/* ========================================
   北京智戒科技有限公司 - 官网样式
   ======================================== */

/* --- CSS 变量 --- */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --accent: #06b6d4;
    --dark: #0f172a;
    --dark-light: #1e293b;
    --gray-900: #111827;
    --gray-800: #1f2937;
    --gray-700: #374151;
    --gray-600: #4b5563;
    --gray-500: #6b7280;
    --gray-400: #9ca3af;
    --gray-300: #d1d5db;
    --gray-200: #e5e7eb;
    --gray-100: #f3f4f6;
    --gray-50: #f9fafb;
    --white: #ffffff;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    --gradient-dark: linear-gradient(135deg, var(--dark) 0%, var(--dark-light) 100%);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --transition: all 0.3s ease;
    --font-sans: -apple-system, BlinkMacSystemFont, \"Segoe UI\", \"PingFang SC\", \"Hiragino Sans GB\", \"Microsoft YaHei\", sans-serif;
}

/* --- 重置与基础 --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-sans);
    color: var(--gray-700);
    line-height: 1.6;
    background: var(--white);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

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

/* --- 按钮 --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    gap: 8px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    border-color: transparent;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border-color: var(--white);
}

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

.btn-full {
    width: 100%;
}

/* --- 导航栏 --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    transition: var(--transition);
    background: transparent;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    padding: 10px 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.logo-icon {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-sub {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--gray-500);
    letter-spacing: 2px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 36px;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--gray-600);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition);
}

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

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

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    transition: var(--transition);
}

/* --- 英雄区域 --- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: var(--gradient-dark);
}

.hero-bg {
    position: absolute;
    inset: 0;
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    padding: 0 24px;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    color: var(--white);
    margin-bottom: 20px;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2.5vw, 1.35rem);
    color: var(--gray-300);
    margin-bottom: 40px;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--gray-400);
    font-size: 0.85rem;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    margin: 8px auto 0;
    border-right: 2px solid var(--gray-400);
    border-bottom: 2px solid var(--gray-400);
    transform: rotate(45deg);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: rotate(45deg) translateY(0); }
    40% { transform: rotate(45deg) translateY(-8px); }
    60% { transform: rotate(45deg) translateY(-4px); }
}

/* --- 数据统计 --- */
.stats {
    padding: 60px 0;
    background: var(--white);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.stat-item {
    text-align: center;
    padding: 24px;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.stat-label {
    font-size: 1rem;
    color: var(--gray-500);
    margin-top: 8px;
}

/* --- 通用标题 --- */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 3px;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
    padding: 6px 16px;
    border-radius: 20px;
    margin-bottom: 16px;
}

.section-header h2 {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--gray-500);
    max-width: 600px;
    margin: 0 auto;
}

/* --- 关于我们 --- */
.about {
    padding: 100px 0;
    background: var(--gray-50);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-img-placeholder {
    position: relative;
    width: 100%;
    aspect-ratio: 4/3;
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.img-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(255,255,255,0.2) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(255,255,255,0.15) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(255,255,255,0.1) 0%, transparent 70%);
}

.about-year {
    position: absolute;
    bottom: 24px;
    right: 24px;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--white);
    opacity: 0.3;
}

.about-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.about-card {
    background: var(--white);
    padding: 24px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--primary);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.about-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.about-card p {
    font-size: 0.95rem;
    color: var(--gray-600);
}

.about-text {
    font-size: 1rem;
    color: var(--gray-600);
    line-height: 1.8;
    margin-top: 8px;
}

/* --- 产品服务 --- */
.services {
    padding: 100px 0;
    background: var(--white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.service-card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

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

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

.service-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

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

.ai-icon { background: rgba(37, 99, 235, 0.1); color: var(--primary); }
.data-icon { background: rgba(6, 182, 212, 0.1); color: var(--accent); }
.cloud-icon { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.security-icon { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.iot-icon { background: rgba(139, 92, 246, 0.1); color: #8b5cf6; }
.consult-icon { background: rgba(236, 72, 153, 0.1); color: #ec4899; }

.service-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 0.95rem;
    color: var(--gray-600);
    margin-bottom: 20px;
    line-height: 1.7;
}

.service-features {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.service-features li {
    font-size: 0.9rem;
    color: var(--gray-500);
    padding-left: 20px;
    position: relative;
}

.service-features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--primary);
    opacity: 0.6;
}

/* --- 客户案例 --- */
.cases {
    padding: 100px 0;
    background: var(--gray-50);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.case-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--gray-200);
}

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

.case-industry {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 1px;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
    padding: 4px 12px;
    border-radius: 4px;
    margin-bottom: 16px;
}

.case-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.case-card p {
    font-size: 0.95rem;
    color: var(--gray-600);
    margin-bottom: 24px;
    line-height: 1.7;
}

.case-metrics {
    display: flex;
    gap: 16px;
    padding-top: 20px;
    border-top: 1px solid var(--gray-200);
}

.metric {
    text-align: center;
    flex: 1;
}

.metric-value {
    display: block;
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--primary);
}

.metric-label {
    font-size: 0.8rem;
    color: var(--gray-500);
    margin-top: 4px;
}

/* --- 联系我们 --- */
.contact {
    padding: 100px 0;
    background: var(--white);
}

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

.contact-item {
    display: flex;
    gap: 20px;
    margin-bottom: 32px;
}

.contact-icon {
    width: 52px;
    height: 52px;
    min-width: 52px;
    border-radius: var(--radius-md);
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-icon svg {
    width: 24px;
    height: 24px;
}

.contact-item h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 4px;
}

.contact-item p {
    font-size: 0.95rem;
    color: var(--gray-600);
    line-height: 1.6;
}

.contact-form {
    background: var(--gray-50);
    padding: 40px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

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

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

.form-group.full-width {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.95rem;
    font-family: var(--font-sans);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    background: var(--white);
    color: var(--gray-700);
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray-400);
}

/* --- 页脚 --- */
.footer {
    background: var(--dark);
    color: var(--gray-400);
    padding: 60px 0 30px;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.footer-logo .logo-icon {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-logo .logo-sub {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--gray-500);
    letter-spacing: 2px;
}

.footer-brand p {
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.social-links {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: var(--dark-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gray-400);
    transition: var(--transition);
}

.social-link:hover {
    background: var(--primary);
    color: var(--white);
    transform: translateY(-2px);
}

.social-link svg {
    width: 20px;
    height: 20px;
}

.footer-links h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 20px;
}

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

.footer-links a {
    font-size: 0.9rem;
    color: var(--gray-400);
}

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

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid var(--dark-light);
    text-align: center;
}

.footer-bottom p {
    font-size: 0.85rem;
    color: var(--gray-500);
}

/* --- 动画 --- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- 响应式设计 --- */
@media (max-width: 1024px) {
    .services-grid,
    .cases-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        gap: 16px;
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .services-grid,
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .stat-number {
        font-size: 2.5rem;
    }
    
    .contact-form {
        padding: 24px;
    }
}