/* CSS Variables */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #0f172a;
    --accent: #f59e0b;
    --success: #10b981;
    --error: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --text-muted: #94a3b8;
    --border: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --gradient-text: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
    --radius: 8px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-weight: 400;
    line-height: 1.7;
    color: var(--text);
    background: var(--background);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--secondary);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.01em;
}

h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h3 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 500;
    font-size: 15px;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    white-space: nowrap;
}

.btn svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

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

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

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

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

.btn-block {
    width: 100%;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 16px;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

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

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

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

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

.logo-main {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary);
}

.logo-sub {
    font-size: 11px;
    color: var(--text-muted);
    font-weight: 400;
}

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

.nav a {
    font-weight: 500;
    color: var(--text);
    position: relative;
    padding: 4px 0;
}

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

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

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

/* Hero Section */
.hero {
    position: relative;
    padding: 160px 0 100px;
    overflow: hidden;
    min-height: 90vh;
    display: flex;
    align-items: center;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse 80% 50% at 50% -10%, rgba(37, 99, 235, 0.12), transparent),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(6, 182, 212, 0.08), transparent),
        var(--background);
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

/* Certifications */
.certifications {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    margin-bottom: 32px;
}

.cert-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 24px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text);
    box-shadow: var(--shadow);
}

.cert-badge svg {
    color: var(--success);
}

.cert-wecom { border-color: #07c160; }
.cert-wecom svg { color: #07c160; }

.cert-weimob { border-color: #ff6b00; }
.cert-weimob svg { color: #ff6b00; }

.cert-tencent { border-color: #07c160; }
.cert-tencent svg { color: #07c160; }

.hero-title {
    font-size: clamp(2.25rem, 5vw, 3.25rem);
    margin-bottom: 20px;
    line-height: 1.2;
}

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

.hero-subtitle {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-ctas {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
    margin-bottom: 60px;
}

/* Hero Stats */
.hero-stats {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 40px;
    padding: 40px;
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.stat-item {
    text-align: center;
    min-width: 100px;
}

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.2;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
}

.stat-divider {
    width: 1px;
    background: var(--border);
}

/* Services Section */
.services {
    padding: 100px 0;
    background: var(--surface);
}

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

.section-tag {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    border-radius: 24px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: 0.02em;
}

.section-title {
    margin-bottom: 16px;
}

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

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.service-card {
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: var(--transition);
    text-align: left;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.service-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white;
    border-radius: var(--radius);
    margin-bottom: 20px;
}

.service-icon svg {
    width: 28px;
    height: 28px;
}

.service-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 12px;
}

.service-tag-highlight {
    background: linear-gradient(135deg, #07c160 0%, #10b981 100%);
    color: white;
}

.service-title {
    font-size: 22px;
    margin-bottom: 12px;
}

.service-desc {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.6;
}

.service-features {
    list-style: none;
    margin-bottom: 20px;
}

.service-features li {
    padding: 8px 0;
    color: var(--text);
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.service-features li::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--success);
    border-radius: 50%;
    flex-shrink: 0;
}

.service-link {
    color: var(--primary);
    font-weight: 600;
    font-size: 14px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.service-link:hover {
    gap: 10px;
}

/* Cases Section */
.cases {
    padding: 100px 0;
    background: var(--background);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 24px;
    margin-bottom: 40px;
}

.case-card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.case-card-large {
    grid-column: span 5;
    background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
    color: white;
    border: none;
}

.case-card-large .case-title,
.case-card-large .case-desc,
.case-card-large .case-industry {
    color: white;
}

.case-card-large .metric-label,
.case-card-large .case-services span {
    color: rgba(255, 255, 255, 0.8);
}

.case-card-large .case-services span {
    background: rgba(255, 255, 255, 0.2);
}

.case-card:not(.case-card-large) {
    grid-column: span 3.5;
}

.case-industry {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--primary);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 12px;
}

.case-industry svg {
    color: var(--success);
}

.case-title {
    font-size: 20px;
    margin-bottom: 20px;
}

.case-metrics {
    display: flex;
    gap: 32px;
    margin-bottom: 20px;
}

.metric {
    display: flex;
    flex-direction: column;
}

.metric-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.2;
}

.case-card-large .metric-value {
    color: white;
}

.metric-label {
    font-size: 13px;
    color: var(--text-muted);
}

.case-desc {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.6;
    font-size: 15px;
}

.case-services {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.case-services span {
    padding: 6px 12px;
    background: var(--background);
    border-radius: 20px;
    font-size: 13px;
    color: var(--text);
}

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

/* Why Us Section */
.why-us {
    padding: 100px 0;
    background: var(--surface);
}

.why-us-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.why-us-card {
    background: var(--background);
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.why-us-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transition: var(--transition);
}

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

.why-us-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.why-us-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    background: rgba(37, 99, 235, 0.1);
    border-radius: 50%;
    color: var(--primary);
}

.why-us-icon svg {
    width: 32px;
    height: 32px;
}

.why-us-number {
    font-size: 48px;
    font-weight: 700;
    color: rgba(37, 99, 235, 0.1);
    line-height: 1;
    margin-bottom: 16px;
}

.why-us-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

.why-us-card p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 0;
}

/* Contact Section */
.contact {
    padding: 100px 0;
    background: var(--background);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
    align-items: start;
}

.contact-info .section-title {
    text-align: left;
    margin-bottom: 16px;
}

.contact-desc {
    color: var(--text-light);
    margin-bottom: 40px;
    font-size: 17px;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-method {
    display: flex;
    align-items: flex-start;
    gap: 16px;
}

.contact-method svg {
    width: 24px;
    height: 24px;
    color: var(--primary);
    flex-shrink: 0;
    margin-top: 2px;
}

.method-label {
    display: block;
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.method-value {
    display: block;
    font-weight: 500;
    color: var(--text);
    font-size: 15px;
}

/* Contact Form */
.contact-form {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-xl);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

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

.form-group:last-of-type {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text);
    font-size: 14px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
    background: var(--surface);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

/* Footer */
.footer {
    background: var(--secondary);
    color: white;
    padding: 80px 0 24px;
}

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

.footer-brand .logo {
    color: white;
    margin-bottom: 20px;
}

.footer-brand .logo-icon {
    color: var(--primary-light);
}

.footer-brand .logo-text .logo-main {
    color: white;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 20px;
    line-height: 1.8;
}

.footer-certs {
    display: flex;
    gap: 16px;
}

.cert-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    font-size: 12px;
    color: rgba(255, 255, 255, 0.8);
}

.cert-item svg {
    color: var(--success);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.footer-column h4 {
    color: white;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 24px;
}

.footer-column a {
    display: block;
    color: rgba(255, 255, 255, 0.6);
    padding: 8px 0;
    font-size: 14px;
    transition: var(--transition);
}

.footer-column a:hover {
    color: var(--primary-light);
    padding-left: 4px;
}

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.4);
    font-size: 14px;
    margin-bottom: 8px;
}

.footer-bottom p:last-child {
    margin-bottom: 0;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

.hero-content > * {
    animation: slideUp 0.6s ease backwards;
}

.hero-content .certifications { animation-delay: 0.05s; }
.hero-content h1 { animation-delay: 0.1s; }
.hero-content .hero-subtitle { animation-delay: 0.15s; }
.hero-content .hero-ctas { animation-delay: 0.2s; }
.hero-content .hero-stats { animation-delay: 0.25s; }

/* Responsive */
@media (max-width: 1024px) {
    .cases-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .case-card-large,
    .case-card:not(.case-card-large) {
        grid-column: span 1;
    }
}

@media (max-width: 768px) {
    .header .container {
        padding: 0 16px;
    }
    
    .nav {
        display: none;
    }
    
    .logo-sub {
        display: none;
    }
    
    .hero {
        padding: 120px 0 60px;
        min-height: auto;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 24px;
        padding: 24px;
    }
    
    .stat-divider {
        display: none;
    }
    
    .hero-ctas {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-ctas .btn {
        width: 100%;
        justify-content: center;
    }
    
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-links {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 480px) {
    .certifications {
        flex-direction: column;
        align-items: center;
    }
    
    .cert-badge {
        width: fit-content;
    }
    
    .case-metrics {
        flex-direction: column;
        gap: 16px;
    }
}