/* NASA Astronaut Health AI System - Professional Styling */

/* ============================================================================
   CSS Variables & Theme
   ============================================================================ */
:root {
    /* NASA Color Palette */
    --nasa-blue: #0B3D91;
    --nasa-red: #FC3D21;
    --nasa-dark: #000B1F;
    --nasa-light: #F0F4F8;
    --space-black: #0A0E1A;
    --star-white: #FFFFFF;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #0B3D91 0%, #1E5A9A 100%);
    --gradient-secondary: linear-gradient(135deg, #FC3D21 0%, #FF6B4A 100%);
    --gradient-space: linear-gradient(180deg, #000B1F 0%, #0B1B2B 50%, #0B3D91 100%);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 12px 48px rgba(0, 0, 0, 0.3);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Orbitron', monospace;
}

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

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

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--space-black);
    background: var(--nasa-light);
    overflow-x: hidden;
}

/* ============================================================================
   Typography
   ============================================================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

/* ============================================================================
   Layout Components
   ============================================================================ */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 2.5rem;
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: #5A6C7D;
    max-width: 800px;
    margin: 0 auto;
}

/* ============================================================================
   Navigation
   ============================================================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nasa-logo {
    height: 50px;
    width: auto;
}

.nav-title {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--nasa-blue);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    font-weight: 500;
    color: var(--space-black);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    transition: all 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--nasa-blue);
    background: rgba(11, 61, 145, 0.1);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--nasa-blue);
    cursor: pointer;
}

/* ============================================================================
   Hero Section
   ============================================================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--gradient-space);
    color: var(--star-white);
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

/* Animated Stars */
@keyframes animateStars {
    from { transform: translateY(0px); }
    to { transform: translateY(-2000px); }
}

.stars, .stars2, .stars3 {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 200%;
    background: transparent;
}

.stars {
    background: radial-gradient(2px 2px at 20px 30px, #eee, rgba(0,0,0,0)),
                radial-gradient(2px 2px at 60px 70px, #fff, rgba(0,0,0,0)),
                radial-gradient(2px 2px at 120px 150px, #ddd, rgba(0,0,0,0));
    background-size: 200px 200px;
    animation: animateStars 100s linear infinite;
}

.stars2 {
    background: radial-gradient(1px 1px at 50px 50px, #fff, rgba(0,0,0,0)),
                radial-gradient(1px 1px at 100px 120px, #eee, rgba(0,0,0,0));
    background-size: 250px 250px;
    animation: animateStars 150s linear infinite;
}

.stars3 {
    background: radial-gradient(1px 1px at 75px 75px, #ddd, rgba(0,0,0,0)),
                radial-gradient(1px 1px at 175px 175px, #fff, rgba(0,0,0,0));
    background-size: 300px 300px;
    animation: animateStars 200s linear infinite;
}

.hero-content {
    position: relative;
    z-index: 10;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

.title-main {
    display: block;
    font-weight: 900;
    background: linear-gradient(135deg, #FFFFFF 0%, #A0C4FF 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.title-sub {
    display: block;
    font-weight: 400;
    font-size: 2.5rem;
    color: rgba(255, 255, 255, 0.9);
}

.hero-description {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
    color: rgba(255, 255, 255, 0.9);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
}

.stat {
    text-align: center;
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--star-white);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 1rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background: var(--gradient-secondary);
    color: var(--star-white);
    box-shadow: 0 4px 16px rgba(252, 61, 33, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(252, 61, 33, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--star-white);
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.5);
}

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

/* Hero Visual */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.astronaut-card {
    position: relative;
    width: 300px;
    height: 400px;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.card-glow {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 50%, rgba(160, 196, 255, 0.3) 0%, transparent 70%);
    animation: pulse 3s ease-in-out infinite;
}

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

.astronaut-icon {
    font-size: 8rem;
    color: var(--star-white);
    margin-bottom: var(--spacing-md);
    z-index: 2;
}

.health-indicators {
    z-index: 2;
}

.indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(46, 213, 115, 0.2);
    border-radius: 20px;
    font-size: 0.875rem;
}

.indicator.pulse i {
    animation: heartbeat 1.5s ease-in-out infinite;
}

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

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.mouse {
    width: 25px;
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 15px;
    position: relative;
}

.wheel {
    width: 3px;
    height: 8px;
    background: rgba(255, 255, 255, 0.8);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll 1.5s ease-in-out infinite;
}

@keyframes scroll {
    0% { opacity: 1; top: 8px; }
    100% { opacity: 0; top: 24px; }
}

.arrow span {
    display: block;
    width: 10px;
    height: 10px;
    border-bottom: 2px solid rgba(255, 255, 255, 0.5);
    border-right: 2px solid rgba(255, 255, 255, 0.5);
    transform: rotate(45deg);
    margin: -5px;
    animation: arrows 2s infinite;
}

.arrow span:nth-child(2) {
    animation-delay: -0.2s;
}

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

/* ============================================================================
   Features Section
   ============================================================================ */
.features {
    background: var(--star-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--star-white);
    border-radius: 16px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    font-size: 2rem;
    color: var(--star-white);
}

.feature-card h3 {
    font-size: 1.5rem;
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: #5A6C7D;
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

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

.feature-list li {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: #5A6C7D;
    margin-bottom: var(--spacing-xs);
    font-size: 0.9rem;
}

.feature-list i {
    color: #2ED573;
    font-size: 0.875rem;
}

/* ============================================================================
   Demo Section
   ============================================================================ */
.demo {
    background: linear-gradient(180deg, #F0F4F8 0%, #E4EBF0 100%);
}

.demo-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    border-bottom: 2px solid #D1DCE5;
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) var(--spacing-lg);
    background: transparent;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    color: #5A6C7D;
    cursor: pointer;
    transition: all 0.3s ease;
    border-bottom: 3px solid transparent;
    position: relative;
    bottom: -2px;
}

.tab-btn:hover {
    color: var(--nasa-blue);
}

.tab-btn.active {
    color: var(--nasa-blue);
    border-bottom-color: var(--nasa-blue);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.demo-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-lg);
}

.input-panel,
.results-panel {
    background: var(--star-white);
    border-radius: 16px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.input-panel h3,
.input-panel h4 {
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

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

.form-group label {
    display: block;
    font-weight: 600;
    color: var(--space-black);
    margin-bottom: var(--spacing-xs);
    font-size: 0.9rem;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #D1DCE5;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: var(--font-primary);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--nasa-blue);
    box-shadow: 0 0 0 3px rgba(11, 61, 145, 0.1);
}

.form-group input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: #D1DCE5;
    outline: none;
    -webkit-appearance: none;
}

.form-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--nasa-blue);
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(11, 61, 145, 0.3);
}

.form-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--nasa-blue);
    cursor: pointer;
    border: none;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

.loading-spinner {
    text-align: center;
    padding: var(--spacing-xl);
}

.spinner {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--spacing-md);
    border: 4px solid #D1DCE5;
    border-top-color: var(--nasa-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.hidden {
    display: none !important;
}

.results-summary {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.result-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: linear-gradient(135deg, #F0F4F8 0%, #E4EBF0 100%);
    border-radius: 12px;
    border-left: 4px solid var(--nasa-blue);
}

.result-icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--star-white);
}

.result-icon.muscle { background: linear-gradient(135deg, #FF6B6B 0%, #EE5A6F 100%); }
.result-icon.bone { background: linear-gradient(135deg, #4ECDC4 0%, #44A08D 100%); }
.result-icon.immune { background: linear-gradient(135deg, #A8E6CF 0%, #56AB91 100%); }
.result-icon.cognitive { background: linear-gradient(135deg, #C7CEEA 0%, #A8B7D1 100%); }

.result-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.result-label {
    font-size: 0.875rem;
    color: #5A6C7D;
    font-weight: 500;
}

.result-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--space-black);
    margin: 0.25rem 0;
}

.result-change {
    font-size: 0.875rem;
    font-weight: 600;
}

.result-change.positive { color: #2ED573; }
.result-change.negative { color: #FF6B6B; }

.risk-assessment,
.recommendations {
    margin-top: var(--spacing-lg);
}

.risk-assessment h4,
.recommendations h4 {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-md);
}

#risk-cards {
    display: grid;
    gap: var(--spacing-sm);
}

.risk-card {
    padding: var(--spacing-md);
    border-radius: 8px;
    border-left: 4px solid;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.risk-card.LOW {
    background: rgba(46, 213, 115, 0.1);
    border-color: #2ED573;
}

.risk-card.MODERATE {
    background: rgba(255, 177, 66, 0.1);
    border-color: #FFB142;
}

.risk-card.HIGH {
    background: rgba(255, 107, 107, 0.1);
    border-color: #FF6B6B;
}

.risk-card.CRITICAL {
    background: rgba(252, 61, 33, 0.1);
    border-color: var(--nasa-red);
}

.recommendations ul {
    list-style: none;
}

.recommendations li {
    padding: var(--spacing-sm);
    background: #FFF9E6;
    border-left: 4px solid #FFB142;
    border-radius: 4px;
    margin-bottom: var(--spacing-xs);
}

.chart-container {
    margin-top: var(--spacing-lg);
    background: var(--star-white);
    padding: var(--spacing-md);
    border-radius: 12px;
}

.intervention-options {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: #F0F4F8;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.checkbox-label:hover {
    background: #E4EBF0;
}

.checkbox-label input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.intervention-info,
.baseline-info {
    background: var(--star-white);
    padding: var(--spacing-md);
    border-radius: 12px;
    margin-bottom: var(--spacing-lg);
    border-left: 4px solid var(--nasa-blue);
}

.ranking-list {
    margin-top: var(--spacing-md);
}

.ranking-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--star-white);
    border-radius: 8px;
    margin-bottom: var(--spacing-sm);
    box-shadow: var(--shadow-sm);
}

.baseline-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.baseline-stat-card {
    padding: var(--spacing-md);
    background: linear-gradient(135deg, #F0F4F8 0%, #E4EBF0 100%);
    border-radius: 12px;
    border-top: 3px solid var(--nasa-blue);
}

.baseline-stat-card h5 {
    font-size: 0.875rem;
    color: #5A6C7D;
    margin-bottom: var(--spacing-xs);
}

.baseline-stat-card .value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--space-black);
}

.baseline-stat-card .uncertainty {
    font-size: 0.875rem;
    color: #5A6C7D;
    margin-top: var(--spacing-xs);
}

/* ============================================================================
   Science Section
   ============================================================================ */
.science {
    background: var(--space-black);
    color: var(--star-white);
}

.science .section-title {
    color: var(--star-white);
}

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

.science-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.science-card {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: var(--spacing-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
}

.science-card:hover {
    transform: translateY(-8px);
    border-color: rgba(160, 196, 255, 0.5);
    box-shadow: 0 8px 32px rgba(160, 196, 255, 0.2);
}

.science-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.science-header i {
    font-size: 2rem;
    color: #A0C4FF;
}

.science-header h3 {
    color: var(--star-white);
}

.equation {
    background: rgba(11, 61, 145, 0.2);
    padding: var(--spacing-md);
    border-radius: 8px;
    margin-bottom: var(--spacing-md);
    font-family: 'Courier New', monospace;
}

.equation-label {
    display: block;
    font-weight: 700;
    color: #A0C4FF;
    margin-bottom: var(--spacing-xs);
}

.equation-formula {
    display: block;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.6;
}

.citation {
    font-size: 0.85rem;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.7);
}

.citation strong {
    color: var(--star-white);
    display: block;
    margin-bottom: 0.25rem;
}

.citation em {
    color: #A0C4FF;
}

/* ============================================================================
   API Documentation
   ============================================================================ */
.api-docs {
    background: var(--star-white);
}

.api-grid {
    display: grid;
    gap: var(--spacing-lg);
}

.api-card {
    background: var(--star-white);
    border-radius: 16px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    border-left: 4px solid var(--nasa-blue);
    display: flex;
    gap: var(--spacing-md);
}

.api-method {
    flex-shrink: 0;
    width: 80px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-weight: 700;
    font-size: 0.875rem;
    color: var(--star-white);
}

.api-method.post { background: #2ED573; }
.api-method.get { background: #4ECDC4; }
.api-method.put { background: #FFB142; }
.api-method.delete { background: #FF6B6B; }

.api-info {
    flex: 1;
}

.api-info h3 {
    font-size: 1.25rem;
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-xs);
}

.api-info p {
    color: #5A6C7D;
    margin-bottom: var(--spacing-md);
}

.btn-expand {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.5rem 1rem;
    background: transparent;
    border: 2px solid var(--nasa-blue);
    border-radius: 6px;
    color: var(--nasa-blue);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-expand:hover {
    background: var(--nasa-blue);
    color: var(--star-white);
}

.api-details {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid #D1DCE5;
}

.api-details h4 {
    color: var(--nasa-blue);
    margin: var(--spacing-md) 0 var(--spacing-xs) 0;
}

.api-details pre {
    background: #0A0E1A;
    color: #A0C4FF;
    padding: var(--spacing-md);
    border-radius: 8px;
    overflow-x: auto;
    font-size: 0.875rem;
    line-height: 1.6;
}

.api-details code {
    font-family: 'Courier New', monospace;
}

.api-info-box {
    background: linear-gradient(135deg, #0B3D91 0%, #1E5A9A 100%);
    color: var(--star-white);
    padding: var(--spacing-lg);
    border-radius: 16px;
    margin-top: var(--spacing-xl);
}

.api-info-box h3 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.api-info-box code {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
}

.api-info-box a {
    color: #A0C4FF;
    text-decoration: underline;
}

/* ============================================================================
   About Section
   ============================================================================ */
.about {
    background: linear-gradient(180deg, #F0F4F8 0%, #E4EBF0 100%);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-xl);
}

.about-text h3 {
    color: var(--nasa-blue);
    margin: var(--spacing-lg) 0 var(--spacing-md) 0;
}

.about-text p,
.about-text li {
    color: #5A6C7D;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.about-text ol,
.about-text ul {
    margin-left: var(--spacing-md);
}

.about-text ol li,
.about-text ul li {
    margin-bottom: var(--spacing-sm);
}

.tech-badges {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.tech-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--star-white);
    border-radius: 20px;
    font-weight: 600;
    color: var(--nasa-blue);
    box-shadow: var(--shadow-sm);
}

.about-metrics {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.metric-card {
    background: var(--star-white);
    padding: var(--spacing-lg);
    border-radius: 16px;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

.metric-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.metric-icon {
    font-size: 2.5rem;
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-sm);
}

.metric-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--nasa-blue);
    margin-bottom: var(--spacing-xs);
}

.metric-label {
    font-size: 0.875rem;
    color: #5A6C7D;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ============================================================================
   Footer
   ============================================================================ */
.footer {
    background: var(--space-black);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

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

.footer-logo {
    height: 60px;
    margin-bottom: var(--spacing-sm);
}

.footer-subtitle {
    font-size: 0.9rem;
    margin-top: var(--spacing-xs);
}

.footer-section h4 {
    color: var(--star-white);
    margin-bottom: var(--spacing-md);
    font-size: 1.1rem;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a:hover {
    color: #A0C4FF;
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: var(--nasa-blue);
    color: var(--star-white);
    transform: translateY(-2px);
}

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

.footer-bottom p {
    margin-bottom: 0.25rem;
    font-size: 0.875rem;
}

/* ============================================================================
   Responsive Design
   ============================================================================ */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
    }
    
    .hero-visual {
        display: none;
    }
    
    .demo-grid {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .title-sub {
        font-size: 1.8rem;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .results-summary {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .demo-tabs {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .title-sub {
        font-size: 1.5rem;
    }
    
    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }
}