/* ============================================
   BlueTurbo DSP - Main Stylesheet
   ============================================ */

/* CSS Variables */
:root {
    --primary-color: #0066FF;
    --primary-light: #00D4FF;
    --primary-dark: #0052CC;
    --secondary-color: #1A1A2E;
    --text-color: #333333;
    --text-light: #666666;
    --text-muted: #999999;
    --bg-color: #FFFFFF;
    --bg-light: #F8FAFC;
    --bg-gradient: linear-gradient(135deg, #0066FF 0%, #00D4FF 100%);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.15);
    --border-radius: 12px;
    --transition: all 0.3s ease;
    --font-zh: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-en: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-zh);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

body.lang-en {
    font-family: var(--font-en);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

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

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-brand .logo {
    height: 40px;
    width: auto;
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-menu a {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-color);
    position: relative;
}

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

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

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

.lang-switch {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
    background: transparent;
    color: var(--primary-color);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.lang-switch:hover {
    background: var(--primary-color);
    color: white;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--text-color);
    transition: var(--transition);
}

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

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.hero-svg {
    width: 100%;
    height: 100%;
}

.float-circle {
    animation: float 8s ease-in-out infinite;
}

.float-circle-reverse {
    animation: float 8s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-20px) scale(1.05); }
}

.hero-content {
    text-align: center;
    color: white;
    padding: 100px 24px;
}

.hero-title {
    font-size: 64px;
    font-weight: 800;
    margin-bottom: 16px;
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 24px;
    font-weight: 500;
    margin-bottom: 16px;
    opacity: 0.95;
}

.hero-desc {
    font-size: 18px;
    max-width: 600px;
    margin: 0 auto 40px;
    opacity: 0.9;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 255, 255, 0.3);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

.scroll-dot {
    animation: scrollDot 2s infinite;
}

@keyframes scrollDot {
    0%, 100% { cy: 12; opacity: 1; }
    50% { cy: 18; opacity: 0.5; }
}

/* ============================================
   Sections
   ============================================ */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   About Section
   ============================================ */
.about {
    background: var(--bg-light);
}

.about-content {
    max-width: 900px;
    margin: 0 auto 60px;
    text-align: center;
}

.about-text {
    font-size: 18px;
    line-height: 1.8;
    color: var(--text-light);
}

.core-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 40px 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
}

.icon-svg {
    width: 100%;
    height: 100%;
}

.feature-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.feature-subtitle {
    font-size: 16px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 16px;
}

.feature-desc {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   Features Section
   ============================================ */
.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.feature-item {
    display: flex;
    gap: 24px;
    padding: 32px;
    background: var(--bg-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.feature-item:hover {
    background: white;
    box-shadow: var(--shadow-md);
}

.feature-number {
    font-size: 48px;
    font-weight: 800;
    background: var(--bg-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.feature-content h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.feature-content p {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   Coverage Section
   ============================================ */
.coverage {
    background: var(--bg-light);
}

.world-map-container {
    max-width: 1100px;
    margin: 0 auto 60px;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, #f8fafc 0%, #e8f4ff 100%);
}

.map-wrapper {
    position: relative;
    width: 100%;
    padding: 20px;
}

.world-map-img {
    display: block;
    width: 100%;
    height: auto;
}

.map-markers {
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    bottom: 20px;
    pointer-events: none;
}

.region-marker {
    position: absolute;
    pointer-events: auto;
    cursor: pointer;
    transition: transform 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    transform: translate(-50%, -50%);
}

.region-marker:hover {
    transform: translate(-50%, -50%) scale(1.15);
}

.marker-circle {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 102, 255, 0.3);
}

.marker-circle.blue {
    background: #0066FF;
}

.marker-circle.cyan {
    background: #00D4FF;
}

.marker-title {
    font-size: 10px;
    color: white;
    font-weight: 600;
}

.marker-value {
    font-size: 14px;
    color: white;
    font-weight: 700;
}

.marker-label {
    margin-top: 4px;
    font-size: 12px;
    color: #0066FF;
    font-weight: 600;
}

.marker-label.cyan {
    color: #00D4FF;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .world-map-container {
        margin: 0 auto 40px;
    }
    
    .map-wrapper {
        padding: 10px;
    }
    
    .map-markers {
        top: 10px;
        left: 10px;
        right: 10px;
        bottom: 10px;
    }
    
    .marker-circle {
        width: 48px;
        height: 48px;
    }
    
    .marker-title {
        font-size: 8px;
    }
    
    .marker-value {
        font-size: 11px;
    }
    
    .marker-label {
        font-size: 10px;
    }
}

.stats-row {
    display: flex;
    justify-content: center;
    gap: 80px;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 56px;
    font-weight: 800;
    background: var(--bg-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 16px;
    color: var(--text-light);
    font-weight: 500;
}

/* ============================================
   Ad Formats Section
   ============================================ */
.ad-formats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.ad-format-card {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
}

.ad-format-card:hover {
    background: white;
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.ad-format-icon {
    width: 100px;
    height: 100px;
    margin: 0 auto 20px;
}

.ad-format-icon svg {
    width: 100%;
    height: 100%;
}

.ad-format-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.ad-format-desc {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.5;
}

/* ============================================
   Security Section
   ============================================ */
.security {
    background: var(--bg-light);
}

.security-flow {
    display: flex;
    align-items: stretch;
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
}

.security-layer {
    flex: 1;
    min-width: 280px;
    max-width: 350px;
}

.security-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 32px 24px;
    height: 100%;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
}

.security-card:hover {
    box-shadow: var(--shadow-md);
}

.security-step {
    position: absolute;
    top: -16px;
    left: 24px;
    width: 32px;
    height: 32px;
    background: var(--bg-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 14px;
}

.security-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 16px;
    padding-top: 8px;
}

.security-card ul {
    padding-left: 0;
}

.security-card li {
    font-size: 14px;
    color: var(--text-light);
    padding: 8px 0;
    padding-left: 20px;
    position: relative;
    line-height: 1.5;
}

.security-card li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 14px;
    width: 8px;
    height: 8px;
    background: var(--primary-light);
    border-radius: 50%;
}

.security-arrow {
    display: flex;
    align-items: center;
    padding: 0 8px;
}

.security-arrow svg {
    width: 40px;
    height: 20px;
}

/* ============================================
   Process Section
   ============================================ */
.process-timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline-line {
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--primary-light) 100%);
}

.process-step {
    display: flex;
    gap: 24px;
    padding: 24px 0;
    position: relative;
}

.step-marker {
    width: 40px;
    height: 40px;
    flex-shrink: 0;
    z-index: 1;
}

.step-marker svg {
    width: 100%;
    height: 100%;
}

.step-content {
    padding-top: 6px;
}

.step-content h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 8px;
}

.step-content p {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   Contact Section
   ============================================ */
.contact {
    background: var(--secondary-color);
    color: white;
}

.contact .section-title {
    color: white;
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.contact-desc {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 32px;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
}

.contact-icon {
    width: 24px;
    height: 24px;
    color: var(--primary-light);
}

.contact-item a {
    color: white;
    font-size: 16px;
}

.contact-item a:hover {
    color: var(--primary-light);
}

.contact-form-wrapper {
    background: white;
    border-radius: var(--border-radius);
    padding: 40px;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-color);
}

.form-group input,
.form-group textarea {
    padding: 12px 16px;
    border: 1px solid #E0E0E0;
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.contact-form .btn-primary {
    background: var(--bg-gradient);
    color: white;
    width: 100%;
    padding: 16px;
}

.contact-form .btn-primary:hover {
    opacity: 0.9;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: #0D0D1A;
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-logo {
    height: 36px;
    margin-bottom: 16px;
    filter: brightness(0) invert(1);
}

.footer-brand p {
    font-size: 14px;
    opacity: 0.7;
    max-width: 300px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.footer-column h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
    color: white;
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-column a {
    font-size: 14px;
    opacity: 0.7;
    transition: var(--transition);
}

.footer-column a:hover {
    opacity: 1;
    color: var(--primary-light);
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-bottom p {
    font-size: 14px;
    opacity: 0.5;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        box-shadow: var(--shadow-md);
    }

    .nav-menu.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-title {
        font-size: 48px;
    }

    .hero-subtitle {
        font-size: 20px;
    }

    .core-features {
        grid-template-columns: 1fr;
        gap: 24px;
    }

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

    .ad-formats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .security-flow {
        flex-direction: column;
        align-items: center;
    }

    .security-arrow {
        transform: rotate(90deg);
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 28px;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .hero-desc {
        font-size: 16px;
    }

    .stats-row {
        gap: 40px;
    }

    .stat-number {
        font-size: 40px;
    }

    .ad-formats-grid {
        grid-template-columns: 1fr;
    }

    .footer-links {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 28px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .feature-item {
        flex-direction: column;
        text-align: center;
    }

    .contact-form-wrapper {
        padding: 24px;
    }
}

/* ============================================
   Animation Classes
   ============================================ */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.slide-in-left {
    opacity: 0;
    transform: translateX(-40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-in-right {
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}