/* ================================
   PHYSTALK - ENHANCED STYLESHEET
   Performance Optimized & Space-Themed
   ================================ */

/* CSS Variables for consistent theming */
:root {
    /* Updated lighter theme to match homepage */
    --primary-bg: #0f1629;
    --secondary-bg: #1e293b;
    --accent-bg: #334155;
    --primary-blue: #60a5fa;
    --secondary-blue: #3b82f6;
    --light-blue: #93c5fd;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: #475569;
    --hover-blue: #2563eb;
    --gradient-primary: linear-gradient(135deg, #60a5fa, #3b82f6);
    --gradient-secondary: linear-gradient(135deg, #1e293b, #334155);
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

/* Performance optimizations */
*,
*::before,
*::after {
    box-sizing: border-box;
}

/* Global Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', 'Segoe UI', system-ui, sans-serif;
    background: var(--primary-bg);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    position: relative;
}

/* Enhanced space elements for all pages - matching homepage */
body::before {
    content: '';
    position: fixed;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: 
        radial-gradient(circle at 25% 25%, rgba(96, 165, 250, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(147, 197, 253, 0.06) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(59, 130, 246, 0.04) 0%, transparent 70%);
    z-index: -1;
    animation: cosmicDrift 60s linear infinite;
    pointer-events: none;
}

/* Enhanced floating space particles */
body::after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(1px 1px at 20px 30px, rgba(255, 255, 255, 0.15), transparent),
        radial-gradient(1px 1px at 40px 70px, rgba(255, 255, 255, 0.12), transparent),
        radial-gradient(0.5px 0.5px at 90px 40px, rgba(255, 255, 255, 0.1), transparent),
        radial-gradient(0.5px 0.5px at 130px 80px, rgba(255, 255, 255, 0.08), transparent),
        radial-gradient(1px 1px at 200px 150px, rgba(96, 165, 250, 0.1), transparent),
        radial-gradient(0.5px 0.5px at 350px 200px, rgba(147, 197, 253, 0.08), transparent);
    background-repeat: repeat;
    background-size: 400px 300px;
    z-index: -1;
    animation: particleDrift 120s linear infinite;
    pointer-events: none;
}

/* Skip link for accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--primary-blue);
    color: white;
    padding: 8px 12px;
    text-decoration: none;
    z-index: 1000;
    border-radius: 4px;
    font-weight: 500;
    transition: top 0.2s;
}

.skip-link:focus {
    top: 6px;
}

/* Loading Spinner */
.loading-spinner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--primary-bg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s, visibility 0.5s;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--accent-bg);
    border-top: 4px solid var(--primary-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

.loading-spinner p {
    color: var(--text-secondary);
    font-weight: 500;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes cosmicDrift {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes particleDrift {
    0% { transform: translateY(0px); }
    100% { transform: translateY(-300px); }
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ================================
   HEADER & NAVIGATION - FIXED DROPDOWN Z-INDEX
   ================================ */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 22, 41, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
    overflow: visible; /* IMPORTANT: Allow dropdown to be visible */
}

.header.scrolled {
    background: rgba(15, 22, 41, 0.98);
    box-shadow: var(--shadow-md);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    position: relative; /* IMPORTANT: For dropdown positioning */
}

/* Enhanced Logo Styles */
.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.logo-img {
    width: 32px;
    height: 32px;
    transform: none;
    filter: drop-shadow(0 0 8px var(--primary-blue));
    transition: var(--transition);
}

.logo-img:hover {
    filter: drop-shadow(0 0 12px var(--primary-blue)) brightness(1.1);
    transform: scale(1.05);
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    letter-spacing: -0.5px;
}

/* Enhanced Navigation Menu - FIXED COMMUNITY OVERFLOW */
.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem; /* Reduced gap to fit Community better */
    position: relative;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 0.8rem; /* Adjusted padding for better fit */
    border-radius: var(--border-radius);
    transition: var(--transition);
    position: relative;
    white-space: nowrap; /* Prevent text wrapping */
    font-size: 0.95rem; /* Slightly smaller to fit better */
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: var(--transition);
    transform: translateX(-50%);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-blue);
    background: rgba(96, 165, 250, 0.1);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 80%;
}

/* FIXED: Navigation Dropdown Styles with proper Z-INDEX */
.nav-dropdown {
    position: relative;
    display: flex;
    align-items: center;
}

.dropdown-arrow {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    margin-left: -0.5rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.dropdown-arrow:hover {
    color: var(--primary-blue);
    background: rgba(96, 165, 250, 0.1);
}

.dropdown-arrow i {
    transition: transform 0.3s ease;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    min-width: 200px;
    z-index: 9999; /* CRITICAL: High z-index to show above everything */
    margin-top: 0.5rem;
}

.dropdown-menu.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    border-bottom: 1px solid var(--border-color);
}

.dropdown-item:last-child {
    border-bottom: none;
}

.dropdown-item:hover,
.dropdown-item.active {
    background: var(--accent-bg);
    color: var(--primary-blue);
}

.dropdown-item i {
    width: 16px;
    text-align: center;
}

/* Mobile Navigation */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    background: none;
    border: none;
    padding: 0.5rem;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
}

/* ================================
   MAIN CONTENT
   ================================ */

.main-content {
    margin-top: 80px;
    position: relative;
}

/* ================================
   ENHANCED HERO SECTION - MATCHING HOMEPAGE
   ================================ */

.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

/* Enhanced space background for hero - from homepage */
.space-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: radial-gradient(ellipse at 20% 50%, rgba(96, 165, 250, 0.15) 0%, transparent 50%), 
                radial-gradient(ellipse at 80% 20%, rgba(147, 197, 253, 0.12) 0%, transparent 50%), 
                radial-gradient(ellipse at 40% 80%, rgba(59, 130, 246, 0.18) 0%, transparent 50%), 
                linear-gradient(135deg, #0f1629 0%, #1e293b 50%, #0f1629 100%);
}

/* Enhanced Star Field with Multiple Layers - from homepage */
.star-field {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        /* Large bright stars */
        radial-gradient(2px 2px at 20px 30px, #ffffff, transparent),
        radial-gradient(2px 2px at 40px 70px, rgba(255, 255, 255, 0.9), transparent),
        radial-gradient(1px 1px at 90px 40px, #ffffff, transparent),
        radial-gradient(1px 1px at 130px 80px, rgba(255, 255, 255, 0.7), transparent),
        radial-gradient(2px 2px at 160px 30px, #ffffff, transparent),
        /* Medium stars */
        radial-gradient(1px 1px at 200px 50px, rgba(147, 197, 253, 0.8), transparent),
        radial-gradient(1px 1px at 250px 100px, rgba(96, 165, 250, 0.8), transparent),
        radial-gradient(1px 1px at 300px 20px, rgba(255, 255, 255, 0.6), transparent),
        /* Small distant stars */
        radial-gradient(0.5px 0.5px at 80px 120px, rgba(255, 255, 255, 0.4), transparent),
        radial-gradient(0.5px 0.5px at 180px 60px, rgba(255, 255, 255, 0.3), transparent),
        radial-gradient(0.5px 0.5px at 320px 140px, rgba(255, 255, 255, 0.4), transparent);
    background-repeat: repeat;
    background-size: 350px 200px;
    animation: twinkle 6s ease-in-out infinite alternate;
}

/* Blue planets and nebulas - from homepage */
.blue-nebula-1 {
    position: absolute;
    width: 400px;
    height: 250px;
    top: 10%;
    right: 15%;
    background: radial-gradient(ellipse 60% 40% at 30% 70%, 
                rgba(96, 165, 250, 0.4) 0%, 
                rgba(147, 197, 253, 0.3) 25%, 
                rgba(59, 130, 246, 0.2) 50%, 
                transparent 75%);
    border-radius: 60% 40% 70% 30%;
    filter: blur(2px);
    animation: nebulaPulse 15s ease-in-out infinite alternate;
}

.blue-nebula-2 {
    position: absolute;
    width: 300px;
    height: 180px;
    bottom: 20%;
    left: 20%;
    background: radial-gradient(ellipse 50% 60% at 70% 30%, 
                rgba(147, 197, 253, 0.4) 0%, 
                rgba(96, 165, 250, 0.3) 40%, 
                rgba(59, 130, 246, 0.2) 60%, 
                transparent 80%);
    border-radius: 50% 60% 40% 70%;
    filter: blur(1.5px);
    animation: nebulaPulse 12s ease-in-out infinite alternate;
    animation-delay: -5s;
}

.grey-planet-1 {
    position: absolute;
    width: 80px;
    height: 80px;
    top: 25%;
    left: 15%;
    background: radial-gradient(circle at 30% 30%, 
                rgba(148, 163, 184, 0.9) 0%, 
                rgba(100, 116, 139, 0.7) 50%, 
                rgba(71, 85, 105, 0.5) 100%);
    border-radius: 50%;
    box-shadow: inset -10px -10px 20px rgba(0, 0, 0, 0.4);
    animation: planetFloat 12s ease-in-out infinite;
}

.blue-planet {
    position: absolute;
    width: 60px;
    height: 60px;
    top: 60%;
    right: 25%;
    background: radial-gradient(circle at 30% 30%, 
                rgba(96, 165, 250, 0.9) 0%, 
                rgba(59, 130, 246, 0.7) 50%, 
                rgba(37, 99, 235, 0.5) 100%);
    border-radius: 50%;
    box-shadow: inset -8px -8px 15px rgba(0, 0, 0, 0.3);
    animation: planetFloat 15s ease-in-out infinite;
    animation-delay: -7s;
}

/* Enhanced Hero Content */
.hero-content {
    text-align: center;
    z-index: 10;
    max-width: 800px;
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -2px;
    animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-weight: 400;
    animation: fadeInUp 1s ease-out 0.2s both;
}

/* ================================
   ENHANCED ANIMATIONS
   ================================ */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes planetFloat {
    0%, 100% { 
        transform: translateY(0px) scale(1);
        opacity: 0.6;
    }
    50% { 
        transform: translateY(-15px) scale(1.1);
        opacity: 1;
    }
}

@keyframes nebulaPulse {
    0%, 100% { 
        opacity: 0.3; 
        transform: scale(1); 
    }
    50% { 
        opacity: 0.6; 
        transform: scale(1.05); 
    }
}

@keyframes twinkle {
    0%, 100% { opacity: 0.8; }
    50% { opacity: 0.4; }
}

/* ================================
   FLOATING SPACE ELEMENTS FOR ALL PAGES
   ================================ */

/* Space background elements for all pages */
.page-space-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
    overflow: hidden;
}

.floating-planet {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, rgba(148, 163, 184, 0.8), rgba(100, 116, 139, 0.6), rgba(71, 85, 105, 0.4));
    box-shadow: inset -5px -5px 15px rgba(0, 0, 0, 0.3);
    animation: planetFloat 12s ease-in-out infinite;
}

.planet-1 {
    width: 40px;
    height: 40px;
    top: 15%;
    right: 8%;
    animation-delay: 0s;
}

.planet-2 {
    width: 25px;
    height: 25px;
    top: 70%;
    left: 5%;
    background: radial-gradient(circle at 30% 30%, rgba(96, 165, 250, 0.8), rgba(59, 130, 246, 0.6), rgba(37, 99, 235, 0.4));
    animation-delay: -6s;
}

.floating-nebula {
    position: absolute;
    border-radius: 60% 40% 70% 30%;
    filter: blur(1px);
    animation: nebulaPulse 15s ease-in-out infinite alternate;
}

.nebula-1 {
    width: 120px;
    height: 80px;
    top: 30%;
    right: 15%;
    background: radial-gradient(ellipse 60% 40% at 30% 70%, 
                rgba(96, 165, 250, 0.3) 0%, 
                rgba(147, 197, 253, 0.2) 50%, 
                transparent 75%);
    animation-delay: 0s;
}

.nebula-2 {
    width: 80px;
    height: 50px;
    bottom: 25%;
    left: 10%;
    background: radial-gradient(ellipse 50% 60% at 70% 30%, 
                rgba(59, 130, 246, 0.3) 0%, 
                rgba(96, 165, 250, 0.2) 50%, 
                transparent 75%);
    animation-delay: -7s;
}

.cosmic-dust {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(1px 1px at 20px 30px, rgba(255, 255, 255, 0.15), transparent),
        radial-gradient(1px 1px at 40px 70px, rgba(255, 255, 255, 0.12), transparent),
        radial-gradient(0.5px 0.5px at 90px 40px, rgba(255, 255, 255, 0.1), transparent),
        radial-gradient(0.5px 0.5px at 130px 80px, rgba(255, 255, 255, 0.08), transparent);
    background-repeat: repeat;
    background-size: 150px 120px;
    animation: cosmicDrift 100s linear infinite;
}

.distant-stars {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(0.5px 0.5px at 15% 25%, rgba(255, 255, 255, 0.8), transparent),
        radial-gradient(0.5px 0.5px at 85% 15%, rgba(147, 197, 253, 0.6), transparent),
        radial-gradient(0.5px 0.5px at 70% 80%, rgba(96, 165, 250, 0.7), transparent),
        radial-gradient(0.5px 0.5px at 25% 60%, rgba(255, 255, 255, 0.5), transparent);
    animation: twinkle 8s ease-in-out infinite alternate;
}

/* ================================
   ENHANCED BUTTONS
   ================================ */

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1s ease-out 0.4s both;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.btn::before {
    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 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-secondary:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateY(-2px);
}

/* ================================
   ENHANCED FEATURES SECTION
   ================================ */

.features {
    padding: 5rem 0;
    background: var(--secondary-bg);
    position: relative;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    width: 60px;
    height: 3px;
    background: var(--gradient-primary);
    transform: translateX(-50%);
    border-radius: 2px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

/* Enhanced Feature Cards */
.feature-card {
    background: var(--accent-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.6s ease-out forwards;
}

.feature-card:nth-child(1) { animation-delay: 0.1s; }
.feature-card:nth-child(2) { animation-delay: 0.2s; }
.feature-card:nth-child(3) { animation-delay: 0.3s; }
.feature-card:nth-child(4) { animation-delay: 0.4s; }
.feature-card:nth-child(5) { animation-delay: 0.5s; }
.feature-card:nth-child(6) { animation-delay: 0.6s; }

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(96, 165, 250, 0.1), transparent);
    transition: left 0.6s;
}

.feature-card:hover::before {
    left: 100%;
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-blue);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    font-size: 3rem;
    color: var(--primary-blue);
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1);
    color: var(--light-blue);
}

.feature-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.feature-link {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.feature-link:hover {
    color: var(--light-blue);
    transform: translateX(3px);
}

/* Feature Badges */
.feature-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.feature-badge.popular {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: white;
}

.feature-badge.new {
    background: linear-gradient(135deg, #10b981, #059669);
    color: white;
}

/* ================================
   ENHANCED ABOUT SECTION
   ================================ */

.about {
    padding: 5rem 0;
    background: var(--primary-bg);
    position: relative;
}

.about-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.about-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    line-height: 1.8;
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.stat {
    text-align: center;
    padding: 1.5rem;
    background: var(--secondary-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.stat:hover {
    transform: translateY(-3px);
    border-color: var(--primary-blue);
}

.stat h3 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
}

.stat p {
    color: var(--text-secondary);
    font-weight: 500;
}

.about-cta {
    margin-top: 3rem;
    padding: 2rem;
    background: var(--secondary-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.about-cta h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.about-cta p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* ================================
   NEWSLETTER SECTION
   ================================ */

.newsletter {
    padding: 4rem 0;
    background: var(--secondary-bg);
    border-top: 1px solid var(--border-color);
    position: relative;
}

.newsletter-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.newsletter h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.newsletter p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

.newsletter-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.newsletter-form input {
    flex: 1;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--accent-bg);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.1);
}

.error-message,
.success-message {
    display: none;
    padding: 0.75rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    text-align: left;
}

.error-message {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid #ef4444;
    color: #ef4444;
}

.success-message {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid #10b981;
    color: #10b981;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ================================
   ENHANCED FOOTER
   ================================ */

.footer {
    background: var(--secondary-bg);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1rem;
    position: relative;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 600;
}

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

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--primary-blue);
}

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

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--accent-bg);
    border-radius: 50%;
    color: var(--text-secondary);
    transition: var(--transition);
}

.social-link:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateY(-2px);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    flex-wrap: wrap;
    gap: 1rem;
}

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

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-blue);
}

.footer-stats {
    margin-top: 1rem;
}

.footer-stats small {
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* ================================
   BACK TO TOP BUTTON
   ================================ */

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

/* ================================
   SHARED PAGE STYLES
   ================================ */

.page-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: calc(100vh - 160px);
    position: relative;
}

.page-header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.content-section {
    background: var(--accent-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.content-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 2px;
    background: var(--gradient-primary);
    transition: left 0.8s;
}

.content-section:hover::before {
    left: 100%;
}

.content-section:hover {
    border-color: rgba(96, 165, 250, 0.3);
}

.section-title {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ================================
   IFRAME FIXES - DARK THEME FOR EMBEDS
   ================================ */

/* Calendar iframe dark theme */
.calendar-container iframe,
.embedded-calendar {
    background: #242424 !important;
    border: 2px solid var(--border-color) !important;
    border-radius: var(--border-radius) !important;
    filter: invert(0.9) hue-rotate(180deg) !important;
}

/* Desmos calculator dark theme */
.desmos-calculator {
    background: var(--secondary-bg) !important;
    border: 2px solid var(--border-color) !important;
    border-radius: var(--border-radius) !important;
    filter: invert(0.85) hue-rotate(180deg) contrast(1.1) !important;
}

/* Drive iframes dark theme */
.drive-iframe,
.paper-iframe {
    background: var(--secondary-bg) !important;
    border: none !important;
    filter: invert(0.9) hue-rotate(180deg) contrast(1.1) brightness(0.9) !important;
}

/* Enhanced iframe containers */
.drive-embed-container,
.paper-embed-container {
    background: var(--secondary-bg);
    border-radius: var(--border-radius);
    overflow: hidden;
    position: relative;
}

/* Enhanced loading overlays */
.drive-overlay,
.paper-overlay {
    background: var(--secondary-bg);
    color: var(--text-secondary);
}

.drive-loading,
.paper-loading {
    color: var(--text-secondary);
}

.drive-loading i,
.paper-loading i {
    color: var(--primary-blue);
}

/* ================================
   ENHANCED RESEARCH CATEGORIES
   ================================ */

.categories-section {
    background: var(--accent-bg);
    border: 1px solid var(--border-color);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.category-card {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(96, 165, 250, 0.05), transparent);
    transition: left 0.6s;
}

.category-card:hover::before {
    left: 100%;
}

.category-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-blue);
    box-shadow: 0 10px 30px rgba(96, 165, 250, 0.2);
}

.category-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    transition: var(--transition);
}

.category-card:hover .category-icon {
    transform: scale(1.1);
}

/* Category-specific colors */
.category-card.nuclear .category-icon { color: #f59e0b; }
.category-card.electromagnetic .category-icon { color: #60a5fa; }
.category-card.quantum .category-icon { color: #a78bfa; }
.category-card.thermal .category-icon { color: #f87171; }
.category-card.cosmology .category-icon { color: #34d399; }
.category-card.solid-state .category-icon { color: #818cf8; }

.category-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.category-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.5;
    font-size: 0.9rem;
}

.view-papers-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient-primary);
    color: white;
    text-decoration: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    font-size: 0.9rem;
}

.view-papers-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(96, 165, 250, 0.3);
}

/* ================================
   ENHANCED DRIVE SECTIONS
   ================================ */

.drive-section {
    background: var(--secondary-bg);
    border: 2px solid var(--primary-blue);
    position: relative;
    overflow: hidden;
}

.drive-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 4px;
    background: var(--gradient-primary);
    transition: left 0.8s;
}

.drive-section:hover::before {
    left: 100%;
}

.drive-header {
    background: linear-gradient(135deg, var(--accent-bg), var(--secondary-bg));
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem;
}

.drive-header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
}

.drive-info {
    flex: 1;
}

.drive-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.drive-title i {
    color: #4285f4;
    font-size: 1.3rem;
}

.drive-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

.drive-controls {
    display: flex;
    gap: 1rem;
}

.drive-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    text-decoration: none;
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
}

.drive-btn.primary {
    background: var(--gradient-primary);
    color: white;
}

.drive-btn.secondary {
    background: var(--accent-bg);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.drive-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(96, 165, 250, 0.3);
}

.drive-btn.secondary:hover:not(:disabled) {
    color: var(--primary-blue);
    border-color: var(--primary-blue);
}

.drive-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* ================================
   RESPONSIVE DESIGN - FIXED COMMUNITY TEXT
   ================================ */

@media (max-width: 1024px) {
    .nav-menu {
        gap: 1rem; /* Further reduce gap for smaller screens */
    }
    
    .nav-link {
        font-size: 0.9rem;
        padding: 0.5rem 0.6rem;
    }
}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 80px;
        flex-direction: column;
        background-color: var(--secondary-bg);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        border-top: 1px solid var(--border-color);
        padding: 2rem 0;
        box-shadow: var(--shadow-lg);
        gap: 0.5rem; /* Reset gap for mobile */
    }

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

    .nav-link {
        font-size: 1rem; /* Reset font size for mobile */
        padding: 0.75rem 1rem; /* Reset padding for mobile */
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .stats {
        grid-template-columns: 1fr;
    }

    .form-group {
        flex-direction: column;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    /* Mobile dropdown adjustments */
    .dropdown-menu {
        left: -50px;
        right: 0;
    }

    .nav-dropdown {
        position: static;
    }

    .nav-menu.active .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        background: var(--accent-bg);
        border: none;
        box-shadow: none;
        margin: 0.5rem 0;
        z-index: 1;
    }

    /* Mobile space elements */
    .floating-planet, .floating-nebula {
        display: none;
    }

    .blue-nebula-1, .blue-nebula-2, .grey-planet-1, .blue-planet {
        display: none;
    }

    /* Mobile drive sections */
    .drive-header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .drive-controls {
        width: 100%;
        justify-content: center;
    }

    .drive-btn {
        flex: 1;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .navbar {
        padding: 1rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .container {
        padding: 0 1rem;
    }

    .hero-content {
        padding: 1rem;
    }

    .feature-card {
        padding: 1.5rem;
    }

    .page-container {
        padding: 1rem;
    }

    .drive-controls {
        flex-direction: column;
    }
}

/* ================================
   PERFORMANCE OPTIMIZATIONS
   ================================ */

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #ffffff;
        --text-secondary: #ffffff;
    }
}