/* ===================================
   CSS Variables - Space Neon Theme
   =================================== */
:root {
    /* Colors - Refined for better readability */
    --bg-dark: #0A0E27;
    --bg-darker: #1A1A2E;
    --neon-cyan: #00D4E6;
    --neon-purple: #9D4EDD;
    --neon-pink: #E63946;
    --neon-green: #2ECC71;
    --text-primary: #FFFFFF;
    --text-secondary: #C5D3E8;
    --text-muted: #8B9DC3;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    
    /* Typography */
    --font-heading: 'Orbitron', sans-serif;
    --font-body: 'Rajdhani', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    
    /* Effects - Subtle glow for readability */
    --glow-cyan: 0 0 8px rgba(0, 212, 230, 0.4), 0 0 15px rgba(0, 212, 230, 0.2);
    --glow-purple: 0 0 8px rgba(157, 78, 221, 0.4), 0 0 15px rgba(157, 78, 221, 0.2);
    --glow-pink: 0 0 8px rgba(230, 57, 70, 0.4), 0 0 15px rgba(230, 57, 70, 0.2);
    --glow-green: 0 0 8px rgba(46, 204, 113, 0.4), 0 0 15px rgba(46, 204, 113, 0.2);
    --glow-subtle: 0 0 5px rgba(0, 212, 230, 0.3);
}

/* ===================================
   Reset & Base Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: linear-gradient(135deg, var(--bg-dark) 0%, var(--bg-darker) 100%);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    position: relative;
}

/* ===================================
   Animated Star Background
   =================================== */
.stars-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: white;
    border-radius: 50%;
    animation: twinkle 3s infinite;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* ===================================
   Container & Layout
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4 {
    font-family: var(--font-heading);
    font-weight: 700;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    text-align: center;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 0 8px rgba(0, 212, 230, 0.3));
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1;
    transition: opacity 0.1s ease-out;
}

.logo-text {
    font-family: var(--font-heading);
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 900;
    color: var(--neon-cyan);
    text-shadow: 0 0 10px rgba(0, 212, 230, 0.5);
    margin-bottom: var(--spacing-md);
    letter-spacing: 3px;
}

.hero-title {
    font-size: clamp(2rem, 6vw, 4rem);
    margin-bottom: var(--spacing-md);
    text-shadow: 0 0 15px rgba(157, 78, 221, 0.4);
    line-height: 1.2;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    font-weight: 400;
}

.hero-details {
    font-size: clamp(1rem, 2vw, 1.3rem);
    color: var(--neon-pink);
    margin-bottom: var(--spacing-lg);
    font-weight: 600;
}

/* ===================================
   Buttons
   =================================== */
.cta-button {
    display: inline-block;
    padding: 1rem 3rem;
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
    border: 2px solid var(--neon-cyan);
    border-radius: 50px;
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: 2px;
    box-shadow: var(--glow-cyan);
    transition: all 0.3s ease;
    cursor: pointer;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 20px var(--neon-cyan), 0 0 40px var(--neon-cyan), 0 0 60px var(--neon-cyan);
    background: linear-gradient(135deg, var(--neon-purple), var(--neon-pink));
    border-color: var(--neon-purple);
}

/* ===================================
   Benefits Section
   =================================== */
.benefits {
    padding: var(--spacing-xl) var(--spacing-md);
    background: linear-gradient(180deg, rgba(10, 14, 39, 0.95) 0%, rgba(10, 14, 39, 0.98) 100%);
    position: relative;
    z-index: 2;
    margin-top: 100vh;
    margin-bottom: var(--spacing-xl);
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
    align-items: start;
}

.benefit-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: var(--spacing-lg);
    text-align: center;
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
    min-height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
}

.benefit-card:hover {
    transform: translateY(-10px);
    border-color: var(--neon-cyan);
    box-shadow: var(--glow-cyan);
}

.benefit-icon {
    margin-bottom: var(--spacing-md);
    display: flex;
    justify-content: center;
    align-items: center;
}

.benefit-icon svg {
    width: 64px;
    height: 64px;
    color: var(--neon-cyan);
    filter: drop-shadow(0 0 8px rgba(0, 212, 230, 0.5));
    transition: all 0.3s ease;
}

.benefit-card:hover .benefit-icon svg {
    transform: scale(1.1);
    filter: drop-shadow(0 0 12px rgba(0, 212, 230, 0.7));
}

.benefit-card h3 {
    font-size: 1.8rem;
    color: var(--neon-cyan);
    margin-bottom: var(--spacing-sm);
    text-shadow: none;
}

.benefit-card p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    line-height: 1.6;
}

/* ===================================
   Registration Section
   =================================== */
.registration {
    padding: var(--spacing-xl) var(--spacing-md);
    background: linear-gradient(180deg, rgba(0, 100, 200, 0.15) 0%, rgba(0, 150, 255, 0.1) 100%);
    position: relative;
    z-index: 3;
    margin-top: var(--spacing-xl);
}

.registration-form {
    max-width: 800px;
    margin: 0 auto;
    background: linear-gradient(135deg, rgba(0, 150, 255, 0.12) 0%, rgba(0, 200, 255, 0.08) 100%);
    backdrop-filter: blur(15px);
    border: 2px solid rgba(0, 212, 230, 0.4);
    border-radius: 20px;
    padding: var(--spacing-lg);
    box-shadow: 0 10px 40px rgba(0, 150, 255, 0.2), 0 0 30px rgba(0, 212, 230, 0.15);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    font-size: 1.1rem;
    font-weight: 600;
    color: #00D4FF;
    margin-bottom: var(--spacing-sm);
    text-shadow: 0 0 8px rgba(0, 212, 255, 0.4);
}

.form-input {
    width: 100%;
    padding: 1rem;
    font-family: var(--font-body);
    font-size: 1rem;
    color: var(--text-primary);
    background: rgba(0, 100, 200, 0.15);
    border: 2px solid rgba(0, 180, 255, 0.3);
    border-radius: 10px;
    transition: all 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: #00D4FF;
    background: rgba(0, 120, 220, 0.2);
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.5), 0 0 25px rgba(0, 180, 255, 0.2);
}

.checkbox-grid,
.radio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-sm);
}

.checkbox-label,
.radio-label {
    display: flex;
    align-items: center;
    padding: 0.8rem;
    background: rgba(0, 100, 200, 0.12);
    border: 2px solid rgba(0, 180, 255, 0.25);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.checkbox-label:hover,
.radio-label:hover {
    background: rgba(0, 120, 220, 0.2);
    border-color: #00D4FF;
    box-shadow: 0 0 10px rgba(0, 212, 255, 0.3);
}

.checkbox-label input,
.radio-label input {
    margin-right: var(--spacing-xs);
    cursor: pointer;
    accent-color: #00D4FF;
    width: 18px;
    height: 18px;
}

.checkbox-label span,
.radio-label span {
    font-size: 1rem;
    color: #E0F0FF;
    font-weight: 500;
}

.form-error {
    color: var(--neon-pink);
    font-size: 0.9rem;
    margin-top: var(--spacing-sm);
    text-align: center;
    min-height: 1.5rem;
}

.submit-button {
    width: 100%;
    padding: 1.2rem;
    font-family: var(--font-heading);
    font-size: 1.3rem;
    font-weight: 700;
    color: #FFFFFF;
    background: linear-gradient(135deg, #0080FF 0%, #00B4FF 100%);
    border: 2px solid #00D4FF;
    border-radius: 50px;
    text-transform: uppercase;
    letter-spacing: 2px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 0 20px rgba(0, 180, 255, 0.5), 0 0 35px rgba(0, 212, 255, 0.3);
}

.submit-button:hover {
    transform: translateY(-3px);
    background: linear-gradient(135deg, #00A0FF 0%, #00D4FF 100%);
    box-shadow: 0 0 30px rgba(0, 180, 255, 0.7), 0 0 50px rgba(0, 212, 255, 0.5), 0 0 70px rgba(0, 180, 255, 0.3);
}

.submit-button:active {
    transform: translateY(0);
}

/* ===================================
   Speakers Section
   =================================== */
.speakers {
    padding: var(--spacing-xl) var(--spacing-md);
    background: linear-gradient(180deg, rgba(26, 26, 46, 0.95) 0%, rgba(10, 14, 39, 0.95) 100%);
    position: relative;
    z-index: 4;
    margin-top: var(--spacing-xl);
}

.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: calc(var(--spacing-lg) * 1.5);
    margin-top: var(--spacing-lg);
    justify-items: center;
    align-items: start;
}

.speaker-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: var(--spacing-md);
    text-align: center;
    transition: all 0.3s ease;
    width: 100%;
    max-width: 350px;
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.speaker-card:hover {
    transform: translateY(-10px);
    border-color: var(--neon-purple);
    box-shadow: var(--glow-purple);
}

.speaker-photo {
    width: 100%;
    height: auto;
    aspect-ratio: 1;
    margin: 0 auto var(--spacing-md);
    border-radius: 15px;
    object-fit: contain;
    box-shadow: var(--glow-cyan);
    transition: all 0.3s ease;
}

.speaker-card:hover .speaker-photo {
    box-shadow: 0 0 20px var(--neon-purple), 0 0 30px var(--neon-purple);
    transform: scale(1.05);
}

.speaker-card h3 {
    font-size: 1.8rem;
    color: var(--neon-cyan);
    margin-bottom: var(--spacing-xs);
    line-height: 1.3;
}

.speaker-title {
    font-size: 1.2rem;
    color: var(--neon-purple);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.speaker-bio {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.speakers-more {
    text-align: center;
    margin-top: var(--spacing-lg);
    padding: var(--spacing-lg);
}

.speakers-more h3 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-family: var(--font-heading);
    font-weight: 900;
    background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple), var(--neon-pink));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
    filter: drop-shadow(0 0 10px rgba(0, 212, 230, 0.4));
    letter-spacing: 3px;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        filter: drop-shadow(0 0 10px rgba(0, 212, 230, 0.4));
    }
    50% {
        filter: drop-shadow(0 0 20px rgba(157, 78, 221, 0.6));
    }
}

/* ===================================
   Thank You Page
   =================================== */
.thank-you-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl) var(--spacing-md);
}

.thank-you-content {
    text-align: center;
    max-width: 900px;
}

.success-checkmark {
    margin-bottom: var(--spacing-lg);
}

.checkmark {
    width: 120px;
    height: 120px;
    margin: 0 auto;
    display: block;
}

.checkmark-circle {
    stroke: var(--neon-green);
    stroke-width: 2;
    stroke-dasharray: 166;
    stroke-dashoffset: 166;
    animation: stroke 0.6s cubic-bezier(0.65, 0, 0.45, 1) forwards;
    filter: drop-shadow(var(--glow-green));
}

.checkmark-check {
    stroke: var(--neon-green);
    stroke-width: 3;
    stroke-linecap: round;
    stroke-dasharray: 48;
    stroke-dashoffset: 48;
    animation: stroke 0.3s cubic-bezier(0.65, 0, 0.45, 1) 0.6s forwards;
    filter: drop-shadow(var(--glow-green));
}

@keyframes stroke {
    100% {
        stroke-dashoffset: 0;
    }
}

.thank-you-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    color: var(--neon-green);
    text-shadow: 0 0 12px rgba(46, 204, 113, 0.5);
    margin-bottom: var(--spacing-md);
}

.thank-you-message {
    font-size: clamp(1.2rem, 3vw, 1.5rem);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

.info-blocks {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    align-items: start;
}

.info-block {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: var(--spacing-md);
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
    min-height: 200px;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
}

.info-block:hover {
    border-color: var(--neon-cyan);
    box-shadow: var(--glow-cyan);
}

.info-icon {
    margin-bottom: var(--spacing-sm);
    display: flex;
    justify-content: center;
    align-items: center;
}

.info-icon svg {
    width: 48px;
    height: 48px;
    color: var(--neon-cyan);
    filter: drop-shadow(0 0 6px rgba(0, 212, 230, 0.4));
    transition: all 0.3s ease;
}

.info-block:hover .info-icon svg {
    transform: scale(1.1);
    filter: drop-shadow(0 0 10px rgba(0, 212, 230, 0.6));
}

.info-block h3 {
    font-size: 1.5rem;
    color: var(--neon-cyan);
    margin-bottom: var(--spacing-sm);
}

.info-block p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: rgba(10, 14, 39, 0.8);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--glass-border);
    padding: var(--spacing-lg) var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.footer-section h4 {
    color: var(--neon-cyan);
    margin-bottom: var(--spacing-sm);
    font-size: 1.2rem;
}

.footer-logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--neon-cyan);
    text-shadow: var(--glow-cyan);
    margin-bottom: var(--spacing-sm);
}

.footer-section p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: var(--spacing-xs);
}

.social-icons {
    display: flex;
    gap: var(--spacing-sm);
}

.social-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 50%;
    color: var(--neon-cyan);
    text-decoration: none;
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.social-icon:hover {
    background: var(--neon-cyan);
    color: var(--bg-dark);
    box-shadow: var(--glow-cyan);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--glass-border);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ===================================
   Animations
   =================================== */
.fade-in {
    animation: fadeIn 1s ease-in;
}

.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease-out forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

/* Stagger animation delays for multiple elements */
.fade-in-up:nth-child(1) { animation-delay: 0.1s; }
.fade-in-up:nth-child(2) { animation-delay: 0.2s; }
.fade-in-up:nth-child(3) { animation-delay: 0.3s; }
.fade-in-up:nth-child(4) { animation-delay: 0.4s; }
.fade-in-up:nth-child(5) { animation-delay: 0.5s; }
.fade-in-up:nth-child(6) { animation-delay: 0.6s; }

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    .benefits-grid {
        grid-template-columns: 1fr;
    }
    
    .speakers-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .checkbox-grid,
    .radio-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .social-icons {
        justify-content: center;
    }
    
    .hero {
        min-height: 80vh;
    }
    
    .benefits {
        margin-top: 80vh;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-md: 1rem;
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
    }
    
    .cta-button {
        padding: 0.8rem 2rem;
        font-size: 1rem;
    }
    
    .registration-form {
        padding: var(--spacing-md);
    }
}

/* ===================================
   Accessibility
   =================================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
a:focus,
button:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid var(--neon-cyan);
    outline-offset: 2px;
}