/* ========================================
   Beijing Sirenda Trade Co., Ltd.
   Main Stylesheet
   ======================================== */

/* CSS Variables */
:root {
    --primary-color: #e94560;
    --primary-light: #ff6b6b;
    --secondary-color: #0f3460;
    --background-dark: #1a1a2e;
    --background-darker: #16213e;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --accent-color: #e94560;
    --gradient-primary: linear-gradient(135deg, #e94560 0%, #ff6b6b 100%);
    --gradient-dark: linear-gradient(180deg, #1a1a2e 0%, #16213e 100%);
    --shadow-primary: 0 10px 40px rgba(233, 69, 96, 0.3);
    --shadow-secondary: 0 20px 60px rgba(0, 0, 0, 0.3);
    --border-radius: 12px;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: all 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--background-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

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

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

/* Scroll Progress Bar */
.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: var(--gradient-primary);
    z-index: 10000;
    transition: width 0.1s linear;
}

/* Loading Screen */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--background-dark);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loader.hidden {
    opacity: 0;
    visibility: hidden;
}

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

.loader-spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(233, 69, 96, 0.2);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

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

.loader-text {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1.5rem 0;
    background: rgba(26, 26, 46, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(233, 69, 96, 0.1);
    z-index: 1000;
    transition: var(--transition-smooth);
}

.header.scrolled {
    padding: 1rem 0;
    background: rgba(26, 26, 46, 0.98);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 2.5rem;
}

.nav-menu a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    padding: 0.5rem 0;
    transition: var(--transition-smooth);
}

.nav-menu a span {
    position: relative;
    z-index: 1;
}

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

.nav-menu a:hover::before,
.nav-menu a.active::before {
    width: 100%;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--text-primary);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: var(--transition-smooth);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding: 120px 2rem 80px;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--primary-color);
    border-radius: 50%;
    opacity: 0.5;
    animation: float 15s infinite;
}

.particle:nth-child(1) { left: 10%; animation-delay: 0s; animation-duration: 20s; }
.particle:nth-child(2) { left: 20%; animation-delay: 2s; animation-duration: 18s; }
.particle:nth-child(3) { left: 30%; animation-delay: 4s; animation-duration: 22s; }
.particle:nth-child(4) { left: 40%; animation-delay: 6s; animation-duration: 16s; }
.particle:nth-child(5) { left: 50%; animation-delay: 8s; animation-duration: 24s; }
.particle:nth-child(6) { left: 60%; animation-delay: 10s; animation-duration: 20s; }
.particle:nth-child(7) { left: 70%; animation-delay: 12s; animation-duration: 18s; }
.particle:nth-child(8) { left: 80%; animation-delay: 14s; animation-duration: 22s; }
.particle:nth-child(9) { left: 90%; animation-delay: 16s; animation-duration: 16s; }
.particle:nth-child(10) { left: 95%; animation-delay: 18s; animation-duration: 20s; }

@keyframes float {
    0%, 100% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.5;
    }
    90% {
        opacity: 0.5;
    }
    100% {
        transform: translateY(-100vh) rotate(720deg);
        opacity: 0;
    }
}

.hero-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.hero-line {
    position: absolute;
    width: 1px;
    height: 100%;
    background: linear-gradient(180deg, transparent 0%, rgba(233, 69, 96, 0.1) 50%, transparent 100%);
}

.hero-line:nth-child(1) { left: 25%; }
.hero-line:nth-child(2) { left: 50%; }
.hero-line:nth-child(3) { left: 75%; }

.hero-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.3;
    animation: orbFloat 20s ease-in-out infinite;
}

.hero-orb:nth-child(1) {
    width: 400px;
    height: 400px;
    background: var(--primary-color);
    top: 10%;
    right: 10%;
}

.hero-orb:nth-child(2) {
    width: 300px;
    height: 300px;
    background: var(--secondary-color);
    bottom: 20%;
    left: 5%;
    animation-delay: -10s;
}

@keyframes orbFloat {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(30px, -30px) scale(1.05); }
    50% { transform: translate(-20px, 20px) scale(0.95); }
    75% { transform: translate(20px, 30px) scale(1.02); }
}

.hero-content {
    text-align: center;
    max-width: 900px;
    z-index: 10;
    position: relative;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #ffffff 0%, #e94560 50%, #ff6b6b 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease-out 0.2s both;
}

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

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1s ease-out 0.4s both;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-smooth);
    text-decoration: none;
    border: none;
    position: relative;
    overflow: hidden;
}

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

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 50px rgba(233, 69, 96, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid rgba(233, 69, 96, 0.5);
}

.btn-secondary:hover {
    background: rgba(233, 69, 96, 0.1);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

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

.section-dark {
    background: var(--background-dark);
}

.section-gradient {
    background: linear-gradient(180deg, #16213e 0%, #1a1a2e 100%);
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 4rem;
}

.section-header h2 {
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.1rem;
}

/* Features Section */
.features-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.features-content h2 {
    margin-bottom: 2rem;
}

.feature-item {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--border-radius);
    border: 1px solid rgba(233, 69, 96, 0.1);
    transition: var(--transition-smooth);
}

.feature-item:hover {
    background: rgba(233, 69, 96, 0.05);
    border-color: rgba(233, 69, 96, 0.3);
    transform: translateX(10px);
}

.feature-icon {
    width: 50px;
    height: 50px;
    flex-shrink: 0;
    color: var(--primary-color);
}

.feature-text h4 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature-text p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

/* Services Grid */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.service-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(233, 69, 96, 0.15);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-smooth);
}

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

.service-card:hover {
    background: rgba(233, 69, 96, 0.05);
    border-color: rgba(233, 69, 96, 0.3);
    transform: translateY(-5px);
    box-shadow: var(--shadow-primary);
}

.service-icon {
    width: 60px;
    height: 60px;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.service-card h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.service-card ul {
    list-style: none;
    margin-top: 1rem;
}

.service-card li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.service-card li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* App Badges */
.app-badges {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.app-badge {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    transition: var(--transition-smooth);
    text-decoration: none;
    color: var(--text-primary);
}

.app-badge svg {
    width: 35px;
    height: 35px;
}

.app-badge-text {
    display: flex;
    flex-direction: column;
}

.app-badge-text small {
    font-size: 0.7rem;
    color: var(--text-secondary);
}

.app-badge-text strong {
    font-size: 0.9rem;
}

.app-badge:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Statistics Section */
.stats-section {
    padding: 80px 0;
    background: linear-gradient(135deg, rgba(233, 69, 96, 0.1) 0%, rgba(15, 52, 96, 0.1) 100%);
    border-top: 1px solid rgba(233, 69, 96, 0.2);
    border-bottom: 1px solid rgba(233, 69, 96, 0.2);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    text-align: center;
}

.stat-item {
    padding: 2rem;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 1rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Grid Layouts */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

/* Cards */
.card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(233, 69, 96, 0.15);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    transition: var(--transition-smooth);
}

.card:hover {
    background: rgba(233, 69, 96, 0.05);
    border-color: rgba(233, 69, 96, 0.3);
}

.card-3d {
    perspective: 1000px;
}

.card-3d-inner {
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

.card-3d:hover .card-3d-inner {
    transform: rotateY(5deg) rotateX(5deg);
}

.card-icon {
    width: 60px;
    height: 60px;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

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

.card h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

/* Footer */
.footer {
    background: var(--background-dark);
    border-top: 1px solid rgba(233, 69, 96, 0.1);
    padding: 80px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand p {
    margin-top: 1rem;
}

.footer-links h4 {
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.footer-links a {
    display: block;
    color: var(--text-secondary);
    padding: 0.5rem 0;
    transition: var(--transition-smooth);
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom p {
    margin-bottom: 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-legal {
    display: flex;
    gap: 2rem;
}

.footer-legal a {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

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

/* Utility Classes */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }
.mb-2 { margin-bottom: 2rem; }

/* Animations */
.morph {
    animation: morphShape 8s ease-in-out infinite;
}

@keyframes morphShape {
    0%, 100% { border-radius: 20px; }
    50% { border-radius: 30px; }
}

.pulse-scale {
    animation: pulseScale 2s ease-in-out infinite;
}

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

/* Responsive */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    h3 { font-size: 1.5rem; }
    
    .hero-title { font-size: 2.5rem; }
    .hero-subtitle { font-size: 1.2rem; }
    
    .nav-menu {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .features-section {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .app-badges {
        flex-direction: column;
    }
    
    .section {
        padding: 60px 0;
    }
}

/* News Grid */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.news-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(233, 69, 96, 0.15);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition-smooth);
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-primary);
    border-color: rgba(233, 69, 96, 0.3);
}

.news-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--background-dark) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.news-image svg,
.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.news-content {
    padding: 2rem;
}

.news-date {
    font-size: 0.85rem;
    color: var(--primary-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.news-content h3 {
    margin: 1rem 0;
    color: var(--text-primary);
}

.news-content p {
    font-size: 0.95rem;
}

/* Contact Form */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: inherit;
    transition: var(--transition-smooth);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    background: rgba(233, 69, 96, 0.05);
}

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.contact-info {
    padding: 2rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(233, 69, 96, 0.15);
    border-radius: var(--border-radius);
}

.contact-info h3 {
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 8px;
}

.contact-icon {
    width: 40px;
    height: 40px;
    color: var(--primary-color);
    flex-shrink: 0;
}

@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .news-grid {
        grid-template-columns: 1fr;
    }
}