:root {
    --ibm-blue: #0062ff;
    --ibm-dark-blue: #001d6c;
    --ibm-light-blue: #d0e2ff;
    --ibm-gray: #f4f4f4;
    --ibm-dark-gray: #8d8d8d;
    --ibm-black: #161616;
    --ibm-white: #ffffff;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    --border-radius: 4px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'IBM Plex Sans', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--ibm-black);
    background-color: var(--ibm-white);
}

h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: 3rem;
}

h2 {
    font-size: 2.25rem;
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: var(--spacing-sm);
}

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

a:hover {
    color: var(--ibm-dark-blue);
}

/* Logo Styles */
.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ibm-blue);
    display: flex;
    align-items: center;
    text-decoration: none;
}

.logo-svg {
    width: 2.5rem;
    height: 2.5rem;
    margin-right: var(--spacing-sm);
    flex-shrink: 0;
}

.logo-text {
    font-weight: 600;
    white-space: nowrap;
}

/* 页脚logo样式 */
.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ibm-white);
    display: flex;
    align-items: center;
    text-decoration: none;
}

.footer-logo .logo-svg {
    width: 2rem;
    height: 2rem;
    margin-right: var(--spacing-xs);
}

.footer-logo .logo-text {
    font-size: 1.25rem;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .logo-svg {
        width: 2rem;
        height: 2rem;
        margin-right: var(--spacing-xs);
    }
    
    .logo-text {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .logo-text {
        display: none; /* 在非常小的屏幕上只显示logo */
    }
    
    .logo-svg {
        margin-right: 0;
    }
}

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--ibm-blue);
    color: var(--ibm-white);
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn:hover {
    background-color: var(--ibm-dark-blue);
    color: var(--ibm-white);
}

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

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

/* Header */
header {
    background-color: var(--ibm-white);
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ibm-blue);
    display: flex;
    align-items: center;
}

.logo i {
    margin-right: var(--spacing-xs);
    font-size: 1.75rem;
}

nav ul {
    display: flex;
    list-style: none;
}

nav li {
    margin-left: var(--spacing-md);
}

nav a {
    font-weight: 500;
    color: var(--ibm-black);
}

nav a:hover {
    color: var(--ibm-blue);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--ibm-black);
    cursor: pointer;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--ibm-dark-blue) 0%, var(--ibm-blue) 100%);
    color: var(--ibm-white);
    padding: var(--spacing-xl) 0;
}

.hero-content {
    max-width: 800px;
}

.hero h1 {
    margin-bottom: var(--spacing-md);
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

/* Features Section */
.features {
    padding: var(--spacing-xl) 0;
    background-color: var(--ibm-gray);
}

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

.section-title p {
    max-width: 700px;
    margin: 0 auto var(--spacing-md);
    color: var(--ibm-dark-gray);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.feature-card {
    background-color: var(--ibm-white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}

.feature-icon {
    background-color: var(--ibm-light-blue);
    color: var(--ibm-blue);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.feature-icon i {
    font-size: 1.5rem;
}

/* Expertise Section */
.expertise {
    padding: var(--spacing-xl) 0;
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.company-logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-md);
    border: 1px solid var(--ibm-gray);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.company-logo:hover {
    border-color: var(--ibm-blue);
    background-color: var(--ibm-light-blue);
}

.company-logo i {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.ibm { color: #0062ff; }
.microsoft { color: #7cbb00; }
.bytedance { color: #000000; }
.tencent { color: #00a4ff; }

/* Business Section */
.business {
    padding: var(--spacing-xl) 0;
    background-color: var(--ibm-gray);
}

.business-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    align-items: center;
}

.business-item {
    background-color: var(--ibm-white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.business-icon {
    background-color: var(--ibm-blue);
    color: var(--ibm-white);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

/* Compliance Section */
.compliance {
    padding: var(--spacing-xl) 0;
}

.compliance-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
}

.compliance-text {
    flex: 1;
    min-width: 300px;
}

.compliance-logos {
    flex: 1;
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    min-width: 300px;
}

.compliance-logo {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.compliance-logo i {
    font-size: 3.5rem;
    margin-bottom: var(--spacing-sm);
}

.apple { color: #000000; }
.google { color: #4285F4; }

/* Contact Section */
.contact {
    padding: var(--spacing-xl) 0;
    background-color: var(--ibm-gray);
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.contact-item {
    background-color: var(--ibm-white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.contact-item i {
    color: var(--ibm-blue);
    margin-right: var(--spacing-xs);
}

/* Footer */
footer {
    background-color: var(--ibm-black);
    color: var(--ibm-white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ibm-white);
    display: flex;
    align-items: center;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a {
    color: var(--ibm-dark-gray);
}

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

.copyright {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid #333;
    color: var(--ibm-dark-gray);
    font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 992px) {
    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: block;
    }
    
    nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--ibm-white);
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    }
    
    nav.active ul {
        display: flex;
    }
    
    nav li {
        margin: var(--spacing-xs) 0;
    }
    
    .hero {
        padding: var(--spacing-lg) 0;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1.125rem;
    }
    
    .features, .expertise, .business, .compliance, .contact {
        padding: var(--spacing-lg) 0;
    }
}

@media (max-width: 576px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    h1 {
        font-size: 1.75rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .compliance-logos {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}