/* ============================================
   璠德（FUNDÉ）官方网站 - 主样式文件
   ============================================ */

/* CSS Variables - 现代化配色方案 */
:root {
    /* 主色调 - 灰金色系 */
    --primary-color: #b8a88a;
    --primary-dark: #8b7d63;
    --primary-light: #d4c8b0;

    /* 辅助色 */
    --secondary-color: #ff6b35;
    --accent-color: #00c853;
    --warning-color: #ffc107;
    --danger-color: #dc3545;

    /* 中性色 */
    --gray-50: #f8f9fa;
    --gray-100: #f1f3f5;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;

    /* 字体 */
    --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --font-family-heading: "Microsoft YaHei", "PingFang SC", -apple-system, sans-serif;

    /* 字号 */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;

    /* 间距 */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;

    /* 圆角 */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    --border-radius-full: 9999px;

    /* 阴影 */
    --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);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* 过渡 */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;

    /* 容器 */
    --container-max-width: 1280px;
    --container-padding: 1rem;

    /* 导航栏 */
    --header-height: 70px;
    --header-height-scrolled: 60px;
}

/* ============================================
   全局重置和基础样式
   ============================================ */

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--gray-800);
    background-color: #ffffff;
    overflow-x: hidden;
}

/* 链接样式 */
a {
    color: var(--primary-dark);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: #343a40;
}

/* 图片样式 */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* 列表样式 */
ul,
ol {
    list-style: none;
}

/* 表单元素 */
input,
button,
textarea,
select {
    font-family: inherit;
    font-size: inherit;
}

/* ============================================
   容器和布局
   ============================================ */

.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.container-fluid {
    width: 100%;
    padding: 0 var(--container-padding);
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 calc(-1 * var(--container-padding));
}

.col {
    flex: 1;
    padding: 0 var(--container-padding);
}

/* 栅格系统 */
.col-1 { flex: 0 0 8.333333%; max-width: 8.333333%; }
.col-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
.col-3 { flex: 0 0 25%; max-width: 25%; }
.col-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
.col-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
.col-6 { flex: 0 0 50%; max-width: 50%; }
.col-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
.col-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
.col-9 { flex: 0 0 75%; max-width: 75%; }
.col-10 { flex: 0 0 83.333333%; max-width: 83.333333%; }
.col-11 { flex: 0 0 91.666667%; max-width: 91.666667%; }
.col-12 { flex: 0 0 100%; max-width: 100%; }

/* ============================================
   头部导航栏
   ============================================ */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--primary-color);
    border-bottom: 3px solid var(--primary-dark);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    transition: all var(--transition-base);
    height: 90px;
}

.header.scrolled {
    height: 70px;
    box-shadow: var(--shadow-lg);
}

.header-top {
    background: var(--primary-dark);
    color: white;
    padding: 0.3rem 0;
    font-size: var(--font-size-sm);
    border-bottom: 1px solid var(--primary-light);
}

.header-top .container {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.header-top .logo {
    order: 1;
    flex-shrink: 0;
}

.header-top .logo img {
    height: 35px;
    width: auto;
}

.header-top .logo-text .name {
    font-size: 1.1rem;
    color: #ffffff;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.header-top .logo-text .tagline {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.9);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.header-main {
    height: 55px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--container-padding);
    max-width: var(--container-max-width);
    margin: 0 auto;
}

/* 语言切换 */
.header-top .language-switch {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    order: 3;
    flex-shrink: 0;
    margin-left: auto;
}

.language-switch a {
    color: rgba(255, 255, 255, 0.8);
    font-size: var(--font-size-sm);
    transition: color var(--transition-fast);
}

.language-switch a:hover,
.language-switch a.active {
    color: #ffffff;
    font-weight: 600;
}

.language-switch span {
    color: rgba(255, 255, 255, 0.5);
}

/* 联系信息 */
.header-top .contact-info {
    display: flex;
    gap: 1.5rem;
    order: 2;
}

.contact-info span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.contact-info i {
    opacity: 0.9;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
}

.logo img {
    height: 55px;
    width: auto;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-text .name {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--primary-dark);
    line-height: 1.2;
    letter-spacing: 1px;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.5);
}

.logo-text .tagline {
    font-size: 0.75rem;
    color: #0066cc;
    letter-spacing: 3px;
    text-transform: uppercase;
    font-weight: 600;
    margin-top: 2px;
}

/* 导航菜单 */
.nav-menu {
    display: flex;
    align-items: center;
}

.nav-menu ul {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu a {
    color: #000000;
    padding: 0.8rem 1.3rem;
    font-size: 1.05rem;
    font-weight: 700;
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0.25rem;
    border: 2px solid transparent;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--gray-900);
    border: none;
}

/* 首页保持白色背景 */
.index-page .nav-menu a:hover,
.index-page .nav-menu a.active {
    background: var(--primary-dark);
    color: #ffffff;
    border: 2px solid var(--primary-dark);
}

.nav-menu a i {
    font-size: 0.75rem;
    transition: transform var(--transition-fast);
}

.nav-menu a:hover i {
    transform: rotate(180deg);
}

/* 下拉菜单 */
.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 240px;
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    box-shadow: var(--shadow-lg);
    border-radius: var(--border-radius-lg);
    padding: 0.5rem 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition-base);
    z-index: 1001;
}

/* 首页保持白色下拉菜单 */
.index-page .dropdown-menu {
    background-color: #ffffff;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu a {
    display: block;
    padding: 0.75rem 1rem;
    color: #ffffff;
    border-radius: 0;
}

.dropdown-menu a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.dropdown-menu a i {
    color: rgba(255, 255, 255, 0.9);
    margin-right: 0.5rem;
}

/* 首页保持黑色下拉菜单文字 */
.index-page .dropdown-menu a {
    color: #000000;
}

.index-page .dropdown-menu a:hover {
    background-color: var(--gray-100);
}

.index-page .dropdown-menu a i {
    color: var(--primary-color);
}

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

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--gray-800);
    transition: all var(--transition-base);
}

/* ============================================
   Banner/Hero区域
   ============================================ */

.hero {
    position: relative;
    height: 600px;
    background: transparent;
    overflow: hidden;
    margin-top: 90px;
}

/* 轮播图内容由 js/banner.js 动态生成，不使用默认的 ::before 样式 */

.hero-content {
    text-align: center;
    color: #ffffff;
    z-index: 1;
    max-width: 800px;
    padding: 0 1rem;
}

.hero h1 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    animation: fadeInUp 0.8s ease-out;
}

.hero h1 .highlight {
    color: var(--secondary-color);
}

.hero p {
    font-size: var(--font-size-xl);
    opacity: 0.95;
    margin-bottom: 2rem;
    animation: fadeInUp 0.8s ease-out 0.2s backwards;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 0.8s ease-out 0.4s backwards;
}

/* ============================================
   按钮样式
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 2rem;
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--border-radius-full);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
}

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

/* 导航栏中的按钮样式改为与普通导航项一致 */
.nav-menu .btn-primary {
    background-color: transparent;
    color: var(--gray-900);
    padding: 0.75rem 1rem;
    border-radius: 0;
    border: none;
}

.nav-menu .btn-primary:hover {
    color: var(--gray-900);
    background-color: transparent;
    transform: none;
    box-shadow: none;
}

.btn-primary:hover {
    background-color: var(--gray-100);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: #ffffff;
    border: 2px solid #ffffff;
}

.btn-secondary:hover {
    background-color: #ffffff;
    color: var(--primary-color);
    transform: translateY(-2px);
}

.btn-accent {
    background-color: var(--primary-color);
    color: #ffffff;
}

.btn-accent:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-lg {
    padding: 1rem 2.5rem;
    font-size: var(--font-size-lg);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: var(--font-size-sm);
}

/* ============================================
   Section通用样式
   ============================================ */

.section {
    padding: var(--spacing-3xl) 0;
}

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

.section-header h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 0.5rem;
}

.section-header h2 span {
    color: var(--primary-color);
}

.section-header p {
    font-size: var(--font-size-lg);
    color: var(--gray-600);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   特性区域
   ============================================ */

.features {
    background-color: var(--gray-50);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.feature-card {
    background-color: #ffffff;
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    text-align: center;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    border-radius: var(--border-radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    font-size: 2rem;
}

.feature-card h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--gray-900);
}

.feature-card p {
    color: var(--gray-600);
    font-size: var(--font-size-sm);
    line-height: 1.7;
}

/* ============================================
   产品展示区域
   ============================================ */

.products {
    background-color: #ffffff;
}

.products-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 2rem;
}

/* 产品分类侧边栏 */
.products-sidebar {
    background-color: var(--gray-50);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    position: sticky;
    top: 100px;
    height: fit-content;
}

.products-sidebar h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--gray-900);
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--primary-color);
}

.category-menu {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.category-menu a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    color: var(--gray-700);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
    font-size: var(--font-size-base);
}

.category-menu a:hover,
.category-menu a.active {
    background-color: var(--primary-color);
    color: #ffffff;
}

.category-menu a i {
    font-size: var(--font-size-sm);
    opacity: 0.5;
    transition: opacity var(--transition-fast);
}

.category-menu a:hover i {
    opacity: 1;
}

/* 产品网格 */
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.product-card {
    background-color: #ffffff;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid var(--gray-200);
}

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

.product-image {
    position: relative;
    padding: 2rem;
    background-color: var(--gray-50);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    overflow: hidden;
}

.product-image img {
    max-width: 100%;
    max-height: 180px;
    object-fit: contain;
    transition: transform var(--transition-base);
}

.product-card:hover .product-image img {
    transform: scale(1.05);
}

.product-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: #ffffff;
    padding: 0.25rem 0.75rem;
    border-radius: var(--border-radius-full);
    font-size: var(--font-size-xs);
    font-weight: 600;
}

.product-info {
    padding: 1.5rem;
}

.product-category {
    font-size: var(--font-size-xs);
    color: var(--primary-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
}

.product-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.product-desc {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
    margin-bottom: 1rem;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

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

.spec-tag {
    font-size: var(--font-size-xs);
    padding: 0.25rem 0.5rem;
    background-color: var(--gray-100);
    color: var(--gray-600);
    border-radius: var(--border-radius-sm);
}

.product-footer {
    display: flex;
    gap: 0.75rem;
}

.product-footer .btn {
    flex: 1;
    padding: 0.5rem 1rem;
    font-size: var(--font-size-sm);
}

/* ============================================
   关于我们区域
   ============================================ */

.about {
    background: linear-gradient(135deg, var(--gray-50) 0%, #ffffff 100%);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 1.5rem;
}

.about-text h2 span {
    color: var(--primary-color);
}

.about-text p {
    color: var(--gray-600);
    margin-bottom: 1.25rem;
    line-height: 1.8;
    font-size: var(--font-size-base);
}

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

.stat-item {
    text-align: center;
    padding: 1.5rem;
    background-color: #ffffff;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
}

.stat-number {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
}

.about-image {
    position: relative;
}

.about-image img {
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-2xl);
}

.about-image::before {
    content: '';
    position: absolute;
    top: -20px;
    left: -20px;
    right: 20px;
    bottom: 20px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    border-radius: var(--border-radius-xl);
    z-index: -1;
    opacity: 0.1;
}

/* ============================================
   新闻资讯区域
   ============================================ */

.news {
    background-color: #ffffff;
}

.news-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.news-tab {
    padding: 0.75rem 2rem;
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--border-radius-full);
    border: 2px solid var(--gray-300);
    background-color: transparent;
    color: var(--gray-700);
    cursor: pointer;
    transition: all var(--transition-base);
}

.news-tab:hover,
.news-tab.active {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: #ffffff;
}

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

.news-card {
    background-color: #ffffff;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.news-image {
    height: 200px;
    background-color: var(--gray-100);
    overflow: hidden;
}

.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-base);
}

.news-card:hover .news-image img {
    transform: scale(1.05);
}

.news-content {
    padding: 1.5rem;
}

.news-date {
    font-size: var(--font-size-xs);
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.news-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.news-excerpt {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ============================================
   联系我们区域
   ============================================ */

.contact {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    color: #ffffff;
}

.contact .section-header h2,
.contact .section-header p {
    color: #ffffff;
}

.contact .section-header h2 span {
    color: var(--secondary-color);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    display: flex;
    gap: 1rem;
    padding: 1.5rem;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius-lg);
    backdrop-filter: blur(10px);
}

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

.info-text h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.info-text p {
    opacity: 0.9;
    font-size: var(--font-size-sm);
}

.contact-form {
    background-color: #ffffff;
    padding: 2rem;
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-2xl);
}

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

.form-label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 0.5rem;
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: var(--font-size-base);
    color: var(--gray-800);
    background-color: var(--gray-50);
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: #ffffff;
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

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

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

/* ============================================
   页脚
   ============================================ */

.footer {
    background-color: var(--gray-900);
    color: var(--gray-300);
    padding: 4rem 0 2rem;
}

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

.footer-logo {
    margin-bottom: 1.5rem;
}

.footer-logo .logo-text .name {
    color: #ffffff;
    font-size: 1.75rem;
}

.footer-logo .logo-text .tagline {
    color: var(--gray-500);
}

.footer-description {
    font-size: var(--font-size-sm);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.footer-social {
    display: flex;
    gap: 0.75rem;
}

.social-link {
    width: 40px;
    height: 40px;
    background-color: var(--gray-800);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gray-300);
    transition: all var(--transition-base);
}

.social-link:hover {
    background-color: var(--primary-color);
    color: #ffffff;
    transform: translateY(-3px);
}

.footer-links h4 {
    color: #ffffff;
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

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

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

.footer-contact {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.contact-item i {
    width: 24px;
    height: 24px;
    background-color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    font-size: var(--font-size-xs);
    flex-shrink: 0;
    margin-top: 2px;
}

.contact-item span {
    font-size: var(--font-size-sm);
    line-height: 1.6;
}

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

.footer-bottom p {
    color: var(--gray-500);
    margin-bottom: 0.5rem;
}

/* ============================================
   动画效果
   ============================================ */

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

/* ============================================
   回到顶部按钮
   ============================================ */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: #ffffff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    z-index: 999;
    cursor: pointer;
    border: none;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-2xl);
}

/* ============================================
   加载动画
   ============================================ */

.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #ffffff;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ============================================
   辅助类
   ============================================ */

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--spacing-md); }
.mt-2 { margin-top: var(--spacing-lg); }
.mt-3 { margin-top: var(--spacing-xl); }
.mt-4 { margin-top: var(--spacing-2xl); }

.mb-1 { margin-bottom: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-lg); }
.mb-3 { margin-bottom: var(--spacing-xl); }
.mb-4 { margin-bottom: var(--spacing-2xl); }

.pt-1 { padding-top: var(--spacing-md); }
.pt-2 { padding-top: var(--spacing-lg); }
.pt-3 { padding-top: var(--spacing-xl); }
.pt-4 { padding-top: var(--spacing-2xl); }

.pb-1 { padding-bottom: var(--spacing-md); }
.pb-2 { padding-bottom: var(--spacing-lg); }
.pb-3 { padding-bottom: var(--spacing-xl); }
.pb-4 { padding-bottom: var(--spacing-2xl); }

.hidden { display: none !important; }

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}