/* ============================================
   EDDY CURRENT EXPLORER - PREMIUM EDITION
   Complete CSS Overhaul with Glassmorphism,
   Advanced Animations, and Perfect Polish
   ============================================ */

/* ===== CSS VARIABLES ===== */
:root {
    /* Colors - Refined Palette */
    --color-bg: #0a0a0f;
    --color-surface: rgba(20, 20, 30, 0.7);
    --color-surface-solid: #14141e;
    --color-surface-light: rgba(30, 30, 45, 0.8);
    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-light: rgba(255, 255, 255, 0.15);
    
    /* Primary Gradient Colors */
    --color-primary: #6366f1;
    --color-primary-light: #818cf8;
    --color-primary-dark: #4f46e5;
    --color-secondary: #ec4899;
    --color-accent: #f59e0b;
    --color-success: #22c55e;
    --color-warning: #eab308;
    --color-error: #ef4444;
    
    /* Text Colors */
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --text-tertiary: #475569;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #ec4899 100%);
    --gradient-secondary: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);
    --gradient-cool: linear-gradient(135deg, #22d3ee 0%, #6366f1 100%);
    --gradient-dark: linear-gradient(180deg, rgba(20,20,30,0) 0%, rgba(10,10,15,1) 100%);
    --gradient-glow: radial-gradient(circle at center, rgba(99,102,241,0.3) 0%, transparent 70%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -1px rgba(0,0,0,0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.5), 0 4px 6px -2px rgba(0,0,0,0.3);
    --shadow-glow: 0 0 30px rgba(99,102,241,0.4);
    --shadow-glow-pink: 0 0 30px rgba(236,72,153,0.4);
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

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

/* ===== LOADING SCREEN ===== */
.loading-screen {
    position: fixed;
    inset: 0;
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

.loading-content {
    text-align: center;
}

.loading-magnet {
    width: 80px;
    height: 120px;
    margin: 0 auto var(--space-lg);
    position: relative;
    animation: magnetPulse 1.5s ease-in-out infinite;
}

.magnet-n, .magnet-s {
    position: absolute;
    width: 100%;
    height: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.5rem;
}

.magnet-n {
    top: 0;
    background: linear-gradient(180deg, #ff6b6b 0%, #ee5a5a 100%);
    border-radius: 8px 8px 0 0;
    color: white;
}

.magnet-s {
    bottom: 0;
    background: linear-gradient(180deg, #5a67d8 0%, #4c51bf 100%);
    border-radius: 0 0 8px 8px;
    color: white;
}

@keyframes magnetPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.loading-text {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: var(--space-md);
}

.loading-bar {
    width: 200px;
    height: 4px;
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    overflow: hidden;
    margin: 0 auto;
}

.loading-progress {
    height: 100%;
    width: 0%;
    background: var(--gradient-primary);
    animation: loadingProgress 2s ease-out forwards;
}

@keyframes loadingProgress {
    0% { width: 0%; }
    100% { width: 100%; }
}

/* ===== BACKGROUND EFFECTS ===== */
.bg-particles {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
}

.bg-particles::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(99,102,241,0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(236,72,153,0.03) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(245,158,11,0.02) 0%, transparent 50%);
}

.gradient-orb {
    position: fixed;
    border-radius: 50%;
    filter: blur(100px);
    pointer-events: none;
    z-index: 0;
    opacity: 0.4;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: var(--color-primary);
    top: -200px;
    right: -200px;
    animation: floatOrb 20s ease-in-out infinite;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: var(--color-secondary);
    bottom: 10%;
    left: -100px;
    animation: floatOrb 25s ease-in-out infinite reverse;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: var(--color-accent);
    top: 40%;
    right: 10%;
    animation: floatOrb 18s ease-in-out infinite;
    animation-delay: -5s;
}

@keyframes floatOrb {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
}

/* ===== NAVIGATION ===== */
.nav {
    position: fixed;
    top: var(--space-md);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-surface);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    z-index: 1000;
    box-shadow: var(--shadow-lg), 0 0 0 1px rgba(255,255,255,0.05);
    max-width: calc(100% - var(--space-xl) * 2);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding-right: var(--space-md);
    border-right: 1px solid var(--color-border);
}

.brand-icon {
    width: 32px;
    height: 32px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.brand-icon svg {
    width: 20px;
    height: 20px;
    color: white;
}

.brand-text {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-primary);
}

.brand-accent {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: var(--space-xs);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: transparent;
    border: none;
    border-radius: var(--radius-full);
    color: var(--text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-btn::before {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-surface-solid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
}

.nav-btn:hover::before {
    opacity: 1;
    visibility: visible;
    bottom: calc(100% + 5px);
}

.nav-btn:hover {
    color: var(--text-primary);
    background: rgba(255,255,255,0.05);
}

.nav-btn.active {
    color: var(--color-primary-light);
    background: rgba(99,102,241,0.15);
}

.nav-icon {
    font-size: 1rem;
}

/* Mobile Menu */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: var(--space-sm);
    background: transparent;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 80px;
    left: var(--space-md);
    right: var(--space-md);
    background: var(--color-surface);
    backdrop-filter: blur(20px);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
    z-index: 999;
    transform: translateY(-10px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

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

.mobile-menu-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.mobile-nav-btn {
    padding: var(--space-md);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 1rem;
    text-align: left;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.mobile-nav-btn:hover,
.mobile-nav-btn.active {
    background: rgba(99,102,241,0.15);
    color: var(--color-primary-light);
}

/* ===== MAIN CONTENT ===== */
.main-content {
    position: relative;
    z-index: 1;
    padding-top: 100px;
    min-height: 100vh;
}

.section {
    display: none;
    padding: var(--space-2xl) var(--space-xl);
    max-width: 1400px;
    margin: 0 auto;
    animation: sectionFadeIn 0.6s ease;
    min-height: 100vh;
}

.section.active {
    display: block !important;
    opacity: 1;
    transform: translateY(0);
}

/* Ensure canvas containers are visible */
.canvas-container,
.exp-canvas-container {
    position: relative;
    min-height: 300px;
    background: var(--color-bg);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.canvas-container canvas,
.exp-canvas-container canvas {
    display: block;
    width: 100% !important;
    height: auto !important;
}

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

/* ===== SECTION HEADERS ===== */
.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
    position: relative;
}

.section-number {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    padding: var(--space-xs) var(--space-md);
    background: rgba(99,102,241,0.1);
    border: 1px solid rgba(99,102,241,0.3);
    border-radius: var(--radius-full);
    margin-bottom: var(--space-md);
}

.section-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-md);
    line-height: 1.2;
}

.section-desc {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== INTRO SECTION ===== */
.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
    min-height: calc(100vh - 200px);
    padding: var(--space-2xl) 0;
}

.hero-content {
    max-width: 600px;
}

.hero-badge {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: rgba(99,102,241,0.1);
    border: 1px solid rgba(99,102,241,0.3);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--color-primary-light);
    margin-bottom: var(--space-lg);
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--space-lg);
}

.title-line {
    display: block;
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 15px rgba(99,102,241,0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99,102,241,0.5);
}

.btn-glow {
    animation: btnGlow 2s ease-in-out infinite;
}

@keyframes btnGlow {
    0%, 100% { box-shadow: 0 4px 15px rgba(99,102,241,0.4); }
    50% { box-shadow: 0 4px 25px rgba(99,102,241,0.6), 0 0 40px rgba(99,102,241,0.3); }
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--color-border-light);
}

.btn-secondary:hover {
    background: rgba(255,255,255,0.05);
    border-color: var(--color-primary);
}

.btn svg {
    width: 20px;
    height: 20px;
}

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

.magnetic-simulation {
    position: relative;
    width: 400px;
    height: 500px;
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    border: 1px solid var(--color-border);
    padding: var(--space-xl);
    overflow: hidden;
}

.magnetic-simulation::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-glow);
    opacity: 0.5;
    pointer-events: none;
}

.field-container {
    position: relative;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.falling-magnet {
    position: relative;
    width: 60px;
    height: 100px;
    animation: magnetFloat 3s ease-in-out infinite;
    z-index: 10;
}

@keyframes magnetFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(30px); }
}

.magnet-pole {
    position: absolute;
    width: 100%;
    height: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.25rem;
    border-radius: var(--radius-sm);
}

.magnet-pole.north {
    top: 0;
    background: linear-gradient(180deg, #ff6b6b, #ee5a5a);
    color: white;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
}

.magnet-pole.south {
    bottom: 0;
    background: linear-gradient(180deg, #5a67d8, #4c51bf);
    color: white;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
}

.field-ring {
    position: absolute;
    border: 2px solid rgba(99,102,241,0.3);
    border-radius: 50%;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: fieldPulse 2s ease-in-out infinite;
}

.field-ring.r1 { width: 140px; height: 140px; animation-delay: 0s; }
.field-ring.r2 { width: 180px; height: 180px; animation-delay: 0.3s; }
.field-ring.r3 { width: 220px; height: 220px; animation-delay: 0.6s; }

@keyframes fieldPulse {
    0%, 100% { 
        opacity: 0.2; 
        transform: translate(-50%, -50%) scale(1); 
    }
    50% { 
        opacity: 0.5; 
        transform: translate(-50%, -50%) scale(1.05); 
    }
}

.conductor-plate {
    position: absolute;
    bottom: 40px;
    width: 200px;
    height: 20px;
    background: linear-gradient(180deg, #b87333, #8b5a2b);
    border-radius: var(--radius-sm);
}

.eddy-currents {
    position: absolute;
    inset: -30px;
    pointer-events: none;
}

.eddy-loop {
    position: absolute;
    border: 2px dashed rgba(255,215,0,0.6);
    border-radius: 50%;
    animation: eddySwirl 2s linear infinite;
}

.eddy-loop.l1 { 
    width: 40px; height: 20px; 
    top: 35px; left: 20px; 
}
.eddy-loop.l2 { 
    width: 50px; height: 25px; 
    top: 30px; right: 30px; 
    animation-direction: reverse;
}
.eddy-loop.l3 { 
    width: 35px; height: 18px; 
    top: 40px; left: 60px; 
    animation-delay: -0.5s;
}
.eddy-loop.l4 { 
    width: 45px; height: 22px; 
    top: 32px; right: 60px; 
    animation-direction: reverse;
    animation-delay: -0.3s;
}

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

.simulation-labels {
    position: absolute;
    bottom: var(--space-md);
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-around;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.label-eddy {
    color: #ffd700;
}

.label-braking {
    color: var(--color-success);
}

/* Section Divider */
.section-divider {
    width: 100%;
    overflow: hidden;
    line-height: 0;
    color: var(--color-surface);
    margin: var(--space-3xl) 0;
}

.section-divider svg {
    width: 100%;
    height: 80px;
}

/* Feature Cards */
.cards-container {
    padding: var(--space-2xl) 0;
}

.cards-container .section-title {
    text-align: center;
    margin-bottom: var(--space-2xl);
    font-size: 2rem;
}

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

.feature-card {
    position: relative;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-glow);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
}

.feature-card:hover::before {
    opacity: 0.5;
}

.card-glow {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.feature-card:hover .card-glow {
    transform: scaleX(1);
}

.card-content {
    position: relative;
    z-index: 1;
}

.card-icon-container {
    width: 60px;
    height: 60px;
    background: var(--color-surface-light);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
}

.card-icon {
    font-size: 2rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: var(--space-md);
}

.card-features {
    display: flex;
    gap: var(--space-xs);
    flex-wrap: wrap;
}

.feature-tag {
    padding: var(--space-xs) var(--space-sm);
    background: rgba(99,102,241,0.1);
    border: 1px solid rgba(99,102,241,0.2);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    color: var(--color-primary-light);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .mobile-menu {
        display: block;
    }
}

@media (max-width: 768px) {
    .nav {
        left: var(--space-md);
        right: var(--space-md);
        transform: none;
        max-width: none;
    }
    
    .nav-brand {
        padding-right: 0;
        border-right: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section {
        padding: var(--space-xl) var(--space-md);
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== ANIMATIONS ===== */
@keyframes float {
    0%, 100% { transform: translateY(0) translateX(0); }
    25% { transform: translateY(-20px) translateX(10px); }
    50% { transform: translateY(-10px) translateX(-10px); }
    75% { transform: translateY(-30px) translateX(5px); }
}

/* ===== UTILITY CLASSES ===== */
.hidden {
    display: none !important;
}

.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;
}
/* ============================================
   EDDY CURRENT EXPLORER - PREMIUM EDITION
   Part 2: Section-Specific Styles
   ============================================ */

/* ===== SCIENCE SECTION ===== */
.science-layout {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: var(--space-2xl);
    margin-bottom: var(--space-3xl);
}

.theory-panel {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.law-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    position: relative;
    overflow: hidden;
}

.law-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient-primary);
}

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

.law-number {
    width: 28px;
    height: 28px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 700;
}

.law-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.formula-container {
    background: var(--color-surface-light);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    margin-bottom: var(--space-md);
    text-align: center;
}

.formula {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
}

.fraction {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    font-size: 1rem;
}

.numerator {
    border-bottom: 2px solid var(--text-primary);
    padding: 0 var(--space-xs);
}

.denominator {
    padding: 0 var(--space-xs);
}

.law-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: var(--space-md);
}

.variables {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
}

.var {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.var-symbol {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--color-primary-light);
    min-width: 20px;
}

.var-meaning {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.lenz-demo {
    margin-top: var(--space-md);
}

.lenz-arrows {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    align-items: center;
}

.arrow-down {
    color: var(--color-error);
    font-weight: 600;
    animation: arrowDown 1.5s ease-in-out infinite;
}

.arrow-up {
    color: var(--color-success);
    font-weight: 600;
    animation: arrowUp 1.5s ease-in-out infinite;
}

@keyframes arrowDown {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(5px); }
}

@keyframes arrowUp {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

/* Demo Panel */
.demo-panel {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.demo-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

.demo-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.demo-status {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.status-dot {
    width: 8px;
    height: 8px;
    background: var(--color-success);
    border-radius: var(--radius-full);
    animation: pulse 2s ease-in-out infinite;
}

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

.canvas-container {
    position: relative;
    padding: var(--space-lg);
}

.canvas-container canvas {
    width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    background: var(--color-bg);
}

.canvas-overlay {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    background: rgba(10, 10, 15, 0.9);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-md);
}

.measurement-display {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.measure {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: 0.875rem;
}

.measure-label {
    color: var(--text-muted);
    min-width: 80px;
}

.measure-value {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--color-primary-light);
    min-width: 50px;
    text-align: right;
}

.measure-unit {
    color: var(--text-tertiary);
    font-size: 0.75rem;
}

.demo-controls {
    display: flex;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    border-top: 1px solid var(--color-border);
    flex-wrap: wrap;
}

.control-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-surface-light);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.control-btn:hover {
    background: rgba(99,102,241,0.1);
    border-color: var(--color-primary);
}

.control-btn svg {
    width: 18px;
    height: 18px;
}

.btn-drop {
    background: rgba(34, 197, 94, 0.1);
    border-color: rgba(34, 197, 94, 0.3);
    color: var(--color-success);
}

.btn-drop:hover {
    background: rgba(34, 197, 94, 0.2);
}

.material-selector {
    padding: var(--space-md) var(--space-lg);
    border-top: 1px solid var(--color-border);
}

.selector-label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: var(--space-sm);
}

.material-options {
    display: flex;
    gap: var(--space-sm);
}

.material-btn {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-md);
    background: var(--color-surface-light);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.material-btn:hover {
    background: rgba(255,255,255,0.05);
}

.material-btn.active {
    border-color: var(--color-primary);
    background: rgba(99,102,241,0.1);
    color: var(--text-primary);
}

.material-color {
    width: 24px;
    height: 24px;
    border-radius: var(--radius-full);
}

.material-color.copper { background: linear-gradient(135deg, #b87333, #d4914d); }
.material-color.aluminum { background: linear-gradient(135deg, #a8a8a8, #d4d4d4); }
.material-color.pvc { background: linear-gradient(135deg, #fff, #e2e8f0); }

.material-btn span {
    font-size: 0.875rem;
    font-weight: 500;
}

.material-btn small {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Factors Section */
.factors-section {
    margin-top: var(--space-3xl);
}

.factors-title {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: var(--space-xl);
    color: var(--text-primary);
}

.factors-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
}

.factor-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    text-align: center;
}

.factor-icon {
    font-size: 2rem;
    margin-bottom: var(--space-sm);
}

.factor-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--text-primary);
}

.factor-bar {
    margin-bottom: var(--space-sm);
}

.bar-track {
    height: 24px;
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    overflow: hidden;
    margin-bottom: var(--space-xs);
}

.bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #b87333, #d4914d);
    border-radius: var(--radius-full);
    transition: width 1s ease;
}

.bar-fill.aluminum {
    background: linear-gradient(90deg, #a8a8a8, #d4d4d4);
}

.bar-fill.steel {
    background: linear-gradient(90deg, #64748b, #94a3b8);
}

.bar-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.field-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    margin: var(--space-md) 0;
}

.field-circle {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
}

.field-circle.weak {
    background: rgba(99,102,241,0.2);
    border: 2px solid var(--color-primary);
    animation: weakPulse 2s ease-in-out infinite;
}

.field-circle.strong {
    background: rgba(99,102,241,0.5);
    border: 2px solid var(--color-primary);
    box-shadow: 0 0 20px rgba(99,102,241,0.4);
    animation: strongPulse 2s ease-in-out infinite;
}

@keyframes weakPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

@keyframes strongPulse {
    0%, 100% { transform: scale(1); box-shadow: 0 0 20px rgba(99,102,241,0.4); }
    50% { transform: scale(1.15); box-shadow: 0 0 40px rgba(99,102,241,0.6); }
}

.field-arrow {
    font-size: 1.5rem;
    color: var(--text-muted);
}

.velocity-visual {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin: var(--space-md) 0;
}

.vel-indicator {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.vel-bar {
    height: 20px;
    border-radius: var(--radius-full);
    background: var(--color-surface-light);
}

.vel-indicator.slow .vel-bar {
    width: 40%;
    background: var(--color-success);
}

.vel-indicator.fast .vel-bar {
    width: 100%;
    background: linear-gradient(90deg, var(--color-warning), var(--color-error));
    animation: fastBar 1s ease-in-out infinite;
}

@keyframes fastBar {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.vel-indicator span {
    font-size: 0.75rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.geometry-visual {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin: var(--space-md) 0;
}

.geo-sample {
    position: relative;
    width: 60px;
    height: 40px;
    background: var(--copper);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
}

.geo-sample.solid {
    overflow: hidden;
}

.current-loop {
    position: absolute;
    width: 30px;
    height: 30px;
    border: 2px dashed rgba(255,215,0,0.8);
    border-radius: 50%;
    animation: loopSpin 3s linear infinite;
}

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

.geo-sample.slotted {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
}

.slot {
    width: 4px;
    height: 100%;
    background: var(--color-bg);
}

.factor-desc {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: var(--space-md);
}

/* ===== ROLLER COASTER SECTION ===== */
.coaster-showcase {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin-bottom: var(--space-2xl);
}

.simulation-viewport {
    position: relative;
    background: linear-gradient(180deg, #87CEEB 0%, #E0F6FF 50%, #B8E0F0 100%);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
}

.coaster-world {
    position: relative;
    height: 450px;
    overflow: hidden;
}

.sky {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, #60a5fa 0%, #93c5fd 50%, #dbeafe 100%);
}

.track-container {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.track-svg {
    width: 100%;
    height: 100%;
    max-width: 1000px;
}

.coaster-hud {
    position: absolute;
    top: var(--space-md);
    right: var(--space-md);
}

.hud-panel {
    background: rgba(10, 10, 15, 0.9);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    display: flex;
    gap: var(--space-lg);
}

.hud-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hud-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.hud-value {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary-light);
}

.hud-unit {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

.coaster-controls-panel {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-xl);
    padding: var(--space-lg);
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
}

.control-group {
    display: flex;
    gap: var(--space-md);
}

.launch-btn, .reset-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.launch-btn {
    background: linear-gradient(135deg, #f59e0b, #ef4444);
    color: white;
}

.launch-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.4);
}

.reset-btn {
    background: var(--color-surface-light);
    color: var(--text-primary);
    border: 1px solid var(--color-border);
}

.reset-btn:hover {
    background: rgba(255,255,255,0.05);
}

.brake-control {
    display: flex;
    align-items: center;
}

.toggle-switch {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
}

.toggle-switch input {
    display: none;
}

.toggle-track {
    width: 48px;
    height: 26px;
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    position: relative;
    transition: background var(--transition-fast);
}

.toggle-switch input:checked + .toggle-track {
    background: var(--color-success);
}

.toggle-thumb {
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: var(--radius-full);
    transition: transform var(--transition-fast);
}

.toggle-switch input:checked + .toggle-track .toggle-thumb {
    transform: translateX(22px);
}

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

/* Info Panels */
.info-panels {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    padding: var(--space-xl);
}

.info-panel {
    background: var(--color-surface-light);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.panel-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
    background: rgba(99,102,241,0.1);
    border-bottom: 1px solid var(--color-border);
}

.panel-icon {
    font-size: 1.25rem;
}

.panel-header h3 {
    font-size: 1rem;
    font-weight: 600;
}

.panel-content {
    padding: var(--space-lg);
}

.process-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.step {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.step-num {
    width: 28px;
    height: 28px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.advantages-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.advantages-list li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.adv-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.advantages-list li div {
    display: flex;
    flex-direction: column;
}

.advantages-list li strong {
    color: var(--text-primary);
    margin-bottom: 2px;
}

.advantages-list li span {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Real World Section */
.real-world-section {
    margin-top: var(--space-2xl);
}

.real-world-section h3 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: var(--space-xl);
}

.example-showcase {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.example-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    transition: all var(--transition-base);
}

.example-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
}

.example-card.featured {
    background: linear-gradient(135deg, rgba(99,102,241,0.1), rgba(236,72,153,0.1));
    border-color: rgba(99,102,241,0.3);
}

.example-image {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.example-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.example-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
}

.example-tag {
    display: inline-block;
    padding: var(--space-xs) var(--space-sm);
    background: rgba(99,102,241,0.1);
    border: 1px solid rgba(99,102,241,0.2);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    color: var(--color-primary-light);
}

/* ===== MAGLEV TRAIN SECTION ===== */
.train-simulator {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin-bottom: var(--space-2xl);
}

.train-viewport {
    position: relative;
}

.train-scene {
    position: relative;
    height: 400px;
    background: linear-gradient(180deg, #0f172a 0%, #1e293b 60%, #0f172a 100%);
    overflow: hidden;
}

.scene-bg {
    position: absolute;
    inset: 0;
}

.city-silhouette {
    position: absolute;
    bottom: 100px;
    left: 0;
    right: 0;
    height: 150px;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1200 200'%3E%3Cpath fill='%231e293b' d='M0,200 L0,150 L50,150 L50,100 L100,100 L100,120 L150,120 L150,80 L200,80 L200,140 L250,140 L250,60 L300,60 L300,130 L400,130 L400,90 L450,90 L450,150 L550,150 L550,70 L600,70 L600,110 L700,110 L700,140 L800,140 L800,50 L850,50 L850,120 L950,120 L950,100 L1000,100 L1000,160 L1100,160 L1100,80 L1150,80 L1150,140 L1200,140 L1200,200 Z'/%3E%3C/svg%3E") repeat-x bottom;
    opacity: 0.5;
}

.ground {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(180deg, #334155 0%, #1e293b 100%);
}

.guideway {
    position: absolute;
    bottom: 60px;
    left: 10%;
    right: 10%;
    height: 40px;
}

.guideway-track {
    position: absolute;
    inset: 0;
    background: #475569;
    border-radius: var(--radius-sm);
}

.guideway-coils {
    position: absolute;
    inset: 5px;
    display: flex;
    justify-content: space-around;
    align-items: center;
}

.coil {
    width: 40px;
    height: 30px;
    background: repeating-linear-gradient(
        0deg,
        #b87333 0px,
        #d4914d 3px,
        #b87333 6px
    );
    border-radius: 4px;
    opacity: 0.8;
}

.maglev-train {
    position: absolute;
    bottom: 110px;
    left: 20%;
    width: 300px;
    height: 80px;
    transition: bottom 0.5s ease;
}

.maglev-train.levitating {
    bottom: 150px;
    animation: trainHover 2s ease-in-out infinite;
}

@keyframes trainHover {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

.train-nose {
    position: absolute;
    left: -30px;
    top: 20px;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #fff, #e2e8f0);
    border-radius: 50% 0 0 50%;
}

.train-body {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, #fff 0%, #e2e8f0 100%);
    border-radius: 40px 10px 10px 40px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.train-cockpit {
    position: absolute;
    left: 20px;
    top: 15px;
    width: 50px;
    height: 30px;
}

.cockpit-window {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #1e293b, #0f172a);
    border-radius: 20px 5px 5px 20px;
}

.train-windows {
    position: absolute;
    left: 80px;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 8px;
}

.window {
    flex: 1;
    height: 25px;
    background: linear-gradient(135deg, #334155, #1e293b);
    border-radius: 4px;
}

.train-logo {
    position: absolute;
    bottom: 15px;
    left: 80px;
    font-weight: 800;
    font-size: 0.875rem;
    color: #1e293b;
}

.train-logo small {
    display: block;
    font-size: 0.625rem;
    font-weight: 500;
    color: #64748b;
}

.levitation-modules {
    position: absolute;
    bottom: -15px;
    left: 40px;
    right: 40px;
    display: flex;
    justify-content: space-around;
}

.module {
    width: 50px;
    height: 15px;
    background: linear-gradient(180deg, #3b82f6, #1d4ed8);
    border-radius: 0 0 4px 4px;
}

.levitation-glow {
    position: absolute;
    bottom: -30px;
    left: 20px;
    right: 20px;
    height: 30px;
    background: radial-gradient(ellipse at center, rgba(59,130,246,0.3) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.5s ease;
}

.levitation-glow.active {
    opacity: 1;
}

.magnetic-field-lines {
    position: absolute;
    bottom: -50px;
    left: 0;
    right: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.magnetic-field-lines.active {
    opacity: 1;
}

.magnetic-field-lines span {
    display: block;
    height: 2px;
    background: rgba(59,130,246,0.5);
    border-radius: var(--radius-full);
    animation: fieldLine 1s ease-in-out infinite;
}

.magnetic-field-lines span:nth-child(1) { width: 200px; animation-delay: 0s; }
.magnetic-field-lines span:nth-child(2) { width: 220px; animation-delay: 0.1s; }
.magnetic-field-lines span:nth-child(3) { width: 240px; animation-delay: 0.2s; }
.magnetic-field-lines span:nth-child(4) { width: 240px; animation-delay: 0.3s; }
.magnetic-field-lines span:nth-child(5) { width: 220px; animation-delay: 0.4s; }
.magnetic-field-lines span:nth-child(6) { width: 200px; animation-delay: 0.5s; }

@keyframes fieldLine {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.7; }
}

.gap-indicator {
    position: absolute;
    bottom: 115px;
    left: 30%;
    display: flex;
    flex-direction: column;
    align-items: center;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.gap-indicator.active {
    opacity: 1;
}

.gap-line {
    width: 2px;
    height: 35px;
    background: repeating-linear-gradient(
        180deg,
        var(--color-primary) 0px,
        var(--color-primary) 5px,
        transparent 5px,
        transparent 10px
    );
}

.gap-label {
    font-size: 0.75rem;
    color: var(--color-primary-light);
    background: rgba(99,102,241,0.2);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    margin-top: 4px;
}

.speed-lines {
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.speed-lines.active {
    opacity: 1;
}

.speed-lines span {
    position: absolute;
    height: 2px;
    background: rgba(255,255,255,0.3);
    border-radius: var(--radius-full);
    animation: speedLine 0.5s linear infinite;
}

.speed-lines span:nth-child(1) { top: 20%; left: -100px; width: 100px; animation-delay: 0s; }
.speed-lines span:nth-child(2) { top: 40%; left: -150px; width: 150px; animation-delay: 0.1s; }
.speed-lines span:nth-child(3) { top: 60%; left: -80px; width: 80px; animation-delay: 0.2s; }
.speed-lines span:nth-child(4) { top: 30%; right: -120px; width: 120px; animation-delay: 0.15s; }
.speed-lines span:nth-child(5) { top: 50%; right: -90px; width: 90px; animation-delay: 0.25s; }
.speed-lines span:nth-child(6) { top: 70%; right: -110px; width: 110px; animation-delay: 0.05s; }

@keyframes speedLine {
    from { transform: translateX(0); }
    to { transform: translateX(calc(100vw + 200px)); }
}

/* Train Dashboard */
.train-dashboard {
    display: grid;
    grid-template-columns: 1fr 2fr 1fr;
    gap: var(--space-xl);
    padding: var(--space-lg);
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    align-items: center;
}

.dash-section {
    text-align: center;
}

.dash-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    margin-bottom: var(--space-sm);
}

.levitation-status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: var(--color-error);
    transition: all var(--transition-fast);
}

.status-indicator.on {
    background: var(--color-success);
    box-shadow: 0 0 10px var(--color-success);
    animation: statusPulse 1s ease-in-out infinite;
}

@keyframes statusPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.status-text {
    font-weight: 600;
}

.speed-section {
    border-left: 1px solid var(--color-border);
    border-right: 1px solid var(--color-border);
    padding: 0 var(--space-xl);
}

.speed-display-large {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.speed-value {
    font-family: var(--font-mono);
    font-size: 3rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.speed-unit {
    font-size: 1rem;
    color: var(--text-muted);
}

.speed-bar-container {
    position: relative;
}

.speed-bar-bg {
    height: 8px;
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.speed-bar-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    width: 0%;
    transition: width 0.3s ease;
}

.speed-markers {
    display: flex;
    justify-content: space-between;
    margin-top: var(--space-xs);
    font-size: 0.625rem;
    color: var(--text-muted);
}

.phase-indicator {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
}

.phase {
    width: 32px;
    height: 32px;
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

.phase.active {
    background: var(--color-success);
    color: white;
    box-shadow: 0 0 15px rgba(34, 197, 94, 0.5);
}

/* Train Controls */
.train-controls {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--color-surface-light);
    border-top: 1px solid var(--color-border);
}

.train-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    border: none;
    border-radius: var(--radius-full);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.train-btn.levitate {
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    color: white;
}

.train-btn.levitate:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.train-btn.propel {
    background: linear-gradient(135deg, #f59e0b, #ef4444);
    color: white;
}

.train-btn.propel:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.4);
}

.train-btn.emergency {
    background: var(--color-error);
    color: white;
}

.train-btn.emergency:hover {
    background: #dc2626;
}

/* Physics Explanation Cards */
.physics-explanation {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    margin-bottom: var(--space-2xl);
}

.physics-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.card-visual {
    height: 200px;
    background: var(--color-surface-light);
    display: flex;
    align-items: center;
    justify-content: center;
    border-bottom: 1px solid var(--color-border);
}

.physics-card .card-content {
    padding: var(--space-xl);
}

.physics-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.physics-card p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    line-height: 1.7;
}

.specs {
    list-style: none;
}

.specs li {
    padding: var(--space-xs) 0;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.specs li strong {
    color: var(--text-primary);
}

/* EDS Animation */
.eds-animation {
    position: relative;
    width: 200px;
    height: 150px;
}

.train-magnet {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
}

.train-magnet .pole {
    display: block;
    width: 40px;
    height: 40px;
    background: #ff6b6b;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: white;
    margin-bottom: var(--space-sm);
}

.field-arrows {
    font-size: 1.5rem;
    color: var(--color-primary);
    animation: arrowBounce 1s ease-in-out infinite;
}

@keyframes arrowBounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(5px); }
}

.guideway-conductor {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 150px;
    height: 20px;
    background: linear-gradient(180deg, #b87333, #8b5a2b);
    border-radius: var(--radius-sm);
}

.eddy-swirl {
    position: absolute;
    top: -30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 2rem;
    color: #ffd700;
    animation: eddySpin 1s linear infinite;
}

@keyframes eddySpin {
    from { transform: translateX(-50%) rotate(0deg); }
    to { transform: translateX(-50%) rotate(360deg); }
}

.repulsion-arrow {
    position: absolute;
    top: -60px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 2rem;
    color: var(--color-success);
    animation: repulseBounce 0.5s ease-in-out infinite;
}

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

/* LSM Animation */
.lsm-animation {
    text-align: center;
}

.coil-sequence {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.coil-phase {
    width: 50px;
    height: 50px;
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

.coil-phase.active {
    background: var(--color-success);
    border-color: var(--color-success);
    color: white;
    box-shadow: 0 0 20px rgba(34, 197, 94, 0.5);
}

.traveling-wave {
    font-size: 2rem;
    color: var(--color-primary);
    animation: waveMove 1s ease-in-out infinite;
}

@keyframes waveMove {
    0%, 100% { transform: translateX(0); opacity: 1; }
    50% { transform: translateX(20px); opacity: 0.7; }
}

/* Comparison Section */
.comparison-section {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
}

.comparison-section h3 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: var(--space-xl);
}

.comparison-table-modern {
    display: flex;
    flex-direction: column;
    gap: 1px;
    background: var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.table-header, .table-row {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    background: var(--color-surface);
    padding: var(--space-md) var(--space-lg);
    align-items: center;
}

.table-header {
    background: var(--color-surface-light);
    font-weight: 600;
}

.col-feature {
    color: var(--text-primary);
}

.col-maglev, .col-traditional {
    text-align: center;
    color: var(--text-secondary);
}

.col-maglev.highlight {
    color: var(--color-success);
    font-weight: 600;
}

.col-traditional.highlight {
    color: var(--color-success);
    font-weight: 600;
}

/* ===== APPLICATIONS SECTION ===== */
.applications-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.app-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    transition: all var(--transition-base);
}

.app-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
}

.app-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.app-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.app-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
}

.app-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-num {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-desc {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ===== LAB SECTION ===== */
.lab-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
}

.experiment-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.experiment-card.wide {
    grid-column: span 2;
}

.exp-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--color-surface-light);
    border-bottom: 1px solid var(--color-border);
}

.exp-number {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-primary);
    padding: var(--space-xs) var(--space-sm);
    background: rgba(99,102,241,0.1);
    border-radius: var(--radius-full);
}

.exp-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.exp-canvas-container {
    position: relative;
    padding: var(--space-lg);
    background: var(--color-bg);
}

.exp-canvas-container canvas {
    width: 100%;
    height: auto;
    border-radius: var(--radius-md);
}

.exp-overlay {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    background: rgba(10, 10, 15, 0.9);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-sm) var(--space-md);
}

.exp-stat {
    display: flex;
    justify-content: space-between;
    gap: var(--space-lg);
    font-size: 0.875rem;
}

.exp-stat span:first-child {
    color: var(--text-muted);
}

.exp-stat span:last-child {
    color: var(--color-primary-light);
    font-weight: 600;
}

.race-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(10, 10, 15, 0.8);
    border-radius: var(--radius-md);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.race-overlay.active {
    opacity: 1;
    visibility: visible;
}

.race-winner {
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-success);
    text-align: center;
}

.exp-controls {
    padding: var(--space-md) var(--space-lg);
    border-top: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.control-row {
    display: flex;
    gap: var(--space-sm);
    align-items: center;
    flex-wrap: wrap;
}

.control-row.buttons {
    justify-content: center;
}

.exp-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-primary);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.exp-btn:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
}

.exp-btn.secondary {
    background: var(--color-surface-light);
    color: var(--text-primary);
    border: 1px solid var(--color-border);
}

.exp-btn.secondary:hover {
    background: rgba(255,255,255,0.05);
}

.exp-btn.highlight {
    background: linear-gradient(135deg, #f59e0b, #ef4444);
}

.exp-btn.power {
    background: var(--color-success);
}

.exp-btn.power.active {
    background: var(--color-error);
}

.control-row label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.control-row select {
    padding: var(--space-sm);
    background: var(--color-surface-light);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
}

.checkbox-label input {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
}

.slider-control {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.slider-control input[type="range"] {
    width: 150px;
    accent-color: var(--color-primary);
}

.info-pill {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
}

.pill-value {
    color: var(--color-primary-light);
    font-weight: 600;
}

.temp-gauge {
    position: absolute;
    bottom: var(--space-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

.gauge-bg {
    width: 200px;
    height: 8px;
    background: var(--color-surface-light);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.gauge-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, #22c55e, #eab308, #ef4444);
    border-radius: var(--radius-full);
    transition: width 0.3s ease;
}

.temp-value {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.material-legend {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    justify-content: center;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.legend-item .dot {
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
}

.legend-item .dot.copper { background: #b87333; }
.legend-item .dot.aluminum { background: #a8a8a8; }
.legend-item .dot.steel { background: #64748b; }

.exp-explanation {
    padding: var(--space-md) var(--space-lg);
    background: var(--color-surface-light);
    border-top: 1px solid var(--color-border);
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.exp-explanation strong {
    color: var(--text-primary);
}

/* Quiz Section */
.quiz-container {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin-top: var(--space-2xl);
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    background: var(--color-surface-light);
    border-bottom: 1px solid var(--color-border);
}

.quiz-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.quiz-progress {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.quiz-card {
    padding: var(--space-xl);
}

.quiz-question {
    font-size: 1.25rem;
    font-weight: 500;
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.quiz-option {
    padding: var(--space-md) var(--space-lg);
    background: var(--color-surface-light);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    text-align: left;
    font-size: 1rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.quiz-option:hover {
    border-color: var(--color-primary);
    background: rgba(99,102,241,0.05);
}

.quiz-option.correct {
    border-color: var(--color-success);
    background: rgba(34, 197, 94, 0.1);
}

.quiz-option.wrong {
    border-color: var(--color-error);
    background: rgba(239, 68, 68, 0.1);
}

.quiz-results {
    padding: var(--space-3xl);
    text-align: center;
}

.result-trophy {
    font-size: 4rem;
    margin-bottom: var(--space-md);
}

.quiz-results h4 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.result-score {
    font-family: var(--font-mono);
    font-size: 3rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-md);
}

.result-message {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: var(--space-xl);
}

/* ===== FOOTER ===== */
.footer {
    margin-top: var(--space-3xl);
    padding: var(--space-2xl);
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.brand-icon {
    font-size: 1.5rem;
}

.footer-text {
    color: var(--text-muted);
    margin-bottom: var(--space-lg);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* ===== RESPONSIVE DESIGN ADDITIONS ===== */
@media (max-width: 1024px) {
    .science-layout {
        grid-template-columns: 1fr;
    }
    
    .factors-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .info-panels {
        grid-template-columns: 1fr;
    }
    
    .example-showcase {
        grid-template-columns: 1fr;
    }
    
    .train-dashboard {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }
    
    .speed-section {
        border: none;
        padding: var(--space-md) 0;
        border-top: 1px solid var(--color-border);
        border-bottom: 1px solid var(--color-border);
    }
    
    .physics-explanation {
        grid-template-columns: 1fr;
    }
    
    .lab-container {
        grid-template-columns: 1fr;
    }
    
    .experiment-card.wide {
        grid-column: span 1;
    }
    
    .applications-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .factors-grid {
        grid-template-columns: 1fr;
    }
    
    .applications-grid {
        grid-template-columns: 1fr;
    }
    
    .coaster-controls-panel {
        flex-direction: column;
        gap: var(--space-md);
    }
    
    .train-controls {
        flex-direction: column;
    }
    
    .comparison-table-modern .table-header,
    .comparison-table-modern .table-row {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .col-maglev, .col-traditional {
        padding: var(--space-xs) 0;
    }
}