/* 心乐电子样式表 */ 

/* 引入高质量Web字体 */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

/* CSS变量 */
:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #64748b;
    --accent: #10b981;
    --dark: #1e293b;
    --light: #f8fafc;
    --neutral-100: #f1f5f9;
    --neutral-200: #e2e8f0;
    --neutral-300: #cbd5e1;
    --neutral-400: #94a3b8;
    --neutral-500: #64748b;
    --neutral-600: #475569;
    --neutral-700: #334155;
    --neutral-800: #1e293b;
    --neutral-900: #0f172a;
    
    /* 字体系统 */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', 'Arial', 'Noto Sans', 'PingFang SC', 'Hiragino Sans GB', 'Source Han Sans SC', 'Source Han Sans CN', 'Microsoft YaHei', 'Wenquanyi Micro Hei', 'WenQuanYi Zen Hei', 'ST Heiti', 'SimHei', sans-serif;
    --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 移除所有元素的默认焦点样式 */
*:focus {
    outline: none;
}

/* 为表单元素添加更好的焦点样式 */
input:focus,
textarea:focus,
select:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.3);
}

/* 导航链接和普通链接不需要焦点框 */
.nav-link:focus,
a:focus {
    outline: none;
    box-shadow: none;
}

/* 按钮保持焦点样式但更精细 */
.btn:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', var(--font-sans);
    font-size: 16px;
    line-height: 1.75;
    color: var(--neutral-800);
    background-color: var(--light);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    font-feature-settings: "kern" 1, "liga" 1, "calt" 1;
    letter-spacing: 0.015em;
}

/* 字体层级系统 */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
    color: var(--dark);
}

/* 数字优化 */
.number, .stat-item .number {
    font-variant-numeric: tabular-nums;
    font-feature-settings: "tnum";
}

h1 {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.1;
}

h2 {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 1.875rem);
    font-weight: 600;
}

h4 {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
    font-weight: 600;
}

p {
    font-weight: 400;
    letter-spacing: 0.01em;
}

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

/* 页面加载器 */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: white;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s, visibility 0.5s;
}

.page-loader.fade-out {
    opacity: 0;
    visibility: hidden;
}

.sound-wave-loader {
    display: flex;
    gap: 6px;
    height: 50px;
    align-items: center;
}

.sound-wave-loader span {
    width: 4px;
    background: var(--primary);
    border-radius: 2px;
    animation: wave 1.2s ease-in-out infinite;
}

.sound-wave-loader span:nth-child(1) { animation-delay: 0s; }
.sound-wave-loader span:nth-child(2) { animation-delay: 0.1s; }
.sound-wave-loader span:nth-child(3) { animation-delay: 0.2s; }
.sound-wave-loader span:nth-child(4) { animation-delay: 0.3s; }
.sound-wave-loader span:nth-child(5) { animation-delay: 0.4s; }

@keyframes wave {
    0%, 100% { height: 20px; }
    50% { height: 50px; }
}

/* 导航栏 */
header {
    position: fixed;
    top: 0;
    width: 100%;
    background: white;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

header.scrolled {
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.625rem;
    font-weight: 800;
    font-family: 'Inter', var(--font-display);
    letter-spacing: -0.03em;
    color: var(--dark);
    text-decoration: none;
}

.logo i {
    color: var(--primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
    list-style: none;
}

.nav-link {
    color: var(--neutral-600);
    font-weight: 500;
    font-size: 0.9375rem;
    font-family: 'Inter', var(--font-display);
    letter-spacing: 0.01em;
    transition: color 0.3s;
    position: relative;
    padding: 0.5rem 0;
    text-decoration: none;
}

.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 0.3s;
}

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

.language-toggle {
    background: none;
    border: none;
    color: var(--neutral-600);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 20px;
    transition: all 0.3s;
}

.language-toggle:hover {
    background: var(--neutral-100);
    color: var(--primary);
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--dark);
}

/* 英雄区域 - 重要：确保背景图片显示 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
    /* 直接设置背景图片 */
    background-image: url('images/background.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

/* 确保移动设备上背景图片显示 */
@supports (-webkit-touch-callout: none) {
    .hero {
        background-attachment: scroll;
    }
}

/* 添加渐变覆盖层以提高文字可读性 */
.hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, 
        rgba(255, 255, 255, 0.05) 0%, 
        rgba(255, 255, 255, 0.1) 30%,
        rgba(248, 250, 252, 0.15) 60%,
        rgba(241, 245, 249, 0.2) 100%
    ); /* 优化的渐变覆盖层，更透明以保持背景可见性 */
    z-index: 1;
}

.hero-content {
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 2;
    /* 确保内容始终居中 */
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero h1 {
    font-size: clamp(2rem, 4.5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--dark);
    text-shadow: 2px 2px 6px rgba(0, 0, 0, 0.3), 0 0 20px rgba(255, 255, 255, 0.8);
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: -0.02em;
    /* 在大屏幕上不允许换行 */
    white-space: nowrap;
    /* 防止孤立字符 */
    word-break: keep-all;
    /* 确保标题始终居中 */
    width: 100%;
    text-align: center;
    /* 优化行高 */
    display: block;
}

/* 英文标题特殊处理 */
.hero h1[data-lang="en"] {
    font-size: clamp(2rem, 4.5vw, 3.5rem);
    letter-spacing: -0.02em;
    white-space: normal;
    line-height: 1.15;
    font-weight: 800;
    /* 优化两行文字的平衡性 */
    text-wrap: balance;
    -webkit-text-wrap: balance;
    /* 确保标题块的整体居中 */
    margin-left: auto;
    margin-right: auto;
    max-width: 100%;
    /* 继承相同的文字阴影效果 */
    text-shadow: 2px 2px 6px rgba(0, 0, 0, 0.3), 0 0 20px rgba(255, 255, 255, 0.8);
}

/* 英文标题换行优化 */
.hero h1[data-lang="en"] br {
    display: block;
    content: "";
    margin-top: 0.15em;
}

.hero p {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    font-weight: 500;
    line-height: 1.7;
    color: var(--neutral-800);
    margin: 0 auto 2rem auto;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.2), 0 0 10px rgba(255, 255, 255, 0.6);
    font-family: 'Noto Sans SC', var(--font-sans);
    letter-spacing: 0.02em;
    /* 确保段落也居中 */
    width: 100%;
    max-width: 700px;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 28px;
    font-weight: 600;
    font-size: 0.9375rem;
    font-family: 'Inter', var(--font-display);
    letter-spacing: 0.02em;
    text-align: center;
    border-radius: 8px;
    transition: all 0.3s;
    cursor: pointer;
    text-decoration: none;
    border: 2px solid transparent;
    outline: none;
}



.btn-primary {
    background: var(--primary);
    color: white;
    border: 2px solid var(--primary);
    box-shadow: 0 4px 10px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.4);
}

.btn-outline {
    background: rgba(255, 255, 255, 0.8);
    color: var(--primary);
    border: 2px solid var(--primary);
    backdrop-filter: blur(10px);
}

.btn-outline:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.4);
}

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

.btn-white:hover {
    background: var(--neutral-100);
}

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

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

.btn-container {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    width: 100%;
}

/* 区块标题 */
.section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title h2 {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 800;
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: -0.03em;
    color: var(--dark);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
}

.section-title p {
    color: var(--neutral-600);
    font-size: 1.125rem;
    font-weight: 400;
    line-height: 1.75;
    letter-spacing: 0.01em;
    max-width: 600px;
    margin: 0 auto;
}

/* 区块 */
section {
    padding: 80px 0;
}

/* 产品展示 */
.product-categories {
    background: var(--neutral-100);
}

/* 产品卡片隐藏状态 */
.product-card.hidden {
    display: none !important;
}

/* 无产品提示信息 */
.no-products-message {
    text-align: center;
    padding: 60px 20px;
    color: var(--neutral-500);
    grid-column: 1 / -1;
}

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

.category-tab {
    padding: 10px 24px;
    background: white;
    border: 2px solid var(--neutral-200);
    border-radius: 30px;
    cursor: pointer;
    font-weight: 500;
    color: var(--neutral-600);
    transition: all 0.3s;
}

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

.category-tab.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    align-items: stretch;
}

.product-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.12);
}

.product-image {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 120px;
    background: var(--neutral-100);
    border-radius: 12px;
    margin-bottom: 1.5rem;
    flex-shrink: 0;
}

.product-info {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.product-info h3 {
    font-size: 1.375rem;
    font-weight: 700;
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: -0.02em;
    color: var(--dark);
    margin-bottom: 0.5rem;
    min-height: 2rem;
    display: flex;
    align-items: center;
}

.product-description {
    font-size: 0.9375rem;
    font-weight: 400;
    line-height: 1.7;
    letter-spacing: 0.01em;
    color: var(--neutral-600);
    margin-bottom: 1rem;
    min-height: 3.5rem;
}

.product-features {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, minmax(140px, 1fr));
    column-gap: 1.25rem;
    row-gap: 0.75rem;
    margin-bottom: 1.5rem;
    flex: 1;
    align-content: start;
}

.product-features li {
    color: var(--neutral-600);
    font-size: 0.875rem;
    font-weight: 400;
    letter-spacing: 0.01em;
    line-height: 1.5;
    display: flex;
    align-items: center;
    position: relative;
    padding-left: 1rem;
}

.product-features li::before {
    content: '\2713';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 600;
    font-size: 0.875rem;
    line-height: 1.5;
}

.product-actions {
    display: flex;
    gap: 0.75rem;
    margin-top: auto;
}

.product-actions .btn {
    flex: 1;
    padding: 10px 20px;
    font-size: 0.875rem;
}

/* 为什么选择我们 */
.why-choose-us {
    background: white;
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    align-items: stretch;
}

.why-card {
    text-align: center;
    padding: 2rem;
    border-radius: 12px;
    transition: all 0.3s;
    background: var(--neutral-100);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.why-card:hover {
    background: white;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transform: translateY(-5px);
}

.why-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
}

.why-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: -0.01em;
    color: var(--dark);
    margin-bottom: 1rem;
    min-height: 2rem;
}

.why-card p {
    font-size: 0.9375rem;
    font-weight: 400;
    line-height: 1.7;
    letter-spacing: 0.01em;
    color: var(--neutral-600);
}

/* 技术规格 */
.tech-specs {
    background: var(--neutral-100);
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    align-items: stretch;
}

.spec-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.spec-card:hover {
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transform: translateY(-3px);
}

.spec-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1rem;
    background: var(--neutral-100);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 1.5rem;
}

.spec-card h3 {
    color: var(--dark);
    margin-bottom: 1rem;
    min-height: 2rem;
}

.spec-card p {
    color: var(--neutral-600);
    line-height: 1.6;
}

/* 服务 */
.services {
    background: white;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    align-items: stretch;
}

.service-card {
    background: var(--neutral-100);
    padding: 2rem;
    border-radius: 12px;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.service-card:hover {
    background: white;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transform: translateY(-5px);
}

.service-icon {
    width: 70px;
    height: 70px;
    margin-bottom: 1.5rem;
    background: rgba(37, 99, 235, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 2rem;
}

.service-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: -0.01em;
    color: var(--dark);
    margin-bottom: 1rem;
    min-height: 2rem;
}

.service-card p {
    font-size: 0.9375rem;
    font-weight: 400;
    line-height: 1.7;
    letter-spacing: 0.01em;
    color: var(--neutral-600);
}

/* 关于我们 */
.about {
    background: var(--neutral-100);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.about-image {
    overflow: hidden;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.about-image img {
    width: 100%;
    height: auto;
    display: block;
}

.about-text h3 {
    color: var(--dark);
    margin-bottom: 1.5rem;
}

.about-text p {
    color: var(--neutral-600);
    margin-bottom: 1.5rem;
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 2rem;
}

.stat-item {
    text-align: center;
    padding: 1rem;
    background: white;
    border-radius: 12px;
}

.stat-item .number {
    font-size: 2.5rem;
    font-weight: 800;
    font-family: 'Inter', var(--font-display);
    letter-spacing: -0.04em;
    color: var(--primary);
    line-height: 1;
}

/* CTA区域 */
.cta-section {
    background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    color: white;
    padding: 5rem 0;
    position: relative;
    overflow: hidden;
}

/* 添加背景装饰效果 */
.cta-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    transform: rotate(45deg);
    pointer-events: none;
}

.cta-section::after {
    content: '';
    position: absolute;
    bottom: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(139,92,246,0.3) 0%, transparent 60%);
    transform: rotate(-45deg);
    pointer-events: none;
}

.cta-section .container {
    position: relative;
    z-index: 2;
}

.cta-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 800;
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: -0.03em;
    color: white;
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.25rem;
    font-weight: 400;
    line-height: 1.7;
    letter-spacing: 0.02em;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1.25rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.cta-visual {
    position: absolute;
    right: 10%;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1;
    opacity: 0.3;
}

.sound-wave {
    display: flex;
    align-items: center;
    gap: 10px;
    height: 100px;
}

.sound-wave span {
    width: 6px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 3px;
    animation: cta-wave 1.5s ease-in-out infinite;
}

.sound-wave span:nth-child(1) { animation-delay: 0s; height: 40px; }
.sound-wave span:nth-child(2) { animation-delay: 0.1s; height: 60px; }
.sound-wave span:nth-child(3) { animation-delay: 0.2s; height: 80px; }
.sound-wave span:nth-child(4) { animation-delay: 0.3s; height: 60px; }
.sound-wave span:nth-child(5) { animation-delay: 0.4s; height: 40px; }

@keyframes cta-wave {
    0%, 100% { transform: scaleY(0.6); opacity: 0.5; }
    50% { transform: scaleY(1); opacity: 1; }
}

/* CTA响应式 */
@media (max-width: 768px) {
    .cta-visual {
        display: none;
    }
    
    .cta-section {
        padding: 3rem 0;
    }
    
    .cta-content h2 {
        font-size: 1.75rem;
    }
    
    .cta-content p {
        font-size: 1rem;
    }
    
    /* 修复移动端背景图片显示问题 */
    .hero {
        background-attachment: scroll; /* 移动端使用 scroll 而不是 fixed */
    }
}

/* 联系我们 */
.contact {
    background: white;
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.contact-info h3 {
    color: var(--dark);
    margin-bottom: 2rem;
}

.contact-detail {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--neutral-100);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 1.25rem;
    flex-shrink: 0;
}

.contact-detail h4 {
    color: var(--dark);
    margin-bottom: 0.25rem;
}

.contact-detail p {
    color: var(--neutral-600);
    margin: 0;
}

.contact-form {
    background: var(--neutral-100);
    padding: 2rem;
    border-radius: 16px;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.9375rem;
    font-family: 'Inter', 'Noto Sans SC', var(--font-display);
    letter-spacing: 0.01em;
    color: var(--neutral-700);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--neutral-200);
    border-radius: 8px;
    font-size: 1rem;
    font-family: 'Noto Sans SC', var(--font-sans);
    letter-spacing: 0.01em;
    transition: border-color 0.3s;
    background: white;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

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

.submit-btn {
    width: 100%;
    padding: 14px 28px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    font-family: 'Inter', var(--font-display);
    letter-spacing: 0.02em;
    cursor: pointer;
    transition: all 0.3s;
}

.submit-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.2);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* 页脚 */
footer {
    background: var(--neutral-900);
    color: var(--neutral-300);
    padding: 3rem 0 1.5rem;
}

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

.footer-column h3 {
    color: white;
    margin-bottom: 1.5rem;
}

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

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

.footer-links a {
    color: var(--neutral-400);
    transition: color 0.3s;
    text-decoration: none;
}

.footer-links a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: var(--neutral-800);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--neutral-400);
    transition: all 0.3s;
}

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

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--neutral-800);
    color: var(--neutral-500);
}

/* 滚动到顶部按钮 */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    z-index: 999;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.scroll-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

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

/* 响应式 */
/* 处理标语换行的临界尺寸 */
@media (max-width: 1024px) {
    .hero-content {
        max-width: 100%;
        padding: 0 40px;
    }
    
    .hero h1 {
        font-size: clamp(1.75rem, 4vw, 3rem);
    }
    
    .hero h1[data-lang="en"] {
        font-size: clamp(1.75rem, 4vw, 2.75rem);
    }
}

@media (max-width: 992px) {
    /* 平板设备背景图片修复 */
    .hero {
        background-attachment: scroll;
    }
    
    .hero h1 {
        font-size: clamp(1.75rem, 4vw, 2.75rem);
    }
    
    .about-content,
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        right: -100%;
        width: 300px;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        transition: right 0.3s;
    }
    
    .nav-links.active {
        right: 0;
    }
    
    .mobile-toggle {
        display: block;
    }
    
    .hero h1 {
        font-size: 2rem;
        white-space: normal;
    }
    
    .hero h1[data-lang="en"] {
        font-size: 1.75rem;
        line-height: 1.25;
    }
    
    .btn-container {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .stats {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .social-links {
        justify-content: center;
    }
    
    .product-features {
        grid-template-columns: 1fr;
        row-gap: 0.625rem;
    }
    
    .product-features li {
        font-size: 0.8125rem;
    }
}

@media (max-width: 576px) {
    h2 {
        font-size: 1.75rem;
    }
    
    .hero {
        min-height: 80vh;
        /* 移动端优化背景图片 */
        background-attachment: scroll !important;
        background-size: cover;
        background-position: center center;
    }
    
    .hero h1 {
        font-size: 1.5rem;
        white-space: normal;
        line-height: 1.3;
    }
    
    .hero h1[data-lang="en"] {
        font-size: 1.375rem;
        line-height: 1.25;
    }
    
    .hero h1[data-lang="en"] br {
        margin-top: 0.1em;
    }
    
    .category-tabs {
        gap: 0.5rem;
    }
    
    .category-tab {
        padding: 8px 16px;
        font-size: 0.875rem;
    }
}

/* 打印样式 */
@media print {
    header,
    footer,
    .page-loader,
    .mobile-toggle,
    .language-toggle,
    .cta-section {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
    }
    
    .container {
        max-width: 100%;
    }
}