/* ========================================
   Sisheng Technology - Main Stylesheet
   ======================================== */

/* CSS Variables */
:root {
    --primary-color: #6366f1;
    --primary-hover: #818cf8;
    --secondary-color: #22d3ee;
    --accent-color: #f472b6;
    --bg-dark: #0a0a0f;
    --bg-card: #12121a;
    --bg-card-hover: #1a1a25;
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --border-color: #27272a;
    --gradient-1: linear-gradient(135deg, #6366f1 0%, #22d3ee 100%);
    --gradient-2: linear-gradient(135deg, #f472b6 0%, #6366f1 100%);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.3);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    position: relative;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-1);
    transition: var(--transition);
}

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

.nav-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.lang-switch {
    display: flex;
    gap: 5px;
    background: var(--bg-card);
    padding: 5px;
    border-radius: 8px;
}

.lang-btn {
    padding: 5px 12px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 5px;
    font-size: 0.9rem;
    transition: var(--transition);
}

.lang-btn.active {
    background: var(--primary-color);
    color: var(--text-primary);
}

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

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

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

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(ellipse at 20% 50%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 50%, rgba(34, 211, 238, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 100%, rgba(244, 114, 182, 0.1) 0%, transparent 50%);
}

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

.hero-text h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
}

.hero-text h1 span {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-text p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
}

.btn {
    padding: 14px 28px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: var(--gradient-1);
    color: var(--text-primary);
}

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

.btn-secondary {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-primary);
}

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

.hero-visual {
    position: relative;
}

.hero-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 30px;
    position: relative;
    overflow: hidden;
}

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

.code-block {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.9rem;
    line-height: 1.8;
}

.code-line {
    display: flex;
    gap: 10px;
}

.code-number {
    color: var(--text-muted);
    min-width: 30px;
}

.code-keyword {
    color: #c792ea;
}

.code-function {
    color: #82aaff;
}

.code-string {
    color: #c3e88d;
}

.code-comment {
    color: var(--text-muted);
}

/* Floating Elements */
.floating-element {
    position: absolute;
    border-radius: 15px;
    padding: 15px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    animation: float 3s ease-in-out infinite;
}

.floating-element.el-1 {
    top: -20px;
    right: -30px;
    animation-delay: 0s;
}

.floating-element.el-2 {
    bottom: 30px;
    left: -40px;
    animation-delay: 1s;
}

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

/* Section Styles */
.section {
    padding: 100px 0;
}

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

.section-tag {
    display: inline-block;
    padding: 8px 16px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 20px;
    color: var(--primary-color);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 15px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 15px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Services Section */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.service-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 35px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

.service-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-1);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
}

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

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-image {
    position: relative;
}

.about-img-wrapper {
    background: var(--gradient-1);
    border-radius: 20px;
    padding: 3px;
}

.about-img-inner {
    background: var(--bg-card);
    border-radius: 18px;
    padding: 40px;
    text-align: center;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 30px;
}

.stat-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 15px;
    padding: 25px;
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 5px;
}

.about-text h2 {
    font-size: 2.2rem;
    margin-bottom: 20px;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.about-features {
    margin-top: 30px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.feature-icon {
    width: 40px;
    height: 40px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-info h2 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.contact-info > p {
    color: var(--text-secondary);
    margin-bottom: 30px;
}

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

.contact-item {
    display: flex;
    align-items: center;
    gap: 15px;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.contact-text h4 {
    font-size: 1rem;
    margin-bottom: 3px;
}

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

.contact-form-wrapper {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 40px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

/* Footer */
.footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand p {
    color: var(--text-secondary);
    margin: 15px 0 20px;
    font-size: 0.95rem;
}

.social-links {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 40px;
    height: 40px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

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

.footer-links h4 {
    font-size: 1.1rem;
    margin-bottom: 20px;
}

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

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

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

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-legal {
    display: flex;
    gap: 20px;
}

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

/* Page Header */
.page-header {
    padding: 150px 0 80px;
    background: 
        radial-gradient(ellipse at 50% 0%, rgba(99, 102, 241, 0.15) 0%, transparent 50%);
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 15px;
}

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

/* Legal Pages */
.legal-content {
    padding: 60px 0 100px;
}

.legal-container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 50px;
}

.legal-container h2 {
    font-size: 1.5rem;
    margin: 40px 0 15px;
    color: var(--primary-color);
}

.legal-container h2:first-child {
    margin-top: 0;
}

.legal-container h3 {
    font-size: 1.2rem;
    margin: 25px 0 10px;
}

.legal-container p {
    color: var(--text-secondary);
    margin-bottom: 15px;
    line-height: 1.8;
}

.legal-container ul {
    color: var(--text-secondary);
    margin: 15px 0;
    padding-left: 25px;
    list-style: disc;
}

.legal-container li {
    margin-bottom: 10px;
    line-height: 1.7;
}

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

.legal-container a:hover {
    text-decoration: underline;
}

.last-updated {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

/* Team Section */
.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.team-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 30px;
    text-align: center;
    transition: var(--transition);
}

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

.team-avatar {
    width: 100px;
    height: 100px;
    background: var(--gradient-1);
    border-radius: 50%;
    margin: 0 auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 700;
}

.team-card h3 {
    font-size: 1.2rem;
    margin-bottom: 5px;
}

.team-card .role {
    color: var(--primary-color);
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.team-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Portfolio Section */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.portfolio-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    overflow: hidden;
    transition: var(--transition);
}

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

.portfolio-image {
    height: 200px;
    background: var(--gradient-1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
}

.portfolio-info {
    padding: 25px;
}

.portfolio-info h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.portfolio-info p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 15px;
}

.portfolio-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.portfolio-tag {
    padding: 5px 12px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 15px;
    font-size: 0.8rem;
    color: var(--primary-color);
}

/* Responsive */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-text p {
        margin: 0 auto 30px;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-visual {
        display: none;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .team-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .portfolio-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-dark);
        flex-direction: column;
        padding: 20px;
        gap: 15px;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero-text h1 {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .services-grid,
    .team-grid,
    .portfolio-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .legal-container {
        padding: 30px 20px;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
}