:root {
    --primary: #1a56db;
    --primary-dark: #1e429f;
    --secondary: #046c4e;
    --accent: #dc2626;
    --light: #f8f9fa;
    --dark: #1f2937;
    --gray: #6b7280;
    --border: #e5e7eb;
    --success: #10b981;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

body {
    background-color: #f9fafb;
    color: var(--dark);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
header {
    background-color: white;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 20px;
}

.logo-text {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-links a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    font-size: 16px;
    transition: color 0.3s;
    position: relative;
}

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

.nav-links a:after {
    content: '';
    position: absolute;
    width: 0;
    height: 3px;
    bottom: -5px;
    left: 0;
    background-color: var(--primary);
    transition: width 0.3s;
}

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

.nav-links a.active {
    color: var(--primary);
    font-weight: 600;
}

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

.auth-buttons {
    display: flex;
    align-items: center;
    gap: 15px;
}

.btn {
    padding: 10px 24px;
    border-radius: 6px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
    text-align: center;
    border: none;
    font-size: 15px;
}

.btn-outline {
    border: 1.5px solid white;
    color: white;
    background: transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 12px rgba(26, 86, 219, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(26, 86, 219, 0.4);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.8);
    transform: translateY(-2px);
}

/* 英雄区域样式 */
.hero {
    background: linear-gradient(135deg, #1a56db 0%, #1e3a8a 100%);
    color: white;
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.hero:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000" preserveAspectRatio="none"><path fill="rgba(255,255,255,0.05)" d="M0,0 L1000,0 L1000,1000 L0,1000 Z"><animate attributeName="d" dur="20s" repeatCount="indefinite" values="M0,0 L1000,0 L1000,1000 L0,1000 Z; M0,0 L1000,0 L1000,800 L0,1000 Z; M0,0 L1000,0 L1000,1000 L0,800 Z; M0,0 L1000,0 L1000,1000 L0,1000 Z"/></path></svg>');
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: 3.2rem;
    margin-bottom: 24px;
    font-weight: 800;
    line-height: 1.2;
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.btn-light {
    background: white;
    color: var(--primary);
    font-weight: 600;
}

.btn-light:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(255, 255, 255, 0.3);
}

.btn-transparent {
    background: transparent;
    color: white;
    border: 1.5px solid rgba(255, 255, 255, 0.5);
}

.btn-transparent:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* 内容区域样式 */
.section {
    padding: 90px 0;
}

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

.section-title h2 {
    font-size: 2.4rem;
    color: var(--dark);
    margin-bottom: 18px;
    position: relative;
    display: inline-block;
}

.section-title h2:after {
    content: '';
    position: absolute;
    width: 70px;
    height: 4px;
    background: linear-gradient(to right, var(--primary), var(--secondary));
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

.section-title p {
    color: var(--gray);
    max-width: 700px;
    margin: 0 auto;
    font-size: 1.1rem;
}

/* 左右图文布局 */
.feature-block {
    display: flex;
    align-items: center;
    margin-bottom: 100px;
    gap: 60px;
}

.feature-block:nth-child(even) {
    flex-direction: row-reverse;
}

.feature-text {
    flex: 1;
}

.feature-text h3 {
    font-size: 1.9rem;
    margin-bottom: 22px;
    color: var(--dark);
    line-height: 1.3;
}

.feature-text p {
    margin-bottom: 22px;
    color: var(--gray);
    font-size: 1.05rem;
}

.feature-list {
    list-style: none;
    margin-bottom: 30px;
}

.feature-list li {
    margin-bottom: 12px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.feature-list li i {
    color: var(--success);
    margin-top: 4px;
    flex-shrink: 0;
}

.feature-image {
    flex: 1;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.5s, box-shadow 0.5s;
}

.feature-image:hover {
    transform: translateY(-10px);
    box-shadow: 0 25px 40px rgba(0, 0, 0, 0.15);
}

.feature-image img,
.feature-image svg,
.feature-image embed {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s;
}

.feature-image:hover img,
.feature-image:hover svg,
.feature-image:hover embed {
    transform: scale(1.05);
}

/* 预警系统样式 */
.alert-system {
    background: white;
    border-radius: 16px;
    padding: 60px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.06);
    margin-top: 40px;
}

.alert-title {
    text-align: center;
    margin-bottom: 50px;
}

.alert-title h3 {
    font-size: 1.8rem;
    color: var(--dark);
    margin-bottom: 15px;
}

.alert-title p {
    color: var(--gray);
    max-width: 600px;
    margin: 0 auto;
}

.alert-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.alert-item {
    text-align: center;
    padding: 30px 20px;
    border-radius: 12px;
    background: var(--light);
    transition: transform 0.3s, box-shadow 0.3s;
    border-top: 4px solid var(--primary);
}

.alert-item.yellow {
    border-top-color: #f59e0b;
}

.alert-item.red {
    border-top-color: var(--accent);
}

.alert-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

.alert-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: white;
    font-size: 28px;
}

.alert-item.yellow .alert-icon {
    background: linear-gradient(135deg, #f59e0b, #d97706);
}

.alert-item.red .alert-icon {
    background: linear-gradient(135deg, var(--accent), #b91c1c);
}

.alert-item h4 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--dark);
}

.alert-item p {
    color: var(--gray);
    font-size: 0.95rem;
}

/* 工作流程区域 */
.workflow {
    background: linear-gradient(135deg, #f5f7fa 0%, #e9ecef 100%);
    border-radius: 16px;
    padding: 60px 40px;
}

.workflow-steps {
    display: flex;
    justify-content: space-between;
    position: relative;
    margin-top: 50px;
}

.workflow-steps:before {
    content: '';
    position: absolute;
    top: 40px;
    left: 10%;
    right: 10%;
    height: 4px;
    background: var(--primary);
    z-index: 1;
}

.step {
    text-align: center;
    position: relative;
    z-index: 2;
    flex: 1;
}

.step-icon {
    width: 80px;
    height: 80px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: var(--primary);
    font-size: 32px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border: 4px solid var(--primary);
}

.step h4 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--dark);
}

.step p {
    color: var(--gray);
    font-size: 0.9rem;
    max-width: 200px;
    margin: 0 auto;
}

/* CTA区域 */
.cta {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    text-align: center;
    padding: 80px 0;
    border-radius: 16px;
    margin-top: 40px;
}

.cta h2 {
    font-size: 2.3rem;
    margin-bottom: 20px;
    font-weight: 700;
}

.cta p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 40px;
    opacity: 0.9;
}

/* 页脚样式 */
footer {
    background-color: #1a2332;
    color: white;
    padding: 70px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 50px;
}

.footer-column h3 {
    font-size: 1.3rem;
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 12px;
}

.footer-column h3:after {
    content: '';
    position: absolute;
    width: 50px;
    height: 3px;
    background: var(--primary);
    bottom: 0;
    left: 0;
    border-radius: 2px;
}

.footer-column p {
    color: #a0a8b7;
    margin-bottom: 20px;
    line-height: 1.7;
}

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

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: #a0a8b7;
    text-decoration: none;
    transition: color 0.3s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-links a i {
    font-size: 14px;
}

.footer-links a:hover {
    color: white;
    transform: translateX(5px);
}

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-links a {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: #2a3446;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #a0a8b7;
    transition: all 0.3s;
}

.social-links a:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid #2a3446;
    color: #a0a8b7;
    font-size: 0.95rem;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .alert-grid, .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .feature-block {
        flex-direction: column;
        gap: 40px;
    }
    
    .feature-block:nth-child(even) {
        flex-direction: column;
    }
    
    .hero h1 {
        font-size: 2.7rem;
    }

    .workflow-steps {
        flex-direction: column;
        gap: 40px;
    }

    .workflow-steps:before {
        display: none;
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        padding: 15px 0;
    }
    
    .nav-links {
        margin: 20px 0;
        flex-wrap: wrap;
        justify-content: center;
        gap: 20px;
    }
    
    .auth-buttons {
        margin-top: 10px;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .alert-grid, .footer-content {
        grid-template-columns: 1fr;
    }
    
    .workflow {
        padding: 40px 20px;
    }

    .alert-system {
        padding: 40px 20px;
    }
}