/* ===================================
   21短信 - 融合云通讯平台
   现代响应式样式表
   =================================== */

/* CSS 变量定义 */
:root {
    /* 主题色 */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #f97316;
    --secondary-dark: #ea580c;
    
    /* 辅助色 */
    --blue: #3b82f6;
    --purple: #8b5cf6;
    --orange: #f97316;
    --pink: #ec4899;
    --green: #10b981;
    --red: #ef4444;
    --cyan: #06b6d4;
    --yellow: #eab308;
    
    /* 灰度色 */
    --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;
    
    /* 文字 */
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --text-white: #ffffff;
    
    /* 背景 */
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-dark: #1e293b;
    
    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #3b82f6 50%, #06b6d4 100%);
    --gradient-secondary: linear-gradient(135deg, #f97316 0%, #ec4899 100%);
    --gradient-dark: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --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-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    
    /* 圆角 */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-2xl: 2rem;
    --radius-full: 9999px;
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 间距 */
    --container-max: 1280px;
    --section-padding: 6rem;
}

/* 重置样式 */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-white);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

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

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

/* 容器 */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ===================================
   顶部通知条
   =================================== */
.top-bar {
    background: var(--gradient-primary);
    color: var(--text-white);
    padding: 0.75rem 0;
    font-size: 0.875rem;
}

.top-bar .container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.top-bar-link {
    font-weight: 500;
    text-decoration: underline;
    text-underline-offset: 2px;
}

.top-bar-link:hover {
    opacity: 0.9;
}

/* ===================================
   导航栏
   =================================== */
.header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    z-index: 1000;
    transition: box-shadow var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.logo i {
    font-size: 1.75rem;
}

.nav-list {
    display: flex;
    gap: 2rem;
}

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    padding: 0.5rem 0;
}

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

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

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

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.hotline {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--primary);
}

.hotline i {
    font-size: 1rem;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition);
}

/* ===================================
   按钮样式
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: var(--radius);
    transition: all var(--transition);
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--text-white);
    box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.39);
}

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

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

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

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

.btn-white:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline-white {
    background: transparent;
    color: var(--text-white);
    border: 2px solid rgba(255, 255, 255, 0.5);
}

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

.btn-large {
    padding: 0.875rem 2rem;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
}

/* ===================================
   首页横幅
   =================================== */
.hero {
    position: relative;
    padding: 5rem 0;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #dbeafe 100%);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.6;
}

.hero-shape.shape-1 {
    width: 500px;
    height: 500px;
    background: linear-gradient(135deg, #3b82f6, #06b6d4);
    top: -100px;
    right: -100px;
}

.hero-shape.shape-2 {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, #8b5cf6, #ec4899);
    bottom: -50px;
    left: -50px;
}

.hero-shape.shape-3 {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, #f97316, #eab308);
    top: 50%;
    left: 30%;
    opacity: 0.3;
}

.hero .container {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    backdrop-filter: blur(10px);
}

.hero-badge i {
    color: #eab308;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.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(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.hero-stats {
    display: flex;
    gap: 3rem;
}

.stat-item .stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-item .stat-number span {
    font-size: 1rem;
}

.stat-item .stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* 手机展示 */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    position: relative;
    width: 320px;
    height: 640px;
    background: linear-gradient(145deg, #1a1a2e 0%, #16213e 100%);
    border-radius: 2.5rem;
    padding: 1rem;
    box-shadow: 
        0 50px 100px -20px rgba(0, 0, 0, 0.4),
        0 30px 60px -30px rgba(0, 0, 0, 0.5),
        inset 0 0 0 2px rgba(255, 255, 255, 0.1);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
    border-radius: 2rem;
    padding: 2rem 1rem;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message-bubble {
    display: flex;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--text-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    animation: slideIn 0.5s ease forwards;
    opacity: 0;
}

.message-bubble.bubble-1 { animation-delay: 0.2s; }
.message-bubble.bubble-2 { animation-delay: 0.5s; }
.message-bubble.bubble-3 { animation-delay: 0.8s; }

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.message-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    flex-shrink: 0;
}

.message-content p {
    font-size: 0.8125rem;
    color: var(--text-primary);
    line-height: 1.5;
    margin-bottom: 0.25rem;
}

.message-time {
    font-size: 0.6875rem;
    color: var(--text-muted);
}

.floating-card {
    position: absolute;
    padding: 0.75rem 1rem;
    background: var(--text-white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    animation: float 3s ease-in-out infinite;
}

.floating-card.card-1 {
    top: 20%;
    right: 0;
    color: #10b981;
}

.floating-card.card-2 {
    bottom: 30%;
    left: -10%;
    color: var(--primary);
    animation-delay: 1s;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* ===================================
   通用区块头部
   =================================== */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header.light {
    color: var(--text-white);
}

.section-header.light .section-title,
.section-header.light .section-desc {
    color: var(--text-white);
}

.section-tag {
    display: inline-block;
    padding: 0.375rem 1rem;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    border-radius: var(--radius-full);
    margin-bottom: 1rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.section-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===================================
   产品区块
   =================================== */
.products {
    padding: var(--section-padding) 0;
    background: var(--bg-white);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.product-card {
    background: var(--bg-white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all var(--transition);
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
}

.product-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--text-white);
    margin-bottom: 1rem;
}

.product-icon.blue { background: linear-gradient(135deg, #3b82f6, #2563eb); }
.product-icon.purple { background: linear-gradient(135deg, #a78bfa, #8b5cf6); }
.product-icon.orange { background: linear-gradient(135deg, #fb923c, #f97316); }
.product-icon.pink { background: linear-gradient(135deg, #f472b6, #ec4899); }
.product-icon.green { background: linear-gradient(135deg, #34d399, #10b981); }
.product-icon.red { background: linear-gradient(135deg, #f87171, #ef4444); }
.product-icon.cyan { background: linear-gradient(135deg, #22d3ee, #06b6d4); }
.product-icon.yellow { background: linear-gradient(135deg, #facc15, #eab308); }

.product-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.product-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.product-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.product-tags li {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.product-tags li i {
    font-size: 0.625rem;
}

.product-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.product-link:hover {
    gap: 0.5rem;
}

.product-link i {
    font-size: 0.75rem;
    transition: transform var(--transition);
}

/* ===================================
   为什么选择我们
   =================================== */
.why-us {
    padding: var(--section-padding) 0;
    background: var(--gradient-dark);
    position: relative;
}

.why-us::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='%23ffffff' fill-opacity='0.03'%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");
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    position: relative;
}

.why-item {
    text-align: center;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    transition: all var(--transition);
}

.why-item:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-5px);
}

.why-icon {
    width: 64px;
    height: 64px;
    background: var(--gradient-primary);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 1.75rem;
    color: var(--text-white);
}

.why-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-white);
    margin-bottom: 0.75rem;
}

.why-item p {
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
}

/* ===================================
   解决方案
   =================================== */
.solutions {
    padding: var(--section-padding) 0;
    background: var(--bg-light);
}

.solutions-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.tab-btn {
    padding: 0.875rem 1.5rem;
    background: var(--text-white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all var(--transition);
}

.tab-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.tab-btn.active {
    background: var(--gradient-primary);
    border-color: transparent;
    color: var(--text-white);
    box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.39);
}

.tab-btn i {
    font-size: 1rem;
}

.solutions-content {
    position: relative;
}

.tab-panel {
    display: none;
    animation: fadeIn 0.5s ease;
}

.tab-panel.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.solution-card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    background: var(--text-white);
    border-radius: var(--radius-xl);
    padding: 3rem;
    box-shadow: var(--shadow-lg);
}

.solution-info h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.solution-info > p {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.solution-features {
    margin-bottom: 1.5rem;
}

.solution-features li {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--gray-100);
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.solution-features li:last-child {
    border-bottom: none;
}

.solution-features li i {
    color: #10b981;
    margin-top: 2px;
}

.solution-tags {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.solution-tags span {
    padding: 0.375rem 0.875rem;
    background: var(--gray-100);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    border-radius: var(--radius-full);
}

.solution-image {
    display: flex;
    align-items: center;
    justify-content: center;
}

.solution-illus {
    width: 280px;
    height: 280px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.solution-illus i {
    font-size: 6rem;
    color: var(--text-white);
}

.solution-illus.sms-illus {
    background: linear-gradient(135deg, #3b82f6, #06b6d4);
}

.solution-illus.robot-illus {
    background: linear-gradient(135deg, #8b5cf6, #ec4899);
}

.solution-illus.marketing-illus {
    background: linear-gradient(135deg, #f97316, #eab308);
}

.solution-illus.shield-illus {
    background: linear-gradient(135deg, #10b981, #06b6d4);
}

.illus-particles span {
    position: absolute;
    width: 8px;
    height: 8px;
    background: var(--text-white);
    border-radius: 50%;
    animation: particle 2s ease-in-out infinite;
}

.illus-particles span:nth-child(1) { top: 20%; left: 20%; animation-delay: 0s; }
.illus-particles span:nth-child(2) { top: 30%; right: 20%; animation-delay: 0.5s; }
.illus-particles span:nth-child(3) { bottom: 30%; left: 25%; animation-delay: 1s; }
.illus-particles span:nth-child(4) { bottom: 20%; right: 25%; animation-delay: 1.5s; }

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

.illus-pulses::before,
.illus-pulses::after {
    content: '';
    position: absolute;
    inset: -20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: pulse 2s ease-out infinite;
}

.illus-pulses::after {
    animation-delay: 1s;
}

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

.illus-lock {
    position: absolute;
    bottom: 30%;
    right: 20%;
    width: 60px;
    height: 60px;
    background: var(--text-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.illus-lock i {
    font-size: 1.5rem;
    color: #10b981;
}

.illus-chart {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    height: 60px;
    position: absolute;
    bottom: 20%;
}

.illus-chart span {
    width: 12px;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 2px;
}

.illus-chart span:nth-child(1) { height: 30px; }
.illus-chart span:nth-child(2) { height: 50px; }
.illus-chart span:nth-child(3) { height: 40px; }

/* ===================================
   数据统计区块
   =================================== */
.stats-section {
    padding: var(--section-padding) 0;
    background: var(--bg-white);
}

.stats-header {
    text-align: center;
    margin-bottom: 3rem;
}

.stats-header h2 {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.stats-header p {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    margin-bottom: 4rem;
}

.stat-card {
    text-align: center;
    padding: 2rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-radius: var(--radius-lg);
    position: relative;
}

.stat-num {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

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

.stat-text {
    margin-top: 0.75rem;
    font-size: 1rem;
    color: var(--text-secondary);
}

.stats-features {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.stats-feature {
    text-align: center;
    padding: 1.5rem;
}

.stats-feature i {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.stats-feature h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.stats-feature p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* ===================================
   客户案例
   =================================== */
.cases {
    padding: var(--section-padding) 0;
    background: var(--bg-light);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.case-card {
    background: var(--text-white);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: all var(--transition);
}

.case-card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-5px);
}

.case-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 1rem;
}

.case-logo i {
    font-size: 1.5rem;
}

.case-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.case-card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.case-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--primary);
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.case-link:hover {
    gap: 0.5rem;
}

/* ===================================
   合作流程
   =================================== */
.process {
    padding: var(--section-padding) 0;
    background: var(--bg-white);
}

.process-steps {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 1rem;
}

.process-step {
    flex: 1;
    max-width: 200px;
    text-align: center;
    position: relative;
}

.step-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--gray-100);
    line-height: 1;
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 0;
}

.step-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 1.75rem;
    color: var(--text-white);
    position: relative;
    z-index: 1;
    box-shadow: 0 10px 30px -10px rgba(37, 99, 235, 0.5);
}

.process-step h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.process-step p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.process-arrow {
    font-size: 1.25rem;
    color: var(--gray-300);
    margin-top: 1.5rem;
}

/* ===================================
   CTA 区块
   =================================== */
.cta-section {
    padding: var(--section-padding) 0;
    background: var(--bg-light);
}

.cta-box {
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    padding: 4rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.cta-box::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%23ffffff' fill-opacity='0.1' fill-rule='evenodd'/%3E%3C/svg%3E");
}

.cta-content {
    position: relative;
    z-index: 1;
}

.cta-content h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 0.5rem;
}

.cta-content p {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.9);
}

.cta-actions {
    display: flex;
    gap: 1rem;
    position: relative;
    z-index: 1;
}

/* ===================================
   联系我们
   =================================== */
.contact {
    padding: var(--section-padding) 0;
    background: var(--bg-white);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 4rem;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.contact-card {
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition);
}

.contact-card:hover {
    background: var(--gray-100);
    transform: translateY(-3px);
}

.contact-card i {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.contact-card h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.contact-card p {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
}

.contact-form-wrapper {
    background: var(--bg-white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
}

.contact-form h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    text-align: center;
}

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

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.form-group label i {
    color: var(--primary);
    margin-right: 0.25rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    font-size: 0.9375rem;
    transition: all var(--transition);
    background: var(--bg-white);
}

.form-group input: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(--gray-900);
    color: var(--text-white);
    padding: 4rem 0 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr 1.5fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand .logo {
    color: var(--text-white);
    margin-bottom: 1rem;
}

.footer-brand p {
    font-size: 0.875rem;
    color: var(--gray-400);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all var(--transition);
}

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

.footer-links h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--gray-400);
    transition: color var(--transition);
}

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

.footer-contact h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
}

.footer-contact p {
    font-size: 0.875rem;
    color: var(--gray-400);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-contact p i {
    color: var(--primary);
}

.footer-bottom {
    border-top: 1px solid var(--gray-800);
    padding-top: 2rem;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.875rem;
    color: var(--gray-500);
}

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

.footer-bottom a:hover {
    color: var(--text-white);
}

/* ===================================
   悬浮工具栏
   =================================== */
.float-tools {
    position: fixed;
    right: 20px;
    bottom: 100px;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    z-index: 999;
}

.float-btn {
    width: 48px;
    height: 48px;
    background: var(--primary);
    color: var(--text-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition);
}

.float-btn:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-xl);
}

.float-btn.back-to-top {
    background: var(--gray-700);
    opacity: 0;
    visibility: hidden;
}

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

/* ===================================
   响应式设计
   =================================== */
@media (max-width: 1200px) {
    .products-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-visual {
        display: none;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
}

@media (max-width: 992px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .why-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stats-grid,
    .stats-features {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .process-steps {
        flex-wrap: wrap;
    }
    
    .process-arrow {
        display: none;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .solution-card {
        grid-template-columns: 1fr;
    }
    
    .solution-image {
        order: -1;
    }
    
    .cta-box {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 4rem;
    }
    
    .nav {
        position: fixed;
        top: 4rem;
        left: 0;
        right: 0;
        background: var(--bg-white);
        padding: 1rem;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition);
    }
    
    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .nav-link {
        display: block;
        padding: 0.75rem 1rem;
        border-radius: var(--radius);
    }
    
    .nav-link:hover,
    .nav-link.active {
        background: var(--gray-100);
    }
    
    .nav-link::after {
        display: none;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .header-actions .btn-outline {
        display: none;
    }
    
    .hotline span {
        display: none;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .why-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid,
    .stats-features {
        grid-template-columns: 1fr;
    }
    
    .solutions-tabs {
        flex-wrap: wrap;
    }
    
    .contact-info {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-social {
        justify-content: center;
    }
    
    .solution-card {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero-actions {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .tab-btn {
        padding: 0.625rem 1rem;
        font-size: 0.8125rem;
    }
    
    .cta-actions {
        flex-direction: column;
    }
}