/* ============================================
   济泽智能官网样式
   设计理念：简约 + 专业 + 现代
   浅色主题
   ============================================ */

/* CSS变量 */
:root {
    /* 主色调 - 科技蓝 */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    
    /* 辅助色 - 靛蓝 */
    --accent: #4f46e5;
    --accent-dark: #4338ca;
    --accent-light: #6366f1;
    
    /* 成功色 */
    --success: #10b981;
    
    /* 中性色 - 浅色主题 */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* 背景色 */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-card: #ffffff;
    --bg-hero: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #f0fdf4 100%);
    
    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    --gradient-light: linear-gradient(135deg, var(--primary-50) 0%, #f0fdf4 100%);
    
    /* 字体 */
    --font-sans: 'Noto Sans SC', 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Outfit', 'Noto Sans SC', sans-serif;
    
    /* 间距 */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;
    
    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 24px;
    --radius-full: 9999px;
    
    /* 阴影 */
    --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 -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);
    --shadow-primary: 0 4px 14px rgba(37, 99, 235, 0.25);
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 层级 */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 400;
    --z-tooltip: 500;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-700);
    background: var(--bg-primary);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

ul, ol {
    list-style: none;
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* 容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* ============================================
   粒子背景
   ============================================ */
#particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    opacity: 0.6;
}

/* ============================================
   导航栏
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    padding: var(--space-md) 0;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--gray-200);
    padding: var(--space-sm) 0;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--gray-900);
    font-weight: 600;
    font-size: 1.25rem;
}

.logo:hover {
    color: var(--gray-900);
}

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

.logo-text {
    font-family: var(--font-display);
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-link {
    position: relative;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--gray-600);
    padding: var(--space-sm) 0;
}

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

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

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-sm);
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--gray-800);
    transition: all var(--transition-base);
}

/* ============================================
   按钮
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    cursor: pointer;
}

.btn svg {
    width: 18px;
    height: 18px;
    transition: transform var(--transition-base);
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35);
    color: var(--white);
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

.btn-secondary {
    background: var(--white);
    color: var(--gray-700);
    border: 1px solid var(--gray-300);
}

.btn-secondary:hover {
    background: var(--gray-50);
    border-color: var(--gray-400);
    color: var(--gray-900);
}

.btn-block {
    width: 100%;
}

/* ============================================
   Hero 首页
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--space-4xl) 0;
    overflow: hidden;
    background: var(--bg-hero);
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -30%;
    width: 100%;
    height: 150%;
    background: radial-gradient(ellipse at center, rgba(79, 70, 229, 0.08) 0%, transparent 50%);
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -20%;
    width: 80%;
    height: 100%;
    background: radial-gradient(ellipse at center, rgba(37, 99, 235, 0.06) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 700px;
    padding: 0 var(--space-xl);
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    background: var(--white);
    border: 1px solid var(--primary-100);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--primary);
    margin-bottom: var(--space-xl);
    animation: fadeInUp 0.8s ease;
    box-shadow: var(--shadow-sm);
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.2); }
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    color: var(--gray-900);
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.8s ease 0.1s both;
}

.title-line {
    display: block;
}

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

.hero-desc {
    font-size: 1.125rem;
    color: var(--gray-600);
    margin-bottom: var(--space-2xl);
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-3xl);
    animation: fadeInUp 0.8s ease 0.3s both;
}

.hero-stats {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
    animation: fadeInUp 0.8s ease 0.4s both;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--gray-900);
    line-height: 1;
}

.stat-suffix {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-top: var(--space-xs);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: linear-gradient(180deg, transparent, var(--gray-300), transparent);
}

/* Hero 视觉元素 */
.hero-visual {
    position: absolute;
    top: 50%;
    right: 5%;
    transform: translateY(-50%);
    width: 500px;
    height: 500px;
    z-index: 0;
}

.visual-orbit {
    position: relative;
    width: 100%;
    height: 100%;
}

.orbit-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    border: 1px solid rgba(37, 99, 235, 0.15);
}

.ring-1 {
    width: 200px;
    height: 200px;
    animation: rotate 20s linear infinite;
}

.ring-2 {
    width: 320px;
    height: 320px;
    animation: rotate 30s linear infinite reverse;
}

.ring-3 {
    width: 450px;
    height: 450px;
    animation: rotate 40s linear infinite;
}

@keyframes rotate {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.orbit-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 120px;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(-50%, -50%) translateY(0); }
    50% { transform: translate(-50%, -50%) translateY(-20px); }
}

.orbit-node {
    position: absolute;
    width: 48px;
    height: 48px;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    animation: float 4s ease-in-out infinite;
    box-shadow: var(--shadow-md);
}

.orbit-node svg {
    width: 24px;
    height: 24px;
}

.node-1 {
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    animation-delay: 0s;
}

.node-2 {
    top: 50%;
    right: 5%;
    transform: translateY(-50%);
    animation-delay: 1s;
}

.node-3 {
    bottom: 15%;
    left: 20%;
    animation-delay: 2s;
}

/* 滚动提示 */
.hero-scroll {
    position: absolute;
    bottom: var(--space-2xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    color: var(--gray-500);
    font-size: 0.75rem;
    animation: fadeIn 1s ease 1s both;
}

.scroll-indicator {
    width: 24px;
    height: 40px;
    border: 2px solid var(--gray-300);
    border-radius: var(--radius-full);
    position: relative;
}

.scroll-dot {
    width: 4px;
    height: 8px;
    background: var(--primary);
    border-radius: var(--radius-full);
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll 2s ease-in-out infinite;
}

@keyframes scroll {
    0%, 100% { top: 8px; opacity: 1; }
    50% { top: 20px; opacity: 0.3; }
}

/* ============================================
   章节通用样式
   ============================================ */
section {
    position: relative;
    padding: var(--space-4xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-header.left {
    text-align: left;
}

.section-tag {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.2em;
    color: var(--primary);
    margin-bottom: var(--space-md);
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-md);
}

.section-desc {
    font-size: 1.125rem;
    color: var(--gray-500);
}

/* ============================================
   关于我们
   ============================================ */
.about {
    background: var(--bg-secondary);
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--gray-200), transparent);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: var(--space-3xl);
    align-items: center;
}

.about-intro {
    margin-bottom: var(--space-2xl);
}

.about-intro p {
    margin-bottom: var(--space-md);
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--gray-600);
}

.about-intro strong {
    color: var(--gray-900);
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.feature-item {
    display: flex;
    gap: var(--space-lg);
    padding: var(--space-lg);
    background: var(--white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-200);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.feature-item:hover {
    border-color: var(--primary-100);
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-50);
    border-radius: var(--radius-md);
    color: var(--primary);
}

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

.feature-content h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--space-xs);
}

.feature-content p {
    font-size: 0.9rem;
    color: var(--gray-500);
}

/* 关于我们视觉卡片 */
.about-visual {
    position: relative;
}

.visual-card {
    position: relative;
    padding: var(--space-2xl);
    background: var(--white);
    border-radius: var(--radius-xl);
    border: 1px solid var(--gray-200);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.card-glow {
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 30%, var(--primary-50) 0%, transparent 50%);
    pointer-events: none;
}

.card-content {
    position: relative;
    z-index: 1;
    text-align: center;
}

.card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--space-xl);
}

.visual-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--space-md);
}

.visual-card p {
    font-size: 1rem;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ============================================
   产品服务
   ============================================ */
.services {
    background: var(--white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
}

.service-card {
    position: relative;
    padding: var(--space-2xl);
    background: var(--white);
    border-radius: var(--radius-xl);
    border: 1px solid var(--gray-200);
    transition: all var(--transition-base);
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.service-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-100);
    box-shadow: var(--shadow-xl);
}

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

.service-card.featured {
    border-color: var(--primary-100);
    background: linear-gradient(180deg, var(--primary-50) 0%, var(--white) 100%);
}

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

.card-badge {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    padding: var(--space-xs) var(--space-sm);
    background: var(--gradient-primary);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
}

.card-number {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    color: var(--gray-100);
    position: absolute;
    top: var(--space-md);
    left: var(--space-lg);
}

.card-icon {
    width: 60px;
    height: 60px;
    margin-bottom: var(--space-lg);
    color: var(--primary);
}

.card-icon svg {
    width: 100%;
    height: 100%;
}

.service-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--space-md);
}

.service-card > p {
    font-size: 0.95rem;
    color: var(--gray-500);
    margin-bottom: var(--space-lg);
    line-height: 1.7;
}

.card-features {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.card-features li {
    padding: var(--space-xs) var(--space-md);
    background: var(--gray-100);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    color: var(--gray-600);
}

/* ============================================
   成功案例
   ============================================ */
.cases {
    background: var(--bg-secondary);
}

.cases-showcase {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
    margin-bottom: var(--space-3xl);
}

.case-item {
    background: var(--white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid var(--gray-200);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.case-item:hover {
    transform: translateY(-4px);
    border-color: var(--primary-100);
    box-shadow: var(--shadow-lg);
}

.case-image {
    height: 200px;
    background: linear-gradient(135deg, var(--primary-50) 0%, #f0fdf4 100%);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.case-image::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%232563eb' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.case-overlay {
    position: relative;
    z-index: 1;
}

.case-tag {
    padding: var(--space-sm) var(--space-lg);
    background: var(--white);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--primary);
    border: 1px solid var(--primary-100);
    box-shadow: var(--shadow-sm);
}

.case-content {
    padding: var(--space-xl);
}

.case-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--space-md);
}

.case-content > p {
    font-size: 0.95rem;
    color: var(--gray-500);
    line-height: 1.7;
    margin-bottom: var(--space-lg);
}

.case-stats {
    display: flex;
    gap: var(--space-xl);
}

.case-stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-name {
    font-size: 0.8rem;
    color: var(--gray-500);
}

/* 合作伙伴 */
.partners {
    text-align: center;
}

.partners h4 {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-500);
    margin-bottom: var(--space-xl);
    letter-spacing: 0.1em;
}

.partner-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-3xl);
    flex-wrap: wrap;
}

.partner-item {
    opacity: 0.5;
    transition: opacity var(--transition-base);
    color: var(--gray-500);
}

.partner-item:hover {
    opacity: 0.9;
}

.partner-item svg {
    width: 120px;
    height: 40px;
}

/* ============================================
   联系我们
   ============================================ */
.contact {
    background: var(--white);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
}

.contact-info {
    padding-right: var(--space-2xl);
}

.info-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}

.info-item {
    display: flex;
    gap: var(--space-lg);
}

.info-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-50);
    border-radius: var(--radius-md);
    color: var(--primary);
}

.info-icon svg {
    width: 22px;
    height: 22px;
}

.info-content h4 {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--gray-500);
    margin-bottom: var(--space-xs);
}

.info-content p {
    font-size: 1.1rem;
    color: var(--gray-900);
}

.social-links {
    display: flex;
    gap: var(--space-md);
}

.social-link {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    color: var(--gray-600);
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--white);
}

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

/* 联系表单 */
.contact-form-wrapper {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    border: 1px solid var(--gray-200);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.form-group label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--gray-700);
}

.form-group input,
.form-group textarea {
    padding: var(--space-md) var(--space-lg);
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    color: var(--gray-900);
    transition: all var(--transition-base);
}

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

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-100);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ============================================
   页脚
   ============================================ */
.footer {
    background: var(--gray-900);
    padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    gap: var(--space-3xl);
    margin-bottom: var(--space-2xl);
    padding-bottom: var(--space-2xl);
    border-bottom: 1px solid var(--gray-700);
}

.footer-brand {
    max-width: 300px;
}

.footer-brand .logo {
    margin-bottom: var(--space-md);
    color: var(--white);
}

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

.footer-brand p {
    color: var(--gray-400);
    font-size: 0.95rem;
}

.footer-links {
    display: flex;
    gap: var(--space-3xl);
}

.footer-col h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--white);
    margin-bottom: var(--space-lg);
}

.footer-col ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

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

.footer-col a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--gray-500);
}

.footer-bottom a {
    color: var(--gray-400);
}

/* ============================================
   返回顶部
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    color: var(--gray-600);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: var(--z-fixed);
    box-shadow: var(--shadow-md);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--white);
    transform: translateY(-4px);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
}

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

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

/* ============================================
   响应式设计
   ============================================ */
@media (max-width: 1200px) {
    .hero-visual {
        width: 400px;
        height: 400px;
        right: 0;
    }
    
    .ring-3 {
        width: 380px;
        height: 380px;
    }
}

@media (max-width: 1024px) {
    .hero-visual {
        display: none;
    }
    
    .hero-content {
        max-width: 100%;
        text-align: center;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-visual {
        order: -1;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
    
    .contact-info {
        padding-right: 0;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--white);
        flex-direction: column;
        justify-content: center;
        gap: var(--space-xl);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }
    
    .nav-links.active {
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        font-size: 1.25rem;
        color: var(--gray-700);
    }
    
    .nav-toggle {
        display: flex;
        z-index: 10;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(6px, -6px);
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-wrap: wrap;
        gap: var(--space-lg);
    }
    
    .stat-divider {
        display: none;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .cases-showcase {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--space-2xl);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--space-sm);
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-md);
    }
    
    .hero-desc br {
        display: none;
    }
    
    .case-stats {
        flex-wrap: wrap;
        gap: var(--space-md);
    }
    
    .partner-logos {
        gap: var(--space-xl);
    }
}