/* ===================================
   国信数安科技 - 官方网站样式
   =================================== */

/* CSS Variables */
:root {
    --primary-blue: #0052A5;
    --secondary-blue: #007BFF;
    --accent-green: #28A745;
    --dark-gray: #343A40;
    --light-gray: #F8F9FA;
    --border-color: #E9ECEF;
    --text-color: #333333;
    --text-light: #6C757D;
    --white: #FFFFFF;
    --gradient-blue: linear-gradient(135deg, #0052A5 0%, #007BFF 100%);
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.15);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

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

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-brand .logo {
    font-size: 28px;
}

.nav-brand .brand-name {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-blue);
}

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

.nav-menu li a {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-color);
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu li a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary-blue);
    transition: width 0.3s ease;
}

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

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-blue);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    background: var(--gradient-blue);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 800"><defs><pattern id="grid" width="40" height="40" patternUnits="userSpaceOnUse"><path d="M 40 0 L 0 0 0 40" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/></pattern></defs><rect width="100%" height="100%" fill="url(%23grid)"/></svg>');
    opacity: 0.5;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 82, 165, 0.9) 0%, rgba(0, 123, 255, 0.8) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--white);
}

.hero-title {
    font-size: 72px;
    font-weight: 900;
    margin-bottom: 20px;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 32px;
    font-weight: 500;
    margin-bottom: 15px;
    opacity: 0.95;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-description {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    animation: fadeInUp 1s ease 0.6s both;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 15px 40px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 50px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--light-gray);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

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

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-blue);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
    animation: bounce 2s infinite;
}

.scroll-indicator span {
    font-size: 30px;
    color: var(--white);
    opacity: 0.8;
}

/* Stats Section */
.stats {
    padding: 60px 0;
    background: var(--light-gray);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    text-align: center;
}

.stat-item {
    padding: 20px;
}

.stat-number {
    font-size: 48px;
    font-weight: 900;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.stat-label {
    font-size: 16px;
    color: var(--text-light);
}

/* Section Styles */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 15px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-light);
}

/* Products Section */
.products {
    padding: 100px 0;
    background: var(--white);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.product-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 15px;
    padding: 40px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-blue);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

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

.product-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.product-card h3 {
    font-size: 26px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 15px;
}

.product-card > p {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.8;
}

.product-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.product-features li {
    font-size: 14px;
    color: var(--text-color);
    padding: 8px 12px;
    background: var(--light-gray);
    border-radius: 5px;
    position: relative;
    padding-left: 25px;
}

.product-features li::before {
    content: '✓';
    position: absolute;
    left: 10px;
    color: var(--accent-green);
    font-weight: 700;
}

/* Solutions Section */
.solutions {
    padding: 100px 0;
    background: var(--light-gray);
}

.solutions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.solution-card {
    background: var(--white);
    border-radius: 15px;
    padding: 30px;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.solution-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--secondary-blue);
}

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

.solution-icon {
    font-size: 36px;
}

.solution-card h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-blue);
}

.solution-card p {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.7;
}

/* About Section */
.about {
    padding: 100px 0;
    background: var(--white);
}

.about-text {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.about-description {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.8;
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    margin-top: 60px;
}

.value-item {
    text-align: center;
    padding: 30px 20px;
    background: var(--light-gray);
    border-radius: 15px;
    transition: all 0.3s ease;
}

.value-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.value-icon {
    font-size: 42px;
    display: block;
    margin-bottom: 15px;
}

.value-item h4 {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.value-item p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* Coverage Section */
.coverage {
    padding: 100px 0;
    background: var(--gradient-blue);
    color: var(--white);
}

.coverage .section-title {
    color: var(--white);
}

.coverage .section-subtitle {
    color: rgba(255, 255, 255, 0.9);
}

.coverage-content {
    max-width: 800px;
    margin: 0 auto;
}

.coverage-info {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.coverage-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    text-align: left;
}

.coverage-icon {
    font-size: 36px;
}

.coverage-item h4 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 5px;
}

.coverage-item p {
    font-size: 15px;
    opacity: 0.9;
}

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

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-top: 40px;
}

.contact-info {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 25px;
    background: var(--light-gray);
    border-radius: 15px;
    transition: all 0.3s ease;
}

.contact-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow);
}

.contact-icon {
    font-size: 32px;
}

.contact-item h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 5px;
}

.contact-item p {
    font-size: 15px;
    color: var(--text-light);
}

.contact-form-wrapper {
    background: var(--light-gray);
    padding: 40px;
    border-radius: 15px;
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px 20px;
    font-size: 16px;
    font-family: inherit;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    transition: all 0.3s ease;
    background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-blue);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

.form-group textarea {
    resize: vertical;
}

/* Footer */
.footer {
    background: var(--dark-gray);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-brand {
    text-align: left;
}

.footer-brand .logo {
    font-size: 36px;
    display: block;
    margin-bottom: 15px;
}

.footer-brand .brand-name {
    font-size: 24px;
    font-weight: 700;
    display: block;
    margin-bottom: 10px;
}

.footer-brand p {
    font-size: 15px;
    opacity: 0.8;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-column h4 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--white);
}

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

.footer-column ul li a {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.8);
    transition: all 0.3s ease;
}

.footer-column ul li a:hover {
    color: var(--white);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 14px;
    opacity: 0.7;
}

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

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* Responsive Design */
@media (max-width: 1024px) {
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .solutions-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .values-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 20px;
        gap: 15px;
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
        transform: translateY(-150%);
        transition: transform 0.3s ease;
    }
    
    .nav-menu.active {
        transform: translateY(0);
    }
    
    .hamburger {
        display: flex;
    }
    
    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .hero-title {
        font-size: 42px;
    }
    
    .hero-subtitle {
        font-size: 24px;
    }
    
    .hero-description {
        font-size: 16px;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 15px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .solutions-grid {
        grid-template-columns: 1fr;
    }
    
    .values-grid {
        grid-template-columns: 1fr;
    }
    
    .coverage-info {
        grid-template-columns: 1fr;
        gap: 25px;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .section-title {
        font-size: 32px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 20px;
    }
    
    .stat-number {
        font-size: 36px;
    }
    
    .product-card {
        padding: 25px;
    }
    
    .product-features {
        grid-template-columns: 1fr;
    }
}