/* ==================== 基础变量 ==================== */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --text-dark: #1f2937;
    --text-gray: #6b7280;
    --text-light: #9ca3af;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --transition: all 0.3s ease;
}

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

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* ==================== 按钮样式 ==================== */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

.btn-block {
    width: 100%;
}

/* ==================== 头部导航 ==================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1rem;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
}

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

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

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

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

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

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    background: none;
    border: none;
    cursor: pointer;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* 移动端菜单遮罩 */
.menu-overlay {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
}

.mobile-only {
    display: none;
}

/* ==================== Hero 区域 ==================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 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='0.1'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.95;
}

.hero-desc {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ==================== 通用区域 ==================== */
.section {
    padding: 5rem 0;
}

.section-bg {
    background: var(--bg-light);
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

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

/* ==================== 关于我们 ==================== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--text-gray);
    line-height: 1.8;
}

.values-list {
    margin-top: 1rem;
}

.values-list li {
    margin-bottom: 0.75rem;
    padding-left: 1.5rem;
    position: relative;
}

.values-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

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

.stat-item {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    display: block;
    font-size: 1rem;
    color: var(--text-gray);
    margin-top: 0.5rem;
}

/* ==================== 产品服务 ==================== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.product-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.product-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.product-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.product-card > p {
    color: var(--text-gray);
    margin-bottom: 1.5rem;
}

.product-features {
    margin-top: 1rem;
}

.product-features li {
    padding: 0.5rem 0;
    color: var(--text-gray);
    border-bottom: 1px solid var(--border-color);
    position: relative;
    padding-left: 1.25rem;
}

.product-features li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* ==================== 解决方案 ==================== */
.solutions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.solution-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

.solution-card:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-lg);
}

.solution-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.solution-card p {
    color: var(--text-gray);
    line-height: 1.7;
}

/* ==================== 联系方式 ==================== */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    padding: 1.5rem;
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.contact-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.contact-details h4 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.contact-details p {
    color: var(--text-gray);
    line-height: 1.6;
}

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.contact-form h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

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

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.required {
    color: #ef4444;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: vertical;
}

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

.form-hint {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: 0.5rem;
}

/* ==================== 法律页面 ==================== */
.legal-section {
    padding-top: 120px;
}

.legal-content {
    max-width: 900px;
    margin: 0 auto;
}

.legal-nav {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1rem;
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    flex-wrap: wrap;
}

.legal-nav a {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: var(--transition);
    color: var(--text-gray);
}

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

.legal-text {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.legal-text h3 {
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.legal-text h3:first-child {
    margin-top: 0;
}

.legal-text h4 {
    font-size: 1.25rem;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.legal-text p {
    margin-bottom: 1rem;
    color: var(--text-gray);
    line-height: 1.8;
}

.legal-text ul {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

.legal-text li {
    margin-bottom: 0.5rem;
    color: var(--text-gray);
    line-height: 1.7;
    position: relative;
    padding-left: 1rem;
}

.legal-text li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* ==================== 投诉入口 ==================== */
.complaint-content {
    max-width: 900px;
    margin: 0 auto;
}

.complaint-intro {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
}

.complaint-intro p {
    color: var(--text-gray);
    line-height: 1.8;
}

.complaint-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.complaint-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition);
}

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

.complaint-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.complaint-card p {
    color: var(--text-gray);
    margin-bottom: 0.5rem;
}

.complaint-form {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.complaint-form h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.footer-section h4 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    color: white;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.footer-logo .logo-text {
    color: white;
}

.footer-section > p {
    color: var(--text-light);
    line-height: 1.7;
}

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

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

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

.footer-contact li {
    margin-bottom: 0.75rem;
    color: var(--text-light);
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-legal p {
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.footer-legal a {
    color: var(--text-light);
}

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

.footer-icp a {
    color: var(--text-light);
    font-size: 0.875rem;
}

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

/* ==================== 返回顶部 ==================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    z-index: 100;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-5px);
}

.back-to-top.show {
    display: flex;
}

/* ==================== 响应式设计 ==================== */

/* 平板 (768px - 1024px) */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
    }

    .form-row {
        grid-template-columns: 1fr;
    }
}

/* 手机 (≤768px) */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .nav-list {
        position: fixed;
        top: 70px;
        right: -100%;
        width: 280px;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        box-shadow: var(--shadow-xl);
        transition: var(--transition);
        z-index: 1000;
        overflow-y: auto;
    }

    .nav-list.active {
        right: 0;
    }

    .nav-list.active ~ .menu-overlay {
        display: block;
    }

    .menu-toggle {
        display: flex;
    }

    .menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .mobile-only {
        display: block;
    }

    .hero {
        min-height: 80vh;
        padding-top: 70px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-desc {
        font-size: 0.95rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
    }

    .section {
        padding: 3rem 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .about-stats {
        grid-template-columns: 1fr 1fr;
        gap: 1rem;
    }

    .stat-item {
        padding: 1.5rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .products-grid,
    .solutions-grid {
        grid-template-columns: 1fr;
    }

    .legal-nav {
        flex-direction: column;
    }

    .legal-nav a {
        text-align: center;
    }

    .legal-text {
        padding: 1.5rem;
    }

    .legal-text h3 {
        font-size: 1.25rem;
    }

    .contact-item {
        flex-direction: column;
        text-align: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-logo {
        justify-content: center;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }

    .complaint-methods {
        grid-template-columns: 1fr;
    }
}

/* 小屏手机 (≤480px) */
@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .about-stats {
        grid-template-columns: 1fr;
    }

    .stat-item {
        padding: 1.25rem;
    }

    .product-card,
    .solution-card {
        padding: 1.5rem;
    }

    .contact-form,
    .complaint-form,
    .legal-text {
        padding: 1.25rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }
}

/* PC端大屏幕 (≥1200px) */
@media (min-width: 1200px) {
    .container {
        padding: 0 2rem;
    }

    .hero-title {
        font-size: 4rem;
    }

    .section {
        padding: 6rem 0;
    }

    .products-grid,
    .solutions-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* 打印样式 */
@media print {
    .header,
    .back-to-top,
    .hero-buttons,
    .contact-form,
    .complaint-form {
        display: none;
    }

    .hero {
        min-height: auto;
        padding: 2rem 0;
    }

    .section {
        padding: 2rem 0;
    }

    .legal-text {
        box-shadow: none;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.product-card,
.solution-card,
.stat-item,
.contact-item,
.complaint-card {
    animation: fadeInUp 0.6s ease-out;
}

.product-card:nth-child(1) { animation-delay: 0.1s; }
.product-card:nth-child(2) { animation-delay: 0.2s; }
.product-card:nth-child(3) { animation-delay: 0.3s; }
.product-card:nth-child(4) { animation-delay: 0.4s; }

.solution-card:nth-child(1) { animation-delay: 0.1s; }
.solution-card:nth-child(2) { animation-delay: 0.2s; }
.solution-card:nth-child(3) { animation-delay: 0.3s; }
.solution-card:nth-child(4) { animation-delay: 0.4s; }
.solution-card:nth-child(5) { animation-delay: 0.5s; }
.solution-card:nth-child(6) { animation-delay: 0.6s; }

/* 无障碍 - 焦点样式 */
a:focus,
button:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* 无障碍 - 跳过链接 */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 1rem;
    z-index: 10000;
    border-radius: var(--radius-md);
}

.skip-link:focus {
    top: 1rem;
}

/* 性能优化 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    html {
        scroll-behavior: auto;
    }
}