/* ==========================================
   Social Effect - Style Guide
   Modern, clean design with Chinese/English bilingual feel
   ========================================== */

/* CSS Variables */
:root {
    --color-primary: #E84A5F;       /* Vibrant red-pink, evokes 小红书 brand colors */
    --color-secondary: #2C3E50;     /* Deep blue-gray for professionalism */
    --color-accent: #F5A623;        /* Warm accent gold */
    --color-bg: #FFFFFF;
    --color-bg-alt: #F8F9FA;
    --color-text: #2C3E50;
    --color-text-light: #6C757D;
    --color-border: #E9ECEF;
    
    --font-heading: 'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-body: 'Segoe UI', system-ui, -apple-system, sans-serif;
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 4rem;
    
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.15);
    
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

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

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

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

a:hover {
    color: var(--color-secondary);
}

h1, h2, h3, h4 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ==========================================
   Navigation
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    padding: var(--spacing-md) 0;
}

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

.logo {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-en {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-secondary);
}

.logo-cn {
    font-size: 0.75rem;
    color: var(--color-primary);
    font-weight: 500;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-links a {
    color: var(--color-text);
    font-weight: 500;
    padding: var(--spacing-sm) 0;
    position: relative;
}

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

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

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

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-secondary);
    transition: var(--transition);
}

/* ==========================================
   Hero Section
   ========================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, #FFF5F5 0%, #FFF9F0 100%);
    padding: 120px var(--spacing-lg) var(--spacing-xl);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(232,74,95,0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(245,166,35,0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    color: var(--color-secondary);
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

.hero-tagline {
    font-size: 1rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
}

/* ==========================================
   Buttons
   ========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 50px;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

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

.btn-primary:hover {
    background: #D63D52;
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ==========================================
   Sections
   ========================================== */
.section {
    padding: var(--spacing-xl) 0;
}

.section-alt {
    background: var(--color-bg-alt);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: 1rem;
    color: var(--color-primary);
    font-weight: 500;
}

/* ==========================================
   About Section
   ========================================== */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.stat {
    padding: var(--spacing-lg);
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.stat-label {
    display: block;
    font-size: 1rem;
    color: var(--color-text);
    font-weight: 500;
}

.stat-label-cn {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-top: var(--spacing-xs);
}

/* ==========================================
   Services Section
   ========================================== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.service-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: var(--transition);
}

.service-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.service-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.service-card h3 {
    font-size: 1.25rem;
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

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

.service-cn {
    margin-top: var(--spacing-sm);
    font-size: 0.875rem !important;
    color: var(--color-primary) !important;
}

/* ==========================================
   News Section
   ========================================== */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.news-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    display: flex;
    transition: var(--transition);
}

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

.news-date {
    background: var(--color-primary);
    color: white;
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 80px;
}

.news-month {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
}

.news-day {
    font-size: 1.5rem;
    font-weight: 700;
}

.news-content {
    padding: var(--spacing-lg);
    flex: 1;
}

.news-content h3 {
    font-size: 1.25rem;
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

.news-content p {
    color: var(--color-text-light);
    font-size: 0.95rem;
    margin-bottom: var(--spacing-md);
}

.news-link {
    font-weight: 600;
    color: var(--color-primary);
}

.news-link:hover {
    color: var(--color-secondary);
}

/* ==========================================
   Contact Section
   ========================================== */
.contact-wrapper {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    max-width: 1000px;
    margin: 0 auto;
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

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

.contact-item h4 {
    color: var(--color-secondary);
    margin-bottom: var(--spacing-xs);
}

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

.subscribe-form {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

.subscribe-form h3 {
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

.subscribe-form p {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}

.subscribe-cn {
    font-size: 0.875rem;
    color: var(--color-primary) !important;
    margin-top: calc(-1 * var(--spacing-md));
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group input {
    width: 100%;
    padding: 14px 18px;
    font-size: 1rem;
    border: 2px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
    font-family: inherit;
}

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

.form-message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    text-align: center;
}

.form-message.success {
    background: #D4EDDA;
    color: #155724;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background: var(--color-secondary);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
}

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

.footer .logo-en {
    color: white;
}

.footer .logo-cn {
    color: var(--color-accent);
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
}

.footer-links a {
    color: rgba(255,255,255,0.8);
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
}

.footer-bottom p {
    color: rgba(255,255,255,0.6);
    font-size: 0.875rem;
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        box-shadow: var(--shadow-md);
        transform: translateY(-10px);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .hero {
        padding-top: 100px;
    }
    
    .section {
        padding: var(--spacing-lg) 0;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .btn {
        width: 100%;
    }
}

/* ==========================================
   Animations
   ========================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}