/* ===========================
   CSS Variables & Base Styles
   =========================== */
:root {
    /* Brand Colors - 白鲸加速器科技蓝配色 */
    --primary: #00d4aa;
    --primary-dark: #00b894;
    --primary-light: #55efc4;
    --secondary: #0984e3;
    --secondary-dark: #0652DD;
    --accent: #6c5ce7;
    
    /* Neutral Colors */
    --dark: #0c1821;
    --dark-secondary: #1a2a3a;
    --text-primary: #ffffff;
    --text-secondary: #a8b9c9;
    --text-muted: #6b7d8e;
    --light: #f8fafc;
    --light-secondary: #e8f4f8;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #00d4aa 0%, #0984e3 100%);
    --gradient-dark: linear-gradient(180deg, #0c1821 0%, #1a2a3a 100%);
    --gradient-hero: linear-gradient(135deg, #0c1821 0%, #1a2a3a 50%, #0c2840 100%);
    --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.05) 0%, rgba(255,255,255,0.02) 100%);
    
    /* Effects */
    --shadow-sm: 0 2px 8px rgba(0, 212, 170, 0.1);
    --shadow-md: 0 8px 30px rgba(0, 212, 170, 0.15);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(0, 212, 170, 0.4);
    
    /* Spacing */
    --section-padding: 100px 0;
    --container-max: 1200px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 30px;
    
    /* Transitions */
    --transition: all 0.3s ease;
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background: var(--dark);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* Section */
.section {
    padding: var(--section-padding);
    position: relative;
}

.bg-dark {
    background: var(--gradient-dark);
}

.bg-light {
    background: var(--dark-secondary);
}

/* Section Header */
.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-header h2 {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 700;
    margin-bottom: 16px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-header.light h2 {
    color: var(--text-primary);
    background: none;
    -webkit-text-fill-color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===========================
   Header & Navigation
   =========================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(12, 24, 33, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-icon {
    font-size: 2rem;
    filter: drop-shadow(0 0 8px rgba(0, 212, 170, 0.5));
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
}

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

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

.nav-link:hover {
    color: var(--primary);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-family: inherit;
}

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

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

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(0, 212, 170, 0.1);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.05rem;
}

.btn-glow {
    box-shadow: var(--shadow-glow);
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from {
        box-shadow: 0 0 20px rgba(0, 212, 170, 0.3);
    }
    to {
        box-shadow: 0 0 40px rgba(0, 212, 170, 0.6);
    }
}

.btn-icon {
    font-size: 1.1rem;
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

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

.hero-gradient {
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
}

.hero-particles {
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(0, 212, 170, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(9, 132, 227, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(108, 92, 231, 0.05) 0%, transparent 50%);
}

.hero .container {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

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

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(0, 212, 170, 0.1);
    border: 1px solid rgba(0, 212, 170, 0.3);
    border-radius: 50px;
    font-size: 0.875rem;
    color: var(--primary);
    margin-bottom: 24px;
}

.badge-icon {
    animation: pulse 2s ease-in-out infinite;
}

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

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
}

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

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}

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

/* Phone Mockup */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: linear-gradient(135deg, #2d3436 0%, #1a1a2e 100%);
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.phone-mockup::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 24px;
    background: #000;
    border-radius: 20px;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #1a2a3a 0%, #0c1821 100%);
    border-radius: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.app-ui {
    text-align: center;
    padding: 20px;
}

.app-ui .app-logo {
    font-size: 4rem;
    margin-bottom: 20px;
    filter: drop-shadow(0 0 20px rgba(0, 212, 170, 0.5));
    animation: float 3s ease-in-out infinite;
}

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

.app-status {
    display: inline-block;
    padding: 8px 24px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.app-status.connected {
    background: rgba(0, 212, 170, 0.2);
    color: var(--primary);
    border: 1px solid var(--primary);
}

.app-location {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.app-speed {
    display: flex;
    justify-content: center;
    gap: 24px;
    font-size: 0.875rem;
    color: var(--text-muted);
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    background: var(--gradient-card);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    padding: 40px 30px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(0, 212, 170, 0.3);
    box-shadow: var(--shadow-md);
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    display: block;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.feature-card h4 {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--primary);
    margin-bottom: 16px;
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===========================
   How It Works Section
   =========================== */
.how-it-works {
    background: var(--gradient-dark);
}

.steps {
    display: flex;
    justify-content: space-between;
    gap: 40px;
    margin-bottom: 60px;
    position: relative;
}

.steps::before {
    content: '';
    position: absolute;
    top: 40px;
    left: 15%;
    right: 15%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--primary), var(--secondary), transparent);
}

.step {
    flex: 1;
    text-align: center;
    position: relative;
    z-index: 1;
}

.step-number {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 700;
    color: var(--dark);
    margin: 0 auto 24px;
    box-shadow: var(--shadow-glow);
}

.step-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.step-content p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    max-width: 280px;
    margin: 0 auto;
}

.cta-center {
    text-align: center;
}

/* ===========================
   Platforms Section
   =========================== */
.platforms {
    background: var(--dark);
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.platform-card {
    background: var(--gradient-card);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    padding: 40px 24px;
    text-align: center;
    transition: var(--transition);
}

.platform-card:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 212, 170, 0.3);
}

.platform-icon {
    font-size: 3rem;
    margin-bottom: 20px;
    display: block;
}

.platform-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.platform-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

/* ===========================
   Reviews Section
   =========================== */
.reviews {
    background: var(--dark-secondary);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.review-card {
    background: var(--gradient-card);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: var(--transition);
}

.review-card:hover {
    border-color: rgba(0, 212, 170, 0.3);
    transform: translateY(-4px);
}

.review-stars {
    font-size: 1.1rem;
    margin-bottom: 16px;
}

.review-text {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 24px;
    font-style: italic;
}

.review-author {
    display: flex;
    align-items: center;
    gap: 16px;
}

.author-avatar {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.author-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

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

/* ===========================
   FAQ Section
   =========================== */
.faq {
    background: var(--dark);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    overflow: hidden;
    background: var(--gradient-card);
    transition: var(--transition);
}

.faq-item:hover {
    border-color: rgba(0, 212, 170, 0.2);
}

.faq-question {
    width: 100%;
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    text-align: left;
    font-family: inherit;
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--primary);
}

.faq-icon {
    font-size: 1.5rem;
    color: var(--primary);
    transition: var(--transition);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.faq-item.active .faq-answer {
    max-height: 300px;
}

.faq-answer p {
    padding: 0 24px 24px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===========================
   CTA Section
   =========================== */
.cta-section {
    background: var(--gradient-primary);
    padding: 80px 0;
}

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

.cta-content h2 {
    font-size: clamp(1.75rem, 3vw, 2.25rem);
    color: var(--dark);
    margin-bottom: 16px;
}

.cta-content p {
    font-size: 1.125rem;
    color: var(--dark-secondary);
    margin-bottom: 32px;
    opacity: 0.8;
}

.cta-section .btn-primary {
    background: var(--dark);
    color: var(--text-primary);
}

.cta-section .btn-primary:hover {
    background: var(--dark-secondary);
}

/* ===========================
   Footer
   =========================== */
.footer {
    background: var(--dark);
    padding: 80px 0 40px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

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

.footer-section h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
}

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

.footer-section ul li {
    margin-bottom: 12px;
}

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

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

.footer-bottom {
    padding-top: 40px;
    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 .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .phone-mockup {
        width: 220px;
        height: 440px;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .platforms-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        right: 0;
        background: rgba(12, 24, 33, 0.98);
        padding: 24px;
        flex-direction: column;
        gap: 20px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-actions {
        display: none;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-stats {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 20px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .steps {
        flex-direction: column;
        gap: 40px;
    }
    
    .steps::before {
        display: none;
    }
    
    .platforms-grid {
        grid-template-columns: 1fr;
    }
    
    .reviews-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .section {
        padding: 60px 0;
    }
    
    .hero-badge {
        font-size: 0.75rem;
        padding: 6px 12px;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .btn-large {
        padding: 14px 24px;
        font-size: 0.95rem;
    }
    
    .feature-card {
        padding: 30px 24px;
    }
    
    .phone-mockup {
        width: 180px;
        height: 360px;
    }
}