/* ============================================
   GLOBAL RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-blue: #0a1628;
    --secondary-blue: #142039;
    --accent-cyan: #00d4ff;
    --accent-purple: #b620e0;
    --lightning-yellow: #ffd700;
    --text-white: #ffffff;
    --text-gray: #b8c5d6;
    --card-bg: rgba(20, 32, 57, 0.8);
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #00d4ff 0%, #0066ff 100%);
    --gradient-3: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-4: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-5: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--primary-blue);
    color: var(--text-white);
    overflow-x: hidden;
    line-height: 1.6;
}

/* ============================================
   REALISTIC LIGHTNING STRIKE INTRO
   ============================================ */
.lightning-intro {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: #000000;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeOutIntro 0.8s ease-in-out 4.5s forwards;
}

@keyframes fadeOutIntro {
    to {
        opacity: 0;
        visibility: hidden;
    }
}

/* Realistic Lightning Strike Effect */
.lightning-strike {
    position: absolute;
    top: 0;
    left: 50%;
    width: 4px;
    height: 100vh;
    transform: translateX(-50%);
    opacity: 0;
}

.lightning-strike::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    width: 6px;
    height: 100%;
    background: linear-gradient(180deg, 
        transparent 0%, 
        #ffffff 10%, 
        #00d4ff 30%, 
        #ffd700 50%, 
        #00d4ff 70%, 
        #ffffff 90%, 
        transparent 100%
    );
    transform: translateX(-50%) skewX(-5deg);
    box-shadow: 
        0 0 20px #ffffff,
        0 0 40px #00d4ff,
        0 0 60px #00d4ff,
        0 0 80px #ffd700,
        0 0 100px #ffd700;
    filter: blur(2px);
    animation: strikeDrop 0.8s ease-out 0.5s forwards,
               flicker 0.1s ease-in-out 0.5s 8;
}

.lightning-strike::after {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    width: 3px;
    height: 100%;
    background: #ffffff;
    transform: translateX(-50%) skewX(-5deg);
    box-shadow: 0 0 10px #ffffff, 0 0 20px #00d4ff;
    animation: strikeDrop 0.8s ease-out 0.5s forwards;
}

@keyframes strikeDrop {
    0% {
        height: 0%;
        opacity: 1;
    }
    50% {
        opacity: 1;
    }
    100% {
        height: 100%;
        opacity: 1;
    }
}

@keyframes flicker {
    0%, 50%, 100% { opacity: 1; }
    25%, 75% { opacity: 0.3; }
}

/* Lightning branches */
.lightning-branch {
    position: absolute;
    width: 2px;
    background: linear-gradient(135deg, #ffffff, #00d4ff, transparent);
    box-shadow: 0 0 10px #00d4ff, 0 0 20px #ffd700;
    transform-origin: top left;
    opacity: 0;
    animation: branchAppear 0.3s ease-out forwards;
}

.branch-1 { top: 15%; left: 50%; height: 80px; transform: rotate(25deg); animation-delay: 0.6s; }
.branch-2 { top: 30%; left: 50%; height: 60px; transform: rotate(-35deg); animation-delay: 0.7s; }
.branch-3 { top: 50%; left: 50%; height: 70px; transform: rotate(30deg); animation-delay: 0.8s; }
.branch-4 { top: 65%; left: 50%; height: 50px; transform: rotate(-40deg); animation-delay: 0.9s; }

@keyframes branchAppear {
    0% { opacity: 0; width: 0; }
    50% { opacity: 1; }
    100% { opacity: 0.8; width: 2px; }
}

/* Flash effect */
.lightning-flash {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #ffffff;
    opacity: 0;
    animation: flashScreen 0.2s ease-in-out 0.5s 3;
}

@keyframes flashScreen {
    0%, 100% { opacity: 0; }
    50% { opacity: 0.8; }
}

.intro-logo {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 72px;
    font-weight: 900;
    letter-spacing: 12px;
    opacity: 0;
    background: linear-gradient(135deg, #ffffff, #00d4ff, #ffd700);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(0, 212, 255, 0.8);
    animation: logoReveal 1s ease-out 1.5s forwards, logoPulse 0.5s ease-in-out 2.5s 2;
}

@keyframes logoReveal {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
    100% { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

@keyframes logoPulse {
    0%, 100% { filter: brightness(1); }
    50% { filter: brightness(2); }
}

/* ============================================
   NAVIGATION BAR WITH LOGO
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px 5%;
    background: rgba(10, 22, 40, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 4px 20px rgba(0, 212, 255, 0.1);
    border-bottom: 2px solid rgba(0, 212, 255, 0.3);
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo-image {
    width: 50px;
    height: 50px;
    object-fit: contain;
    filter: drop-shadow(0 0 10px rgba(0, 212, 255, 0.6));
    animation: logoFloat 3s ease-in-out infinite;
}

@keyframes logoFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.logo-text {
    font-size: 32px;
    font-weight: bold;
    background: linear-gradient(135deg, var(--accent-cyan), var(--lightning-yellow));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 3px;
    animation: logoGlow 2s ease-in-out infinite;
    position: relative;
}

.logo-text::after {
    content: '⚡';
    position: absolute;
    right: -30px;
    top: -5px;
    animation: boltSpin 3s linear infinite;
}

@keyframes logoGlow {
    0%, 100% { filter: brightness(1); }
    50% { filter: brightness(1.5); }
}

@keyframes boltSpin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.nav-links {
    display: flex;
    gap: 30px;
    list-style: none;
    align-items: center;
}

.nav-links a {
    color: var(--text-white);
    text-decoration: none;
    font-size: 16px;
    transition: all 0.3s ease;
    position: relative;
    padding: 8px 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-cyan);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-links a:hover {
    color: var(--accent-cyan);
    text-shadow: 0 0 10px var(--accent-cyan);
}

.login-btn {
    padding: 10px 25px;
    background: linear-gradient(135deg, var(--accent-cyan), #0066ff);
    border: none;
    border-radius: 25px;
    color: var(--text-white);
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 212, 255, 0.3);
    animation: buttonPulse 2s ease-in-out infinite;
}

@keyframes buttonPulse {
    0%, 100% { box-shadow: 0 4px 15px rgba(0, 212, 255, 0.3); }
    50% { box-shadow: 0 4px 25px rgba(0, 212, 255, 0.6); }
}

.login-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 30px rgba(0, 212, 255, 0.5);
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
    margin-top: 80px;
    padding: 100px 5%;
    min-height: 90vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 50% 50%, rgba(0, 212, 255, 0.1) 0%, transparent 70%);
    animation: pulseGradient 4s ease-in-out infinite;
}

@keyframes pulseGradient {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.hero-content {
    text-align: center;
    z-index: 1;
    max-width: 900px;
}

.premium-badge {
    display: inline-block;
    padding: 10px 30px;
    background: rgba(182, 32, 224, 0.2);
    border: 2px solid var(--accent-purple);
    border-radius: 30px;
    font-size: 14px;
    font-weight: bold;
    letter-spacing: 3px;
    margin-bottom: 20px;
    animation: badgeFloat 3s ease-in-out infinite;
}

@keyframes badgeFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.hero h1 {
    font-size: 72px;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--text-white), var(--accent-cyan), var(--lightning-yellow));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: heroTextShine 3s ease-in-out infinite;
    font-weight: 900;
    letter-spacing: 2px;
}

@keyframes heroTextShine {
    0%, 100% { filter: brightness(1); }
    50% { filter: brightness(1.3); }
}

.hero p {
    font-size: 20px;
    color: var(--text-gray);
    margin-bottom: 40px;
    line-height: 1.8;
}

.cta-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.cta-btn {
    padding: 18px 45px;
    font-size: 18px;
    font-weight: bold;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.cta-primary {
    background: linear-gradient(135deg, var(--accent-cyan), #0066ff);
    color: var(--text-white);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.4);
}

.cta-primary:hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 12px 35px rgba(0, 212, 255, 0.6);
}

.cta-secondary {
    background: transparent;
    color: var(--text-white);
    border: 2px solid var(--accent-cyan);
}

.cta-secondary:hover {
    background: var(--accent-cyan);
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.4);
}

/* ============================================
   FLIP CARD FEATURE
   ============================================ */
.flip-card-section {
    padding: 100px 5%;
    background: var(--secondary-blue);
}

.section-title {
    text-align: center;
    font-size: 48px;
    margin-bottom: 60px;
    background: linear-gradient(135deg, var(--text-white), var(--accent-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.flip-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    max-width: 1400px;
    margin: 0 auto;
}

.flip-card {
    perspective: 1000px;
    height: 400px;
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s;
    transform-style: preserve-3d;
}

.flip-card:hover .flip-card-inner {
    transform: rotateY(180deg);
}

.flip-card-front, .flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 20px;
    padding: 40px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 2px solid rgba(0, 212, 255, 0.3);
}

.flip-card-front {
    background: var(--card-bg);
}

.flip-card-back {
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.2), rgba(182, 32, 224, 0.2));
    transform: rotateY(180deg);
}

.flip-card-icon {
    font-size: 80px;
    margin-bottom: 20px;
    animation: iconBounce 2s ease-in-out infinite;
}

@keyframes iconBounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

.flip-card h3 {
    font-size: 28px;
    margin-bottom: 15px;
    color: var(--accent-cyan);
}

.flip-card p {
    color: var(--text-gray);
    line-height: 1.8;
    text-align: center;
}

.flip-card-back p {
    font-size: 16px;
    color: var(--text-white);
}

/* ============================================
   FEATURES SECTION WITH ENHANCED EFFECTS
   ============================================ */
.features {
    padding: 100px 5%;
    position: relative;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    max-width: 1400px;
    margin: 0 auto;
}

.feature-card {
    background: var(--card-bg);
    padding: 40px 30px;
    border-radius: 20px;
    border: 2px solid transparent;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1), rgba(182, 32, 224, 0.1));
    opacity: 0;
    transition: opacity 0.4s ease;
}

.feature-card:hover {
    border-color: var(--accent-cyan);
    transform: translateY(-10px) rotateX(5deg);
    box-shadow: 0 20px 50px rgba(0, 212, 255, 0.3);
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-icon {
    font-size: 50px;
    margin-bottom: 20px;
    display: inline-block;
    animation: iconFloat 3s ease-in-out infinite;
}

@keyframes iconFloat {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-15px) rotate(5deg); }
}

.feature-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--text-white);
}

.feature-card p {
    color: var(--text-gray);
    line-height: 1.7;
}

/* ============================================
   ANIMATED STATISTICS COUNTER
   ============================================ */
.stats-showcase {
    padding: 100px 5%;
    background: var(--primary-blue);
    position: relative;
}

.stats-showcase::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 30% 50%, rgba(182, 32, 224, 0.1), transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(0, 212, 255, 0.1), transparent 50%);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.stat-box {
    background: var(--card-bg);
    padding: 50px 30px;
    border-radius: 20px;
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.stat-box::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(0, 212, 255, 0.1), transparent);
    transform: rotate(45deg);
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
    100% { transform: translateX(100%) translateY(100%) rotate(45deg); }
}

.stat-box:hover {
    border-color: var(--accent-cyan);
    transform: scale(1.05);
    box-shadow: 0 20px 50px rgba(0, 212, 255, 0.4);
}

.stat-number {
    font-size: 64px;
    font-weight: 900;
    background: linear-gradient(135deg, var(--accent-cyan), var(--lightning-yellow));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 15px;
    position: relative;
}

.stat-label {
    font-size: 20px;
    color: var(--text-gray);
    font-weight: 600;
}

/* ============================================
   COURSES SECTION
   ============================================ */
.courses {
    padding: 100px 5%;
    background: var(--secondary-blue);
}

.courses-container {
    max-width: 1400px;
    margin: 0 auto;
}

.course-tabs {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 15px 35px;
    background: var(--card-bg);
    border: 2px solid transparent;
    border-radius: 30px;
    color: var(--text-white);
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    border-color: var(--accent-cyan);
    background: rgba(0, 212, 255, 0.1);
    transform: translateY(-3px);
}

.tab-btn.active {
    background: linear-gradient(135deg, var(--accent-cyan), #0066ff);
    border-color: var(--accent-cyan);
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 40px;
}

.course-card {
    background: var(--card-bg);
    border-radius: 20px;
    overflow: hidden;
    border: 2px solid transparent;
    transition: all 0.4s ease;
    position: relative;
}

.course-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.6s ease;
}

.course-card:hover::after {
    left: 100%;
}

.course-card:hover {
    border-color: var(--accent-cyan);
    transform: scale(1.03);
    box-shadow: 0 20px 60px rgba(0, 212, 255, 0.3);
}

.course-header {
    padding: 30px;
    background: var(--gradient-2);
    position: relative;
}

.course-header.purple {
    background: var(--gradient-1);
}

.course-header.pink {
    background: var(--gradient-3);
}

.course-tag {
    display: inline-block;
    padding: 5px 15px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 15px;
    font-size: 12px;
    font-weight: bold;
    margin-bottom: 15px;
}

.course-card h3 {
    font-size: 28px;
    margin-bottom: 10px;
}

.course-duration {
    font-size: 14px;
    opacity: 0.9;
}

.course-body {
    padding: 30px;
}

.course-stats {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-gray);
    font-size: 14px;
}

.course-topics {
    margin-top: 20px;
}

.course-topics h4 {
    font-size: 18px;
    margin-bottom: 15px;
    color: var(--accent-cyan);
}

.topics-list {
    list-style: none;
}

.topics-list li {
    padding: 10px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-gray);
    position: relative;
    padding-left: 25px;
}

.topics-list li::before {
    content: '⚡';
    position: absolute;
    left: 0;
    color: var(--lightning-yellow);
    animation: sparkle 2s ease-in-out infinite;
}

@keyframes sparkle {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.enroll-btn {
    width: 100%;
    padding: 15px;
    margin-top: 25px;
    background: linear-gradient(135deg, var(--accent-cyan), #0066ff);
    border: none;
    border-radius: 30px;
    color: var(--text-white);
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
}

.enroll-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 212, 255, 0.5);
}

/* ============================================
   INTERACTIVE TIMELINE
   ============================================ */
.timeline-section {
    padding: 100px 5%;
    background: var(--primary-blue);
    position: relative;
}

.timeline {
    max-width: 1000px;
    margin: 0 auto;
    position: relative;
    padding: 50px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--accent-cyan), var(--accent-purple), var(--lightning-yellow));
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 60px;
    width: 45%;
}

.timeline-item:nth-child(odd) {
    margin-left: 0;
    text-align: right;
    padding-right: 50px;
}

.timeline-item:nth-child(even) {
    margin-left: 55%;
    text-align: left;
    padding-left: 50px;
}

.timeline-item::before {
    content: '⚡';
    position: absolute;
    top: 20px;
    font-size: 30px;
    background: var(--primary-blue);
    padding: 15px;
    border-radius: 50%;
    border: 4px solid var(--accent-cyan);
    z-index: 2;
    animation: pulseTimeline 2s ease-in-out infinite;
}

.timeline-item:nth-child(odd)::before {
    right: -50px;
}

.timeline-item:nth-child(even)::before {
    left: -50px;
}

@keyframes pulseTimeline {
    0%, 100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(0, 212, 255, 0.7); }
    50% { transform: scale(1.1); box-shadow: 0 0 0 15px rgba(0, 212, 255, 0); }
}

.timeline-content {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 15px;
    border: 2px solid rgba(0, 212, 255, 0.3);
    transition: all 0.3s ease;
}

.timeline-content:hover {
    border-color: var(--accent-cyan);
    transform: scale(1.05);
    box-shadow: 0 15px 40px rgba(0, 212, 255, 0.3);
}

.timeline-content h4 {
    color: var(--accent-cyan);
    font-size: 24px;
    margin-bottom: 15px;
}

.timeline-content p {
    color: var(--text-gray);
    line-height: 1.7;
}

/* ============================================
   LECTURE DETAILS SECTION
   ============================================ */
.lecture-details {
    padding: 100px 5%;
}

.lecture-container {
    max-width: 1200px;
    margin: 0 auto;
}

.lecture-card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 40px;
    margin-bottom: 40px;
    border: 2px solid rgba(0, 212, 255, 0.2);
}

.lecture-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 20px;
}

.lecture-number {
    background: linear-gradient(135deg, var(--accent-cyan), #0066ff);
    padding: 10px 20px;
    border-radius: 20px;
    font-weight: bold;
}

.lecture-title {
    font-size: 32px;
    flex: 1;
    margin-left: 20px;
}

.video-demo-space {
    width: 100%;
    height: 450px;
    background: var(--primary-blue);
    border-radius: 15px;
    margin-bottom: 30px;
    position: relative;
    overflow: hidden;
    border: 3px solid var(--accent-cyan);
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-placeholder {
    text-align: center;
    z-index: 1;
}

.video-placeholder::before {
    content: '▶';
    font-size: 80px;
    color: var(--accent-cyan);
    display: block;
    margin-bottom: 20px;
    animation: playPulse 2s ease-in-out infinite;
}

@keyframes playPulse {
    0%, 100% { transform: scale(1); opacity: 0.7; }
    50% { transform: scale(1.2); opacity: 1; }
}

.video-demo-space::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.3), transparent);
    transform: translate(-50%, -50%);
    animation: videoPulse 3s ease-in-out infinite;
}

@keyframes videoPulse {
    0%, 100% { width: 300px; height: 300px; opacity: 0.3; }
    50% { width: 400px; height: 400px; opacity: 0.6; }
}

.lecture-summary {
    margin-top: 30px;
}

.lecture-summary h3 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--accent-cyan);
}

.summary-content {
    background: rgba(0, 0, 0, 0.3);
    padding: 25px;
    border-radius: 15px;
    border-left: 4px solid var(--accent-cyan);
    line-height: 1.9;
}

.summary-points {
    list-style: none;
    margin-top: 20px;
}

.summary-points li {
    padding: 12px 0;
    padding-left: 30px;
    position: relative;
    color: var(--text-gray);
}

.summary-points li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-cyan);
    font-weight: bold;
    font-size: 20px;
}

.subtopics {
    margin-top: 40px;
}

.subtopics h3 {
    font-size: 24px;
    margin-bottom: 25px;
    color: var(--lightning-yellow);
}

.subtopic-accordion {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 15px;
    overflow: hidden;
    margin-bottom: 15px;
}

.accordion-header {
    padding: 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
    border-left: 4px solid transparent;
}

.accordion-header:hover {
    background: rgba(0, 212, 255, 0.1);
    border-left-color: var(--accent-cyan);
}

.accordion-icon {
    transition: transform 0.3s ease;
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    padding: 0 20px;
}

.subtopic-accordion:target .accordion-content {
    max-height: 500px;
    padding: 20px;
}

.subtopic-accordion:target .accordion-icon {
    transform: rotate(180deg);
}

/* ============================================
   ALL COURSES CATALOG
   ============================================ */
.courses-catalog {
    padding: 100px 5%;
    background: var(--secondary-blue);
}

.catalog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    max-width: 1400px;
    margin: 0 auto;
}

.catalog-card {
    background: var(--card-bg);
    padding: 35px;
    border-radius: 20px;
    border: 2px solid transparent;
    transition: all 0.3s ease;
    position: relative;
}

.catalog-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 80px;
    height: 80px;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.2), transparent);
    border-radius: 0 20px 0 0;
}

.catalog-card:hover {
    border-color: var(--accent-cyan);
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0, 212, 255, 0.3);
}

.catalog-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.catalog-card h3::before {
    content: '⚡';
    font-size: 28px;
    color: var(--lightning-yellow);
}

.course-meta {
    display: flex;
    gap: 15px;
    margin: 20px 0;
    flex-wrap: wrap;
}

.meta-badge {
    padding: 5px 12px;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid var(--accent-cyan);
    border-radius: 15px;
    font-size: 12px;
    color: var(--accent-cyan);
}

.course-description {
    color: var(--text-gray);
    margin: 20px 0;
    line-height: 1.8;
}

.learn-more-btn {
    padding: 12px 30px;
    background: transparent;
    border: 2px solid var(--accent-cyan);
    border-radius: 25px;
    color: var(--text-white);
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 15px;
    width: 100%;
}

.learn-more-btn:hover {
    background: var(--accent-cyan);
    transform: scale(1.05);
}

/* ============================================
   MENTOR SECTION
   ============================================ */
.mentor-section {
    padding: 100px 5%;
}

.mentor-slider-container {
    max-width: 1400px;
    margin: 0 auto;
    overflow: hidden;
}

.mentor-slider {
    display: flex;
    width: 200%;
    animation: mentor-slide 20s infinite ease-in-out;
}

.mentor-card {
    width: 50%;
    background: var(--card-bg);
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
    flex-shrink: 0;
}

@keyframes mentor-slide {
    0%, 40% { transform: translateX(0); }
    50%, 90% { transform: translateX(-50%); }
    100% { transform: translateX(0); }
}

.mentor-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1), rgba(255, 215, 0, 0.1));
    opacity: 0;
    transition: opacity 0.4s ease;
}

.mentor-card:hover::before {
    opacity: 1;
}

.mentor-card:hover {
    border-color: var(--lightning-yellow);
    transform: scale(1.05) rotateY(5deg);
    box-shadow: 0 20px 50px rgba(255, 215, 0, 0.3);
}

.mentor-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    font-size: 50px;
    animation: avatarFloat 3s ease-in-out infinite;
    object-fit: cover;
}

@keyframes avatarFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

.mentor-card h3 {
    font-size: 24px;
    margin-bottom: 10px;
}

.mentor-role {
    color: var(--accent-cyan);
    font-size: 14px;
    margin-bottom: 20px;
}

.mentor-card p {
    color: var(--text-gray);
    line-height: 1.7;
}

/* ============================================
   PLACEMENT SECTION
   ============================================ */
.placement-section {
    padding: 100px 5%;
    background: var(--secondary-blue);
}

.placement-content {
    max-width: 1200px;
    margin: 0 auto;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.stat-card {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.3s ease;
}

.stat-card:hover {
    border-color: var(--accent-cyan);
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 212, 255, 0.3);
}

.stat-number {
    font-size: 56px;
    font-weight: bold;
    background: linear-gradient(135deg, var(--accent-cyan), var(--lightning-yellow));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 15px;
    animation: countGlow 2s ease-in-out infinite;
}

@keyframes countGlow {
    0%, 100% { filter: brightness(1); }
    50% { filter: brightness(1.5); }
}

.stat-label {
    font-size: 18px;
    color: var(--text-gray);
}

.placement-features {
    margin-top: 60px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.placement-feature {
    background: rgba(0, 0, 0, 0.3);
    padding: 30px;
    border-radius: 15px;
    border-left: 4px solid var(--accent-cyan);
}

.placement-feature h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: var(--accent-cyan);
}

/* ============================================
   PROGRESS BAR ANIMATION
   ============================================ */
.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-cyan), var(--lightning-yellow));
    border-radius: 10px;
    animation: progressLoad 3s ease-in-out forwards;
}

@keyframes progressLoad {
    from { width: 0; }
    to { width: 85%; }
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    padding: 80px 5% 30px;
    background: var(--primary-blue);
    border-top: 2px solid rgba(0, 212, 255, 0.2);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 50px;
    margin-bottom: 50px;
}

.footer-section h3 {
    font-size: 22px;
    margin-bottom: 25px;
    color: var(--accent-cyan);
}

.footer-section p,
.footer-section a {
    color: var(--text-gray);
    line-height: 2;
    text-decoration: none;
    display: block;
    transition: all 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent-cyan);
    padding-left: 10px;
}

.social-links {
    display: flex;
    gap: 20px;
    margin-top: 20px;
}

.social-icon {
    width: 45px;
    height: 45px;
    background: var(--card-bg);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.social-icon:hover {
    background: var(--accent-cyan);
    border-color: var(--accent-cyan);
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 212, 255, 0.4);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-gray);
}

/* ============================================
   3D CARD EFFECTS
   ============================================ */
.card-3d {
    transform-style: preserve-3d;
    perspective: 1000px;
}

.card-3d:hover {
    transform: rotateY(10deg) rotateX(10deg);
}

/* ============================================
   FLOATING PARTICLES BACKGROUND
   ============================================ */
.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: -1;
}

.particle {
    position: absolute;
    width: 3px;
    height: 3px;
    background: var(--accent-cyan);
    border-radius: 50%;
    animation: float 15s infinite ease-in-out;
    opacity: 0.3;
}

.particle:nth-child(1) { left: 10%; animation-delay: 0s; }
.particle:nth-child(2) { left: 20%; animation-delay: 2s; }
.particle:nth-child(3) { left: 30%; animation-delay: 4s; }
.particle:nth-child(4) { left: 40%; animation-delay: 6s; }
.particle:nth-child(5) { left: 50%; animation-delay: 8s; }
.particle:nth-child(6) { left: 60%; animation-delay: 10s; }
.particle:nth-child(7) { left: 70%; animation-delay: 12s; }
.particle:nth-child(8) { left: 80%; animation-delay: 14s; }
.particle:nth-child(9) { left: 90%; animation-delay: 16s; }

@keyframes float {
    0%, 100% {
        transform: translateY(100vh) translateX(0);
        opacity: 0;
    }
    10%, 90% {
        opacity: 0.3;
    }
    50% {
        transform: translateY(-100vh) translateX(100px);
    }
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 42px;
    }

    .hero p {
        font-size: 16px;
    }

    .section-title {
        font-size: 36px;
    }

    .nav-links {
        display: none;
    }

    .courses-grid,
    .catalog-grid {
        grid-template-columns: 1fr;
    }

    .lecture-title {
        font-size: 24px;
    }

    .video-demo-space {
        height: 250px;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .cta-btn {
        width: 100%;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        margin-left: 0 !important;
        padding-left: 60px !important;
        padding-right: 0 !important;
        text-align: left !important;
    }

    .timeline-item::before {
        left: 0 !important;
        right: auto !important;
    }

    .intro-logo {
        font-size: 48px;
    }

    .logo-image {
        width: 40px;
        height: 40px;
    }

    .logo-text {
        font-size: 24px;
    }
}

/* ============================================
   SCROLL ANIMATIONS
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.8s ease-out forwards;
}

/* ============================================
   HOVER GLOW EFFECTS
   ============================================ */
.hover-glow:hover {
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.6),
               0 0 40px rgba(0, 212, 255, 0.4),
               0 0 60px rgba(0, 212, 255, 0.2);
}

/* ============================================
   ROTATING ICON ANIMATION
   ============================================ */
@keyframes rotateIcon {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.rotate-icon {
    animation: rotateIcon 20s linear infinite;
}

/* Intro Animation Styles */
.cyber-scene {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: 
        radial-gradient(circle at 30% 20%, rgba(138, 43, 226, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 70% 80%, rgba(0, 255, 255, 0.2) 0%, transparent 50%),
        linear-gradient(135deg, #0a0015 0%, #1a0033 50%, #0d0020 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    z-index: 10001;
    animation: fadeOutCyber 1s ease-in-out 8s forwards;
}

@keyframes fadeOutCyber {
    to {
        opacity: 0;
        visibility: hidden;
    }
}

/* 3D Lightning Bolts */
.lightning-bolt {
    position: absolute;
    width: 4px;
    height: 400px;
    background: linear-gradient(to bottom,
        #fff 0%,
        #00ffff 25%,
        #fff 50%,
        #ff00ff 75%,
        transparent 100%
    );
    box-shadow: 
        0 0 10px #00ffff,
        0 0 20px #00ffff,
        0 0 30px #00ffff,
        0 0 40px #ff00ff;
    transform-style: preserve-3d;
    opacity: 0;
}

.lightning-bolt::before,
.lightning-bolt::after {
    content: '';
    position: absolute;
    width: 4px;
    background: inherit;
    box-shadow: inherit;
}

.lightning-bolt::before {
    height: 120px;
    top: 100px;
    left: -60px;
    transform: rotate(35deg) rotateY(20deg);
}

.lightning-bolt::after {
    height: 150px;
    top: 220px;
    left: 50px;
    transform: rotate(-40deg) rotateY(-20deg);
}

.bolt-1 {
    top: 10%;
    left: 20%;
    transform: translateZ(100px) rotate(15deg);
    animation: bolt-strike-1 5s infinite;
}

.bolt-2 {
    top: 15%;
    right: 25%;
    transform: translateZ(-50px) rotate(-10deg);
    animation: bolt-strike-2 6s infinite 1s;
}

.bolt-3 {
    bottom: 20%;
    left: 30%;
    transform: translateZ(80px) rotate(20deg) rotateY(180deg);
    animation: bolt-strike-3 4.5s infinite 0.5s;
}

.bolt-4 {
    bottom: 15%;
    right: 20%;
    transform: translateZ(-30px) rotate(-15deg) rotateY(180deg);
    animation: bolt-strike-4 5.5s infinite 2s;
}

@keyframes bolt-strike-1 {
    0%, 100% { opacity: 0; transform: translateZ(100px) rotate(15deg) scaleY(0); }
    2% { opacity: 1; transform: translateZ(100px) rotate(15deg) scaleY(1); }
    4% { opacity: 0; }
    5% { opacity: 0.8; }
    6% { opacity: 0; }
}

@keyframes bolt-strike-2 {
    0%, 100% { opacity: 0; transform: translateZ(-50px) rotate(-10deg) scaleY(0); }
    3% { opacity: 1; transform: translateZ(-50px) rotate(-10deg) scaleY(1); }
    5% { opacity: 0; }
    6% { opacity: 1; }
    7% { opacity: 0; }
}

@keyframes bolt-strike-3 {
    0%, 100% { opacity: 0; transform: translateZ(80px) rotate(20deg) rotateY(180deg) scaleY(0); }
    4% { opacity: 1; transform: translateZ(80px) rotate(20deg) rotateY(180deg) scaleY(1); }
    6% { opacity: 0; }
}

@keyframes bolt-strike-4 {
    0%, 100% { opacity: 0; transform: translateZ(-30px) rotate(-15deg) rotateY(180deg) scaleY(0); }
    1% { opacity: 1; transform: translateZ(-30px) rotate(-15deg) rotateY(180deg) scaleY(1); }
    3% { opacity: 0; }
    4% { opacity: 0.7; }
    5% { opacity: 0; }
}

/* Portal Effect */
.portal {
    position: relative;
    width: 400px;
    height: 400px;
    transform-style: preserve-3d;
    animation: portal-rotate 20s linear infinite;
}

@keyframes portal-rotate {
    0% { transform: rotateY(0deg) rotateX(10deg); }
    100% { transform: rotateY(360deg) rotateX(10deg); }
}

.portal-ring {
    position: absolute;
    border-radius: 50%;
    border: 3px solid;
    animation: ring-pulse 2s ease-in-out infinite;
}

.ring-1 {
    width: 400px;
    height: 400px;
    top: 0;
    left: 0;
    border-color: #00ffff;
    box-shadow: 
        0 0 20px #00ffff,
        inset 0 0 20px #00ffff;
    animation-delay: 0s;
}

.ring-2 {
    width: 300px;
    height: 300px;
    top: 50px;
    left: 50px;
    border-color: #ff00ff;
    box-shadow: 
        0 0 20px #ff00ff,
        inset 0 0 20px #ff00ff;
    animation-delay: 0.6s;
}

.ring-3 {
    width: 200px;
    height: 200px;
    top: 100px;
    left: 100px;
    border-color: #ffff00;
    box-shadow: 
        0 0 20px #ffff00,
        inset 0 0 20px #ffff00;
    animation-delay: 1.2s;
}

@keyframes ring-pulse {
    0%, 100% { 
        transform: scale(1) translateZ(0px);
        opacity: 1;
    }
    50% { 
        transform: scale(1.1) translateZ(50px);
        opacity: 0.7;
    }
}

.portal-core {
    position: absolute;
    width: 100px;
    height: 100px;
    top: 150px;
    left: 150px;
    background: radial-gradient(circle, 
        #fff 0%,
        #00ffff 30%,
        #ff00ff 60%,
        transparent 100%
    );
    border-radius: 50%;
    box-shadow: 
        0 0 40px #fff,
        0 0 80px #00ffff,
        0 0 120px #ff00ff;
    animation: core-pulse 1.5s ease-in-out infinite;
}

@keyframes core-pulse {
    0%, 100% { 
        transform: scale(1);
        box-shadow: 
            0 0 40px #fff,
            0 0 80px #00ffff,
            0 0 120px #ff00ff;
    }
    50% { 
        transform: scale(1.2);
        box-shadow: 
            0 0 60px #fff,
            0 0 120px #00ffff,
            0 0 180px #ff00ff;
    }
}

/* Electric Particles */
.particles {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.particle {
    position: absolute;
    width: 3px;
    height: 3px;
    background: #00ffff;
    border-radius: 50%;
    box-shadow: 0 0 10px #00ffff;
    animation: particle-float 4s ease-in-out infinite;
}

.particle:nth-child(1) { top: 20%; left: 10%; animation-delay: 0s; }
.particle:nth-child(2) { top: 40%; left: 80%; animation-delay: 0.5s; background: #ff00ff; box-shadow: 0 0 10px #ff00ff; }
.particle:nth-child(3) { top: 60%; left: 15%; animation-delay: 1s; }
.particle:nth-child(4) { top: 80%; left: 70%; animation-delay: 1.5s; background: #ff00ff; box-shadow: 0 0 10px #ff00ff; }
.particle:nth-child(5) { top: 30%; left: 90%; animation-delay: 2s; }
.particle:nth-child(6) { top: 70%; left: 25%; animation-delay: 2.5s; background: #ff00ff; box-shadow: 0 0 10px #ff00ff; }
.particle:nth-child(7) { top: 15%; left: 60%; animation-delay: 3s; }
.particle:nth-child(8) { top: 85%; left: 50%; animation-delay: 3.5s; background: #ff00ff; box-shadow: 0 0 10px #ff00ff; }

@keyframes particle-float {
    0%, 100% {
        transform: translateY(0) translateX(0) scale(1);
        opacity: 0;
    }
    25% {
        opacity: 1;
    }
    50% {
        transform: translateY(-100px) translateX(50px) scale(1.5);
        opacity: 0.8;
    }
    75% {
        opacity: 0.5;
    }
}

/* Content Overlay with Logo and Loading */
.content-overlay {
    position: relative;
    z-index: 100;
    text-align: center;
    color: #fff;
}

.strike-logo {
    width: 200px;
    height: auto;
    margin-bottom: 20px;
    opacity: 0.8;
}

.loading-bar-container {
    width: 300px;
    height: 10px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 5px;
    overflow: hidden;
    margin: 0 auto;
}

.loading-bar {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, #00ffff, #ff00ff);
    animation: loading-animation 5s ease-in-out forwards;
}

@keyframes loading-animation {
    0% { width: 0%; }
    100% { width: 100%; }
}