/* ============================================
   Helium AI Assistant - Design System
   Modern, Vibrant, Professional
   ============================================ */

/* CSS Variables - Color Palette: Modern Tech */
:root {
    --primary: #6366F1;
    --primary-dark: #4F46E5;
    --primary-light: #818CF8;
    --secondary: #EC4899;
    --accent: #06B6D4;
    --success: #10B981;
    --warning: #F59E0B;
    --error: #EF4444;
    
    --bg-primary: #0F0F1A;
    --bg-secondary: #1A1A2E;
    --bg-tertiary: #252542;
    --bg-card: #1E1E3A;
    
    --text-primary: #FFFFFF;
    --text-secondary: #A1A1AA;
    --text-muted: #71717A;
    
    --gradient-1: linear-gradient(135deg, #6366F1 0%, #EC4899 100%);
    --gradient-2: linear-gradient(135deg, #06B6D4 0%, #6366F1 100%);
    --gradient-3: linear-gradient(135deg, #EC4899 0%, #F59E0B 100%);
    
    --font-display: 'Outfit', sans-serif;
    --font-body: 'Plus Jakarta Sans', sans-serif;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.3);
    
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
}

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

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

.gradient-text {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 15, 26, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    color: var(--primary);
    font-size: 1.75rem;
}

.logo-text {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-links a:hover {
    color: var(--text-primary);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-1);
    transition: width var(--transition-normal);
}

.nav-links a:hover::after {
    width: 100%;
}

.cta-btn {
    background: var(--gradient-1);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

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

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

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
    animation: float 20s ease-in-out infinite;
}

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

.orb-2 {
    width: 400px;
    height: 400px;
    background: var(--secondary);
    bottom: -100px;
    left: -100px;
    animation-delay: -5s;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: var(--accent);
    top: 50%;
    left: 30%;
    animation-delay: -10s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(50px, -50px) scale(1.1); }
    50% { transform: translate(0, 50px) scale(0.95); }
    75% { transform: translate(-50px, -25px) scale(1.05); }
}

.hero-content {
    max-width: 700px;
    z-index: 1;
    text-align: center;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    padding: 0.5rem 1rem;
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--primary-light);
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 4rem;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid rgba(255, 255, 255, 0.2);
    padding: 1rem 2.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient-2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

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

/* Phone Mockup */
.hero-visual {
    position: absolute;
    right: 5%;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1;
}

.phone-mockup {
    width: 300px;
    height: 600px;
    background: var(--bg-secondary);
    border-radius: 40px;
    padding: 12px;
    box-shadow: 
        0 25px 50px -12px rgba(0, 0, 0, 0.5),
        0 0 0 1px rgba(255, 255, 255, 0.1),
        inset 0 0 0 2px rgba(255, 255, 255, 0.05);
    animation: phoneFloat 6s ease-in-out infinite;
}

@keyframes phoneFloat {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(2deg); }
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    border-radius: 32px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    overflow: hidden;
}

.chat-bubble {
    padding: 1rem;
    border-radius: var(--radius-lg);
    max-width: 85%;
    animation: messageSlide 0.5s ease-out;
}

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

.chat-bubble.bot {
    background: var(--bg-tertiary);
    align-self: flex-start;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.chat-bubble.user {
    background: var(--gradient-1);
    align-self: flex-end;
}

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

.chat-bubble p {
    font-size: 0.875rem;
    line-height: 1.5;
}

/* ============================================
   Features Section
   ============================================ */
.features {
    padding: 8rem 2rem;
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 4rem;
}

.section-header.left {
    text-align: left;
    margin-left: 0;
}

.section-tag {
    display: inline-block;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-light);
    padding: 0.5rem 1rem;
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: 1rem;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

.features-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: 2rem;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-1);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: var(--shadow-lg);
}

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

.feature-icon {
    width: 60px;
    height: 60px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

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

/* ============================================
   Task Demo Section
   ============================================ */
.task-demo {
    padding: 8rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
    gap: 4rem;
}

.task-demo-content {
    flex: 1;
}

.task-examples {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.task-item {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all var(--transition-normal);
}

.task-item:hover {
    border-color: rgba(99, 102, 241, 0.3);
    transform: translateX(10px);
}

.task-command {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.command-text {
    font-family: 'Courier New', monospace;
    color: var(--primary-light);
    font-size: 0.9rem;
}

.copy-btn {
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    color: var(--primary-light);
    padding: 0.4rem 0.8rem;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.copy-btn:hover {
    background: var(--primary);
    color: white;
}

.task-result {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.result-icon {
    width: 20px;
    height: 20px;
    background: var(--success);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.75rem;
}

.task-demo-visual {
    flex: 0 0 400px;
    height: 400px;
    position: relative;
}

.floating-card {
    position: absolute;
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow-lg);
    animation: cardFloat 4s ease-in-out infinite;
}

.card-1 {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.card-2 {
    top: 50%;
    right: 10%;
    animation-delay: -1.3s;
}

.card-3 {
    bottom: 10%;
    left: 30%;
    animation-delay: -2.6s;
}

@keyframes cardFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

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

.card-text {
    font-weight: 600;
    color: var(--text-primary);
}

/* ============================================
   Commands Section
   ============================================ */
.commands {
    padding: 8rem 2rem;
    background: var(--bg-secondary);
}

.commands-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.command-category {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: 2rem;
}

.command-category h3 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.command-category ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.command-category li {
    background: rgba(0, 0, 0, 0.2);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    color: var(--text-secondary);
    border-left: 3px solid var(--primary);
    transition: all var(--transition-fast);
}

.command-category li:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--text-primary);
    transform: translateX(5px);
}

/* ============================================
   CTA Section
   ============================================ */
.cta-section {
    padding: 6rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-1);
    opacity: 0.1;
}

.cta-content {
    position: relative;
    z-index: 1;
    max-width: 600px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: 1rem;
}

.cta-content p {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 2rem;
}

.btn-primary.large {
    padding: 1.25rem 3rem;
    font-size: 1.125rem;
}

.cta-note {
    margin-top: 1.5rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding: 4rem 2rem 2rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    gap: 4rem;
    margin-bottom: 3rem;
}

.footer-brand {
    max-width: 300px;
}

.footer-brand .logo {
    margin-bottom: 1rem;
}

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

.footer-links {
    display: flex;
    gap: 4rem;
}

.link-group h4 {
    font-size: 1rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.link-group ul {
    list-style: none;
}

.link-group li {
    margin-bottom: 0.5rem;
}

.link-group a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color var(--transition-fast);
}

.link-group a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    max-width: 1200px;
    margin: 0 auto;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
}

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

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .hero-visual {
        position: relative;
        right: auto;
        top: auto;
        transform: none;
        margin-top: 3rem;
    }
    
    .hero {
        flex-direction: column;
        padding-top: 6rem;
    }
    
    .task-demo {
        flex-direction: column;
    }
    
    .task-demo-visual {
        flex: none;
        width: 100%;
        max-width: 400px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .commands-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 2rem;
    }
    
    .footer-links {
        flex-wrap: wrap;
        gap: 2rem;
    }
    
    .phone-mockup {
        width: 260px;
        height: 520px;
    }
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card {
    animation: fadeInUp 0.6s ease-out backwards;
}

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

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}