {
        justify-content: center;
    }
    .stats-ribbon {
        grid-template-columns: 1fr 1fr;
    }
    .expertise-grid, .about-grid, .stream-layout, .news-grid, .contact-grid, .schedule-grid {
        grid-template-columns: 1fr;
    }
    .mobile-toggle {
        display: block;
    }
    .nav-menu {
        display: none; /* JS will toggle responsive menu */
    }
}