/* Reset & Variables */
:root {
    --bg-dark: #050a15;
    --bg-darker: #02040a;
    --text-primary: #f0f4f8;
    --text-secondary: #a0aec0;
    
    /* Sky Blue Theme Colors */
    --accent-primary: #0ea5e9;    /* Sky blue */
    --accent-secondary: #38bdf8;  /* Light sky blue */
    --accent-glow: rgba(14, 165, 233, 0.4);
    
    --card-bg: rgba(15, 23, 42, 0.6);
    --card-border: rgba(56, 189, 248, 0.15);
    
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

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

/* Typography */
h1, h2, h3, h4, h5 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
}

.highlight {
    color: var(--accent-secondary);
    text-shadow: 0 0 15px var(--accent-glow);
}

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

/* Buttons */
.btn-primary {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: #fff;
    padding: 0.75rem 1.75rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-family: var(--font-heading);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 15px var(--accent-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--accent-glow);
}

.btn-primary-outline {
    display: inline-block;
    background: transparent;
    color: var(--accent-secondary);
    padding: 0.5rem 1.25rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-family: var(--font-heading);
    border: 1px solid var(--accent-secondary);
    transition: var(--transition);
}

.btn-primary-outline:hover {
    background: rgba(56, 189, 248, 0.1);
    box-shadow: 0 0 10px var(--accent-glow);
}

.btn-secondary {
    display: inline-block;
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    padding: 0.75rem 1.75rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-family: var(--font-heading);
    border: 1px solid rgba(255,255,255,0.1);
    transition: var(--transition);
}

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

.w-100 {
    width: 100%;
}

/* Glassmorphism utility */
.glass-panel {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: var(--transition);
    padding: 1.5rem 0;
}

.navbar.scrolled {
    padding: 1rem 0;
    background: rgba(2, 4, 10, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--card-border);
}

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

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    color: white;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
    align-items: center;
}

.nav-links a:not(.btn-primary-outline) {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    font-family: var(--font-heading);
}

.nav-links a:not(.btn-primary-outline):hover {
    color: var(--accent-secondary);
}

.hamburger {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 8rem 2rem 4rem;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: url('BIT2.jpeg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    z-index: -2;
}

.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: -1;
}

.hero-bg-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 20s infinite ease-in-out;
}

.shape-1 {
    width: 600px;
    height: 600px;
    background: var(--accent-primary);
    top: -100px;
    left: -200px;
    animation-delay: 0s;
}

.shape-2 {
    width: 500px;
    height: 500px;
    background: #1e3a8a;
    bottom: -100px;
    right: -100px;
    animation-delay: -5s;
}

.shape-3 {
    width: 400px;
    height: 400px;
    background: #0284c7;
    top: 30%;
    left: 40%;
    animation-delay: -10s;
    opacity: 0.2;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    33% { transform: translate(30px, -50px); }
    66% { transform: translate(-20px, 20px); }
}

.hero-content {
    max-width: 900px;
    z-index: 10;
    color: #ffffff;
}

.hero .badge,
.hero-title,
.hero-subtitle,
.hero-meta,
.hero-meta .meta-item,
.hero-actions a {
    color: #ffffff;
}

.hero-subtitle {
    color: rgba(255, 255, 255, 0.8);
}

.hero-actions .btn-secondary {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.25);
}

.hero .badge {
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero .meta-item {
    color: rgba(255, 255, 255, 0.85);
}


.badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(14, 165, 233, 0.15);
    border: 1px solid rgba(14, 165, 233, 0.3);
    border-radius: 30px;
    color: var(--accent-secondary);
    font-weight: 600;
    margin-bottom: 2rem;
    font-size: 0.9rem;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 5rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 700px;
    margin-inline: auto;
}

.hero-meta {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.meta-item i {
    color: var(--accent-secondary);
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

/* Sections Common */
section {
    padding: 6rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.section-title p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 3rem;
    align-items: center;
}

.intro-box {
    padding: 3rem;
}

.intro-box h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.intro-box p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.org-badge {
    margin-top: 2rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.03);
    border-left: 4px solid var(--accent-primary);
    border-radius: 4px;
}

.objectives-box h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

.objectives-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.objectives-list li {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.obj-icon {
    min-width: 40px;
    height: 40px;
    background: rgba(14, 165, 233, 0.1);
    color: var(--accent-secondary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.obj-text {
    font-size: 1.1rem;
    color: var(--text-primary);
    padding-top: 5px;
}

/* Topics Grid */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.topic-card {
    padding: 2.5rem 2rem;
    transition: var(--transition);
    cursor: default;
    position: relative;
    overflow: hidden;
}

.topic-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at top right, rgba(14, 165, 233, 0.1), transparent);
    opacity: 0;
    transition: var(--transition);
}

.topic-card:hover {
    transform: translateY(-10px);
    border-color: rgba(56, 189, 248, 0.4);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.4);
}

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

.topic-icon {
    font-size: 2.5rem;
    color: var(--accent-secondary);
    margin-bottom: 1.5rem;
}

.topic-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

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

/* Speakers Section */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.speaker-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: var(--transition);
}

.speaker-card:hover {
    transform: translateY(-5px);
    border-color: rgba(56, 189, 248, 0.3);
}

.speaker-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-family: var(--font-heading);
    font-weight: 800;
    color: white;
    box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

/* Avatar Gradients */
.avatar-1 { background: linear-gradient(135deg, #0ea5e9, #3b82f6); }
.avatar-2 { background: linear-gradient(135deg, #10b981, #059669); }
.avatar-3 { background: linear-gradient(135deg, #f59e0b, #d97706); }
.avatar-4 { background: linear-gradient(135deg, #8b5cf6, #6d28d9); }
.avatar-5 { background: linear-gradient(135deg, #ec4899, #be185d); }
.avatar-6 { background: linear-gradient(135deg, #06b6d4, #0891b2); }
.avatar-7 { background: linear-gradient(135deg, #6366f1, #4338ca); }
.avatar-8 { background: linear-gradient(135deg, #f43f5e, #e11d48); }

.speaker-info h3 {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.speaker-topic {
    color: var(--accent-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.speaker-bio {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Details Section */
.details-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    padding: 4rem;
}

.detail-items {
    margin-top: 3rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.d-item {
    display: flex;
    gap: 1.5rem;
}

.d-icon {
    font-size: 1.5rem;
    color: var(--accent-secondary);
    padding-top: 5px;
}

.d-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

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

.registration-form {
    background: rgba(0, 0, 0, 0.2);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.registration-form h3 {
    margin-bottom: 2rem;
    font-size: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input {
    width: 100%;
    padding: 1rem 1.25rem;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--card-border);
    color: white;
    font-family: var(--font-body);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-primary);
    background: rgba(255, 255, 255, 0.08);
}

/* Footer */
footer {
    border-top: 1px solid var(--card-border);
    padding: 4rem 0 2rem;
    background: rgba(2, 4, 10, 0.9);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 4rem;
    margin-bottom: 4rem;
}

.footer-logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.footer-grid p {
    color: var(--text-secondary);
    max-width: 400px;
}

.footer-grid h4 {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.footer-grid ul {
    list-style: none;
}

.footer-grid ul li {
    margin-bottom: 0.75rem;
}

.footer-grid ul li a, .footer-grid ul li {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

.footer-grid ul li a:hover {
    color: var(--accent-secondary);
}

.footer-bottom {
    text-align: center;
    color: var(--text-secondary);
    border-top: 1px solid rgba(255,255,255,0.05);
    padding-top: 2rem;
    font-size: 0.9rem;
}

/* Animations */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.5, 0, 0, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 992px) {
    .about-grid, .details-wrapper {
        grid-template-columns: 1fr;
    }
    
    .intro-box {
        padding: 2rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-dark);
        flex-direction: column;
        justify-content: center;
        transition: var(--transition);
        padding: 2rem;
    }

    .nav-links.active {
        left: 0;
    }

    .hamburger {
        display: block;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .details-wrapper {
        padding: 2rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}